KR100557754B1 - Apparatus for generating soft x-ray using hybrid target containing nano-phase particle - Google Patents

Abstract

The present invention relates to an X-ray generating apparatus, and more particularly, to a soft X-ray having a micro size using a sample target containing nano powder dispersed in a liquid solvent, a gas, or a liquefied gas. The present invention relates to a soft x-ray generating apparatus and a method thereof. An X-ray generator according to the present invention comprises: a sample target containing one or more nanopowders dispersed in a liquid solvent, a gas or a liquefied gas; A plasma energy supply system for generating a high power laser or pulsed discharge; And an X-ray generator configured to generate a high-temperature plasma by concentrating energy provided from the plasma energy supply system to the sample target, thereby generating X-rays by transition of expensive ions in the plasma.

X-ray light source, X-ray, nano powder, soft X-ray, laser, pulse discharge, laser induced fluorescence, hybrid target

Description

Soft X-ray generator using a hybrid target containing nano powder {APPARATUS FOR GENERATING SOFT X-RAY USING HYBRID TARGET CONTAINING NANO-PHASE PARTICLE}

1 is a block diagram schematically showing a soft x-ray generating apparatus using a hybrid target containing a nanopowder according to an embodiment of the present invention.

FIG. 2 is a photo of a micrometer-sized aerosol generated from an aerosol generating unit of an X-ray generating apparatus according to an embodiment of the present invention by laser induced fluorescence method. FIG.

3A and 3B are photographs visualizing a micrometer-sized laser-induced plasma generated by the interaction of an aerosol including a nanopowder and a laser by an X-ray generator according to an embodiment of the present invention. The size of is 240㎛, 340㎛ respectively.

Figure 4 is a schematic block diagram showing a soft x-ray generating apparatus using a hybrid liquid jet target containing a nano-powder according to another embodiment of the present invention.

FIG. 5 is a block diagram schematically illustrating a soft X-ray generator using a hybrid gas jet target containing nanopowders according to another embodiment of the present invention. FIG.

FIG. 6 is a block diagram schematically illustrating a soft X-ray generating apparatus using a hybrid liquefied gas jet target containing nanopowders according to another embodiment of the present invention. FIG.

<Explanation of symbols for the main parts of the drawings>

100: solution storage unit 110: aerosol generating unit

120: laser system 130: camera system

140: Spectroscope 150: Computer System

160: aerosol collection / circulation 170: vacuum chamber

180: aerosol

The present invention relates to an X-ray generating apparatus, and more particularly, to a soft X-ray having a micro size using a sample target containing nano powder dispersed in a liquid solvent, a gas, or a liquefied gas. The present invention relates to a soft x-ray generating apparatus and a method thereof.

Soft X-ray refers to X-rays that are relatively easily absorbed by a material and have a small transmittance, with a wavelength ranging from 10 ^-1 to 10 nm, which is sometimes referred to as soft X-rays or soft X-rays. In contrast, X-rays with short wavelengths and high transmittance are called hard X-rays.

X-ray light sources using X-rays generated from radiation accelerators such as synchrotron, which have been mainly used in the past, provide high average output, but they are large and complex, which is expensive in manufacturing and limited in installation place. Therefore, it is difficult to be used in various fields such as life sciences, medicine, and semiconductor manufacturing processes, and users have limitations in using it freely.

In addition, a device that generates X-rays by irradiating accelerated electrons to a target is used, and Mo, W, Cu, Ag, Ni, Co, Cr, Fe, Ti, Rh, etc. are used to implement a high-power device. An X-ray generator having a large cathode structure having a target made of a metal material and a substrate made of a high thermal conductivity material such as diamond is proposed (Korean Patent No. 172,651).

In addition, X-ray light sources using electric pulse discharge such as capillary discharge (Korean Patent No. 1997-9743) or X-pinch, Z-pinch (Korean Patent No. 1993-1322) have also been proposed. In such light sources, since a very thin metal wire is generally used to explode, there is a problem that it is very difficult to continuously generate X-rays because the metal wire must be remounted each time. In addition, many metal fragments are generated due to the explosion of the metal wires due to the high voltage and the high current, thereby causing side effects such as damaging the X-ray optical system or coating foreign substances.

X-ray light sources using high-power lasers and solid targets have also been proposed, which mainly target solid samples such as copper (Cu), aluminum (Al), or plastics. Laser-induced plasma, which is generated by condensing high-power light such as Nd: YAG laser to tens of micrometers, is used. However, even in a generator using such a laser-induced plasma, many sample debris are generated during a process of generating soft X-rays by interacting with a plasma induced by focusing a laser beam on a target such as metal or plastic. ) Is generated to coat or damage the optical system for focusing the X-ray light source. In addition, there is a problem that the generation efficiency of the X-ray light source is extremely low since the re-absorbing laser light focused on the fine plume generated by the generated sample debris.

In addition, the X-ray generators as described above are inexpensive because they use consumable targets (for example, solid targets, metal wires, etc.) to generate X-rays, are time-consuming to replace them, and also have a specific type of operation. X-rays generated by using only a target have a limit of having only a specific spectrum determined thereby.

The present invention is to solve the above problems, a new method using one or more nano-powder dispersed in a liquid solvent, gas or liquefied gas as a sample target (we call it a 'hybrid type target') We propose a versatile, environmentally friendly and compact soft X-ray light source.                         

In addition, a second object of the present invention is to provide a soft X-ray generating apparatus using a sample target of a hybrid type that does not generate sample fragments and can obtain a relatively large efficiency.

The third object of the present invention is to use a soft x-ray that can be used semi-permanently, there is no need for replacement work, and can be used continuously by collecting and reusing a used sample without using a consumable target such as a solid sample. To provide a device.

A fourth object of the present invention is to provide a multi-functional customized X-ray generator having various spectra suitable for the intended use because the intensity, luminance, and spectrum of the X-ray light source can be easily controlled.

An X-ray generating apparatus according to the present invention for achieving the above object comprises: a sample target containing at least one nanopowder dispersed in a liquid solvent, a gas or a liquefied gas; A plasma energy supply system for generating a high power laser or pulsed discharge; And an X-ray generator configured to generate a high-temperature plasma by concentrating energy provided from the plasma energy supply system to the sample target to generate X-rays by transition of expensive ions in the plasma.

Here, preferably, the X-ray generator includes: a storage unit for storing the liquid solvent, gas or liquefied gas in which the nanopowder is dispersed and providing the same as the sample target; And an aerosol generating unit for processing the liquid solvent, gas, or liquefied gas in which the nanopowder provided from the storage unit is dispersed, into an aerosol state containing one or more nanopowders, wherein the sample target Is the aerosol supplied by the aerosol generating unit.

The X-ray generator may further include an aerosol collecting / circulating unit which collects the used aerosol and sends it back to the storage unit. This enables continuous X-ray supply without the need for replacement of the sample target.

Here, the nanopowder may include at least one kind of nano-size carbon nanotubes, ceramic powders, and metallic powders.

In addition, the liquid solvent for dispersing the nanopowder is to include at least one of alcohol (alcohol), distilled water (distilled water), urea solution (urea solution), ammonium hydroxides, fluorocarbon (fluorocarbon) Can be.

Preferably, the intensity and spectrum of the X-rays generated from the X-ray generator may be controlled by adjusting the size of the aerosol, the concentration of the nanopowder, and the components of the material constituting the nanopowder.

Preferably, the size of the aerosol can be controlled by controlling at least one of the vibration frequency, the flow rate, the size of the capillary flows out of the aerosol in the converter.

The X-ray generator may be configured to further include a laser sheet and a camera system, so that the size of the aerosol can be monitored in real time by laser induced fluorescence.

In addition, the X-ray generator may further include an X-ray detector and a spectrometer, so that the intensity and spectrum of the generated X-rays may be analyzed in real time.

The X-ray generator of the present invention according to this configuration is a hybrid type liquid target in which nano-size metallic powders, nano-powders such as ceramics, carbon nanotubes, etc. are dispersed in a liquid solvent, a gas, a liquefied gas, or the like. By using it, it provides a clean and environment-friendly working environment because it does not generate sample debris, and because of the use of a medium with a metal nano-powder with a good X-ray efficiency, it is possible to provide a relatively high X-ray light source efficiency. In addition, according to the present invention, it is possible to generate X-rays having various spectra.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the X-ray generating apparatus according to an embodiment of the present invention.

1 is a block diagram schematically illustrating an X-ray generator according to an exemplary embodiment of the present invention. Referring to FIG. 1, the X-ray generating apparatus according to the present invention includes a storage unit 100, an aerosol generating unit 110, a laser system 120, a camera system 130, a spectrometer 140, a computer system 150, An aerosol collection / circulation unit 160 and a vacuum chamber 170.

The X-ray generator according to the present invention uses a micrometer-sized aerosol containing a solid nano-powder such as metal, ceramic, carbon nanotubes as a sample target, the laser formed by focusing the laser light to supply energy An apparatus for generating an X-ray light source from a laser-induced plasma, which will be described in detail below.

First, the storage unit 100 is a device for storing a hybrid sample target in which nano-size nanopowders are dispersed in a liquid solvent. The aerosol generating unit 110 stores the liquid sample target in which the nanopowders are dispersed. Will be sent to. In this case, the nano-powder is a metallic nano-powder such as copper, aluminum, gold, silver, or a nano-powder such as ceramics, semiconductors such as aluminum nitride (AIN), titanium nitride (TiN), carbon nanotubes (C ₆₀ ), etc. It may be any one of them, and depending on the specific needs such as obtaining various spectra, a mixed powder in which two or more kinds thereof are mixed may be used. In addition, as a liquid solvent for dispersing such nano powders, alcohols such as ethanol and methanol, alcohol, urea solution, distilled water, ammonium hydroxide, and flow One of a variety of liquids, such as Fluorocarbon, or the like, or a mixed solution of two or more thereof may be used.

The aerosol generating unit 110 uses a liquid sample target transferred from the solution storage unit 100 to contain a metal such as aluminum, copper, gold, silver, or an aerosol containing nano powder such as ceramic or carbon nanotubes. Generates 180. The size of the aerosol 180 generated at this time is approximately 10 ~ 500㎛, the size is adjustable. At this time, various variables such as vibration frequency, fluid velocity, size of capillary through which aerosol flows, and the like can be produced by controlling various variables of the aerosol generating unit. FIG. 2 is a photo of the aerosol 180 made from the aerosol generating unit 110 visualized using a laser induced fluorescence method, and shows a micrometer-sized aerosol containing solid nanopowders such as metal, ceramic, and carbon nanotubes. . The size of the aerosol measured at this time is about 200㎛. As such, laser-induced plasma is generated by concentrating strong energy by a high power laser to the aerosol generated from the aerosol generating unit.

In general, when a laser having an intensity of 10 ¹³ -10 ¹⁵ W / cm 2 is irradiated to a metal, liquid, or gas target, the sample target is ionized to generate many electrons, and the generated electrons are further caused by the electric field of the laser. Acceleration generates X-rays through collision recombination with surrounding ions, electron collision excitation, photoionization of cabinet electrons, relatively unstable metastable states, and multi-photon phenomena. X-rays refer to electromagnetic waves with very short wavelengths ranging from 0.1 nm to 30 nm, and their energy ranges from approximately 40 eV to 12 KeV, and is about 20-6000 times higher than visible light. In addition, X-rays are generated when expensive ions of elements having a large atomic number (mainly metal materials) are radiatively transitioned, and therefore, in order to generate an X-ray light source, a high-temperature plasma environment is required to generate a large amount of expensive ions. Therefore, a high intensity focused laser with a pulse width of several nanoseconds or less forms a plasma of high temperature and high pressure for a very short time when it collides with a material, thereby making it possible to generate soft X-rays by using it as an energy transfer means. .

On the other hand, the laser system 120 used in the X-ray generator of this embodiment is a high power laser of 10 ¹³ -10 ¹⁵ W / ㎠ it is preferably configured to generate a short pulse of several ns, excimer laser, Nd It is preferable to use a high power laser such as a YAG laser or a femtosecond (fs) titanium sapphire laser.

Laser pulses are focused on the aerosol containing the nanopowder generated from the aerosol generating unit 110, so that a high temperature and high pressure laser induced plasma is instantaneously generated. At this time, when the electrons in the laser-induced plasma are further heated during the laser pulse and accelerated by the strong electric field of the laser and have high energy, they collide with surrounding ions to generate soft X-rays.

When the laser power is kept constant, the intensity, luminance, and spectral line of the generated X-rays depend on the characteristics of the hybrid aerosol used, that is, the physical and chemical properties of the liquid solvent and nanopowder used. It depends on the size of the aerosol, the concentration of the liquid and the nanopowder used. 3a and 3b show the shape of the generated laser induced plasma, the size of the plasma is measured to 240㎛ and 340㎛, respectively.

The soft X-rays generated in this way are focused through an X-ray optical system installed in the vacuum chamber 170 and transmitted to an X-ray light source application system over an X-ray beam line formed of an optical fiber or the like. It is also desirable to have a pump system mounted in the vacuum chamber to maintain the pressure in the vacuum chamber at an appropriate level.

On the other hand, since the size of the aerosol and the concentration of the nanopowder are closely related to the intensity and spectrum of the generated X-ray light source, it is preferable that these measurements can be performed. Laser-induced fluorescence may be used to measure the size of the aerosol, and for this purpose, a laser sheet (apart from the laser system 120 for energy supply for plasma generation described above) and the camera system 130 This can be used. In addition, the laser-induced plasma generated by the interaction of the aerosol and the laser can be visualized through the camera, the spectrograph 140 is a device for obtaining the wavelength or energy distribution of the X-rays detected by the X-ray detector 145, Computer system 150 is used to analyze the X-ray light source detected by the spectrometer 140.

The aerosol generator 110 may be configured to synchronize with the laser system 120, the spectrometer 140, and the camera system 130 in time. By referring to the intensity and spectral data of the output X-rays measured by the spectroscope 140, the concentration of nanoparticles contained in the solution in the storage unit 100 may be changed to obtain desired intensity and spectrum of the X-rays, It is possible to control such as changing the size. The size of the aerosol can be observed and controlled in real time by controlling various parameters of the aerosol generating unit 110, for example, vibration frequency, flow rate, the size of the capillary through which the aerosol flows.

Meanwhile, the aerosol collecting / circulating unit 160 of the X-ray generating apparatus according to the present exemplary embodiment is a device for collecting the aerosol again and recycling the aerosol to the aerosol generating unit 110 so that the used aerosol can be recycled. Configured together, the generator can be used economically and semi-permanently. By using such an aerosol collecting / circulating unit 160, the X-ray generation technology according to the present invention, unlike other conventional methods, not only can be used semi-permanently for a long time without frequently changing the target for generating the X-ray light source, Has the advantage of being able to be recycled at

In the above embodiment, a case where a high power laser is used as an energy supply means for generating a plasma has been mainly described, but not only a laser-induced plasma by a high power laser, but also a pulse discharge by an electric energy supply method. In the case of generating a high-temperature plasma and obtaining X-rays, the configuration of all parts except for the laser system 120 described above may be applied in the same manner, and as long as a sample target having nanoparticles dispersed therein is used, the scope of the present invention. Of course, it will be obvious to those skilled in the art.

In addition, in the above-described embodiment, as an example of a hybrid sample target, a case where the nanopowder is dispersed in a liquid solvent, and the aerosol containing the nanopowder is generated using the sample is used as a sample target. The technical idea of the present invention is not limited thereto, and the nano powder is dispersed in various other media such as gas or liquefied gas and used as a sample target.

4 is a block diagram schematically illustrating a soft X-ray generating apparatus using a hybrid liquid jet target containing nanopowder according to another embodiment of the present invention. As shown, the apparatus of this embodiment includes a storage unit 200, a hybrid liquid jet target generator 210, a laser system 220, a hybrid liquid jet target collection / circuit unit 260, and detection and control. Camera system 230, detector 245, spectrometer 240, and the like.

The hybrid liquid jet target is different from the above-described embodiment in which a liquid solvent in which the nanopowder is dispersed is sprayed in the form of an aerosol and used as a target, and directly sprays the liquid solvent in which the nanopowder is dispersed as shown in FIG. 4. The case where the hybrid liquid jet 280 that is the liquid solvent injected in this way is used as a target is shown. In this case, a high-power laser or electrical pulse energy is supplied to a portion of the liquid jet 280 to generate a local high temperature plasma, and X-rays are generated by the transition of expensive ions in the plasma.

The hybrid liquid jet target 280 is collected again in the collecting / circulating unit 260 and sent to the generator 210 for reuse. The thickness of the jet of liquid jet 280 is preferably in the range of about 10-500 um.

FIG. 5 is a block diagram schematically illustrating a soft X-ray generator using a hybrid gas jet target containing nanopowders according to another embodiment of the present invention. In this embodiment, the nanopowder is dispersed in a gas and stored in the storage unit 300, sprayed from the hybrid gas jet target generator 310, and the injected gas jet 380 is used as a target for X-ray generation. It becomes the structure to say. Here too, in order to generate a local high temperature plasma, plasma generation energy is supplied to a part of the gas jet by applying a laser or an electrical pulse. In addition, as the type of gas used, xenon (Xe), neon (Ne), argon (Ar) and the like may be used, but are not limited thereto, and any other gas such as nitrogen (N 2) and oxygen may be used.

FIG. 6 is a block diagram schematically illustrating a soft X-ray generator using a hybrid liquefied gas jet target containing nanopowder according to another embodiment of the present invention. In the present embodiment, the nanopowder is dispersed in the gas in a liquefied state and stored in the storage unit 400, which is sprayed through the hybrid type liquefied gas jet target generation unit 410, and the liquefied gas jet thus injected ( 480 is used as a target to generate X-rays. Through this configuration, it becomes possible to easily collect / circulate the used target material again and to recycle it. In this embodiment as well, there is no particular restriction on what kind of gas the liquefied gas liquefies. .

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the technical idea of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

 Multi-functional and compact micro-scale soft X-ray generator using a hybrid type sample target containing nanopowder according to the present invention is an eco-friendly X-ray light source that can continuously use the sample target with little generation of sample debris For example, it may be used for the purpose of X-ray microscopy or bio-holography, which is mainly used for genetic research, which is an essential research in the life sciences and medical fields. In addition, the present invention can be applied to the next-generation semiconductor exposure technology that can significantly reduce the semiconductor line width by an excimer laser, which is currently used in the semiconductor lithography technology, to 50 nm or less. In addition, it can be used for thin film structure analysis or basic research to study the physicochemical properties of plasma at high temperature and high pressure.

Claims (9)

delete delete A sample target containing one or more nanopowders dispersed in a liquid solvent, gas or liquefied gas; A storage unit for storing the liquid solvent, gas or liquefied gas in which the at least one nanopowder is dispersed, and providing the same as a sample target for laser generation; An aerosol generating unit for processing the liquid solvent, gas or liquefied gas in which the nanopowder is dispersed, which is provided from the storage unit, and converting the aerosol into aerosol state containing at least one nanopowder; A plasma energy supply system for generating a high power laser or pulsed discharge; An X-ray generator configured to generate a high-temperature plasma by concentrating energy provided from the plasma energy supply system to the sample target to generate X-rays by transition of expensive ions in the plasma; A laser sheet and a camera system for visualizing a laser induced plasma generated by the interaction of the aerosol and the laser by laser induced fluorescence to enable real-time monitoring of the size of the aerosol; An X-ray detector and a spectrometer that detects X-rays generated by the X-ray generator and analyzes the intensity and spectrum of the X-rays in real time; And an aerosol collecting / circulating unit capable of collecting the aerosol used in the X-ray generating unit and sending it back to the storage unit. The method of claim 3, wherein the nano powder, An x-ray generator, characterized in that it comprises at least one kind of nano-size carbon nanotube, ceramic powder and metallic powder. According to claim 3, The liquid solvent for dispersing the nanopowder, An x-ray generator comprising at least one of alcohol, distilled water, urea solution, ammonium hydroxides, and fluorocarbons. The intensity and spectrum of the X-rays generated from the X-ray generator, X-ray generator, characterized in that the controllable by adjusting the size of the aerosol, the concentration of the nano-powder and the components of the material constituting the nano-powder. The method of claim 3, wherein the aerosol generating unit, X-ray generator, characterized in that for controlling the size of the aerosol by controlling at least one variable of the vibration frequency in the aerosol generating unit, the flow rate, the size of the capillary flows out of the aerosol. delete delete

Images