9 Time-Of-Flight Detector in Heavy-Ion Exp ALICE ☆a STAR at RHIC ALICE at LHC High multiplicity:103-104 particles produced Large coverage ~102 m2 Strong magnetic field:0.5-2 T High event rate:102-103 Hz/cm2 2023/6/28 Talk for EM group 伍健 6
2023/6/28 Talk for EM group 伍健 6 Time-Of-Flight Detector in Heavy-Ion Exp. STAR at RHIC ALICE at LHC High multiplicity : 103 – 104 particles produced Large coverage : ~102 m2 Strong magnetic field : 0.5 – 2 T High event rate: 102 – 103 Hz/cm2
p/πSeparation =+mc/p2-1+mc21p） ID 111 E ntries 378 Mean 6.2象88E-B1 RMS 4.110 红 UDFLW 0. Momentum: OVFLW 0. T80 x/ndf 8T62124 3GeV/c PI 815.8 P2 -1,g19 60 P3 1.490 P4 1T1.5 Flight path length: 7.0B9 P6 1.T32 277cm 4日 8t=432ps 300 (prediction) 20 6t=441ps 100 (experiment) .20 10 20 Tim e (50ps/ch) 2023/6/28 Talk for EM group伍健 7
2023/6/28 Talk for EM group 伍健 7 Momentum: 3GeV/c Flight path length: 277cm t=432ps （prediction） t=441ps （experiment） ( ) 2 2 2 2 2 2 2 1 1 m c / p 1 m c / p c L t + − + = p/ Separation
Options of TOF To reduce occupancy ~10%,need small size strip>105-106 channels "Standard"TOF system built of fast scintillators plus phototubes would cost too much !(80 MCHF for ALICE) Gaseous detectors route to large area detectors at affordable price 2023/6/28 Talk for EM group伍健 8
2023/6/28 Talk for EM group 伍健 8 Options of TOF To reduce occupancy ~10%, need small size strip → 105 -106 channels “Standard” TOF system built of fast scintillators plus phototubes would cost too much ! ( ~ 80 MCHF for ALICE) Gaseous detectors route to large area detectors at affordable price
Gaseous Detector Advantages Can be made at almost any shape and size Low noise Excellent dynamics range Can make simultaneous measurements of energy and position Important detector Charged particles X-and y-ray Visible light Application fields √ particle nuclear physics space-borne astro-particle physics medical imaging x-ray crystallography environmental monitoring 2023/6/28 Talk for EM group伍健 9
2023/6/28 Talk for EM group 伍健 9 Gaseous Detector Advantages ✓ Can be made at almost any shape and size ✓ Low noise ✓ Excellent dynamics range ✓ Can make simultaneous measurements of energy and position Important detector ✓ Charged particles ✓ X- and - ray ✓ Visible light Application fields ✓ particle & nuclear physics ✓ space-borne astro-particle physics ✓ medical imaging ✓ x-ray crystallography ✓ environmental monitoring
Passage of Particles through Matter uon Cu (b)Lead (Z=82) a-experimental Giot I Mb Bethe-Bloch Radiative Anderson- Ziegler 10 Radiative Radiative Minimum effects losses Nuclear ionization reach 1% losses Vithoutδ 10b 0.001 0.01 0.1 1 10 100 1000 104 105 106 10eV I keV 1 MeV 1 GeV 100GeV Y Photon Energy TTTTTTT Positrons 0.20 Lead (Z=82) Electrons Photon cross section 1.0 Bremsstrahlung 的 158 一四 0.10 charged particles (other Ionization 0.5 Moller (e) than electrons)energy lose Bhabha (e+) 0.05 Positron annihilation 10 100 1000 electrons energy lose E (MeV) 2023/6/28 Talk for EM group 伍健 10
2023/6/28 Talk for EM group 伍健 10 Passage of Particles through Matter charged particles (other than electrons) energy lose electrons energy lose Photon cross section