JP2985469B2 - Pulse magnetic field generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse magnetic field generator capable of generating a strong magnetic field with a small pulse current.

[0002]

2. Description of the Related Art FIG. 4 shows, for example, "Study 1975, Research Grant-in-Aid for Scientific Research A-834021, SOR-RING"
REPORT.NO3 "is a perspective view showing the configuration of the conventional pulse electromagnet shown in FIG. 5, and FIG. 5 is a circuit diagram showing a drive power supply circuit for the pulse electromagnet in FIG. In the figure, 1
Is a core formed in a U-shaped cross section, and 2 is a coil mounted in a gap of the core 1, and these are used as pulse electromagnets 3.
Is composed. Reference numeral 4 denotes a pulse power supply, and 5 denotes a discharge switch interposed between the pulse power supply 4 and the coil 2 of the pulse electromagnet 3.

[0003] Next, the operation of the conventional apparatus configured as described above will be described. First, when the discharge switch 5 is turned on, a pulse current is supplied from the pulse power supply 4 to the coil 2 of the pulse electromagnet 3, and a pulse magnetic field is generated in the gap of the yoke 1 and used as a test magnetic field for various purposes. Now, if the magnetic permeability of the material forming the yoke 1 is sufficiently large compared to the magnetic permeability in the air gap, the magnetic flux density B of the magnetic flux generated in the air gap is I, the pulse current is I, the air gap width is d, and the air gap is d. Is given by the following equation (1), where μ is the magnetic permeability. B = μI / d (1)

[0004]

The conventional pulse magnetic field generator is constructed as described above, and the strength of the magnetic field in the test magnetic field is determined by the magnitude of the magnetic flux density B obtained by the equation (1). Therefore, in order to increase the strength of the magnetic field, the width d of the air gap must be reduced or the pulse current flowing through the coil 2 must be increased. However, when the width d of the air gap is reduced, the magnetic field region is limited. There have been problems such as a narrower application range and a need for a large-capacity pulse power supply 4 to increase the pulse current.

The present invention has been made to solve the above problems, and has as its object to provide a pulse magnetic field generator capable of obtaining a strong magnetic field with a small pulse current. .

[0006]

A pulse magnetic field generator according to the present invention includes a magnetic field generator for applying a magnetic field to a test magnetic field, a ferromagnetic material having a saturation characteristic, and a part of a magnetic path of the test magnetic field. And a yoke that allows the magnetic flux from the magnetic field generator to flow through a part of the magnetic path and a magnetic field generator that flows through a part of the magnetic path by applying a pulse magnetic field to the yoke to saturate the yoke A pulse power supply for causing a magnetic flux to flow on the test magnetic field side.

[0007]

The pulse power supply of the pulse magnetic field generator according to the present invention uses a magnetic field generated by the magnetic field generator, which normally flows through a part of the magnetic path of the yoke, to saturate the yoke by applying a pulse current to the yoke. Pour into

[0008]

【Example】

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a pulse magnetic field generator according to Embodiment 1 of the present invention. In the figure, 6 is a yoke 6a, a coil 6b wound around the yoke 6a,
Power supply 6c for generating magnetic field for supplying current I to coil 6b
An external magnetic field generator 7; a test magnetic field to be tested for various purposes; 8, a yoke in which a portion 8a of a magnetic path is arranged in parallel with the test magnetic field 7; The coil 10 to be turned is a pulse power supply for supplying a pulse current I 'to the coil 9, and 11 is a discharge switch for turning on and off a circuit connecting the coil 9 and the power supply 10.

Next, the operation of the pulse magnetic field generator according to the first embodiment of the present invention will be described. First, as shown in FIG. 1- (A), a current I is applied to the coil 6b in advance by the magnetic field generating power supply 6c, and a magnetic field near the saturation of a part 8a of the magnetic path of the yoke 8 is generated via the yoke 6a. Let it. At this time, near the part 8a of the magnetic path,
That is, at the point P in the test magnetic field 7, the external magnetic field generator 6
Generates a small magnetic field because it flows through a portion 8a of the magnetic path of the yoke 8 having high magnetic permeability. next,
As shown in FIG. 1- (B), the discharge switch 11 is turned on, a pulse current I ′ flows through the coil 9, and the same as the magnetic flux generated by the external magnetic field generator 6 flowing through the magnetic path 8 a in the yoke 8. A magnetic flux flowing in the direction is generated to saturate the yoke 8.
When the yoke 8 saturates, the magnetic permeability decreases, so that the magnetic flux that has passed through a portion 8a of the magnetic path of the yoke 8 now flows at the point P, that is, the test magnetic field 7 side. A magnetic field can be generated.

The pulsed magnetic field generated in the test magnetic field 7 depends on the width of the gap of the yoke 6a of the external magnetic field generator 6 and the length of the magnetic flux passing through the yoke 6a. Therefore, the pulse current that has to be supplied by the pulse power supply 10 is a minimum current that can saturate the yoke 8. At this time, assuming that the magnetic permeability in the yoke 8 is μ ′, the magnetic flux density at which the yoke 8 saturates is B ′, and the length of the magnetic flux in the yoke 8 is L, the necessary pulse current I ′
Is obtained by the following equation (2). I ′ = B′L / μ ′ (2) Here, the pulse current I required in the conventional method is given by the following equation (3) from the equation (1). I = Bd / μ (3) Now, from the above equations (2) and (3), when a magnetic field of B to B ′ is generated, L to d and μ << μ ′. It is clear that the desired magnetic field can be obtained with an extremely small pulse current I '.

Embodiment 2 FIG. FIG. 2 is a perspective view showing a pulse magnetic field generator according to Embodiment 2 of the present invention. As is clear from the figure, the device itself is the same as that of the first embodiment shown in FIG. 1, but the test magnetic field 7 is applied as a deflection magnetic field of the electron beam 12 of the charged particle beam device.

Embodiment 3 FIG. FIG. 3 is a perspective view showing a pulse magnetic field generator according to Embodiment 3 of the present invention. In the figure, reference numeral 13 denotes a synchrotron or a storage ring deflection electromagnet, and the same parts as those in the above-described embodiments are denoted by the same reference numerals and description thereof is omitted. In the second embodiment described above, the test magnetic field 7 of the magnetic field generator of the first embodiment is applied to the beam deflection magnetic field of the charged particle beam device, whereas in the third embodiment, the magnetic field generator of the first embodiment is applied. The external magnetic field generator 6 is also used as a synchrotron or a storage ring deflecting electromagnet 13. The same effects as those of the above embodiments can be obtained, and the external magnetic field generator 6 can be omitted. Simplification and downsizing can be achieved.

[0013]

As described above, according to the present invention, a magnetic field generator for applying a magnetic field to a test magnetic field and a ferromagnetic material having a saturation characteristic and a part of a magnetic path are provided in parallel with the test magnetic field. A yoke that allows the magnetic flux generated by the magnetic field generator to flow through a part of the magnetic path and a magnetic field generated by the magnetic field generator that flows through a part of the magnetic path by applying a pulse magnetic field to the yoke to saturate the yoke Since a pulse power supply is provided to flow on the magnetic field side, a pulse magnetic field generator capable of obtaining a strong magnetic field with a small pulse current can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a pulse magnetic field generating device according to a first embodiment of the present invention, in which (A) shows a state before power is turned on, and (B) shows a state after power is turned on.

FIG. 2 is a perspective view showing a pulse magnetic field generator according to Embodiment 2 of the present invention.

FIG. 3 is a perspective view showing a pulse magnetic field generator according to Embodiment 3 of the present invention.

FIG. 4 is a perspective view showing a configuration of a conventional pulse electromagnet.

FIG. 5 is a circuit diagram showing a drive power supply circuit for the pulse electromagnet in FIG. 4;

[Explanation of symbols]

 Reference Signs List 6 magnetic field generator 7 test magnetic field 8 yoke 8a part of magnetic path 10 pulse power supply 11 discharge switch 13 deflection electromagnet

Claims (2)

(57) [Claims] A magnetic field generator for applying a magnetic field to a test magnetic field, a ferromagnetic material having a saturation characteristic, and a part of a magnetic path is juxtaposed to the test magnetic field and a part of the magnetic path is provided. A yoke that allows the magnetic flux generated by the magnetic field generator to flow, and a magnetic field generated by the magnetic field generator that flows through a part of the magnetic path by applying a pulse magnetic field to the yoke to saturate the yoke. A pulsed magnetic field generator, comprising: a pulsed power supply for flowing. 2. The pulse magnetic field generator according to claim 1, wherein the yoke is disposed in a gap between the deflection electromagnets of the circular accelerator, and the deflection electromagnets are used also as a magnetic field generator.