TY - JOUR AB - 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 towardsoptimising directional technology. The drift velocity in DRIFT-IIa was 59:3 0:2 (stat) 7:5 (sys) ms 1based on an analysis ofnaturally occurring alpha-emitting background. The drift velocity in DRIFT-IIb was 57 1 (stat) 3 (sys) ms 1determined by theanalysis of alpha particle tracks from a210Po source. Three-dimensional range reconstruction and range spectra were used to identifyalpha particles from the decay of222Rn,218Po,220Rn and216Po. This study found thatð22 2Þ%of218Po progeny (from222Rn decay)did not plate out and remained suspended in the 40 Torr CS2gas fill until they decayed. A likely explanation for this is that some of thepolonium progeny are produced in an uncharged state. For216Po progeny (from220Rn decay) the undeposited fraction was apparentlymuch higher atð100þ0 35Þ% most likely due to a shorter lifetime, causing a larger fraction of the progeny to decay whilst drifting to the cathode plane. This explanation implies a much slower drift time for positively charged polonium progeny compared to CS2 ions. AU - Burgos,S AU - Forbes,J AU - Ghag,C AU - Gold,M AU - Kudryavtsev,VA AU - Lawson,TB AU - Loomba,D AU - Majewski,P AU - Muna,D AU - Murphy,ASJ AU - Nicklin,GG AU - Paling,SM AU - Petkov,A AU - Plank,SJS AU - Robinson,M AU - Sanghi,N AU - Smith,NJT AU - Snowden-Ifft,DP AU - Spooner,NJC AU - Sumner,TJ AU - Turk,J AU - Tziaferi,E DO - 10.1016/j.nima.2007.10.013 EP - 128 PY - 2008/// SN - 0168-9002 SP - 114 TI - Track reconstruction and performance of DRIFT directional dark matter detectors using alpha particles T2 - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment UR - http://dx.doi.org/10.1016/j.nima.2007.10.013 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000252559100008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202 UR - http://hdl.handle.net/10044/1/63581 VL - 584 ER -