Operation of Rich Single Photon Detectors With Optically Shielded Wires in Transverse Magnetic Fields

Abstract The operation of TPC-type photon detectors with optical shields between the sense wires has been investigated in magnetic fields up to 1.4 T. The field was applied perpendicularly to the drift direction. Three types of MWPCs with different optical shield designs were tested. Ethane and iso-butane were used as drift gases. TMAE vapour was added to obtain photon sensitivity. The results show that MWPCs with printed circuit board shields can be operated without loss of efficiency even at high magnetic fields. The MWPC with tubular cathode shows losses already at low fields.