JPH03226999A - Small-sized sor synchrotron device - Google Patents

Abstract

PURPOSE:To reduce extinction of electrons due to an ion trapping phenomen by circulating an electron beam inside a synchrotron and making a positive electron beam to circulate in the periphery of the same electron beam and reversely in order to take out radiation light (SOR light) from each beam. CONSTITUTION:When circulating electrons and positive electron beams circulate in a synchrotron 11, SOR light is incident on the outside wall of the deflection part inside a vacuum container 15, thereby, gas inside a wall is expelled to be released to the inside of a vacuum container 15, but in this case, positive electron beams are circulating outside so that gas is repelled by positive electron beams so as to prevent an ion trapping phenomen by the circulating electron beams circulating inside. Further, this gas is collected by an ion pump or the like provided along the vacuum container 15 so as to maintain a vacuum degree inside the vacuum container 15 excellent. In this way, since the ion trapping phenomen can be prevented, accumulation efficiency of electrons and positive electrons is good also a life of electrons and positive electron beams during SOR operation is long thus to perform SOR operation for long hours.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a compact SOR device that circulates electron and positron beams at the speed of light within a synchrotron without extracting synchrotron radiation.

[Prior Art] Recently, SOR devices have been attracting attention as light sources for semiconductor lithography.

The SOR device rotates an electron beam in a storage ring at the speed of light and extracts synchrotron radiation (SOR light) emitted when the electron beam is deflected by a magnetic field.

Normally, a large SOR device consists of three devices: a linear accelerator, a synchrotron, and a storage ring, but a small SOR device
An OR device that combines a synchrotron and a storage ring is currently being developed.

In this small SOR device, low-energy electrons with electron energy of 100 M e V or less are repeatedly injected into the synchrotron from a linear accelerator, and once a predetermined accumulated current is secured in the synchrotron, the synchrotron is The electron beam energy is increased to a final energy (for example, 800 M e V), and the SOR light is extracted by performing continuous SOR operation for several tens of hours with that energy until the electron beam disappears.

[Problems to be Solved by the Invention] By the way, the SOR light generated in the synchrotron during the electron accumulation operation and SOR operation hits the inner wall of the vacuum vessel, and the gas contained in the inner wall is caused to flow inside the synchrotron. This causes an ion trapping phenomenon in which the electrons are attracted to the orbiting electron beam and collide with the electrons.The electrons are easily annihilated, the lifetime of the electron beam is short, and the electrons in the synchro 1 heron are There is a problem that storage operation requires a long time.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a small-sized SOR device that can reduce the annihilation of electrons due to the ion 1-rat pink phenomenon.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides synchro 1 to
In this system, an electron beam is made to circulate within the electron beam, and a positron beam is made to circulate in the opposite direction around the outer periphery of the electron beam, and SOR light is extracted from each beam.

[Function] According to the above configuration, the positron beam orbits around the outer circumference of the electron beam in the synchrotron, so even if debris is generated mainly from the outer peripheral wall of the synchrotron, it will not turn into the positron beam because it has the same polarity as the positron. It is not attracted and can be collected by Synchro 1 ~ Ron's ion pump, and Synchro 1 ~
As the vacuum level of the RON improves, the lifetime of each beam becomes longer, and SOR light can be extracted for a long time.

[Example] Hereinafter, preferred embodiments of the present invention will be described based on the accompanying drawings.

First, the configuration of the SOR device will be explained with reference to FIG.

In FIG. 1, ■ is an electron generator, an accelerator tube 2 is connected to the electron generator 1, a deflection magnet 4 is connected to the beam line 3 at the output end of the accelerator tube 2, and a switching electromagnet 5 is connected. be done. A first branch line 6 that extends in line with the beam line 3 and a second branch line 7 that guides the electron beam deflected by the switching electromagnet 5 are connected to the switching electromagnet 5 . An incident bending electromagnet 8 is connected to the first branch line 6, an incident line 9 is connected to the incident bending electromagnet 8, and electrons are transmitted from the incident line 9 to the synchronizers 1 to 11 via the septum electromagnet 10. It is designed to be incident. Further, a target 12 such as tantalum or tungsten is connected to the second branch line 7, and an input line 13 for inputting positrons generated from the target 12 to the synchrotron 11 is connected, and a septum electromagnet 14 is provided at the input section. It will be done.

The synchrotron 11 includes an annular vacuum vessel 15 in which electron beams and positron beams orbit in opposite directions, a high-frequency acceleration cavity 16 that supplies energy to the electron beams and positron beams orbiting inside the vacuum vessel 15, and a vacuum It consists of deflecting electromagnets 17 that are provided at the four corners of the container 15 and deflect electron beams and positron beams. A plurality of light extraction lines 18 for the SOR light emitted from the electron beam are connected to the deflection portions of the synchronizers 1 to 11, and a plurality of first extraction lines for the SOR light emitted from the positron beam are connected, Each line 18.1
Exposure devices 20 and 21 are connected to 9.

Further, the electron beam incident from the incident line 9 via the septum electromagnet 10 into the vacuum vessel 15 of the synchrotron 11 and the positron beam incident from the incident line 13 via the septum electromagnet 14 into the vacuum vessel 15 are shown in FIG. As shown, the beams 22 and 23 are separated from each other by a predetermined distance d within the vacuum vessel 15, and the positron beam 23 is incident on the electron beam 22 so as to orbit around the electron beam 22 (111).

Next, the operation of this embodiment will be explained.

First, the case where the electron beam is incident on the synchronizers 1 to 11 will be described. In this case, the switching electromagnet 5 and the positron-side septum electromagnet 14 are brought into a non-excited state.

Electrons from the electron generator 1 are accelerated to several +MeV in an accelerating tube 2, deflected by a deflection electromagnet 4 from the emission end, and then directly extended from the beam line 3 in a straight line with the beam line 3 without being deflected by a switching electromagnet 5. The electrons pass through the first branch line 6 and are deflected by the deflection electromagnet 8 for incidence, and are incident from the deflection electromagnet 8 for incidence into the synchrotron 11 via the septum electromagnet 10 from the incidence line 9 .

When a positron beam is incident, the switching electromagnet 5 is energized, and the electron rm septum electromagnet 10 is de-energized.

Electrons accelerated to several tens of MeV in the accelerating tube 2 are deflected from the emission end by a deflection electromagnet 4, and from the beam line 3 by a switching electromagnet 5, pass through a second branch line 7, and hit a target 12. When electrons collide with this target 12, comma rays are generated due to the interaction between the electrons and a strong electric field, and then electron pair generation occurs due to the interaction between the comma rays and the strong electric field. The generated positrons are transferred from the incident line 13 to the synchrotron 11 by the septum electromagnet 14.
is incident on the

The electrons and positrons incident on this synchrotron 7 are
For example, the electron beam orbits counterclockwise as shown by the arrow 24 in the figure, the positron beam orbits clockwise as shown by the arrow 25 in the figure, and the positron beam orbits outside the electron beam. Inject it as follows. Also, a positron is an antiparticle of an electron, and both are equivalent in terms of energy, so if they orbit in opposite directions, the bending electromagnet 17
can be deflected with the same magnetic field strength. In order to prevent the beams from colliding with each other, the magnetic field distribution strength of the deflecting magnet 17 is maintained so that the beams are always separated from each other.The injection of electrons and positrons is repeated until a predetermined number of positrons are accumulated in the synchrotron 11. , the magnetic field of the bending electromagnet 17 is increased from the incident energy key to the final energy to make the electrons and positrons orbit, and the SOR light emitted in the tangential direction when the electron beam and the positron beam are deflected by the bending electromagnet 17 is extracted. Exposure device 2 from line 18.19
0.21 and perform phosphorography on semiconductors, etc.

When the electron and positron beams orbit in the synchrotron 11, the outer wall of the deflection section in the vacuum chamber 15 is
The R light hits the force plate, which knocks out the debris in the wall and releases it into the vacuum chamber 15. In this case, since the positron beam is orbiting on the outside, the debris is repelled by the positron beam, and the debris is repelled by the inside. It is possible to prevent the ion trapping phenomenon caused by the orbiting electron beam. Although not shown, this gas is collected by an ion pump or the like provided along the vacuum container 15, and the degree of vacuum in the vacuum container 15 (10-9 to
10) are well maintained.

In this way, since the ion trapping phenomenon can be prevented, the storage efficiency of electrons and positrons is improved, and the lifetime of the electron and positron beams during SOR operation is long, so that SOR operation can be performed for a long time.

In the above embodiment, the electron generator 1 and the acceleration tube 2
and switch the direction of the electrons with the switching electromagnet 5,
Although electrons and positrons are made to enter the synchronizers 1 to 11, separate injection devices for electrons and positrons may be provided. In this case, the electrons may be introduced from the inside of the vacuum container 15. By making the electrons incident, the electrons at the time of incidence do not intersect with the positron beam orbiting the synchrotron 11, and the injection timing can be easily controlled.

[Effects of the Invention 1 As is clear from the above explanation, the present invention exhibits the following excellent effects.

(1) Electrons and positrons are introduced into a synchrotron, and SOR light can be extracted from the electron and positron beams.

(2) Ion trapping phenomenon can be prevented and SO can be used for long periods of time.
R driving is possible.

[Brief explanation of drawings]

FIG. 1 is an overall plan view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the vacuum container shown in FIG. 1. In the figure, 1 is an electron generator, 2 is an acceleration tube, 5 is a switching electromagnet, 9 is an incident line for electron injection, 11 is a synchro 1 heron, 12 is a target, 13 is an incident line for positron injection, and 17 is a deflection Magnet 18.19 is a light extraction line.

Claims (1)

[Claims] 1. A small SOR device characterized in that an electron beam is circulated within a synchrotron, a positron beam is circulated around the outer periphery of the electron beam in the opposite direction, and SOR light is extracted from each beam.