Aerogel Ring Imaging Cherenkov for segmented PID Akira Konaka - - PowerPoint PPT Presentation

Canada’s national laboratory for particle and nuclear physics and accelerator-based science

Aerogel Ring Imaging Cherenkov for segmented PID Akira Konaka (TRIUMF)

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Hadron production measurement with hybrid emulsion

• Add secondary particle detectors for hadron production
• Hadron production for 30GeV proton beam
• Hadron interactions below 10GeV/c (for T2K secondary interaction) 2

Emulsion track selections

• Tagging of emulsion tracks
• Select emulsion track that matches with the silicon strip detector hits
• selection of emulsion tracks that happens at the event time provided by silicon
• secondary PID: ~1mm hit accuracy with Aerogel Rich
• in principle, downstream emulsion tracks can be selected with Aerogel Rich
• want silicon tracker in the central region with dense tracks

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Particle Identification by Aerogel-RICH (Belle2)

• Aerogel ring imaging Cherenkov
• π / K / p separation in 1-5 GeV/c
• more flexible than threshold Cherenkov
• Momentum range extended by lower index aerogel
• Multi-track (multi-ring) capability for secondaries
• Time of flight with the central hit (PMT glass Cherenkov)

Iijima et. al. NIMA548(2005)383 4

PMT glass Cherenkov

Rough estimation of PID

5 Belle2 achieves 7σ π/K separation at 5GeV/c for n~1.05 Lower index helps for higher momentum

discrimination power for each photoelectron

Particle identification

• Aerogel ring imaging Cherenkov hardware
• Aerogel
• 10cm x 10cm x 1cm of n=1.01, 1.015, 1.03 purchased from JFCC
• Collaboration with Chiba university (Kawai) for n=1.0026-1.3 Aerogel
• JFCC, Nobosivilsk, NASA and Chiba are the only producers
• $4k per batch (cost for student labour) covered by US-Japan funds

» one batch can make up to eight 10cm x 10cm x 2cm plates » received n=1.02 sample with 10cm x 10cm x 2cm in size

• PMT: multi-anode(MA) PMT (~$3k/piece and we need 9)
• we have one MA-PMT (8x8=64 6mmx6mm pads) : ~$3000/PMT
• No magnetic field: no need for Belle2 like Hybrid Avalanche Photodetector (~$10,000/PMT)
• Electronics
• One TRB3 board purchased from GSI: FPGA based TDC
• A 2600EUR card can take up to 192 channels (3 MA-PMT): one ordered
• Electron ID will be done by the lead glass counter (at Fermilab)

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Cosmic ray test of Aerogel (Khalid Gameil)

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pe pe pe

PMT only
 (glass) N=12pe

PMT+Aerogel
 2cm, n=1.03 N=20pe (Naerogel=8pe) PMT+Aerogel
 2cm, n=1.015 N=16pe (Naerogel=4pe)

single 
 photoelectron peak

trigger scintillator Aerogel 2-inch PMT

Photoelectron yield study with a cosmic ray test stand

• Npe = α x d x (1-1/n2) for β=1 particles
• Belle2 measurement:
• 4cm n=1.05 aerogel with PMT coverage of 48%: Npe=11.4
• α = Npe / d / (1-1/1.052) /0.48 = 63.5
• Expected Npe from Belle2 compared with cosmic ray test
• assuming that the quantum efficiency is the same
• Observed Cherenkov light yields are consistent assuming PMT glass is 3mm thick

8 Material thickness(d) index(n) phoelectons(Npe) expected (*) PMT glass 0.3cm 1.54 12 11.0 Lucite 2cm 1.5 72 70.6 Aerogel 015 2cm 1.030 8 7.3 Aerogel 030 2cm 1.015 4 3.7

Summary

• Aerogel Rich provides compact multi-track PID
• Well established technology by Belle2 for up to p=5GeV/c
• Lower index of refraction extends the momentum coverage
• Aerogel R&D under way with Chiba university group
• Cosmic ray test confirms the expected light yield:
• N=4pe even for n=1.015 and 2cm-thick Aerogel
• Started an evaluation of FPGA based TDC from GSI
• Used for Rich with the same multi-anode PMT we use
• Economical: 2600EUR for 192 channels
• One PMT prototype due to limited budge/human resource

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