JPH0542800B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electron storage ring, and more specifically, the present invention relates to an electron storage ring. The present invention relates to an electron storage ring.

[Conventional technology]

Figure 5, for example, is from Yoshikazu Miyahara, Koji Takata, and Tetsuya Nakanishi, "Superconducting Racetrack Electron Storage Ring and Coexistent Injector Microtron Four Synchrotron Radiation" Technical Report of ISP. 21 (1984,
9) [Yoshikazu Miyahara, Koji Takata and
Tetsuya Nakanishi
“Superconducting Racetrack Electron Storage
Ring and Coexistent Injector Microtron for
Synchrotron Radiation” TECHNICAL
REPORT of ISSP.21 (1984, 9)], the figure shows a deflection magnet 2 for bending the electron beam along the center trajectory 1 of the electron beam, and a deflection magnet 2 A sextupole magnet 3 for non-linear magnetic field correction or chromaticity correction, a quadrupole magnet 4 for converging the electron beam, a high frequency acceleration cavity 5 for accelerating the electron beam, and a A kicker 6 for shifting the center orbit of the electron beam to make it easier to enter the ring, and an inflector 7 for making the electron beam enter the ring along the center orbit of the electron beam are provided.

As shown in FIGS. 6 and 7, the deflection magnet 2 includes a vacuum chamber 8 for keeping the space through which the electron beam passes in a vacuum, and a vacuum chamber 8 for keeping the vacuum chamber 8 evacuated during operation of the electron storage ring. A built-in pump 9 is provided.

With the above configuration, the center orbit 1 of the electron is shifted by the kicker 6, and then the electron beam is made to enter the ring through the inflector 7. The electron beam within the ring is bent by a deflection magnet 2 and emits synchrotron orbital synchrotron radiation. The quadrupole magnet 4 serves to converge the electron beam so that the width of the electron beam does not widen. The high frequency acceleration cavity 5 has the role of accelerating electrons to compensate for the energy released by synchrotron orbital radiation. The sextupole magnet 3 serves to correct the non-uniformity of the magnetic field in the radial direction of the deflection magnet 2 or to correct chromaticity. The vacuum chamber 8 drawn to an ultra-high vacuum prevents electrons from colliding with gas molecules and losing energy, thereby shortening the life of the electron beam. However, since the synchrotron radiation hits the wall surface of the vacuum chamber 8 in the second portion of the deflection magnet, a large amount of outgas is emitted.
The built-in pump 9 draws this outgas and maintains the inside of the vacuum chamber 8 at an ultra-high vacuum even when the ring is in operation.

Electrons are stored in the electron storage ring in the manner described above.

[Problem that the invention seeks to solve]

In the conventional electron storage ring as described above, the hexapole magnet 3 must be disposed outside the deflection magnet 2, resulting in a large size.

This invention was made to solve the above-mentioned problems, and its object is to obtain a small electron storage ring by incorporating a hexapole magnet into a deflection magnet.

[Means for solving problems]

In the electron storage ring according to the present invention, a part of the built-in pump of the deflection magnet part is removed, and a multipolar magnet such as a hexapole magnet is installed therein.

[Effect]

In this invention, the multipole magnet compensates for the non-uniform magnetic field components of the deflection magnet without compromising the pumping capacity of the built-in pump.

[Example] Figures 1 to 4 show an example of this invention,
In FIG. 1, a vacuum chamber 8 and a built-in pump 9 separate a part of the built-in pump 9 of two deflected magnets arranged side by side, and a hexapole magnet 3 is built in between. The built-in six-pole magnet 3 is connected to a six-pole coil 3 as shown in FIG.
a, and an insulating support member 3b that supports the six-pole coil 3a. Figure 3 shows the part of the vacuum chamber 8 in which the hexapole magnet 3 is not installed.
and a built-in pump 9 are shown.

With the above structure, the electron storage ring shown in FIG. 4 is constructed. Note that the same reference numerals as in FIG. 5 indicate the same parts.

With the above configuration, the electron beam incident on the kicker 6 and the inflector 7 is bent by the deflection magnet 2 and converged by the quadrupole magnet 4 so that the beam width does not widen. In this way, electrons are stored in the electron storage ring. However, although the magnetic field generated by the deflection magnet 2 must be uniform, since the actual deflection magnet 2 has a finite size, it has some non-uniform magnetic field components. Since most of this non-uniform magnetic field component is the same as the magnetic field of the sextupole magnet 3, this non-uniform magnetic field component is corrected by the sextupole magnet 3. By thus dividing the built-in pump 9 and incorporating the sextupole magnet 3 between them, it is possible to correct the non-uniform magnetic field component of the deflection magnet 2 without impairing the pumping ability of the built-in pump 9.

In the above embodiment, the air-core hexapole magnet 3 is incorporated into the deflection magnet 2, but the hexapole magnet may be an iron core. Further, although the hexapole magnet 3 is used for correcting the non-uniform magnetic field component of the deflection magnet 2, it may also be used for chromaticity correction. Further, although the hexapole magnet 3 is incorporated into the deflection magnet 2, other multipole magnets having four or more poles such as a quadrupole magnet or an octupole magnet may be used.

Further, in the above embodiment, the case of an electron storage ring has been described, but a synchrotron accelerator may be used, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the built-in pump is separated and the multi-pole magnet is built in between, so the multi-pole magnet can be built into the deflection magnet section without impairing the pumping capacity of the built-in pump. This has the effect of providing a compact electron storage ring.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
Figure 1 is a partial plan cross-sectional view, Figure 2 is a cross-sectional view of the main part,
FIG. 3 is a partial cross-sectional view, and FIG. 4 is a plan view.
Figures 5 to 7 show conventional electron storage rings,
FIG. 5 is a plan view, FIG. 6 is a partial plan sectional view, and FIG. 7 is a cross-sectional view of the main part. 1... Center orbit of electron beam, 2... Bending magnet, 3... Hexapole magnet (multipole magnet), 8... Vacuum chamber, 9... Built-in pump.
In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A deflection magnet disposed along the central trajectory of the electron beam for bending the electron beam, and a deflection magnet disposed at the portion of the deflection magnet for evacuating a vacuum chamber through which the electron beam passes. An electron storage ring comprising: a built-in pump; and at least a quadrupole multipole magnet built into a partial section of the built-in pump for correcting a non-uniform magnetic field component of the deflection magnet. 2. The electron storage ring according to claim 1, wherein the multipole magnet is a hexapole magnet.