Negative Ion Drift and Diffusion in a TPC near 1 Bar

Department of Physics, Temple University, Filadelfia, Pennsylvania, United States
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment (Impact Factor: 1.32). 06/2004; 555(1-2). DOI: 10.1016/j.nima.2005.08.103
Source: arXiv

ABSTRACT Drift velocity and longitudinal diffusion measurements are reported for a Negative Ion TPC (NITPC) operating with Helium + carbon disulfide gas mixtures at total pressures from 160 to 700 torr. Longitudinal diffusion at the thermal-limit was observed for drift fields up to at least 700 V/cm in all gas mixtures tested. The results are of particular interest in connection with mechanical simplification of Dark Matter searches such as DRIFT, and for high energy physics experiments in which a low-Z, low density, gaseous tracking detector with no appreciable Lorentz drift is needed for operation in very high magnetic fields. Comment: 7 pages, 3 figures

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