TW201633327A - Radioisotope production - Google Patents

Abstract

A system comprising a free electron laser and a radioisotope production apparatus, wherein the free electron laser comprises an electron injector, an energy recovery linear accelerator and an undulator, and the radioisotope production apparatus comprises a further linear accelerator, an electron target support structure configured to hold an electron target and a photon target support structure configured to hold a photon target, wherein the further linear accelerator is positioned to receive an electron beam after it has been accelerated then decelerated by the energy recovery linear accelerator, the further linear accelerator being configured to accelerate electrons of the electron beam to an energy of around 14 MeV or more for subsequent delivery to the electron target.

Description

Radioisotope production

The present invention relates to radioisotope generating devices and associated methods. The invention also relates to a system comprising a free electron laser and a radioisotope generating device.

Radioisotopes are unstable isotopes. The radioisotope will decay due to the emission of protons and/or neutrons over time. Radioisotopes are used for medical diagnosis and for medical treatment, and are also used in industrial applications.

The most commonly used medical radioisotope is Tc-99m (鎝), which is used in diagnostic applications. The production of Tc-99m uses a high throughput nuclear reactor. The highly enriched uranium comprising a mixture of U-238 and U-235 is bombarded with neutrons in a nuclear reactor. This causes some of U-235 to undergo fission and separate into Mo-99+Sn(x13)+neutrons. Mo-99 is separated from other fission products and delivered to the radiopharmaceutical. Mo-99 has a half-life of 66 hours and decays to Tc-99m. Tc-99m has a half-life of only 6 hours (which is suitable for medical diagnostic techniques). At radiopharmaceuticals, Tc-99m is separated from Mo-99 and subsequently used in medical diagnostic techniques.

Mo-99 is widely used worldwide to produce Tc-99m for medical diagnostic technology. However, there are only a few high-throughput nuclear reactors that can be used to produce Mo-99. Other radioisotopes are also made using these high throughput nuclear reactors. All high-throughput nuclear reactors have been in operation for more than 40 years and are not expected to continue to operate indefinitely.

It may be considered desirable to provide alternative radioisotope generating devices and associated methods and/or associated systems.

According to one aspect of the present invention, a system is provided comprising a free electron laser and a radioisotope generating apparatus, wherein the free electron laser comprises an electron injector, an energy recovery linear accelerator, and a undulator, and the radioisotope generating apparatus comprises another a linear accelerator, an electronic target support structure configured to hold the electronic target, and a photon target support structure configured to hold the photon target, wherein the other linear accelerator is positioned to accelerate and then decelerate by the linear accelerator that has been recovered by the energy recovery An electron beam is then received, the other linear accelerator being configured to accelerate the electrons of the electron beam to an energy of about 14 MeV or more for subsequent delivery to the electronic target.

This system is advantageous because free electron lasers (which can be used to generate EUV radiation for use by lithographic apparatus) also use components for radioisotope generation. This provides cost savings compared to the cost that would result if the radioisotope generating device and the free electron laser were provided to be completely separate from each other (eg, at different locations). The radioisotope production can be performed in parallel with the operation of the free electron laser (e.g., in parallel with the generation of the EUV radiation beam). An electron beam can be used to generate EUV radiation and then used to generate a radioisotope.

The kicker can be configured to switch the electron beam between another linear accelerator and the beam trap.

According to a second aspect of the present invention, there is provided a system comprising a free electron laser and a radioisotope generating apparatus, wherein the free electron laser comprises a plurality of electron injectors, a linear accelerator and a undulator, and the radioisotope generating apparatus comprises Another linear accelerator, an electronic target support structure configured to hold the electronic target, and a photonic target support structure configured to hold the photon target, wherein the other linear accelerator is positioned to be used to provide the electron beam to the linear accelerator The electron beam is received from one of the electron injectors, the other linear accelerator being configured to accelerate electrons of the electron beam to energy of 14 MeV or more for subsequent delivery to the electron target and the photon target.

This system is also advantageous because free electron lasers (which can be used to generate EUV radiation for use by lithographic apparatus) also use components for radioisotope generation. This provides cost savings compared to the cost that would result if the radioisotope generating device and the free electron laser were provided to be completely separate from each other (eg, at different locations). The radioisotope production can be performed in parallel with the operation of the free electron laser (e.g., in parallel with the generation of the EUV radiation beam). That is, one linear injector can be used to generate a radioisotope while the other is used to provide an electron beam for a free electron laser.

A plurality of radioisotope generating devices can be provided.

A kickback can be positioned after each electron injector configured to switch the electron beam generated by the electron injector between one of the free electron laser linear accelerator and the radioisotope generating device .

The number of electron injectors can be one more than the number of radioisotope generating devices.

The free electron laser linear accelerator can be an energy recovery linear accelerator.

Another linear accelerator can be configured to accelerate the electrons of the electron beam to an energy of about 30 MeV or more.

The system can further comprise an electron target held by the electron target support structure, the electron target comprising a material that will decelerate the electrons and generate photons, and the system can further comprise a photon target held by the photon target support structure, the photon target comprising A material upon which a photon is incident when it is incident on the photon and thus will form a radioisotope.

The photon target can comprise Mo-100.

According to a third aspect of the present invention, there is provided a system comprising a free electron laser and a radioisotope generating apparatus, wherein the free electron laser comprises an electron injector, a linear accelerator and a undulator, and the radioisotope generating apparatus comprises another line An accelerator, an electronic target support structure configured to hold an electronic target, and a photon target support structure configured to hold a photon target, wherein the electron injector is configured to generate an electron beam having a current of 10 mA or more, and A linear accelerator is configured to accelerate electrons from the electron beam to 14 MeV Or above for subsequent delivery to the electronic target and photon target.

It is advantageous to provide an electron beam having a current of 10 mA or more as compared to providing a lower beam current because it increases the radioactivity ratio of the radioactive isotope which can be generated by the electron beam.

The electron injector can be configured to generate an electron beam having a current of 30 mA or more. The electron injector can be configured to generate an electron beam having a current of 100 mA or more.

Another linear accelerator can be configured to accelerate the electrons of the electron beam to an energy of about 30 MeV or more.

According to a fourth aspect of the present invention, there is provided a radioisotope generating apparatus comprising a linear accelerator, an electronic target support structure configured to hold an electron target, and a photon target support structure configured to hold a photon target, wherein the electron beam The distribution device is configured to receive an electron beam after being accelerated by the linear accelerator, and the electron beam distribution device is configured to control a surface area of the electron target on which the electron beam is incident before the electron beam is incident on the electron target.

It is advantageous to distribute the electron beam because it distributes the heat delivered by the electron beam, thereby reducing local heating of the electron target.

The electron beam distribution device can include a lens configured to increase the cross-sectional area of the electron beam.

The lens can include a defocused quadrupole magnet.

The electron beam distribution device can include a beam recoiler configured to scan the electron beam across the surface of the electron target.

According to a fifth aspect of the present invention, there is provided a radioisotope generating apparatus comprising a linear accelerator, a beam recoil, a plurality of electron target support structures configured to hold an electron target, and a plurality configured to hold a photon target An associated photon target support structure, wherein the beam recoiler is configured to receive an electron beam after acceleration by a linear accelerator and is configured to sequentially direct the electron beam to each of the electron target support structures.

It is advantageous to distribute the electron beams to different electron target support structures such that the electron beams are incident on different electron targets because they distribute the heat delivered by the electron beams, thereby reducing localized heating of the electron targets.

According to a sixth aspect of the present invention, there is provided a radioisotope generating apparatus comprising a linear accelerator, an electron target support structure configured to hold an electron target, and a photon target support structure configured to hold a photon target, wherein the radioisotope The generating device further includes one or more coolant fluid conduits configured to deliver a coolant fluid through the photon target and/or the electron target held by the support structure, and thereby removing heat from the photon target and/or the electron target And wherein the radioisotope generating device further comprises a waste heat recovery system configured to recover some of the heat removed from the photon target and/or the electron target.

The waste heat recovery system advantageously allows for the recovery of some of the power used to produce the radioisotope.

The waste heat recovery system can be configured to generate electricity using the recovered heat.

The waste heat recovery system can include a closed loop using a working fluid.

The closed loop working fluid may be different than the coolant fluid used to cool the photon target and/or the electron target, and wherein the system further includes a heat exchanger configured to transfer heat from the coolant fluid to the working fluid.

The closed loop may include an expansion turbine configured to drive a generator.

According to a seventh aspect of the invention, there is provided a system comprising the radioisotope generating device of any one of the fourth to sixth aspects of the invention, and further comprising a free electron laser.

The system of any of the aspects of the invention may further comprise a plurality of lithography devices.

According to an eighth aspect of the present invention, a method of producing a radioisotope comprising: injecting an electron beam into an energy recovery linear accelerator of a free electron laser; using an energy recovery linear accelerator to accelerate the subsequent deceleration of the electron beam; using another line Sex accelerator Accelerating the decelerated electron beam, the electron beam is accelerated to an energy of about 14 MeV or more; and directing the electron beam onto the electron target to generate photons, which are then incident on the photon target to produce a radioisotope.

According to a ninth aspect of the present invention, there is provided a method of producing a radioisotope using the injector when the injector of the free electron laser is not used to provide electrons to a free electron laser, the method comprising: generating an electron using the injector Beam; accelerates the electron beam to an energy of about 14 MeV or more using a linear accelerator; and directs the electron beam onto the electron target to produce photons that are then incident on the photon target to produce a radioisotope.

The injector can be one of a plurality of injectors, and one of the other injectors can simultaneously provide electrons to the free electron laser.

The electron beam guided to the electron target may have a current of 10 mA or more.

According to a tenth aspect of the present invention, a method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; using a linear accelerator to accelerate an electron beam, passing the electron beam through an electron beam distribution device; and e. Light is directed onto the electron target to generate photons that are then incident on the photon target to produce a radioisotope, wherein the electron beam distribution device controls the surface area of the electron target onto which the electron beam is incident.

According to an eleventh aspect of the present invention, a method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; using a linear accelerator to accelerate an electron beam; and sequentially guiding the electron beam using a beam recoiler Each of the plurality of electron targets is generated to generate photons that are then incident on the associated photon target to produce a radioisotope.

According to a twelfth aspect of the present invention, a method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; using a linear accelerator to accelerate an electron beam; and guiding the electron beam onto the electron target to generate a photon The photons are then incident on the photon target to produce a radioisotope, wherein the method further comprises: transporting the coolant fluid through the electron target and/or the photon target to remove heat from the electron target and/or the photon target; Some of the heat removed from the electron target and/or photon target is recovered using a waste heat recovery system.

Features of any given aspect of the invention may be combined with features of other aspects of the invention.

The various aspects and features of the invention described above or below may be combined with various other aspects and features of the invention as will be readily apparent to those skilled in the art.

21a‧‧‧Electronic injector

21b‧‧‧Electronic injector

22‧‧‧ Linear Accelerator

24‧‧‧ undulator

30a‧‧‧ Linear Accelerator

30b‧‧‧ Linear Accelerator

30c‧‧‧ Linear Accelerator

31‧‧‧Backlash

32‧‧‧Backlash

33‧‧‧Backflush

40a‧‧‧Components/targets

40b‧‧‧ target

40c‧‧ Target

42a-c‧‧‧Electronic target

43a-c‧‧‧Support structure

44a-c‧‧‧Photon target

45a-c‧‧‧Support structure

100‧‧‧beam trap

121a‧‧‧Electronic injector

121b‧‧‧Electronic injector

121c‧‧‧Electronic injector

121d‧‧‧Electronic injector

122‧‧‧ Linear Accelerator

122a‧‧‧Electronic source

122b‧‧‧Electronic source

122c‧‧‧Electronic source

122d‧‧‧Electronic source

123a‧‧‧ booster

123b‧‧‧ booster

123c‧‧‧ booster

123d‧‧‧ booster

130a‧‧‧ Linear Accelerator

130b‧‧‧ Linear Accelerator

130c‧‧‧ Linear Accelerator

240‧‧‧ target

242‧‧‧Electronic target

244‧‧‧Photon target

251‧‧‧ board

252‧‧‧ Pipes

253‧‧‧ board

254‧‧‧ Pipes

257‧‧‧Support

260‧‧‧heater

261‧‧‧Expansion turbine

262‧‧‧Condenser

263‧‧‧ pump

264‧‧‧Power generator

300‧‧‧ lens

301‧‧‧ lens

305‧‧‧Backlash

306‧‧‧Backlash

340a‧‧ Target

340b‧‧‧ target

340c‧‧‧ target

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIG. 1 is a schematic illustration of a system including a free electron laser and radioisotope generating apparatus; - Figure 2 is a schematic illustration of a radioisotope generating apparatus in accordance with an embodiment of the present invention; - Figure 3 is a schematic illustration of a portion of a system including a free electron laser and radioisotope generating apparatus in accordance with an embodiment of the present invention; - Figure 4 is a schematic illustration of an electronic target and a photon target of a radioisotope generating device in accordance with an embodiment of the present invention; - Figure 5 is a schematic illustration of a waste heat recovery system that can form part of a system in accordance with an embodiment of the present invention - Figure 6 is a schematic illustration of an electron beam distribution device that can form part of a radioisotope generating device in accordance with an embodiment of the present invention; - Figure 7 is a portion of a radioisotope generating device that can be formed in accordance with an embodiment of the present invention Illustrative illustration of an alternative electron beam distribution device; and - Figure 8 is a diagram of a radioisotope generating device that can be formed in accordance with an embodiment of the present invention Per schematically illustrates another alternative means of electron beam distribution.

Figure 1 schematically shows a system comprising a free electron laser FEL and a radioisotope generating device RI _ac . The free electron laser FEL is capable of generating an EUV radiation beam B _FEL that is sufficiently strong to supply a plurality of lithographic devices LA ₁ - _n having an EUV radiation beam that can be used to project a pattern onto the substrate.

The free electron laser FEL includes two electron injectors 21a, 21b, a linear accelerator 22, a undulator 24, and a beam trap 100. The free electron laser may also include a bunching compressor (not shown). The system of Figure 1 can be switched between different modes of operation in which the electron beam E follows a different path. In the illustrated mode, the electron beam E is depicted by a solid line, wherein the alternate electron beam path is depicted by a dashed line.

Each of the electron injectors 21a, 21b is configured to produce a bunched electron beam and includes an electron source (eg, a photocathode illuminated by a pulsed laser beam) and a booster that provides an accelerating electric field. The accelerating electric field provided by the booster can, for example, accelerate the electrons of the electron beam to an energy of about 10 MeV. The radioisotope generating device RI _ab comprises components 30a, 30b, 40a, 40b downstream of the electron injectors 21a, 21b, which are further described below. In the depicted mode of operation, the second electron injector 21b provides an electron beam E that is used by a free electron laser to produce an EUV radiation beam B _FEL . The first electron injector 21a provides an electron beam E _{I for} generating a radioisotope (as described further below).

The electrons in the electron beam E are diverted to the linear accelerator 22 by a magnet (not shown). The linear accelerator accelerates the electron beam E. In one example, linear accelerator 22 can include an axially spaced plurality of RF cavities, and one or more RF power sources operable to control the electromagnetic fields along a common axis as they are transferred between the electromagnetic fields so that Accelerate each electron bunching. The cavities can be superconducting radio frequency cavities. Advantageously, this situation allows for the application of a relatively large electromagnetic field with a high duty cycle; a larger beam aperture, resulting in less loss due to the wake field; and allowing for increased transmission to the beam (as opposed to dissipation via the cavity wall) The fraction of RF energy. Alternatively, the cavities may be conventionally conductive (ie, non-superconducting) and may be formed of, for example, copper. Other types of linear accelerators can be used, such as a laser wake field accelerator or a reverse free electron laser accelerator.

Although the linear accelerator 22 is depicted as being placed along a single axis in Figure 1, the linear accelerator may include modules that are not located on a single axis. For example, there may be bends between some linear accelerator modules and other linear accelerator modules.

After acceleration by the linear accelerator 22, the electron beam E is diverted to the undulator 24 by a magnet (not shown). Optionally, the electron beam E can pass through a bunching compressor (not shown) disposed between the linear accelerator 22 and the undulator 24. The bunched compressor can be configured to spatially compress the existing electron bunching in the electron beam E.

The electron beam E then passes through the undulator 24. Typically, undulator 24 includes a plurality of modules. Each module includes a periodic magnet structure operable to generate a periodic magnetic field and configured to be guided by the electron injectors 21a, 21b and the linear accelerator 22 along a periodic path within the module The generated electron beam E. The periodic magnetic field generated by each undulator module causes the electrons to follow an oscillating path around the central axis. Thus, in each undulator module, electrons typically radiate electromagnetic radiation in the direction of the central axis of the undulator module. The irradiated electromagnetic radiation forms an EUV radiation beam B _FEL which is transmitted to the lithography apparatus LA _1-n and used by its lithography apparatus to project a pattern onto the substrate.

The path followed by the electrons can be sinusoidal and planar, with electrons periodically traversing the central axis. Alternatively, the path can be helical with the electrons rotating about a central axis. The type of oscillating path can affect the polarization of the radiation emitted by the free electron laser. For example, a free electron laser that propagates electrons along a helical path can emit elliptically polarized radiation, which may be desirable for exposure of substrate W by some lithography apparatus.

As the electron moves through each of the undulator modules, it interacts with the electric field of the radiation to exchange energy with the radiation. In general, the amount of energy exchanged between electrons and radiation will oscillate rapidly unless the conditions are close to the resonant condition. Under resonant conditions, the mutual interaction between electrons and radiation causes the electrons to bunch together into a micro-convergence that is modulated at the wavelength of the radiation within the undulator and stimulates the coherent emission of radiation along the central axis. The resonance condition can be given by the following: Where λ _em is the wavelength of the radiation, λ _u is the undulator period for the undulator module through which the electron propagates, γ is the Lorentz factor of the electron, and K is the undulator parameter. A depends on the geometry of the undulator 24: for a spiral undulator that produces circularly polarized radiation, A = 1, for a planar undulator, A = 2, and for radiation that produces elliptically polarized (which is neither circular Polarized, non-linearly polarized) spiral undulator, 1 < A < 2. In practice, each electron bunching will have an energy spread, but this expansion can be minimized as much as possible (by generating an electron beam E with a low emissivity). The undulator parameter K is typically about 1 and is given by: Where q and m are the charge and electron mass, B ₀ is the amplitude of the periodic magnetic field, and c is the speed of light.

The resonant wavelength λ _em is equal to the first harmonic wavelength radiated spontaneously by the electrons moving through each undulator module. The free electron laser FEL operates in self-amplifying spontaneous emission (SASE) mode. Operation in the SASE mode may require low energy expansion of the electron bunching in the electron beam E before the electron beam E enters each undulator module. Alternatively, the free electron laser FEL can include a seed radiation source that can be amplified by the stimulated emission within the undulator 24. The free electron laser FEL can operate as a recirculating amplifier free electron laser (RAFEL), wherein a portion of the radiation produced by the free electron laser FEL is used to further generate the inoculated radiation.

The electron beam E of the exit undulator 24 is turned back into the linear accelerator 22 by a magnet (not shown). The electron beam E enters the linear accelerator 22 with a phase difference of 180 degrees with respect to the electron beams generated by the electron injectors 21a, 21b. Therefore, the RF field in the linear accelerator is used to decelerate the electrons output from the undulator 24 and accelerate the electrons output from the electron injectors 21a, 21b. As the electrons decelerate in the linear accelerator 22, some of their energy is transferred to the RF field in the linear accelerator 22. The energy from the decelerating electrons is thus recovered by the linear accelerator 22 and used to accelerate the electron beam E output from the electron injector 21. This configuration is known as the Energy Recovery Linear Accelerator (ERL).

After deceleration by the linear accelerator 22, the electron beam E _{R is} absorbed by the beam trap 100. Further comprising the components described hereinafter 30c, 40c of the radioisotope generator RI _c. Beam trap 100 can include a sufficient amount of material to absorb electron beam E _R . The material can have a threshold energy for inducing radioactivity. Electrons entering the beam trap 100 with energy below the threshold energy can only produce gamma ray showers, but will not induce any significant level of radioactivity. The material can have a high threshold energy for inducing radioactivity by electron impact. For example, beam trap 100 can comprise aluminum (Al) having a threshold energy of approximately 17 MeV. The electron energy of the electron beam E after exiting the linear accelerator 22 may be less than 17 MeV (which may be, for example, about 10 MeV), and thus may be lower than the threshold energy of the beam trap 100. This situation removes or at least reduces the need to remove and place radioactive waste from the beam trap 100.

In addition to the free electron laser FEL and lithography apparatus LA _1-n , the system depicted in Figure 1 further comprises a radioisotope generating device RI _ac . Three radioisotope generating devices RI _{ac are} depicted, each of which has the same general configuration. The first radioisotope generating device RI _a includes a linear accelerator 30a configured to accelerate electrons supplied by the electron injector 21a. Linear accelerator 30a can, for example, accelerate electrons to an energy of about 14 MeV or more. Linear accelerators can accelerate electrons to an energy of about 30 MeV or more (eg, up to about 45 MeV). It may be beneficial not to accelerate the electrons to an energy greater than about 45 MeV because at these energies a large amount of undesired products other than the desired radioisotope may be produced. In an embodiment, linear accelerator 30a can accelerate electrons to an energy of approximately 35 MeV.

The radioisotope generating device RI _a further comprises a target 40a configured to receive electrons and to convert the source material to a radioisotope using electrons. An example of targets 40a-c are schematically depicted in Figure 2 (the targets have the same configuration for each of the radioisotope generating devices RI _ac ). In Fig. 2, electron beam E is incident on electronic targets 42a-c. The electronic targets 42a-c can be formed, for example, from tungsten, tantalum, or some other material that will decelerate electrons and produce photons. The electronic target is held by the support structures 43a-c. The electron target can be formed from the same material as the photon target (eg, Mo-100). The mechanism through which photons are generated is Bramsstrahlung radiation (in the UK: braking radiation). The energy of photons produced in this manner can be, for example, greater than 100 keV, can be greater than 1 MeV, and can be greater than 10 MeV. Photons can be described as extremely hard X-rays.

In an embodiment, the photon target is Mo-100, which will be converted to Mo-99 via photon induced neutron emission. This reaction has a threshold energy of 8.29 MeV and will therefore not occur when photons incident on the photon target have an energy of less than 8.29 MeV. The reaction has a cross section that peaks at about 14 MeV (the reaction cross section indicates the probability of a reaction induced by photons of a given energy). In other words, the reaction has a resonance peak at about 14 MeV. Thus, in an embodiment, photons having an energy of about 14 MeV or more can be used to convert the Mo-100 photon target to Mo-99.

The energy of a photon generated by a photon target has an upper limit that is set by the energy of the electrons in the electron beam. Photons will have an energy distribution, but the upper limit of the distribution will not extend beyond the energy of the electrons in the electron beam. Thus, in an embodiment for converting a Mo-100 photon target to Mo-99, the electron beam will have an energy of at least 8.29 MeV. In an embodiment, the electron beam can have an energy of about 14 MeV or more.

As the energy of the electron beam increases, the photons above (the same current for the electrons) will be produced with enough energy to cause the desired reaction. For example, as described above, Mo-99 produces a cross section that peaks at approximately 14 MeV. If the electron beam has an energy of about 28 MeV, each electron can produce two photons with an energy of about 14 MeV, thereby increasing the conversion of the photon target to Mo-99. However, when the energy of the electron beam increases, Photons with higher energy will induce other unintended reactions. For example, photon-induced neutrons and proton emission have a threshold energy of 18 MeV. This reaction is undesirable because it does not produce Mo-99, but rather produces an undesired reaction product.

In general, the choice of energy of the electron beam (and thus the maximum energy of the photon) can be based on a comparison between the yield of the desired product (e.g., Mo-99) and the yield of the undesired product. In an embodiment, the electron beam can have an energy of about 14 MeV or more. The electron beam can, for example, have an energy of about 30 MeV or more (e.g., up to about 45 MeV). This range of electron beam energies provides good productivity of photons with an energy of the reaction resonance peak of about 14 MeV. The electron beam can, for example, have an energy of about 35 MeV.

Photons are emitted from the electron targets 42a-c and are incident on the photon targets 44a-c held by the support structures 45a-c. Photons are schematically depicted by wavy line γ in FIG. Photon targets 44a-c comprise a plurality of plates comprising Mo-100 (Mo-100 is a stable and naturally occurring isotope of Mo). When the photon γ is incident on the Nu-100 nucleus, it causes a photonuclear reaction through which the neutron is emitted from the nucleus. The Mo-100 atom is thus converted to a Mo-99 atom.

Photon targets 44a-c receive photons γ over a period of time during which the proportion of Mo-99 in the photon target increases and the proportion of Mo-100 in the photon target decreases. 44a-c then target photons from a radioisotope generator RI _a removed for processing and delivery of radiopharmaceuticals. Tc-99, which is a decay product of Mo-99, is extracted and used in medical diagnostic applications.

Although the photon targets 44a-c shown in Figure 2 comprise three plates, the photon target can comprise any suitable number of plates. Although the photon target described comprises Mo-100, the photon target can comprise any suitable material. Similarly, the material of the photon target can be provided in any suitable shape and/or configuration. A shield (eg, a lead shield) can be provided around the electronic targets 42a-c and the photon targets 44a-c.

Although the electronic targets 42a-c are depicted as a single block of material, they can be provided in a plurality of plates. The plates may, for example, have configurations corresponding to the photon targets 44a-c described above. Similarly, the support structures 43a-c can be configured to hold a plurality of electronic targets.

Electronic targets 42a-c and photon targets 44a-c can be provided in the conduit through which the coolant liquid flows, as further described below.

Referring again to FIG. 1, when the electron beam E _I generated by the first electron injector 21a is not used by the free electron laser FEL to generate the EUV radiation beam B _FEL , the radioisotope using the first radioisotope generating device RI _{a is performed} . Produced. The recoiler 31 directs the electron beam E _I toward the first radioisotope generating device RI _a . The second electron injector 21b is operable to provide an electron beam E to the free electron laser FEL during this time. The backflush 32 provided after the second electron injector 21b does not direct the electron beam E toward the second radioisotope generating device, but allows the electron beam to travel to the linear accelerator 22. The two electron injectors 21a, 21b operate simultaneously, the first electron injector 21a provides an electron beam for generating a radioisotope and the second electron injector 21b provides an electron used by the free electron laser FEL to generate an EUV radiation beam B _FEL bundle.

The second radioisotope generating device RI _b has the same configuration as the first radioisotope generating device RI _a and thus comprises a linear accelerator 30b and a target 40b. When the second electron injecting 21b is provided by the generating means RI _b radioisotopes used in the generation of an electron beam radioisotopes, electron injector 21a provides a first free electrons using FEL laser beam to generate EUV radiation of the electron beam B _FEL. The path traveled by the electron beam E is thus opposite to the path depicted in Figure 1. The switching of the electron beam path is achieved by switching the configuration of the recoilers 31, 32. A first electron beam 21a of a recoil generating device 31 is no longer guided by the first electron injection to the first generating means radioisotope RI _a, but allows linear accelerator electron beam travels to the free electron laser 22. The second electron beam 32 by the recoil electron injector second guide 21b to the second generation of radioisotopes generating means RI _b.

The third radioisotope generating device RI _{c is} positioned after the linear accelerator 22. The linear accelerator 22 is an energy recovery linear accelerator and provides an electron beam E _R from which energy has been recovered. The electron beam E _R has an energy substantially corresponding to the energy of the electron beam E supplied from the electron injectors 21a, 21b before being accelerated by the linear accelerator 22. The energy of the electron beam, such as output from the electron injectors 21a, 21b and after energy recovery in the linear accelerator 22, can be, for example, about 10 MeV.

Radioisotopes generating the same as the previously described apparatus, the third generating means RI _c radioisotope comprises a linear accelerator 30c, which was configured to increase the energy of the electron beam of electrons. The linear accelerator 30c can, for example, accelerate electrons to an energy of 15 MeV or more. Linear accelerator 30c can accelerate electrons to an energy of 30 MeV or more (eg, up to about 45 MeV). In an embodiment, linear accelerator 30c can accelerate electrons to an energy of approximately 35 MeV. The radioisotope generating device further comprises a target 40c. Target 40c corresponds to the target described above in connection with Figure 2 and comprises electronic targets 42a-c and photon targets 44a-c (see Figure 2).

When the radioisotope is generated without the use of a third means generating a radioisotope RI _c, E _R electron beam directed to the beam trap 100 rather than a radioisotope guided to the third generation means. In FIG 1, an electron beam 100 (as indicated by a solid line) is channeled to the beam trap, and not directed to the third generating means radioisotope RI _c (as indicated by a broken line). However, the electron beam E _R can be directed toward the third radioisotope generating device RI _c by the recoil 33. In an embodiment, the third radioisotope generating device RI _c may be operable to simultaneously generate a radio isotope with the first (or second) radioisotope generating device RI _a , RI _b .

A combiner (not shown) can be used to combine the electron beam provided by the electron injectors 21a, 21b with the recycled electron beam E. A splitter (not shown) can be used to separate the electron beam E _R from which energy has been recovered and the electron beam E that has been accelerated by the linear accelerator 22.

Although FIG. 1 shows a radioisotope generating device RI _ac positioned before and after the linear accelerator 22 of the free electron laser FEL, in other embodiments, the radioisotope generating device may be provided only in one of its positions ( That is, it is provided only before the linear accelerator or only after the linear accelerator).

Although the embodiment illustrated in Figure 1 is an energy recovery linear accelerator, the radioactivity is the same The morphogenetic device can be provided as part of a system comprising a free electron laser FEL having an accelerator that is not an energy recovery linear accelerator. For example, a radioisotope generating device can be provided after one or more electron injectors of a free electron laser that includes a linear accelerator that is not an energy recovery linear accelerator.

Although only a single linear accelerator 22 is depicted in FIG. 1, a free electron laser FEL may include two or more linear accelerators. For example, a linear accelerator can be provided at the location of undulator 24 depicted in FIG. In this case, the electron beam can pass through the linear accelerator a plurality of times such that the electron beam is accelerated twice or more by each linear accelerator. In this configuration, the beam splitter can be used to separate the accelerated electron beam such that it passes through the undulator to produce an EUV radiation beam. The beam combiner can then be used to direct the electron beam from the undulator back into the linear accelerator for subsequent deceleration.

FIG. 3 schematically depicts an arrangement of an electron injector and a radioisotope generating apparatus according to an embodiment of the present invention. In Figure 3, four electron injectors 121a-d are shown and three radioisotope generating devices _{RIdf are shown} . Each of the electron injectors 121a-d includes electron sources 122a-d and boosters 123a-d that provide an accelerating electric field. Each electron source can, for example, comprise a photocathode that is illuminated by a pulsed laser beam generated by a laser (not shown). The accelerating electric field provided by each of the boosters 123a-d can, for example, accelerate the electrons provided by the electron sources 122a-d to an energy of about 10 MeV (or some other relativistic energy).

Each radioisotope generating device RI _df includes linear accelerators 130a-c. Each linear accelerator is depicted as three modules, but may include any suitable number of modules (including, for example, a single module). Each linear accelerator 130a-c can accelerate electrons in the electron beam to an energy of 15 MeV or more. Each linear accelerator 130a-c can accelerate electrons to an energy of 30 MeV or more (eg, up to about 45 MeV). In an embodiment, each linear accelerator 130a-c can accelerate electrons to an energy of approximately 35 MeV.

Each radioisotope generating device RI _df further comprises targets 140a-c. The target can correspond to the target shown in Figure 2. Targets 140a-c receive electrons that have been accelerated by linear accelerators 130a-c and convert the source material to a radioisotope.

A linear accelerator 122 that forms part of a free electron laser FEL is also depicted in FIG. Linear accelerator 122 receives the electron beam generated by one of electron injectors 121a-d and accelerates it for EUV generation using a undulator (not shown) in the manner described further above in connection with FIG.

As will be understood from Figure 3, due to the presence of four electron injectors 121a-d and only three radioisotope generating devices _RIdf , all radioisotope generating devices can be operable to generate EUV radiation beams by free electron lasers. At the same time, radioisotopes are produced. A backflush (not depicted) can be used to switch the electron beam between the radioisotope generating device RI _df and the free electron laser linear accelerator 122. The electron beam path is configured such that each radioisotope generating device RI _df can receive an electron beam from two different electron injectors 121a-d. For example, the first generating means RI _d may be a radioisotope from the first electron injector 121a or 121b is received a second electron injection from the electron beam. Thus, for example, a first electron injector 121a may be used to provide an electron beam to the linear accelerator 122, and the second electronic device 121b for injecting an electron beam generating means provided to the first radioisotope RI _d. Alternatively, the first electron injector 121a may be used to provide an electron beam generating means to the first radioisotope RI _d, 121b and the second electron injection is used to provide an electron beam 122 to a linear accelerator. Various combinations of electron beam paths are possible, as will be understood from the considerations of FIG.

In an embodiment, a system comprising a free electron laser and radioisotope generating device can be configured to provide an electron beam having a current of 10 mA or more. The current provided by the system can be, for example, 20 mA or more or can be 30 mA or more. The current can be, for example, at most 100 mA or more. An electron beam having a high current (e.g., 10 mA or more) is advantageous because it increases the radioactivity ratio of the radioisotope produced by the radioisotope generating device.

As explained further above, Mo-100 can be converted to Mo-99 (the desired radioisotope) using extremely hard X-ray photons generated by electron beam hitting the electron target. Mo-99 The half-life is 66 hours. Due to this half-life, there is a limit to the radioactivity ratio of Mo-99, which can be provided at the beginning of Mo-100, which is determined by the rate at which Mo-99 is produced. If Mo-99 is produced at a relatively low rate (e.g., using a beam current of about 1 to 3 mA), it may not be possible to provide a radioactivity ratio in the target that exceeds about 40 Ci/g of Mo-99. This is due to the fact that although the irradiation time can be increased to allow for the production of more Mo-99 atoms, a significant proportion of their atoms will decay during the irradiation time. The radioactivity ratio of Mo-99 for medical applications in Europe should be 100 Ci/g, and thus Mo-99 having a radioactivity ratio of 40 Ci/g or less is not applicable.

When a higher beam current is used, the rate at which Mo-99 atoms are produced increases correspondingly (assuming that the volume of Mo-99 receiving photons remains the same). Thus, for example, for a given volume of Mo-99, a beam current of 10 mA will produce Mo-99 at a rate 10 times that produced by a beam current of 1 mA. The beam current used by embodiments of the present invention can be sufficiently high to achieve a radioactivity ratio of Mo-99 in excess of 100 Ci/g. For example, embodiments of the present invention can provide an electron beam having a beam current of approximately 30 mA. The simulation indicates that for a beam current of about 30 mA, if the electron beam has an energy of about 35 MeV and the volume of the Mo-100 target is about 5000 mm ³ , a radioactivity ratio of Mo-99 exceeding 100 Ci/g can be obtained. The Mo-100 target can, for example, comprise 20 plates having a diameter of about 25 mm and a thickness of about 0.5 mm. Other numbers of plates that may have a non-circular shape and may have other thicknesses may be used.

As further described above, the electron injector of an embodiment of the invention may be a photocathode illuminated by a pulsed laser beam. The laser can, for example, comprise a Nd:YAG laser along with an associated optical amplifier. The laser can be configured to generate picosecond laser pulses. The current of the electron beam can be adjusted by adjusting the power of the pulsed laser beam. For example, increasing the power of a pulsed laser beam will increase the number of electrons emitted from the photocathode and thus increase the beam current.

Electron beam received by a radioisotope generating device according to an embodiment of the present invention It may, for example, have a diameter of 1 mm and a divergence of 1 milliretre. Increasing the current in the electron beam will tend to disperse the electrons due to the space charge effect and thus increase the diameter of the electron beam. Increasing the current of the electron beam can thus reduce the brightness of the electron beam. However, the radioisotope generating device does not require an electron beam having a diameter of, for example, 1 mm and can utilize an electron beam having a larger diameter. Therefore, increasing the current of the electron beam may not reduce the brightness of the beam to such a range that significantly adversely affects the production of the radioisotope. In fact, as explained further below, it may be advantageous to provide an electron beam having a diameter greater than 1 mm due to its thermal loading by electron beam delivery.

Figure 4 schematically shows a target 240 of a radioisotope generating device in accordance with an embodiment of the present invention. Target 240 includes a photon target 242 and an electron target 244. The photon target comprises four plates 251 held by a support structure (not shown). Although four panels are shown, any number of panels can be provided. The plate 251 can be, for example, in the shape of a dish. The board can have any suitable shape. Plate 251 may be formed of tungsten, tantalum, or some other material that will decelerate electrons and produce photons. Plate 251 is located in conduit 252 that is connected to a source of coolant fluid (not shown). During operation of the radioisotope generating device, the electron beam will deliver a significant amount of heat to the plate 251. The coolant fluid flowing through conduit 252 removes some of this heat from plate 251 and carries it away. The coolant fluid can be water or some other suitable liquid, or can be a gas such as helium.

In an alternative configuration, lead-bismuth eutectic (LBE) can be used as both an electron target and a coolant liquid. LBE offers the advantage of having a higher boiling point than other coolant liquids (eg, water). Other suitable liquids can be used as both the electron target and the coolant liquid.

The photon target shown in Figure 4 comprises twenty plates 253 formed of a material that will be converted to a radioisotope upon the incidence of very hard X-rays thereon. The material can be, for example, Mo-100. Although twenty boards are shown, any number of boards can be provided. Plate 253 can be, for example, a dish. The board can have any suitable shape. The plate 253 is held by a support structure including a pair of supports 257. Plate 253 is located in conduit 254 that is configured to deliver coolant liquid. The conduit 254 extends in a direction transverse to the plane of the drawing. The photons incident on the plate 253 will be handed over Send a lot of heat to the board. Some of this heat is transferred to the coolant liquid flowing through conduit 254, and the coolant liquid carries heat away from plate 253. The coolant liquid can be water or can be some other suitable fluid.

The photon target plate 253 is held by a support structure comprising a pair of supports 257 having a groove. The plate 253 is embedded in the recess and is thus held in place by the support 257. The support 257 is configured such that it does not prevent the flow of cooling liquid through the conduit 254 (the support extends primarily in the direction of coolant fluid flow, rather than extending across the direction of coolant fluid flow). Any suitable support structure can be used to support the photon target plate 253. Although not illustrated, the support structure is also used to support the electronic target plate 251. The support structure can have a configuration corresponding to the photonic board support structure, or can have any other suitable form.

Figure 5 schematically depicts a Rankine cycle waste heat recovery system that can form part of a radioisotope generating device in accordance with an embodiment of the present invention. The waste heat recovery system includes a closed circuit around which the fluid circulates (the direction of fluid circulation is indicated by arrows). The closed circuit includes a heater 260, an expansion turbine 261, a condenser 262, and a pump 263. The expansion turbine 261 is coupled to the generator 264 and drives the generator as it rotates.

Heater 260 receives heat from electronic target 242 and/or photon target 244. In an embodiment, the closed loop coolant liquid is heated by flowing through either or both of the conduits 252, 254 depicted in FIG. The generated heated fluid is transferred to expansion turbine 261 and through the expansion turbine, thereby causing it to rotate. The expansion turbine 261 drives the generator 264 to rotate, thereby generating electric power. Since the heated fluid performs work by driving the expansion turbine 261 and the generator 264, energy is removed from the fluid. The fluid is then condensed by condenser 262. The resulting liquid is pumped into heater 260 by pump 263. The waste heat recovery cycle is then repeated.

In the embodiments described above, the liquid that cools the electronic target and the photon target is the working fluid of the waste heat recovery system. In any alternative configuration, the liquid used to cool the electronic target and the photon target can remain separated from the working fluid of the waste heat recovery system. In this case, the heat exchanger can be used for liquid transfer heat of the working fluid used to cool the electronic target and the waste heat recovery system. the amount. The advantage of having two separate fluids here avoids the possibility of the material entering the expansion turbine 261 or other parts of the waste heat recovery system from the electronic target or photon target. Another advantage is that the fluid can be used in a waste heat recovery system that has properties different from those used to cool the electronic target and the photon target. For example, the waste heat recovery system may use an organic working fluid, such as HFC (eg, R134a or R245fa), which may not be suitable as a cooling liquid for electronic target 242 or photon target 244.

Although the waste heat recovery system shown in Figure 5 is a Rankine cycle system, any suitable waste heat recovery system can be used. For example, a Stirling engine or a Brayton cycle system can be used.

In an embodiment, the electron beam E incident on the electron target comprises electrons having an energy of about 35 MeV, and the beam current is between 30 mA and 100 mA. Thus, power between about 1 MW and about 3.5 MW can be delivered to the electronic target and photon target. This significant proportion of power can be converted to electricity using embodiments of the present invention. Power can be used as a component for generating and accelerating the power of the electron beam.

As noted above, the electron beam can deliver a significant amount of power (eg, up to about 3.5 MW) to the electron target. The electron beam can, for example, have a diameter of about 1 mm. To avoid possible damage to the electronic target, the radioisotope generating device can include an electron beam distribution device configured to control the surface area of the electron target onto which the electron beam is incident.

An embodiment of an electron beam distribution device is schematically depicted in Figure 6. In this embodiment, the lens 300 is used to defocus the electron beam E and thus increase its diameter. The diameter of the electron beam E can be increased, for example, by a factor of 10 or more. The diameter of the electron beam can be increased, for example, to a few centimeters (e.g., up to about 10 cm). The diameter of the electron beam can be increased to a size generally corresponding to the size of the electronic target. Increasing the diameter of the electron beam E is advantageous because it increases the area of the electron target to which the thermal load is applied.

In FIG. 6, the second lens 301 is used to collimate the electron beam E after defocusing caused by the first lens 300. Since the diverging electron beam will increase the divergence of photons generated by the electron target Degree, the collimation of the electron beam E is applicable. This in turn will require larger photons to collect photons, which will reduce the radioactivity ratio of Mo-99 (or other radioisotope) produced at the photon target.

The lenses 300, 301 can be formed, for example, from a magnet. The lens can be, for example, a quadrupole lens.

Figure 7 shows another embodiment of an electron beam distribution device. This embodiment includes a recoil 305 that is configured to move the electron beam E across the surface of an electron beam target (not shown). The kickback can, for example, be configured to move the electron beam throughout the surface of the electron beam target during the scanning motion. This can be achieved by applying a plate that continuously changes the voltage to the backflush.

Figure 8 depicts another embodiment of an electron beam distribution device. In this embodiment, the recoiler 306 moves the electron beam E such that it is directed toward one of the three targets 340a-c. Each target comprises an electron target and a photon target (eg, as further described above). The kicker 306 is configured to periodically switch the direction of the electron beam E between the three targets 340a-c. This can be achieved by periodically switching between three different voltages applied to the kickback 306. Switching the electron beam E between three different targets 340a-c is advantageous because it distributes the thermal load of the electron beam between the three targets.

The embodiment depicted in Figure 6 can be used in combination with the embodiments depicted in Figures 7 and 8. That is, the cross-sectional area of the electron beam E can be increased before the distribution of the backflush is used.

Although embodiments of the invention have been described in connection with the generation of the radioisotope Mo-99, embodiments of the invention can be used to generate other radioisotopes. In general, embodiments of the invention can be used to create any radioisotope that can be formed onto the source material via the direction of the extremely hard X-rays.

An advantage of the present invention is that it provides for the production of radioisotopes without the need to use high throughput nuclear reactors. Another advantage is that it does not require the use of highly concentrated uranium (dangerous materials subject to non-proliferation rules).

Since it has utilized the means required for free electron lasers, it is advantageous to provide a radioisotope generating device as part of a system that also includes free electron lasers. That is, radiation Sex isotope production uses a device that has been partially provided. Similarly, a radioisotope generating device can be located in an underground space (which can be referred to as a silo) that includes a shield that contains radiation and prevents radiation from diffusing to the environment. At least some of the underground space and the shield may have been provided as part of a free electron laser and thus avoid the expense of providing a completely separate underground space and associated shield for the radioisotope generating device.

In an embodiment, the system can include free electron laser and radioisotope generating devices that can operate independently of each other. For example, a free electron laser can operate without the operation of a radioisotope generating device, and the radioisotope generating device can operate without a free electron laser operation. Free electron laser and radioisotope generating devices can be provided in a common silo.

While the embodiment of the radiation source SO has been described and depicted as including a free electron laser FEL, it should be understood that the radiation source can include any number of free electron laser FELs. For example, the radiation source can include more than one free electron laser FEL. For example, two free electron lasers can be configured to provide EUV radiation to a plurality of lithography devices. This is to allow some redundancy. This may allow for the use of another free electron laser while a free electron laser is being repaired or undergoing maintenance.

Although embodiments of the invention have been described as using Mo-100 to produce a Mo-99 radioisotope that decays to Tc-99, other medically applicable radioisotopes can be produced using embodiments of the invention. For example, embodiments of the invention may be used to generate Ge-68 that decays into Ga-68. Embodiments of the invention can be used to generate W-188 that decays into Re-188. Embodiments of the invention can be used to generate Ac-225 which decays into Bi-213.

Although lithography system LS of the described embodiment includes eight lithographic apparatus LA ₁ -LA _n, but lithography system may include any number of LS lithography apparatus. For example, the number of lithographic devices that form the lithography system LS may depend on the amount of radiation output from the radiation source SO and the amount of radiation lost in the beam delivery system BDS. The number of lithography devices forming the lithography system LS may additionally or alternatively depend on the layout of the lithography system LS and/or the layout of the plurality of lithography systems LS.

Embodiments of the lithography system LS may also include one or more reticle inspection devices MIA and/or one or more airborne detection measurement systems (AIMS). In some embodiments, the lithography system LS can include a plurality of reticle detection devices to allow for some redundancy. This may allow one reticle detecting device to be used when another reticle detecting device is repaired or undergoes maintenance. Therefore, a reticle inspection device is always available. The reticle detecting device can use a lower power radiation beam than a lithography device. Additionally, it should be appreciated that radiation generated using free electron laser FEL of the type described herein can be used for applications other than lithographic or lithographic related applications.

It should be further appreciated that a free electron laser comprising an undulator as described above can be used as a source of radiation for a variety of uses including, but not limited to, lithography.

The term "relativistic electrons" should be interpreted as an electron that has relativistic energy. Electrons can be considered to have relativistic energies when their kinetic energy is comparable to or greater than their resting mass energy (511 keV, in natural units). In practice, a particle accelerator that forms a component of a free electron laser can accelerate electrons to a much greater energy than their rest mass energy. For example, a particle accelerator can accelerate electrons to an energy of >10 MeV, >100 MeV, >1 GeV or greater.

Embodiments of the invention have been described in the context of a free electron laser FEL that outputs an EUV radiation beam. However, a free electron laser FEL can be configured to output radiation having any wavelength. Accordingly, some embodiments of the invention may include free electrons that output a radiation beam that is not an EUV radiation beam.

The term "EUV radiation" can be considered to encompass electromagnetic radiation having a wavelength in the range of 4 nm to 20 nm (eg, in the range of 13 nm to 14 nm). The EUV radiation can have a wavelength of less than 10 nm, for example, a wavelength in the range of 4 nm to 10 nm, such as 6.7 nm or 6.8 nm.

The lithography devices LA _a to LA _n can be used in the manufacture of ICs. Alternatively, the micro described herein Movies to LA _n LA _a device may have other applications. Other applications include the fabrication of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads, and the like.

Different embodiments may be combined with each other. Features of the embodiments may be combined with features of other embodiments.

Although the specific embodiments of the invention have been described above, it is understood that the invention may be practiced otherwise than as described. The above description is intended to be illustrative, and not restrictive. Therefore, it will be apparent to those skilled in the art that the invention as described herein may be modified without departing from the scope of the appended claims.

21a‧‧‧Electronic injector

21b‧‧‧Electronic injector

22‧‧‧ Linear Accelerator

24‧‧‧ undulator

30a‧‧‧ Linear Accelerator

30b‧‧‧ Linear Accelerator

30c‧‧‧ Linear Accelerator

31‧‧‧Backlash

32‧‧‧Backlash

33‧‧‧Backflush

40a‧‧‧Components/targets

40b‧‧‧ target

40c‧‧ Target

100‧‧‧beam trap

Claims (32)

A system comprising a free electron laser and a radioisotope generating device, wherein: the free electron laser comprises an electron injector, an energy recovery linear accelerator and a undulator; and the radioisotope generating device comprises another a linear accelerator configured to hold an electronic target support structure of an electronic target, and configured to hold a photon target support structure of a photon target; wherein the other linear accelerator is positioned to have been The energy recovery linear accelerator accelerates and then decelerates to receive an electron beam that is configured to accelerate the electrons of the electron beam to one of about 14 MeV or more for subsequent delivery to the electronic target. A system as claimed in claim 1, wherein a backflush is configured to switch the electron beam between the other linear accelerator and a beam trap. A system comprising a free electron laser and a radioisotope generating device, wherein: the free electron laser comprises a plurality of electron injectors, a linear accelerator and a undulator; and the radioisotope generating device comprises a further line An accelerator, configured to hold an electronic target support structure of an electronic target, and configured to hold a photon target support structure of a photon target; wherein the other linear accelerator is positioned to not be used for an electron When the beam is supplied to the linear accelerator, an electron beam is received from one of the electron injectors, the other linear accelerator being configured to accelerate the electrons of the electron beam to one of 14 MeV or more for subsequent delivery To the electron target and the photon target. A system of claim 3, wherein a plurality of radioisotope generating devices are provided. The system of claim 4, wherein a backflush is positioned after each electron injector, the recoil being configured to be one of the linear accelerator and the radioisotope generating device of the free electron laser The electron beam generated by the electron injector is switched between. The system of claim 4 or 5, wherein the number of electron injectors is one more than the number of radioisotope generating devices. The system of any one of claims 3 to 5, wherein the linear accelerator of the free electron laser is an energy recovery linear accelerator. The system of any one of claims 3 to 5, wherein the another linear accelerator is configured to accelerate electrons of the electron beam to one of about 30 MeV or more. The system of any one of claims 3 to 5, further comprising holding, by the electronic target support structure, an electronic target comprising a material that will decelerate the electrons and generate photons, and the system further comprises A photon target is held by the photon target support structure, the photon target comprising a material that will emit neutrons when the photons are incident thereon and thereby form a radioisotope. The system of claim 9, wherein the photon target comprises Mo-100. A system comprising a free electron laser and a radioisotope generating device, wherein: the free electron laser comprises an electron injector, a linear accelerator and a undulator; and the radioisotope generating device comprises a further linear An accelerator, an electronic target support structure configured to hold an electronic target, and configured to hold a photon target support structure of a photon target; wherein the electron injector is configured to generate a current having a current of 10 mA or more One electron beam, and the other linear accelerator is configured to accelerate the electrons of the electron beam to 14 MeV or more for subsequent delivery to the electronic target and the photon target. The system of claim 11, wherein the electronic injector is configured to generate an electron beam having one of currents of 30 mA or more. A system of claim 11 or claim 12, wherein the another linear accelerator is configured to accelerate electrons of the electron beam to one of about 30 MeV or more. A radioisotope generating apparatus comprising a linear accelerator, an electronic target supporting structure configured to hold an electronic target, and a photon target supporting structure configured to hold a photon target; wherein an electron beam distributing device Configuring to receive an electron beam after acceleration by the linear accelerator, and before the electron beam is incident on the electron target, the electron beam distribution device is configured to control the electron target on which the electron beam is incident Surface area. The radioisotope generating device of claim 14, wherein the electron beam distributing device comprises a lens configured to increase the cross-sectional area of the electron beam. A radioisotope generating apparatus according to claim 15, wherein the lens comprises a defocused quadrupole magnet. The radioisotope generating device of any one of claims 14 to 16, wherein the electron beam distributing device comprises a beam recoil device configured to scan the electron beam across a surface of the electron target. A radioisotope generating apparatus comprising a linear accelerator, a beam recoiler, a plurality of electron target support structures configured to hold an electron target, and a plurality of associated photon target support structures configured to hold the photon target Wherein the beam recoil is configured to receive an electron beam after acceleration by the linear accelerator and is configured to sequentially direct the electron beam to each of the electronic target support structures. A radioisotope generating device comprising a linear accelerator configured to Holding an electronic target support structure of an electronic target, and configured to hold a photon target support structure of a photon target; wherein the radioisotope generating device further comprises one or more coolant fluid conduits configured to deliver a coolant fluid by holding a photon target and/or an electron target by the support structures, and thereby removing heat from the photon target and/or the electron target, and wherein the radioisotope generating device further comprises a A waste heat recovery system configured to recover some of the heat removed from the photonic target and/or the electronic target. The system of claim 19, wherein the waste heat recovery system is configured to generate electricity using the recovered heat. The system of claim 19 or claim 20, wherein the waste heat recovery system comprises a closed loop using one of the working fluids. The system of claim 21, wherein the working fluid of the closed loop is different from the coolant fluid used to cool the photon target and/or an electronic target, and wherein the system further comprises a heat exchanger configured to Heat is transferred from the coolant fluid to the working fluid. The system of claim 21, wherein the closed loop includes an expansion turbine configured to drive a generator. A system comprising the radioisotope generating device of any one of claims 14 to 24, and further comprising a free electron laser. The system of claim 24, wherein the system further comprises a plurality of lithography devices. A method of producing a radioisotope, comprising: injecting an electron beam into an energy recovery linear accelerator of a free electron laser; using the energy recovery linear accelerator to accelerate and then decelerating the electron beam; using another linear accelerator to accelerate The electron beam after deceleration, the electron beam Accelerating to one of about 14 MeV or more; and directing the electron beam onto an electron target to produce photons, which are then incident on a photon target to produce the radioisotope. A method of producing a radioisotope using the injector when an injector is not used to provide electrons to the free electron laser, the method comprising: using the injector to generate an electron beam; using a linear The accelerator accelerates the electron beam to an energy of about 14 MeV or more; and directs the electron beam onto an electron target to generate photons, which are then incident on a photon target to produce the radioisotope. The method of claim 27, wherein the injector is one of a plurality of injectors, and wherein one of the other injectors simultaneously supplies electrons to the free electron laser. The method of claim 27 or claim 28, wherein the electron beam directed to the electron target has a current of 10 mA or more. A method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; accelerating the electron beam using the linear accelerator; passing the electron beam through an electron beam distribution device; and directing the electron beam to an electron target Generating to generate photons, which are then incident on a photon target to produce the radioisotope; wherein the electron beam distribution device controls the surface area of the electron target on which the electron beam is incident. A method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; Using the linear accelerator to accelerate the electron beam; and sequentially directing the electron beam to each of the plurality of electron targets using a beam recoiler to generate photons, which are then incident on the associated photon target The radioisotope is produced. A method of producing a radioisotope, comprising: injecting an electron beam into a linear accelerator; using the linear accelerator to accelerate the electron beam; and directing the electron beam onto an electron target to generate photons, which are then incident on the electron beam Generating a radioactive isotope on a photon target; wherein the method further comprises transporting a coolant fluid through the electron target and/or the photon target to remove heat from the electron target and/or the photon target, and using a waste heat recovery The system recovers some of the heat removed from the electronic target and/or the photon target.