JPH01292800A - Accumulation accelerator for charged particle - Google Patents

Abstract

PURPOSE:To aim at curtailment of a rise time for a charged particle emitted from a kicker by defining an auxiliary kicker which has been excited between a kicker and a deflector and is demagnetized anticharacteristically of the kicker. CONSTITUTION:A charged particle is deflected from a normal rotational trajectory by means of a kicker 4 which deflects a charged particle at a small angle and then it enters a deflector 5 that is formed outside of the rotational trajectory. An auxiliary kicker 18 that is formed between the kicker 4 and the deflector 5 is excited beforehand and demagnetized in reverse to the excitation characteristics of the kicker 4. Thereby it is possible to extract a charged particle also during the rise time of the kicker, thus the outgoing efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a compact charged particle accelerating and accumulating device that is an improved device for ejecting charged particles from an accelerating ring (for example, a synchrotron).

(Prior Art) Charged particle accelerating and accumulating devices generally include a low-energy charged particle injector (also called an injector) and an acceleration ring (also called an injector) for accelerating the low-energy charged particles to a predetermined high energy.
For example, it consists of a synchrotron) and an accumulation ring (also called a storage ring) for storing charged particles taken out from an acceleration ring for a long time.

FIG. 5 is a block diagram of a general charged particle accelerating and accumulating device. In Fig. 5, low-energy charged particles from the injector (1) pass through the injecting beam duct (2), and are moved through the approximately circular accelerating ring (30) using the accelerating ring inflector (3).
), and after being accelerated to a predetermined energy by the acceleration ring (30), the kicker (4) and the deflector (5)
, the acceleration ring (30
) is emitted to the outside of the storage ring inflector (
7), the light enters and accumulates in the storage ring (31), and the storage ring bending electromagnet (13) generates light for LSI exposure.

In Fig. 5, the acceleration ring (30) is the acceleration ring inflector (3), kicker (4), and deflector (5).
, is the name of a device consisting of an acceleration ring beam duct (8), an acceleration ring high frequency acceleration cavity (9), and an acceleration ring bending electromagnet (10).

The storage ring (31) is the storage ring inflector (7)
, a storage ring beam duct (11), a storage ring high frequency acceleration cavity (12), and a storage ring bending electromagnet (13) having a light emitting section that generates light for LSI exposure.

FIG. 3 shows the emission path of charged particles in a conventional example of the charged particle accelerating and accumulating device shown in FIG.

In Fig. 3, the accelerated charged particles have their original rotational orbits (
15) by the killer force (4), is further bent by the deflector (5), passes through the output beam duct (6), and is taken out in the direction of the output trajectory (16). The basic operation of ejection is to deflect the charged particles rotating inside the accelerator ring (30) using a magnetic field to remove them from the equilibrium orbit and take them out of the accelerator ring. ~10 degrees.

Furthermore, in order for the particles to be taken out, the rise time of the deflection magnetic field of the Kira force (4) needs to be shorter than the time it takes for the particles to make one revolution inside the accelerator ring. This is because the charged particles that pass through the extraction magnet, that is, the Kira force (4) before the magnetic field reaches a predetermined value, deviate from the trajectory toward the extraction port and collide with the deflector (5) or beam duct (6). This is because the data will be lost.

FIG. 4 is a curve diagram for explaining this.

The horizontal axis is time t with the origin at the Kira force excitation start time.

The vertical axis shows the magnetic field strength B of the Kira force (4). In Fig. 3, the solid curve shows the magnetic field strength B of the Kira force (4).
wax and B win are the maximum and minimum values, respectively, indicating the range of the magnetic field required to correctly guide the charged particles to the extraction trajectory. Therefore, the time t is the time when the Kira force (4) starts to work effectively. In other words, the charged particles that have passed through the Kira force (4) between time 0 and t1 are sent to the exit beam duct (
6) and is lost due to collision.

When the time for a charged particle to go around the acceleration ring is T, the output efficiency η is η=(T-t,)/T=1-t□/T. In other words, charged particles can be extracted with high efficiency by using the Kira force (4) with a fast rise, but if the rise time is longer than T, the efficiency η becomes zero and no charged particles can be extracted.

In general, in an electron acceleration ring, the number of ring directors is several tens or more.
Since it is about several 100, T=several 10 to several 100 m/C If C=3X10"m/S, T=several to several 10 nanoseconds
It is c. It is technically extremely difficult to manufacture the Kira force (4) that achieves this fast rise time and deflection angle of several to ten degrees. Therefore, normally, as shown in Figure 3, a chira force (4) that deflects charged particles by a minute angle (several to tens of mrad) is used to shift the charged particles from their normal rotational orbits, and to set them outside the normal rotational orbits. incident on the deflector (5).

Since the deflector (5) is installed outside the normal rotational orbit of the charged particles, it is only necessary to slowly start up the deflector (5) before the Kira force (4) operates, thereby generating a magnetic field necessary and sufficient to bend the charged particles significantly. I was able to do that. In this way, the combination of the Kira force (4) and the deflector (5) usually realizes an emission device with a rise number of 10 nsac and a deflection angle of 10 degrees.

(Problem to be solved by the invention) However, recently, small SOR (Synchrotron 0rbit) has been attracting attention as a light source for VLSI exposure.
alRadiation) equipment, the ring director
Since it is several meters, the rise of the Kira force (4) is several tens of ns.
In AC, almost no charged particles can be emitted.For example, when the ring circumference L=15m, T=L/C=15m/3XlO"m/5=5
Since it is 0nsec, the rise time of Kira force is 50ns
It must be sufficiently shorter than ec and have a faster rise.

SUMMARY OF THE INVENTION An object of the present invention is to provide an accelerating and accumulating device for charged particles that includes a charged particle emitting device in which the rise time of charged particles emitted by a chira force is sufficiently short, that is, the rise is fast.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, an auxiliary killer force is provided between the killer force and the deflector, which is previously excited and demagnetized to have a characteristic opposite to that of the rikicker.

(Function) In this way, charged particles that collided with and were lost outside the beam duct in the conventional configuration can be effectively emitted with a fast rise time.

(Example) An example of the present invention will be described below with reference to FIG.

In this example, the kill force (4) and the deflector (
An auxiliary killer force (18) is provided between the magnet and the killer force (18), which is previously excited and is demagnetized with a characteristic opposite to that of the killer force (4). Other than that, change the position of the deflector (5) in Figure 5 to the acceleration ring (3).
This is similar to the conventional example shown in FIG. 3, which is improved by moving the rotary orbit (15) to the outside of the rotary orbit (15) of 0). Therefore, it is the same as the general one shown in FIG. 5 except that the above-mentioned main parts have been improved.

Next, the operating principle of this embodiment is explained in Figs. 2(a) and (b).
) and (C).

Fig. 2(a) shows the case with only the Kira force (4) and the deflector (5), Fig. 2(b) shows the case with only the auxiliary Kira force (18), and Fig. 2(c) shows the case with the It is a time chart which shows the principle of operation which combined (a) and (b). Figure 2 (
Since a) includes only the killer force (4) and the deflector (5), the charged particle extraction efficiency is determined by the rise time t2 of the killer force (4).

Let's use numerical values as an example. Ring circumference L = 1
5 m, kicker rise time t = 40 nsec, the extraction efficiency of charged particles is η = l-t, /T = 1-
40ns150nsac=1-0.8=0.2 That is, 80% of the beam collides with the beam duct and is lost, and only 20% of the beam can be extracted.

Therefore, as in the present invention shown in FIG. 1, an auxiliary squirting force (18) is provided between the squirting force (4) and the deflector (5).

The auxiliary killer force (18) is excited in advance as shown by the broken line, and the auxiliary killer force (18) is opposite to the excitation characteristic of the killer force (4).
demagnetize. By doing so, charged particles between time 0 and t2, which were almost all dead in the conventional system, can also be guided to the deflector (5).

Therefore, the output efficiency is approximately 100%.

〔Effect of the invention〕

As explained above, according to the present invention, the auxiliary kill force that is previously excited between the kill force of the conventional system and the deflector is demagnetized to have a characteristic opposite to that of the kill force, which cannot be extracted with the conventional system. The rise time of the Kira force was 0-1. Charged particles in between can also be taken out, and a charged particle accelerating and accumulating device having a small emission device with extremely high emission efficiency can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a principle explanatory diagram showing the main part of an embodiment of the present invention, and Fig. 2 (a), (b), and (e) show the magnetic field of the magnetic field versus time of the magnetic force, auxiliary force, and deflector shown in Fig. 1. A curve diagram showing the change in strength. Figure 3 is a principle explanatory diagram showing the main part of the conventional example shown in Figure 5 with an improved position of the deflector. Figure 4 is a diagram showing the change in magnetic field strength with respect to time in the conventional example shown in Figure 3. A curve diagram showing
FIG. 5 is a component layout diagram showing a general charged particle accelerating and accumulating device. 30...Acceleration ring 31...Storage ring 4...Kira force 5...Deflector 6...Output beam duct 18...Auxiliary kick force agent Patent attorney Norio Ogo 3rd figure B Oso/ 7:01

Claims (1)

[Claims] An acceleration ring that accelerates low-energy charged particles to a predetermined high energy, and receives and accumulates the charged particles emitted from the acceleration ring via a kicker, a deflector, and an output beam duct to generate light for VLSI exposure. A device for accelerating and accumulating charged particles comprising a storage ring having a light-emitting portion, characterized in that an auxiliary kicker is provided between the kicker and the deflector, and is previously excited and demagnetized to have opposite characteristics to the kicker. Accelerating and accumulating charged particles.