The design and performance of a prototype water Cherenkov optical time-projection chamber
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- 作者：Eric Oberla ; ejo@uchicago.edu" class="auth_mail" title="E-mail the corresponding author ; Henry J. Frisch
- 关键词：Time-of-flight ; Cherenkov light ; Optical time projection chamber ; Microchannel plate photomultiplier ; Track reconstruction ; Particle detector
- 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
- 出版年：2016
- 出版时间：1 April 2016
- 年：2016
- 卷：814
- 期：Complete
- 页码：19-32
- 全文大小：4100 K
文摘
A first experimental test of tracking relativistic charged particles by ‘drifting’ Cherenkov photons in a water-based optical time-projection chamber (OTPC) has been performed at the Fermilab Test Beam Facility. The prototype OTPC detector consists of a 77 cm long, 28 cm diameter, 40 kg cylindrical water mass instrumented with a combination of commercial b=MathURL&_method=retrieve&_eid=1-s2.0-S0168900216000462&_mathId=si0009.gif&_user=111111111&_pii=S0168900216000462&_rdoc=1&_issn=01689002&md5=2562798f1418cce7f8d8c279065404cd">
micro-channel plate photo-multipliers (MCP-PMT) and b=MathURL&_method=retrieve&_eid=1-s2.0-S0168900216000462&_mathId=si0010.gif&_user=111111111&_pii=S0168900216000462&_rdoc=1&_issn=01689002&md5=3531a525c530cc26b7088166de1cd9ed"> mirrors. Five MCP-PMTs are installed in two columns along the OTPC cylinder in a small-angle stereo configuration. A mirror is mounted opposite each MCP-PMT on the inner surface of the detector cylinder, effectively increasing the photo-detection efficiency and providing a time-resolved image of the Cherenkov light on the opposing wall. Each MCP-PMT is coupled to an anode readout consisting of thirty 50 Ω microstrips. A 180-channel data acquisition system digitizes the MCP-PMT signals on one end of the microstrips using the PSEC4 waveform sampling-and-digitizing chip operating at a sampling rate of 10.24 Gigasamples-per-second. The single-ended microstrip readout determines the time and position of a photon arrival at the face of the MCP-PMT by recording both the direct signal and the pulse reflected from the unterminated far end of the strip. The detector was installed on the Fermilab MCenter secondary beam-line behind a steel absorber where the primary flux is multi-GeV muons. Approximately 80 Cherenkov photons are detected for a through-going muon track in a total event duration of ~2 ns. By measuring the time-of-arrival and the position of individual photons at the surface of the detector to b=MathURL&_method=retrieve&_eid=1-s2.0-S0168900216000462&_mathId=si0011.gif&_user=111111111&_pii=S0168900216000462&_rdoc=1&_issn=01689002&md5=072ef6ffcc0217979bec398fb2f1c4e2"> and a few mm, respectively, we have measured a spatial resolution of ~15 mm for each MCP-PMT track segment, and, from linear fits over the entire track length of ~40 cm, an angular resolution on the track direction of ~60 mrad.
micro-channel plate photo-multipliers (MCP-PMT) and b=MathURL&_method=retrieve&_eid=1-s2.0-S0168900216000462&_mathId=si0010.gif&_user=111111111&_pii=S0168900216000462&_rdoc=1&_issn=01689002&md5=3531a525c530cc26b7088166de1cd9ed"> mirrors. Five MCP-PMTs are installed in two columns along the OTPC cylinder in a small-angle stereo configuration. A mirror is mounted opposite each MCP-PMT on the inner surface of the detector cylinder, effectively increasing the photo-detection efficiency and providing a time-resolved image of the Cherenkov light on the opposing wall. Each MCP-PMT is coupled to an anode readout consisting of thirty 50 Ω microstrips. A 180-channel data acquisition system digitizes the MCP-PMT signals on one end of the microstrips using the PSEC4 waveform sampling-and-digitizing chip operating at a sampling rate of 10.24 Gigasamples-per-second. The single-ended microstrip readout determines the time and position of a photon arrival at the face of the MCP-PMT by recording both the direct signal and the pulse reflected from the unterminated far end of the strip. The detector was installed on the Fermilab MCenter secondary beam-line behind a steel absorber where the primary flux is multi-GeV muons. Approximately 80 Cherenkov photons are detected for a through-going muon track in a total event duration of ~2 ns. By measuring the time-of-arrival and the position of individual photons at the surface of the detector to b=MathURL&_method=retrieve&_eid=1-s2.0-S0168900216000462&_mathId=si0011.gif&_user=111111111&_pii=S0168900216000462&_rdoc=1&_issn=01689002&md5=072ef6ffcc0217979bec398fb2f1c4e2"> and a few mm, respectively, we have measured a spatial resolution of ~15 mm for each MCP-PMT track segment, and, from linear fits over the entire track length of ~40 cm, an angular resolution on the track direction of ~60 mrad.