Compact radiation shield for a superconducting array molecule detector

Recent development on large-scale superconducting array detectors requires a large through hole along the molecular flight path in a cryostat. The through hole causes degradation of detector performance due to the 300 K radiation and a short holding time at the cryostat base temperature. To realize a compact detector system, we designed and fabricated infrared radiation shields with a fine-honeycomb collimator and a micro-structured metal-mesh. The infrared flux through the honeycomb collimator located at 50 K was 300-500 μW. A test run in a cryostat showed a holding time of 8 hours. We fabricated a metal-mesh consisting of a self standing Cr/Cu film with an array of 2.0 μm holes having a pitch of 3.5 μm. The metal-mesh was supported by a Si reinforce structure. Spectral measurement indicates that the transmission of the 300 K radiation is less than 1%.