A squid-based beam current monitor for FAIR / CRYRING

The high energy beam transport lines (HEBT) at FAIR require a non-intercepting, absolute and precise detection of high brightness, high intensity primary ion beams as well as low intensities of rare isotope beams. The expected beam currents in these beam lines are in the range of few nA up to several µA for continuous as well as bunched beams. This requires a detector with a low detection threshold, a high resolution, and as well as high bandwidth from DC to several kHz. A superconducting pick-up coil and SQUID system are the main components of a Cryogenic Current Comparator. Superconducting pick-up coils allow the detection of DC magnetic fields created by continuous beams without applying modulation techniques. A SQUID acting as current sensor for the pick-up coil enables the detection of lowest currents. Therewith the CCC optimally fulfils the requirements for the FAIR beam parameters. Such a detector is also interesting for the beam current measurement in storage rings because interfering systems would decrease the life time of the stored particles. Depending on the revolution frequency and the charge state, particle numbers down to 102 would be reachable. This CCC should is foreseen to be installed in the CRYRING facility, working as a test bench for FAIR. In this talk results of the completed CCC for FAIR/CRYRING will be presented and also arrangements that have been done for the installation of the CCC at CRYRING, regarding the cryostat design.