Presentation Information
[9p-N404-5]Magnetic field measurements in magnetic shields at low and room temperatures for superconducting tunnel junction X-ray detectors
〇Shigetomo Shiki1, Go Fujii1 (1.AIST)
Keywords:
superconducting detector,magnetic shield,Josephson junction
We are developing an X-ray detector array using superconducting tunnel junctions (STJ) for use in X-ray absorption spectroscopy and SEM-EDX in the soft X-ray region. To prevent magnetic flux trapping due to the earth's magnetic field, a magnetic shield using soft magnetic material is attached on the outside of the radiation shield, but magnetic flux trapping still occurs. In this study, we aimed to eliminate magnetic flux trapping and investigated the strength of the magnetic field inside the magnetic shield at room and low temperatures. The magnetic field perpendicular to the junction at the detector position is about 30 nT. It is highly likely that the cause of the magnetic flux trap is something other than the leakage magnetic field of the magnetic shield.