Development of a helium collection and liquefied system for Magnetoencephalograph-measurement system

Abstract

According to increasing number of SQUID in Magnetoencephalography (MEG) system, cryostat and the amount of liquid helium consumption have been getting larger. At some large institution with liquid helium production center, it has carried out collection and re-liquefaction of helium. However, gasified helium is discharged in many institutions, because (1) large-scale systems are necessary for re-liquefied, (2) the measurement noise will increase. We developed a helium collection and re-liquefied system for MEG measurement system. The system does not increase any noise and it consists with minimum units. We have used the system applying to 195-channel SQUID system over 6 month. The helium purchase quantity became half the amount.