JP3482564B2 - Normal conduction high magnetic field coil device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil device for generating a normal conducting high magnetic field, and more particularly to an electromagnet coil device for a small cyclotron.

[0002]

2. Description of the Related Art The precise magnetic field distribution of a cyclotron that generates a high magnetic field of normal conduction, for example, a maximum magnetic field of 3 Tesla, is not accurate because the magnetic field reaches the saturation region of the iron core. Greatly affected. In the conventional coil device for electromagnets applied to such a cyclotron, there was a shape error mainly due to the method of winding and molding the conductor.

FIG. 5 is a schematic view showing the structure of a conventional coil device, (A) is a plan view thereof, and (B) is a sectional view taken along the line XX in FIG. That is, the conventional coil device has the insulated conductor 4 as shown in FIG.
1 is wound in a predetermined direction on the same plane from the outermost diameter portion of the radius Ro to the innermost diameter portion of the radius Ri, and in a plane lowered by the diameter of the insulated conductor 41 at the innermost diameter portion, From the innermost diameter portion to the outermost diameter portion, it is wound in the same direction as the winding direction. In this way, FIG.
As shown in (B), a so-called pancake-shaped coil unit 4 in which an insulated conductor 41 is wound in two layers one above the other.
2 is configured.

As shown in FIG. 5 (B), the insulated conductor 41 has a water passage hole 43 formed at the center of the conductor, and cooling water can be circulated through the water passage hole 43. There is.
That is, the cooling water is, as shown in FIG. 5A, the cooling water inlet portion 44 at the winding start end of the insulated conductor 41 at the outermost diameter portion.
Is introduced from the cooling water outlet portion 45 at the end of the winding end of the insulated conductor 41 at the outermost diameter portion. Then, the entire coil device has a coil unit 42 as described above, as a part thereof is shown in FIG.
Have been stacked and completed.

Next, in order to realize economy and downsizing of the normal conducting high magnetic field type cyclotron, it is necessary to design in consideration of the balance between the size of the coil and the power consumption.
In a coil cross section with the same magnetomotive force and the same average diameter,
The power consumption is inversely proportional to the total area of the cross section. That is, the smaller the cross-sectional area (equivalent diameter d) of the water passage hole 43 shown in FIG. 6, the larger the total cross-sectional area, and the coil with less power consumption can be realized. On the other hand, when the pressure loss is P and the water passage length of the water passage 43 is L, the flow rate Q is calculated by the following mathematical formula 1.
It is represented by.

[0006]

[Equation 1]

When the amount of heat generated in the water passage hole 43 of the coil is W, and the temperature rise of the cooling water is ΔT, ΔT
Is expressed by the following mathematical formula 2.

[0008]

[Equation 2]

From these equations 1 and 2, if the equivalent diameter d of the water passage hole 43 is reduced, the flow rate Q is reduced and the water temperature rises Δ.
T becomes larger. Usually, ΔT is the outlet temperature To of the cooling water.
However, the temperature is limited to about 60 ° C. or lower which is the allowable temperature of the coil portion and the piping parts. Conventionally, an appropriate equivalent diameter d of the water passage hole has been determined from the balance between the power consumption and the temperature rise value.

[0010]

In the above normal conducting high magnetic field coil device, as shown in FIG. 5 (A),
Within the range of the central angle α where the winding start and the winding end of the insulated conductor 41 in the coil unit 42 exist, the following various winding shape errors exist. That is, in the innermost diameter portion, there is a transition from the upper layer 61 to the lower layer 62 of the two-layer structure winding as shown in FIG. 7A, and the rows formed by the windings in the upper and lower layers (see FIG. 7
There is a transition between 63) in (B). The movement between the rows is as shown in FIG.
The movement from the first row 64 to the second row 65 shown in (A) and (B) is shown in FIG. 7 (B). Due to the transition between the winding layers and between the windings, δ in FIG.
From the error of the surface flatness in the bent portion of the coil indicated by h, the variation of the radius Rα of each row, and the ideal shape of the winding cross section shown in FIG. 7B (shown in FIG. 7C). There is a gap.

FIG. 7A is a view of the coil unit 42 of FIG. 5A in the direction of arrow AA at the innermost diameter portion, and FIGS. 7B and 7C are respectively FIG. It is sectional drawing which cut | disconnects and shows the coil unit 42 of (A) in the part of arrow B and C. FIG.

In addition, in the conventional cooling water channel structure in the coil device, the insulation between the cooling water inlet portion 44 and the cooling water outlet portion 45 is formed by the heat radiation and heat reception between the adjacent conductor layers. The temperature of the surface of the conductor 41 has a distribution as shown in FIG. 8, and a portion having a temperature Tmax higher than the outlet temperature To occurs inside the coil. From this, it can be said that the cooling structure in the conventional coil device does not fully utilize the cooling effect of the cooling water.

Further, the insulated conductor 41 constituting the coil is usually covered with an insulating material such as glass base cloth or epoxy resin, and the influence of this insulating material on the heat resistance is also a problem.

Therefore, an object of the present invention is to eliminate the above-mentioned problems of the conventional coil device for normal magnetic field of high magnetic field, to avoid disturbing the accuracy of high magnetic field distribution which is almost saturated, to be small in size, to save power and to be economical. An object of the present invention is to provide an excellent normal-conduction high-field coil device.

[0015]

According to the present invention, an insulated conductor having a water passage hole formed in the center thereof is wound in a predetermined direction on the same plane to allow cooling water to flow into the water passage hole. In the water passage hole, the first coil unit configured to circulate and the insulated conductor having the water passage hole formed in the center portion are wound in the same plane in the opposite direction to the predetermined direction. A second coil unit configured to allow cooling water to flow therethrough, and configured by alternately superposing these first and second coil units. A coil system is obtained.

Further, according to the present invention, the cooling water inlet portions of the insulated conductors constituting the first and second coil units are respectively on the outer diameter side of these coil units, and the first and second coil units are provided. A normal conducting high magnetic field coil device is obtained in which the coil units are arranged at positions symmetrical to each other with respect to a straight line passing through the centers of the coil units on the wound plane.

Further, according to the present invention, the cooling water outlet portions of the insulated conductors constituting the first and second coil units are respectively on the inner diameter side of these coil units and with respect to the straight line, the cooling water inlet portion. A coil device for a normal conducting high magnetic field, which is characterized in that it is arranged on the opposite side to and at a position symmetrical to each other.

[0018]

EXAMPLES Examples of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic view showing the configuration of a normal conducting high magnetic field coil device according to the present invention, in which (A) and (B) are plan views thereof, and (C) is a straight line XX in FIGS. (A) and (B). It is sectional drawing along. That is, in the coil device of the present invention, as shown in FIG.
The first coil unit 12 is formed by winding in a predetermined direction on the same plane from the outermost diameter portion of the radius Ro to the innermost diameter portion of the radius Ri. A water passage hole 13 is formed in the center of the insulated conductor 11, and cooling water flows through the water passage hole 13 from the outer diameter toward the inner diameter. That is, as shown in FIG. 1A, the cooling water is introduced from the cooling water inlet portion 14 at the winding start end portion of the insulated conductor 11 at the outermost diameter portion,
It is configured so as to be led out from the cooling water outlet portion 15 at the winding end end portion of the insulated conductor 11 at the innermost diameter portion.

Next, in the coil device of the present invention, as shown in FIG. 1 (B), the insulated coil 11 extends from the outermost diameter portion to the innermost diameter portion on the same plane. A second coil unit 16 wound in a direction opposite to the winding direction of the unit 12 is formed. The insulated conductor 11 includes
Similar to the first coil unit 12, a water passage hole 13 is formed in the central portion thereof, and cooling water flows through the water passage hole 13 from the outer diameter toward the inner diameter. That is, as shown in FIG. 1B, the cooling water is introduced from the cooling water inlet portion 17 at the winding start end of the outermost diameter insulated conductor 11, and the winding end of the innermost diameter insulated conductor 11 is ended. It is configured to be led out from the cooling water outlet portion 18 at the end portion. As shown in the cross-sectional view of FIG. 1C, the first and second coil units 12 and 16 are alternately laminated in multiple layers to form the entire coil device.

Therefore, in the coil device of the present invention,
Since the coil units 12 and 16 are composed of only one layer, the shape error of the winding due to the transition between the upper and lower layers or the rows in the innermost diameter portion of the insulated conductor found in the conventional coil device is reduced.

FIG. 2 is a diagram showing the structure of the winding start portion and the winding end portion, the cooling water inlet portion, and the cooling water outlet portion of the insulated conductor of the coil device of the present invention configured as described above. Is a partial plan view, (B) and (C) of FIG.
It is a side view which shows the structure of a cooling water inlet part and a cooling water outlet part. In the figure, a third coil unit 19 is stacked on the first coil unit 12, and a fourth coil unit 20 is stacked below the second coil unit 16. Then, the first and second coil units 12, 16
The cooling water inlet portions 14 and 17 of the insulated conductor 41 constituting the above are respectively positions symmetrical to each other with respect to the straight line passing through the center of these coil units on the outer diameter side and the plane around which these coil units are wound. It is located in. On the other hand, the cooling water outlet portions 15 and 18 are arranged on the inner diameter side of the coil unit, on the opposite side of the cooling water inlet portions 14 and 17 with respect to the straight line, and at positions symmetrical to each other.

FIG. 3 is a sectional view of the coil device showing the structure of the cooling water channel in the coil device of the present invention. In the water channel structure of the present invention, the cooling water flows from the outermost diameter portion of each of the coil units 12 and 16 to the innermost diameter portion while circulating, and the water channel length is half that of the conventional coil device described above. Therefore, in the case of the same pressure loss and the same water channel diameter as those of the conventional coil device, the quantity Q of the cooling water flowing through the water channel structure of the present invention is about 1 in comparison with that of the conventional coil device from the above-mentioned formula 1. It is 5 times (= ^20.57 ). Therefore,
From the equation (2), the temperature rise ΔT of the cooling water in the coil device of the present invention can be suppressed lower than that in the conventional device.

Further, the cooling water structure in the coil device of the present invention has a short length of the cooling water channel, and heat is not transferred between the adjacent channels. Therefore, the temperature distribution along the entire length of the water channel on the surface of the coil conductor is as shown in FIG.
It can be seen that the temperature changes linearly to the outlet temperature To and there is no portion higher than the outlet temperature To, and the cooling effect is fully utilized.

[0024]

As described above, since the normal conducting high magnetic field type cyclotron requires a precise magnetic field distribution due to the magnetic field in almost the saturation region, the shape and position of the coil itself is required to be accurate. Then, in order to adjust to a theoretical magnetic field distribution for ensuring isochronism of ion acceleration, in practice, the shape of the iron core is locally changed while measuring the magnetic field. On the other hand, in the coil device of the present invention, since the coil shape error is reduced, the above-described adjustment work can be largely omitted, and the reproducibility of the required magnetic field distribution can be easily ensured.

Further, in the cooling water structure of the coil device of the present invention, since the cooling water channel length is short and heat is not transferred between adjacent channels, the temperature distribution along the entire channel length on the coil conductor surface is: The temperature changes linearly from the inlet temperature or Ti to the outlet temperature To, and there is no part higher than the outlet temperature To.
The cooling effect is fully utilized.

Further, in the cooling water structure of the coil device of the present invention, the water passage length of the cooling water is halved as compared with the conventional device. Therefore, when the same cooling effect as the conventional device is obtained, the equivalent diameter of the water passage hole is obtained. d can be reduced. This means that the total area of the coil cross section can be increased, which can reduce power consumption and improve economic efficiency.

[Brief description of drawings]

FIG. 1 is a schematic view showing the configuration of a normal conducting high magnetic field coil device of the present invention, (A) and (B) of which are plan views and (C).
FIG. 6 is a cross-sectional view taken along the line XX in FIGS.

FIG. 2 is a diagram showing a structure of a winding start portion and a winding end portion, a cooling water inlet portion, and a cooling water outlet portion of an insulated conductor of a normal conducting high magnetic field coil device of the present invention, FIG. The drawings, (B) and (C) are side views showing the configurations of the cooling water inlet portion and the cooling water outlet portion, respectively.

FIG. 3 is a cross-sectional view of a coil device showing a water channel structure of cooling water in the normal conducting high magnetic field coil device of the present invention.

FIG. 4 is a diagram showing a temperature distribution on a conductor surface along the entire water channel length in the normal conduction high magnetic field coil device of the present invention.

5A and 5B are schematic diagrams showing a configuration of a conventional normal conducting high magnetic field coil device, in which FIG. 5A is a plan view thereof, and FIG. 5B is a sectional view taken along a line XX in FIG.

FIG. 6 is a cross-sectional view of a coil device showing a water channel structure of cooling water in a conventional normal conducting high magnetic field coil device.

FIG. 7 is a diagram for explaining an example of a coil shape error in a conventional normal conducting high magnetic field coil device; FIG.
5A is a view of the coil unit 42 of FIG. 5A in the direction of the arrow AA at the innermost diameter portion, and FIGS. 7B and 7C show the coil unit 42 of FIG. It is sectional drawing which cuts and shows in the part of C.

FIG. 8 is a graph showing a temperature distribution on a conductor surface along the entire water channel length in a conventional normal conduction high magnetic field coil device.

[Explanation of symbols]

11 insulated conductor 12 First coil unit 13 water holes 14, 17 Cooling water inlet 15, 18 Cooling water outlet 16 Second coil unit 19 Third coil unit 20 Fourth coil unit

Claims (3)

(57) [Claims] 1. A first structure configured such that an insulated conductor having a water passage hole formed in a central portion is wound in a predetermined direction on the same plane to allow cooling water to flow in the water passage hole. A coil unit and an insulated conductor having a water passage hole formed in the same center are wound on the same plane in a direction opposite to the predetermined direction,
A second coil unit configured to circulate the cooling water in the water passage, the first coil unit and the second coil unit being alternately superposed. Normal conducting high magnetic field coil device. 2. The normal conducting high magnetic field coil device according to claim 1, wherein the cooling water inlets of the insulated conductors constituting the first and second coil units are respectively located on the outer diameter side of these coil units. And the first and second coil units are arranged at positions symmetrical to each other with respect to a straight line passing through the centers of these coil units on a plane on which the first and second coil units are wound. apparatus. 3. The normal conducting high magnetic field coil device according to claim 2, wherein the cooling water outlets of the insulated conductors constituting the first and second coil units are on the inner diameter side of these coil units. And the coil device for high-conductivity normal magnetic field, wherein the coil device is arranged on the side opposite to the cooling water inlet and symmetrically with respect to the straight line.