JPS589307A - superconducting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting device, and more particularly, a superconducting device comprising a superconducting coil maintained at an extremely low temperature and a measurement line connecting a measuring instrument for observing the temperature state etc. at room temperature. Regarding.

Normally, in order to obtain a superconducting phenomenon in a superconducting device, it is first necessary to cool the coil to an extremely low temperature. Furthermore, in order to maintain an extremely low temperature state, it is essential to prevent heat intrusion from the atmosphere, and economical effects can be improved by reducing the consumption of liquid helium, etc., which is a cooling medium.

Conventional superconducting devices were relatively small and required only a small number of measurement lines, so the above points did not pose much of a problem. However, in recent years, superconducting devices have become larger and a large number of measurement wires are required to conduct electricity through superconducting coils and investigate various phenomena.With a certain measurement wire diameter, heat penetration increases and the stability of superconductivity decreases. There were drawbacks such as: In other words, as mentioned above, it is necessary to cool the superconducting coil to an extremely low temperature (42'K), but in the extremely low temperature region and room temperature region, even if there are many measurement wires, heat conduction occurs and heat intrusion occurs. becomes. This can be prevented by making the measurement wire as thin as possible, but this is not desirable because it increases the electrical resistance and there is a considerable risk of wire breakage, which causes a decrease in measurement accuracy.

The present invention has been made in view of the above-mentioned points, and its purpose is to
It is an object of the present invention to provide a superconducting device that can maintain a stable superconducting state without increasing heat penetration.

The present invention is provided in a room-temperature part outside a vacuum insulated container that is maintained at an extremely low temperature and houses a plurality of superconducting coils to which measurement elements are attached, and which is pre-cooled and thermally isolated inside. The thickness of the measurement line connecting the measuring device and the measurement element is changed depending on the temperature range in which the measurement line is located, thereby achieving all of the intended objectives.

In other words, a relatively thick measurement line is used in the extremely low temperature region (4.2°K), and the measurement line is Make it thinner. On the other hand, the pre-cooling area and the normal temperature area (300'
Between K), use a thicker measurement line than above,
The thickness of the measurement line is changed appropriately for each section of the temperature range.

Hereinafter, the present invention will be described in detail based on embodiments of the drawings.

The figure shows a torus-shaped fusion device, with toroidal coil 1
A plurality of toroidal coils 1 are supported by a common base 3 installed at the bottom of the toroidal coils 1, and are housed in a vacuum insulation container 4 that performs the function of cutting off heat. has been done. The superconducting coil 2 includes various measuring elements (for example, a heater, a thermometer, a strain meter, a displacement meter, etc.) 5
is attached, and the signal is extracted from this measuring element 5,
The supply current is supplied through the measurement line 6, and the vacuum insulation container 4
It is connected to a meter 7 provided outside the device and measured. These six measurement lines pass from the mounting position A of the measuring element 5 to point B, which is an extremely low temperature region, and then to point D, which is a room temperature region, via point 0 on the common base 3, which is pre-cooled with liquid nitrogen. It is connected to point E of the external meter 7 via the terminal. In this embodiment, the ultra-low temperature region (4, 2°
K) uses a relatively thick '4 line (0,2+m2), and B-
In the area between C (4.2° to 77°K), use a very thin wire (0.14-2) to prevent heat intrusion. Between C and D (77°
~300°K) region is for low temperatures and has a relatively thick line (0,5°K).
■2) Use a line of normal thickness (1
, 2512) is used.

With this configuration of this embodiment, an extremely thin measurement line is used between the cryogenic area and the precooling area (B-C) where heat intrusion is a problem, so heat intrusion is reduced and the cryogenic temperature is reduced. Heat intrusion into the area is also reduced, which is economically beneficial as the consumption of expensive liquid helium is reduced accordingly. Furthermore, by reducing heat penetration, the superconducting state can be stabilized, and the reliability of the device can be improved.

In addition, as in this example, by using an extremely thin measurement wire between the cryogenic region and the pre-cooling region, there is a concern that heat generation due to current or an increase in electrical resistance may occur. This part does not pose a problem because it is cooled to a low temperature with liquid nitrogen, and the electrical resistance can be solved by limiting the length of the extremely thin section.

Also, use a thick measurement line sound between the pre-cooling area and the room temperature area! Therefore, the amount of liquid nitrogen consumed increases to prevent heat from entering the pre-cooling area, but this does not pose a problem because liquid nitrogen is inexpensive.

According to the ρ superconducting device of the present invention as described above, a plurality of superconducting coils that are maintained at an extremely low temperature and equipped with measurement elements are housed outside the vacuum insulated container that is pre-cooled and thermally isolated. The thickness of the gauge wire that connects the measuring element to the meter installed in the normal temperature section of the machine is changed depending on the temperature range in which the measurement wire is located, so it This is effective for this type of superconducting device because it can reduce the thickness of the measurement line, eliminate the increase in heat penetration into the cryogenic state, and keep the superconducting state stable.

[Brief explanation of the drawing]

The figure is a sectional view schematically showing a nuclear fusion device employing an embodiment of the superconducting device of the present invention. 1... Toroidal coil, 2... Superconducting coil, 3
...Common pace, 4...Vacuum insulation container, 5...Measuring element, 6...Measuring line, 7...Meter.

Claims (1)

[Claims] 1. A plurality of superconducting coils that are maintained at an extremely low temperature and equipped with measurement elements, and a vacuum that houses the superconducting coils and pre-cools them internally to cut off heat. In a superconducting device comprising a heat insulating container and a meter provided in a normal temperature part outside the vacuum heat insulating container and connected to the measurement element via a measurement line, the thickness of the measurement line is A superconducting device characterized by changing the temperature depending on the temperature region in which it is located. 2. The measurement line is a relatively thick line in the cryogenic region, an extremely thin line between the cryogenic region and the pre-cooling region, and a thicker line than the cryogenic region between the pre-cooling region and the normal temperature region. A superconducting device according to claim 1, wherein the superconducting device is used. 3. The superconducting device according to claim 1 or 2, wherein each of the superconducting coils is supported at a common pace within a vacuum insulation container.