JPS63308897A - Pulse electromagnet for storage ring - Google Patents

Abstract

PURPOSE:To make the incident course of electrons correct by arranging a permanent magnet with the equal magnitude in the opposite direction to the residual magnetic field of a pulse electromagnet to remove the residual magnet ism of the pulse electromagnet. CONSTITUTION:A permanent magnet 4 is arranged in the core 1 of a pulse electromagnet. The direction of the magnetic field of the permanent magnet 4 is set opposite to the direction of the residual magnetic field generated by a coil 2, and its magnitude is set equal to the magnitude of the residual mag netic field generated by the coil 2. The residual magnetism due to the current of the coil 2 is eliminated when no current flows through the coil 2 by the existence of the magnetic field of this permanent magnet 4, and electrons are correctly guided into the expected incident course.

Description

[Detailed Description of the Invention] [Summary] In order to eliminate the influence of residual magnetization of a pulsed electromagnet used for injecting electrons into a storage ring, for example, an electron storage ring, a structure in which a permanent magnet with a magnetic field opposite in direction is added is added. Lift up the pulsed electromagnet for the storage ring.

[Industrial application field]

The present invention relates to a pulsed electromagnet used for injecting electrons, positrons, etc. into a storage ring, and more particularly to a pulsed electromagnet for injection without a residual magnetic field in the core of the electromagnet.

In recent years, the use of synchrotron radiation (SOR) for ultra-fine pattern lithography in the manufacture of semiconductor devices has been considered.

Synchrotron radiation is powerful light emitted from an electron storage ring, a type of particle accelerator conventionally used in elementary particle experiments, and has a wide continuous spectrum ranging from the X-ray region to the infrared region.

[Conventional technology]

Before explaining the conventional pulsed electromagnet for injection.

FIG. 3 schematically shows an electron storage ring as an example of a storage ring.

FIG. 3 is a schematic plan view showing the outline of the structure of the electron storage ring.

As shown in the figure, the electron storage ring consists of a beam duct connected in a ring, various electromagnets arranged along the beam duct, a high frequency acceleration cavity, a vacuum pump, etc.

The beam duct is maintained at a high vacuum of less than IQ-''Pa, and electrons with high energy of several hundred MeV or more circulate inside as punches.The greater the number of electrons (current amount), the stronger the synchrotron. Synchrotron radiation will be generated.

Even a small electron storage ring has a diameter of about 10 m, and miniaturization is desired for use in manufacturing semiconductor devices.

FIG. 4 is a schematic plan view illustrating the incidence of electrons into the storage ring.

In the figure, in order to inject electrons e- into the storage ring 41, a pulse electromagnet (park beta electromagnet in FIG. 3) 42
, 43 must be operated to create an incident bump 44 shown by a dotted line, and electrons must be deflected into this bump trajectory.

Park beta electromagnets are pulsed electromagnets that operate only when incident electrons arrive, and the magnetic field is 0 except when incident electrons arrive.
Must.

FIG. 2 (11 and 21 are a perspective view and a sectional view of a conventional pulsed electromagnet.

In the figure, a coil 2 is placed within a ferrite core 1. The shape of the coil 2 is shaped as shown outside the core 1 so that the beam duct passes through it.

The cross-sectional view is taken along the plane A-A indicated by one dotted line, in which a beam duct passes through the gap 3, and the arrow indicates the direction of the magnetic field.

[Problem that the invention seeks to solve]

In the conventional pulsed electromagnet, the core 1 of the ferrite 1-
Even if the current is returned to 0 without flowing through coil 2 due to residual magnetization,
The magnetic field in gap 3 did not go to zero.

[Means for solving problems]

The solution to the above problem is to use a core made of a cylindrical ferromagnetic material that surrounds the beam duct of the storage ring, a coil that generates a magnetic field inside the core, and a permanent magnet that has a magnetic field in the opposite direction to the magnetic field. This is achieved by a pulsed electromagnet for the storage ring.

[Effect]

The present invention provides a permanent magnet having a magnetic field in the opposite direction so as to cancel the residual magnetization of the pulsed electromagnet, so that when the current in the coil is O, the magnetic field in the gap becomes O.

〔Example〕

FIG. 1 (11, (2)) is a perspective view and a sectional view of a pulsed electromagnet of the present invention.

In the figure, a coil 2 and a permanent magnet 4 are arranged in a ferrite core 1. As in the conventional example, the shape of the coil 2 is shaped such that it is divided into upper and lower halves as shown in the figure outside the core 1 so that the beam duct can pass therethrough.

The cross-sectional view is taken along the line A-A indicated by single dot hatching, and a permanent magnet 4 is disposed in the gap 3, through which a beam duct passes, although not shown.

The arrow indicates the direction of the magnetic field of the permanent magnet 4, and its magnitude was chosen to be equal to the magnitude of the residual magnetic field.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to eliminate the influence of residual magnetization of the pulsed electromagnet, form a predetermined incident bump, and accurately inject electrons into the storage ring.

[Brief explanation of the drawing]

Figures 1+1) and (2) are a perspective view and a sectional view of the pulsed electromagnet of the present invention. FIG. 2 fl), (2) is a perspective view and a sectional view of a conventional pulsed electromagnet. FIG. 3 is a schematic plan view showing the outline of the configuration of the electron storage ring. FIG. 4 is a schematic plan view illustrating the incidence of electrons into the storage ring. In fig. 1 is the ferrite core. 2 is the coil. 3 is the gap. 4 is a permanent magnet cl) / 1 thousand ancestors 2 (2) A-Mucho 酊嵜宸宸例Qin (口(1) Oblique diagram (2) A-A 說誼设宸例子 2 口B: Rijiku Yariishi & PynD and: B-o-da 2 [ρD', (X, 'n, Kei-shaishi RFCavtv:
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Claims (1)

[Claims] A core made of a cylindrical ferromagnetic material that surrounds the beam duct of the storage ring, and a coil that generates a magnetic field inside the core.
A pulsed electromagnet for a storage ring, comprising a permanent magnet having a magnetic field in the opposite direction to the magnetic field.