NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY
发明人:
MATSUI, TOSHIAKI,OOTA, HIROSHI
申请号：
EP04807369
公开号：
EP1829476A4
申请日:
2004.12.20
申请国别(地区):
EP
年份:
2012
代理人:
摘要：
Disclosed is a measuring structure for a magneto encephalographic equipment superconducting magnetic-shield comprising a vacuum-tight body comprising an outer enclosure wall, a first inner enclosure wall inserted in the outer enclosure wall to define an upper closed space, and a second inner enclosure wall to define a lower open space. The first and second inner enclosure walls are arranged with the bottom of the first inner enclosure wall facing the ceiling of the second inner enclosure wall. A first enclosure of high critical temperature superconductor and a second enclosure of high permeability material are concentrically arranged in the annular vacuum space defined between the first and second inner enclosure walls and the outer enclosure wall. A head-accommodating area is delimited by the hollow partition between the bottom of the first inner enclosure wall and the ceiling of the second inner enclosure wall both facing each other, and a plurality of SQUID sensors are arranged in the upper closed space, encircling the head-accommodating area. The SQUID sensors are cooled by the liquid helium contained in the upper closed space whereas the first enclosure is cooled by the circulating helium gas from a closed-cycle helium refrigerator. An adiabatic expansion compartment may be placed in the upper closed space. The adiabatic expansion compartment is supplied with cooled helium gas, which is converted into liquid helium by adiabatic expansion, and the so converted liquid helium is fed into the liquid helium bath in the form of drops to make up for the consumption of liquid helium during operation. Otherwise, the adiabatic expansion compartment is connected to the SQUID magnetic sensors to indirectly cool the sensors by the thermal conduction body.
