Volume 78, Issue 7, July 2007
Index of content:
- PARTICLE SOURCES, OPTICS AND ACCELERATION; PARTICLE DETECTORS
Development of superconducting contacts for the CRESST II 66-channel superconducting quantum interference device readout system78(2007); http://dx.doi.org/10.1063/1.2754397View Description Hide Description
The CRESST experiment is designed to search for weakly interacting massive particle dark matter with cryogenic detectors. CRESST II will use up to 33 crystals with a total mass of . These many detectors require a readout system based on 66-channel superconducting quantum interference devices(SQUIDs). In this article we report on the development of a modular superconductingconnector for the 66-channel SQUID readout circuit. We show that the technique developed reliably produces superconducting contacts.
78(2007); http://dx.doi.org/10.1063/1.2756628View Description Hide Description
Plasmas produced in a cold-cathode Penning discharge have been studied for possible use as an active ionizing medium in commercial quadrupole mass/energy analyzers for detection of low-energy neutral beams. Two distinct Penning discharge modes have been examined: (1) high-pressure (HP) mode and (2) high magnetic field (HMF) mode. It is shown that the ionization efficiency in the HP mode is independent of the length of ionization region; however, somewhat high working pressures and large discharge currents limit the practical use of this mode. This is not the case in the HMF mode, which appears at lower pressures, with an effective ionization region length of the order of electron cyclotron radius. The design and operation of a compact , low-maintenance ionizer based on a Penning cell with permanent magnets is described. The ability to ionize neutral-argon beams with subsequent detection in a Hiden EQP energy-resolved mass spectrometer is shown. The ionization efficiency of the ionizer was found to be as high as . Unlike conventional electron impact ionizers, the Penning discharge configuration allows to eliminate the thermal background component in the detected signal. The ionizer has potential application for the detection of hyperthermal neutral beams of various species.