JPH0782933B2 - Superconducting magnet - Google Patents

Description

The present invention relates to a superconducting magnet for beam deflection in an electron storage ring.

2. Description of the Related Art When an electron beam circulating in a vacuum duct of an electron storage ring is deflected by a deflecting electromagnet, radiant light from an infrared ray to an X-ray region is emitted in a tangential direction of a beam orbit. Since this emitted light is extremely strong and has a good directivity, it has a high utility value in industrial applications such as printing of a fine pattern in an integrated circuit.

An example of using a superconducting magnet as a deflection magnet in such an electron storage ring is described in Japanese Examined Patent Publication No. 61-2274.
In this type of device, the slit width of the radiant light outlet and the arrangement of the windings of the superconducting magnet are adjusted so that a predetermined gradient can be obtained in the magnetic field generated by the superconducting magnet. . The gradient n of the generated magnetic field is Where r ₀ is the beam radius and B is the magnetic flux density.

[Problems to be Solved by the Invention] Therefore, once the windings of the superconducting magnets are formed in a desired arrangement, the value of the gradient n is fixed and cannot be adjusted to an arbitrary value. .

The present invention has been made to eliminate the above-mentioned problems, and an object thereof is to provide a superconducting magnet capable of adjusting the gradient of a generated magnetic field.

[Means for Solving the Problems] A superconducting magnet according to the present invention is a beam-deflecting superconducting magnet used in an electron storage ring, and includes a superconducting coil having a winding arrangement of cos θ type current distribution and a coil of cos 2 θ type current distribution. It is characterized in that it is combined with a superconducting coil of a line array.

[Operation] As shown in FIG. 1, a two-pole coil 1 having a cos θ type current distribution
, And a quadrupole coil 2 having a cos 2 θ type current distribution, are provided on the outer circumference of the beam duct 3 of the electron storage ring. The current distribution by the two-pole coil 1 is shown in FIG. In the figure, the cross-sectional area of the shaded area shows the current value at that angle, and in order to increase the current distribution in the horizontal direction, the two-pole coil 1 is wound in two layers in the horizontal direction as shown in FIG. . Here, since the current value at a certain angle θ is proportional to cos θ, such a current distribution is called a cos θ type current distribution. In addition, the quadrupole coil having the cos2θ type current distribution shows the current value as shown in FIG. 5, and the current value at a certain angle θ is co
It is proportional to s2θ. By combining two sets of coils in this way, it becomes easy to adjust the generated magnetic field, and as described in claim (2), the current supplied to each coil 1 and 2 is controlled individually or only one of them is controlled. As a result, a magnetic field distribution having a desired gradient can be obtained in the beam duct 3. Although the two-pole coil 1 is arranged outside the four-pole coil 2 in FIG. 1 because of the shape of the coil, it is not particularly limited to this structure.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. FIG. 2 is a cross-sectional view of the deflection magnet in the electron storage ring as seen from the end face thereof, and FIG. 3 is a cross-sectional view taken along the circumferential direction of the deflection magnet in the electron storage ring.

3 shows a beam duct in the electron storage ring. The four-pole coil 2 (2a, 2b, 2c, 2d) is the beam duct 3
Is wound around a winding core 4 made of an insulating material provided on the outer periphery of
Further, two winding cores 6 and 7 made of an insulating material are provided in two layers on the outer circumference of the four-pole coil 2 with a cooling channel 5 for cooling the coil sandwiched between the winding cores 6 and 7. 1
Is wound. At that time, the two-pole coil 1 and the four-pole coil 2
And, as shown in FIG. 1, they are concentrically provided so that each horizontal level is the same. A cooling channel 8 is further provided on the outer periphery of the two-pole coil 1, and finally, the outer periphery of the cooling channel 8 is surrounded to prevent the wire rod from being deformed by the electromagnetic force of the two-pole and four-pole coils 1 and 2. As described above, the reinforcing collars 9a and 9b having a semicircular cross section are provided, and the reinforcing collars 9a and 9b are fastened together by the bolt and the nut 10 so as to be integrated. The plurality of small holes 11 provided in the reinforcing collars 9a and 9b are provided to improve the conductance of the refrigerant in the cooling channel 8.
Further, the beam port 12 in FIG. 3 is the SOR light extraction port, and Q indicates the beam orbit.

Separate power supplies (not shown) are provided for the two-pole coil 1 and the four-pole coil 2, respectively, and the currents supplied to the coils 1 and 2 are individually controlled.

In this way, by controlling the currents supplied to the two sets of coils 1 and 2, it is possible to obtain a desired gradient n with the combined magnetic field in the beam duct 3. Further, it is possible to appropriately correct the error in the magnetic field distribution due to the dimensional error of the superconducting magnet.

[Effects of the Invention] As described above, according to the present invention, since two sets of coils are provided, it is easy to adjust the generated magnetic field. For example, by controlling the energization current to at least one coil, Moreover, it is possible to obtain the desired gradient n due to the combined magnetic field, and it is possible to appropriately correct the error in the magnetic field distribution due to the size of the superconducting magnet.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a superconducting magnet of the present invention, and FIG. 2 is a cross-sectional view of a superconducting magnet showing an embodiment of the present invention as seen from an end face of a deflection magnet in an electron storage ring. 3 and 4 are cross-sectional views of the superconducting magnet shown in FIG. 2 taken in the circumferential direction of the electron storage ring, and FIG. 4 is a view showing the current distribution of the cos θ type winding coil, and FIG. FIG. 6 is a diagram showing a current distribution of a cos2θ type winding coil. 1 ... 2-pole coil, 2 ... quadrupole coil, 3 ... beam duct,
4,6,7 ... cores, 5,8 ... cooling channels, 9a, 9b ... reinforcement collars, 10 ... bolts and nuts.

Claims (3)

[Claims] 1. A superconducting magnet for beam deflection used in an electron storage ring, comprising a combination of a superconducting coil having a winding arrangement of cos θ type current distribution and a superconducting coil having a winding arrangement of cos 2 θ type current distribution. Characteristic superconducting magnet. 2. A desired magnetic field distribution is obtained by using two power sources for the two superconducting coils and changing a value of a current flowing through at least one of the superconducting coils.
The superconducting magnet described. 3. A superconducting coil having a cos2θ type current distribution is
The superconducting magnet according to claim 1, which is arranged inside a superconducting coil having a θ-shaped current distribution.