RIKEN Nishina Center, Wako, Japan
TEP Corporation, Tokyo, Japan
A high critical temperature (HTc) superconducting quantum interference device (SQUID) beam current monitor (SQUID monitor) has been built and installed in the beam transport line in the radioactive isotope beam factory (RIBF) at RIKEN in Japan. The SQUID monitor can measure the DC current of heavy-ion beams non-destructively at high resolution. Unlike at other existing facilities, as a low vibration, pulse-tube refrigerator cools the HTc fabrications including the SQUID, the size of the system is reduced and the running costs are lowered. Recently, the magnetic shielding system has been greatly reinforced. The measurement resolution is determined by the signal to noise ratio, which is improved by attenuating the external magnetic noise. Furthermore, the data acquisition and control program, currently being written using LabVIEW is providing the trend graph of the measured beam current. In this graph it was observed that the amplitude of ripples in the modulated beam current increased with the beam current. Here we report the details of SQUID monitoring system and the results of the beam measurement.
