The Dual-Cryogenic Current Comperator (DCCC) as a new Prototype CCC for Beamline Monitoring

Cryogenic Current Comperators (CCC) are an innovative concept for non-destructive measurements of nA currents caused by moving charged particles in beam lines. Classical CCC designs consist of a toroidal pickup coil around a highly magnetic permeable core inductively coupled to a Direct Current Superconducting Quantum Interference Device (DC-SQUID) in combination with a meander shaped superconducting shield. Previous experiments have shown that increasing the inductance of the pickup coil by utilizing a larger amount of the same ring core material reduces the noise density by the square root of the inductance change. We introduce a novel prototype, the Dual-CCC (DCCC), which doubles the pickup inductance in respect to the previous design by adding a second identical core with a second pickup coil and SQUID, which can be read out independently. The combined output exhibits a current sensitivity of about 2 pAHz−1/2 in the white noise region.