Track Reconstruction and Performance of DRIFT Directional Dark Matter Detectors using Alpha Particles
Abstract
First results are presented from an analysis of data from the DRIFT-IIa and DRIFT-IIb directional dark matter detectors at Boulby Mine in which alpha particle tracks were reconstructed and used to characterise detector performance--an important step towards optimising directional technology. The drift velocity in DRIFT-IIa was [59.3 +/- 0.2 (stat) +/- 7.5 (sys)] m/s based on an analysis of naturally-occurring alpha-emitting background. The drift velocity in DRIFT-IIb was [57 +/- 1 (stat) +/- 3 (sys)] m/s determined by the analysis of alpha particle tracks from a Po-210 source. 3D range reconstruction and energy spectra were used to identify alpha particles from the decay of Rn-222, Po-218, Rn-220 and Po-216. This study found that (22 +/- 2)% of Po-218 progeny (from Rn-222 decay) are produced with no net charge in 40 Torr CS2. For Po-216 progeny (from Rn-220 decay) the uncharged fraction is (100 +0 -35)%.
Cite
@article{arxiv.0707.1758,
title = {Track Reconstruction and Performance of DRIFT Directional Dark Matter Detectors using Alpha Particles},
author = {S. Burgos and J. Forbes and C. Ghag and M. Gold and V. A. Kudryavtsev and T. B. Lawson and D. Loomba and P. Majewski and J. E. McMillan and D. Muna and A. StJ. Murphy and G. G. Nicklin and S. M. Paling and A. Petkov and S. J. S. Plank and M. Robinson and N. Sanghi and N. J. T. Smith and D. P. Snowden-Ifft and N. J. C. Spooner and T. J. Sumner and J. Turk and T. Tziaferi},
journal= {arXiv preprint arXiv:0707.1758},
year = {2008}
}
Comments
27 pages, 12 figures, 5 tables. Submitted to Nuclear Instruments and Methods in Physics Research, Section A. Subj-class: Instrumentation and Detectors