in: Superconductor Science & Technology (2019) 014002-1
We report on a novel concept and prototype development of a coreless non-destructive SQUID-based charged particle beam monitor for accelerator facilities. Omitting the typically used pickup coil with high permeability core leads to a significant improvement in low-frequency noise performance. A revised shielding geometry moreover allows for very compact and rather lightweight device designs. Based on highly sensitive SQUIDs featuring sub-micron cross-type Josephson tunnel junctions our prototype device exhibits a current sensitivity of about 6 pA/Hz1/2 in the white noise region. Together with a measured shielding factor of about 135 dB this opens up the way for its widespread use in modern accelerator facilities.