JPH07297456A - Dewar device - Google Patents

Abstract

PURPOSE:To easily, freely, and finely adjust the position of a SQUID sensor by making a Dewar device which houses the sensor and its cooling medium in a heat-insulating state three-dimensionally rotatable around the center of curvature of a spherical convex or concave section. CONSTITUTION:A Dewar device 2A is equipped with an inner tank 11A for housing a SQUID sensor 21A which has a SQUID element composed of such a superconducting material, that indicates a superconducting state at the temperature 4K of liquid helium and liquid helium L, heat insulating tank l3A surrounding the tank 11A, and outer tank 12A. The Dewar device 2A can be easily rotated around the rotating shaft 42 of the device 2A passing through the center P of curvature of the spherical convex section 33A of a section 3A to be supported or the centers of curvature of the spherical concave sections 31L and 3lR of supporting sections 4L and 4R. In addition, the center P11 of curvature and the rotating shaft 42 itself of the device 2A can be rotated around a vertical axis 41 by + or -alpha Or, the device 2A can perform these two operations simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical diagnostic device for measuring a magnetic field generated from a human body or a living body, a physical property measuring device for measuring magnetic permeability of a material, and a magnetic signal transmission interface. SQUID (Superconducting Quantum Interference D)
evice: A dewar device suitable for storing a superconducting quantum interference device. Here, SQUID is
SQU, which is a superconducting loop that is maintained at a low temperature in a heat-insulating container (cryostat, dewar, etc.) by liquid helium, liquid nitrogen, etc. and that contains a Josephson junction in the loop.
When a DC current is applied as a bias current to the ID loop to drive it, and a magnetic flux from the outside is coupled and applied to this SQUID loop via a pickup coil, an input coil, etc., a circulating current is induced in the SQUID loop, An element that measures minute magnetic flux changes by utilizing the fact that it acts as a transducer that converts weak changes in the applied external magnetic flux into large changes in output voltage due to the quantum interference effect in the Josephson junction in the loop. is there.

[0002]

2. Description of the Related Art Conventionally, as a dewar device of this type,
A device such as a cylindrical dewar that is provided with a support mechanism capable of rotating around the cylinder axis and a support mechanism that can tilt the cylinder axis so that the dewar can be adjusted independently, or the dewar can be adjusted in the X direction and A device or the like configured to be movable in the Y direction is known.

[0003]

However, in the above-mentioned conventional dewar device, even when it is desired to adjust the position of the sensor unit such as the dewar tip according to the posture, position, state, etc. of the subject, the coordinate position is adjusted. It is often difficult to make a delicate adjustment, or it takes a long time to make a fine adjustment, because of the necessity of giving it and the position adjusting mechanism being strict and large. The present invention has been made to solve the above problems, and an object of the present invention is to provide a dewar device in which the sensor position can be easily and freely finely adjusted according to the subject or the like.

[0004]

In order to solve the above-mentioned problems, a dewar device according to the present invention comprises a support having a spherical concave portion forming a part of a spherical surface, and a convex surface having substantially the same curvature as the spherical surface of the spherical concave portion. A supported portion which has a spherical convex portion forming a part of the spherical convex portion and is placed so that the spherical convex portion is substantially in contact with the spherical concave portion and is supported by the supporting tool, and the SQUID sensor and its cooling medium are provided inside the supported portion. And a dewar that is housed in and held in a heat-insulated state, and is configured to be three-dimensionally rotatable about the center of curvature of the spherical convex portion or spherical concave portion.

[0005]

According to the present invention having the above structure, the dewar is rotated around the rotation axis of the Dewar passing through the center of curvature of the spherical convex portion or the spherical concave portion, or the center of curvature of the spherical convex portion or spherical concave portion is rotated. The SQUID sensor position can be easily and freely fine-tuned according to the subject by rotating the Dewar rotary shaft itself as the center or performing the above two operations at the same time.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are diagrams showing the configuration of a dewar device according to a first embodiment of the present invention.

As shown in the figure, this dewar device 1A
Is an arm 5L, 5R suspended and supported from a ceiling 6 of a test room or the like and provided with support portions 4L, 4R at its tip, a supported portion 3A supported by the support portions 4L, 4R, and a supported portion. The dewar 2A is inserted and supported in the dewar insertion hole 32 of the 3A. Here, the support portions 4L and 4R and the arms 5L and 5R form a support tool.

Dewar 2A has a liquid helium temperature of about 4K.
The SQUID sensor 21A having an SQUID element made of a superconducting material such as niobium that exhibits a superconducting state, a substantially cylindrical inner tank 11A that can store liquid helium L that is a cooling medium thereof, and the inner tank 11A are An outer tank 12A which surrounds and forms a heat insulating layer 13A such as a vacuum layer between the inner tank 11A and the SQUID sensor 21A and the liquid helium L in a heat insulating state, and a connector provided outside the outer tank 12A. The portion 24A, a neck plug 23A that is inserted into a portion corresponding to the neck of the inner tank 11A and is connected to the connector portion 24A, a lid 17A that shields liquid helium L and its evaporative gas from the external air, and a SQUID sensor portion 21A is a liquid. Support in helium L and SQUID21A
And a wiring portion 22A capable of fixing or incorporating wiring or the like for guiding the measurement signal from the outside of the dewar 2A. At the abdomen near the center of the outer tub 12A of the dewar 2A, a brim-shaped locking projection 15 is provided which is locked and supported by the locking recess 16 in the dewar insertion hole 32 of the supported portion 3A, At the bottoms of the outer tub 12A and the inner tub 11A near the SQUID sensor portion 21A, there is provided a head storage recess 14A in which the head H of the subject can be completely stored (FIG. 1, FIG.
2).

The dewar 2A is inserted into the supported portion 3A having a dewar insertion hole 32 formed in the center thereof, and the locking projection 15 on the outer side of the dewar 2A is locked in the dewar insertion hole 32. It is locked and supported by the recessed portion 16. The supported portion 3A has a spherical convex portion 33A whose outer surface is a part of the spherical surface.

As described above, the spherical convex portion 33A of the supported portion 3A in which the dewar 2A is locked and supported therein has spherical concave portions 31L, 31 forming a part of a spherical surface having substantially the same curvature as the spherical surface.
The support portions 4L and 4R having R are placed and supported on the concave surfaces. In this case, the convex surface of the spherical convex portion 33A substantially contacts the concave surfaces of the spherical concave portions 31L and 31R. That is,
The radius of curvature of the spherical concave portions 31L and 31R is the same as the spherical convex portion 33A.
Is slightly larger than the radius of curvature of the dewar 2A and the spherical convex portion 33A mounted on the support portions 4L and 4R, that is, the curvatures are substantially the same when the support portions 4L and 4R are loaded. In addition, they form a kind of universal joint that is configured to be easily slidable with respect to each other and that does not hinder the mutual sliding due to mutual friction.

With the above construction, as shown in FIG. 4, the spherical protrusion 33A of the supported portion 3A or the supporting portions 4L, 4 are formed.
It is possible to easily rotate the dewar 2A around the rotation axis 42 of the dewar 2A passing through the center of curvature P of the spherical concave portions 31L and 31R of R. Further, the Dewar rotation shaft 42 itself can be rotated about the vertical axis 41 by the angle ± α with the center of curvature P as the rotation center. Alternatively, the above two operations can be performed simultaneously. Therefore, as shown in FIG. 5, the position of the SQUID sensor 21A can be easily and freely fine-tuned according to the position, posture, etc. of the head H of the subject. In the above, if the center of curvature of the dewar 2A and the center of curvature P are made to coincide with each other, fine adjustment of the dewar 2A becomes easier.

Next, a dewar device according to a second embodiment of the present invention will be described. FIG. 6 is a diagram showing the configuration of the dewar device according to the second embodiment of the present invention. As shown in the figure, this dewar device 1B is supported by being suspended from a ceiling 6 of a test room or the like, and arms 5L and 5R provided with supporting portions 4L and 4R at their tips, and supporting portions 4L and 4R. And a dewar 2B provided with a supported portion 3B. The difference from the first embodiment is that the outer surface of the abdomen of the dewar 2B protrudes spherically to form the supported portion 3B. Here, the support portions 4L, 4
The R and the arms 5L and 5R form a support tool.

Dewar 2B has a liquid helium temperature of about 4K.
The SQUID sensor 21B having a SQUID element made of a superconducting material such as niobium, which exhibits a superconducting state, and a liquid helium L that is a cooling medium for the SQUID sensor 21B have substantially cylindrical ends and a substantially spherical center. 11B and this inner tank 11
An outer tank 12B that surrounds B and forms a heat insulating layer 13B such as a vacuum layer with the inner tank 11B to hold the SQUID sensor 21B and the liquid helium L in a heat insulating state.
And a connector portion 24B provided outside the outer tank 12B
And a neck plug 23B inserted into a portion corresponding to the neck of the inner tank 11B and connected to the connector portion 24B, a lid 17B for blocking liquid helium L and its evaporative gas from the outside air.
And a wiring portion 22B which supports the SQUID sensor portion 21B in the liquid helium L and which can fix or incorporate a wiring or the like for guiding the measurement signal from the SQUID 21B to the outside of the dewar 2B. This Dewar 2B
As described above, the abdomen near the center of the outer tub 12B and the inner tub 11B of the outer tub 12B protrudes so that the outer surface thereof forms a part of the sphere surface, forms the spherical convex portion 33B, and forms the supported portion 3B. There is.

Then, the spherical convex portion 3 of the supported portion 3B described above.
3B is placed and supported on the concave surface of the supporting portions 4L and 4R having spherical concave portions 31L and 31R forming a part of a spherical surface having substantially the same curvature as the spherical surface. In this case, the spherical projection 3
The convex surface of 3B substantially contacts the concave surfaces of the spherical concave portions 31L and 31R. That is, the radius of curvature of the spherical concave portions 31L and 31R is set to be slightly larger than the radius of curvature of the spherical convex portion 33B, and the dewar 2A and the spherical convex portion 33A are supported portions 4L and 4L.
When mounted on the R, that is, in a state where a load is applied to the support portions 4L and 4R, the curvatures are substantially the same, and the slide portions are configured to be easily slidable with each other, and are slidable by mutual friction. Form a kind of universal joint that is not disturbed.

With the above structure, the spherical projection 33B of the supported portion 3B or the supporting portion 4 is formed as in the first embodiment.
It is possible to easily rotate the dewar 2B around the rotation axis (not shown) of the dewar 2B passing through the centers of curvature (not shown) of the spherical recesses 31L and 31R of the L and 4R. Further, the Dewar rotation shaft itself can be rotated about the vertical axis by a predetermined angle with the center of curvature as the rotation center. Alternatively, the above two operations can be performed simultaneously. Therefore, the position of the SQUID sensor 21B can be easily and freely fine-tuned according to the position, posture, etc. of the head H of the subject. Further, in the case of the second embodiment, unlike the first embodiment, the supported portion 3B is integrated with the dewar 2B, so that the movable mechanism is further simplified, and liquid helium that can be stored in the dewar 2B is provided. The capacity of can also be increased. In the above, Dewar 2
If the center of gravity of B and the center of curvature are matched, fine adjustment of the dewar 2B becomes easier.

The material of the supporting portion and the supported portion is as follows.
Resins such as FRP and Duracon are suitable. If a fluororesin-based lubricant is applied to either or both of the spherical convex portions or the spherical concave portions, mutual frictional resistance can be considerably reduced. Alternatively, the surface friction can be cut off by forming a large number of minute holes on either surface of the spherical convex portion or the spherical concave portion and ejecting air or the like from the holes. Further, if a ball bearing or the like is embedded in a range serving as a fulcrum on the surface side of the spherical recess, the rolling resistance of the ball bearing makes the mutual frictional resistance between the supporting portion and the supported portion extremely small.

In consideration of the case where the supporting portion and the supported portion are too slippery to stand still in a predetermined posture, a means which can physically fix the dewar at a predetermined position in a predetermined inclined state, for example, , A wire, a bolt fastening mechanism or the like may be provided. In addition, in order to accurately know the position and inclination angle of the dewar, scales such as latitude, longitude, and angle are provided at appropriate positions on the spherical convex portion, and a reference line and pointer are provided on the stationary support side. You may keep it.

The present invention is not limited to the above embodiment. The above-mentioned embodiment is an exemplification, has substantially the same configuration as the technical idea described in the scope of the claims of the present invention, and has any similar effect to the present invention. It is included in the technical scope of the invention.

For example, in the above embodiment, an example of using liquid helium as the cooling medium has been described.
The SQUID sensor is not limited to this, and the SQUID sensor may be formed of yttrium / barium / copper oxide, which is a high critical temperature superconducting material, and liquid nitrogen or the like may be used as the cooling medium. Further, in the above embodiment, an example in which the dewar shape is a cylindrical shape has been described, but the dewar shape is not limited to this, and the dewar itself may have another three-dimensional shape as long as the vicinity of the supporting portion of the dewar is spherical. Absent. Further, in the above embodiment, an example in which the dewar is suspended and supported from the ceiling has been described, but the dewar is not limited to this and may be supported from the floor surface or the wall surface. Further, the number of supporting portions is not limited to two as in the above embodiment, and may be three or more, or one bowl-shaped supporting portion having an open bottom. Good.

In the above embodiment, the case where the dewar inclination angle is not so large has been described as an example, but the dewar inclination angle may be in a considerably large range. In that case, the spherical convex portion itself is inclined and set. Just keep it. For example, in the above-mentioned embodiment, the respective support portions are held at the same height from the ceiling, but by making the heights of the support portions different, it is possible to incline the dewar from the beginning. it can.

[0021]

As described above, according to the present invention having the above-described structure, the dewar is rotated around the rotation axis of the dewar passing through the center of curvature of the spherical convex portion or the spherical concave portion, or the spherical convex portion is rotated. Alternatively, the SQUID sensor position can be easily and freely fine-tuned according to the subject by rotating the Dewar rotating shaft itself with the center of curvature of the spherical recess as the center of rotation or performing the above two operations simultaneously. There is an advantage.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a configuration of a dewar device according to a first embodiment of the present invention.

FIG. 2A in FIG. 1 showing the configuration of the dewar device shown in FIG.
FIG.

FIG. 3 is a perspective view (1) showing a relationship between a spherical convex portion and a support portion in the Dewar device shown in FIG.

4 is a perspective view (2) showing a relationship between a spherical convex portion and a support portion in the dewar device shown in FIG.

5 is a perspective view showing a mode of implementation of the dewar device shown in FIG. 1. FIG.

FIG. 6 is a front sectional view showing a configuration of a dewar device according to a second embodiment of the present invention.

[Explanation of symbols]

 1A, 1B Dewar device 2A, 2B Dewar 3A, 3B Supported part 4L, 4R Support part 5L, 5R Arm 6 Ceiling 11A, 11B Inner tank 12A, 12B Outer tank 13A, 13B Thermal insulation layer 14A, 14B Head recess 15 Locking convex part 16 Locking concave part 17A, 17B Lid 21A, 21B Sensor part 22A, 22B Wiring part 23A, 23B Neck plug 24A, 24B Connector part 31L, 31R Spherical concave part 32 Dewar insertion hole 33A, 33B Spherical convex part 41 Vertical axis 42 Dewar axis H Subject head L Liquid helium P Center of curvature

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisashi Kado 1-4-1 Umezono, Tsukuba-shi, Ibaraki Electronic Technology Research Institute, Industrial Technology Institute (72) Inoue Hisao Nagisa Inzai-cho, Inba-gun, Chiba Prefecture Tai 2-1200 Co., Ltd. Superconducting Sensor Laboratory (72) Inventor Masayuki Ueda Takenishi Gakuen, Inzai-cho, Inba-gun, Chiba Stand 2-1200 Superconducting Sensor Laboratory, Ltd.

Claims (1)

[Claims] 1. A support having a spherical concave portion forming a part of a spherical surface, and a spherical convex portion forming a part of a convex surface having substantially the same curvature as the spherical surface of the spherical concave portion, the spherical convex portion being the spherical concave portion. The SQUID sensor is provided with a supported portion that is placed so as to be substantially in contact with each other and is supported by the supporting tool, and the dewar that has a cooling medium stored therein and is held in a heat-insulated state is provided. A dewar device characterized in that the dewar can be rotated three-dimensionally around a center of curvature of a spherical recess.