JP2608947B2 - Charged particle storage device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a charged particle storage device, and more specifically, to a charged particle storage device used as, for example, a synchrotron radiation light source.

[Prior Art] FIG. 3 shows, for example, TELL-TERAS ACTIVITY REPORT (1980-1986) P.2
2 is a conventional charged particle storage device shown in FIG. 2, wherein (1) is a donut-shaped vacuum vessel, (2) is a bending electromagnet, (3) is a quadrupole electromagnet, (4) is a low-speed pulse electromagnet,
(5) is a high-speed pulse electromagnet for generating a vertical magnetic field, (6)
Are high-frequency cavities, which together form a storage ring. (7) is an electron linear accelerator for high-speed electron generation.

FIG. 4 shows the trajectory of charged particles on the phase plane at the exit of the low-speed pulse electromagnet. (8) in the figure shows the position of the incident charged particles at the exit of the low-speed pulse electromagnet. (9)
Indicates the state of the incident charged particles at the position of the high-speed pulse electromagnet. (10) shows the state of the charged particles after passing through the pulse electromagnet. (11) shows the state of the incident charged particles when returning to the position of the low-speed pulse electromagnet thereafter. (12) is the position after one rotation of the storage ring. (13), (14), (15), (16), and (17) are the positions of accumulated charged particles. (18) shows the side wall of the low-speed pulse electromagnet.

The conventional charged particle storage device is configured as described above, and the state when charged particles are incident will be described. The trajectory of the electrons generated by the electron linear accelerator (7) is deflected by the low-speed pulse electromagnet (4), and the state is changed to (8) in FIG. When the electron arrives at the position of the high-speed pulse electromagnet (5), the position becomes (9) on the phase plane. At this time, the inclination of the electrons changes stepwise due to the vertical magnetic field of the high-speed pulse electromagnet (5) and comes to the position (10). Then, when it comes again to the low-speed pulse electromagnet (4), it is at the position (11). afterwards,
When the low-speed pulse electromagnet (4) arrives at the position of (12) under the same action, it comes to the position of (12). By repeating this, the electrons move on the phase plane. Unless the magnetic field of the high-speed pulsed electromagnet (5) ceases to collide with the side wall (18), incident electrons from the outside have been stored in this storage device. On the other hand, the charged particles that have been accumulated are subjected to the same action and sequentially move from the position (13) to the position (17).

[Problems to be Solved by the Invention] The conventional charged particle storage device as described above has the following problems.

1) Since a uniform vertical magnetic field is generated, the trajectory of the stored charged particles is also disturbed.

2) Since the space of the generated magnetic field is large, the power supply capacity for the high-speed pulse electromagnet increases.

3) Since the trajectory of the stored electrons changes, charged particles cannot be injected from the outside again until the trajectories attenuate.

4) Therefore, it cannot be used as a synchrotron radiation light source at the time of incidence.

5) If the pulse width of the high-speed pulsed electromagnet is not very fast, incident charged particles will collide with the side wall of the low-speed pulsed electromagnet.

6) For this reason, the power supply capacity is further increased.

7) The charged particles after the incidence pass through a place far away from the central trajectory, and the effective magnetic field area of the bending electromagnet and the quadrupole electromagnet of the storage ring must be increased.

The present invention has been made in order to solve such a problem, and has a high-speed pulse electromagnet which can be incident without disturbing the stored charged particles, has a certain pulse width, and can reduce the power supply capacity. It is another object of the present invention to obtain a charged particle storage device that can be used as a light source even when charged particles are incident.

[Means for Solving the Problems] A charged particle storage device according to the present invention includes a high-speed pulse electromagnet that generates at least a quadrupole magnetic field component.

[Operation] In the present invention, since a magnetic field having at least a quadrupole magnetic field component is generated, the directions of the magnetic field generated by the high-speed pulse electromagnet are opposite with respect to the central axis as a symmetric axis. Also, the magnetic field strength increases in proportion to the distance from the axis. Charged particles incident from the outside receive a stronger magnetic field force as they move away from the central axis. Further, since the charged particles that have entered come to a position with the origin as a target point every round, the charged particles are always subjected to a force in the direction of the central axis, so that they are converged on the central axis.

FIG. 1 shows an embodiment of the present invention, in which a high-speed pulse electromagnet (19) generates a quadrupole magnetic field.

 In addition, the same reference numerals as those in FIG. 3 denote the same parts.

FIG. 2 shows the trajectory of the charged particles on the phase plane at the exit of the low-speed pulse electromagnet (4), and (8) in the figure shows the position of the incident charged particles at the exit of the low-speed pulse electromagnet (4). I have. (9) shows the state of the incident charged particles at the position of the high-speed pulse electromagnet. (10) shows the state of the charged particles after passing through the pulse electromagnet. (11) shows the state of the incident charged particles when returning to the position of the low-speed pulse electromagnet (4). (12) is the position after one rotation of the storage ring. (13) (14) (15) (16) (1
7) is that of stored charged particles. (18) shows the side wall of the low-speed pulse electromagnet.

With the above configuration, the trajectory of the electrons generated by the electron linear accelerator (7) is deflected by the low-speed pulse electromagnet (4), and the state shown in (8) in FIG. 2 is obtained. When the electron arrives at the position of the high-speed pulse electromagnet (19), the position becomes (9) on the phase plane. At this time, the inclination of the electrons changes stepwise due to the vertical magnetic field of the high-speed pulse electromagnet (19) and comes to the position (10). By appropriately selecting the strength of the high-speed pulse electromagnet (19), when the low-speed pulse electromagnet (4) is subsequently returned, the position of (11) can be brought to a position symmetrical to the origin (8). . Assuming that the applied current of the high-speed pulse electromagnet (19) is rectangular, the generated magnetic field of the high-speed pulse electromagnet (19) is proportional to the distance from the center.
The incident charged particles always move on a straight line connecting (9) and the origin. After that, when the same action is taken to reach the low-speed pulse electromagnet (4), it comes to the position (12). By repeating this, the electrons move on the phase plane to converge to the origin. For this reason, even if the pulse width of the high-speed pulse electromagnet (19) is increased, the incident charged particles are not lost but are accumulated in the ring. On the other hand, the accumulated charged particles are on the origin, so a high-speed pulsed electromagnet (19)
Since the generated magnetic field is zero, it is hardly affected by the high-speed pulse electromagnet (19).

In the above embodiment, a quadrupole electromagnet was considered as the high-speed pulse electromagnet, but a similar operation can be expected with a multipole electromagnet for generating a higher-order magnetic field.

In the above embodiment, a rectangular wave was used as the applied current to the high-speed pulse electromagnet.
Similar operation can be expected even with a current having a triangular wave or the like.

[Effects of the Invention] As described above, the present invention uses a multi-pole electromagnet as the conventional high-speed pulse electromagnet for generating a vertical magnetic field, thereby allowing charged particles to be incident from the outside without substantially affecting the accumulated beam. Can be. In addition, since the deviation of the charged particles from the central axis after the incidence can be rapidly reduced, the effective magnetic field area of the deflection electromagnet and the quadrupole electromagnet of the storage ring can be narrowed, so that the size of the electromagnet is small. Become.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of one embodiment of the present invention, FIG. 2 is a phase plan view for explaining the operation of FIG. 1, FIG. 3 is a schematic plan view of a conventional charged particle storage device, Figure 4 is the third
It is a phase plan view for explaining operation of the thing of the figure. (1) Vacuum container (2) Bending electromagnet (3)
... quadrupole electromagnet, (4) ... low-speed pulse electromagnet, (6) ...
… High frequency cavity, (7)… Electronic linear accelerator, (19) ……
High-speed pulse electromagnet. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A bending electromagnet for deflecting the trajectory of charged particles by a magnetic field, a quadrupole electromagnet for converging the charged particles, a high-frequency cavity for accelerating the charged particles, and a donut-shaped vacuum vessel for accumulating the charged particles. A low-speed pulsed electromagnet for deflecting the incident charged particles supplied from outside the vacuum vessel to approach the trajectory of the stored charged particles, and disturbing the trajectory of the incident charged particles to match the trajectory of the stored charged particles. A charged particle storage device comprising: a storage ring including a high-speed pulsed electromagnet having at least a quadrupole magnetic field component; and an electron linear accelerator for generating the incident charged particles from outside the vacuum vessel.