The The On On bi bit Pe Performance of of DA DAMP MPE Tr Trigger - PowerPoint PPT Presentation

The The On On ‐ bi bit Pe Performance of of DA DAMP MPE Tr Trigger Syst System Yongqiang Zhang, Yang Liu*, Jianhua Guo (DAMPE Collaboration) Purple Mountain Observatory 7/15/2017 ICRC 2017 Busan, Korea 1

Out Outline ine Introduction to DAMPE Trigger System: Concept & Hardware On ‐ orbit Performance: Trigger Rate On ‐ orbit Performance: Calibration & Efficiency Summary 7/15/2017 ICRC 2017 Busan, Korea 2

The The DA DAMP MPE Mission ssion Motivation: electron, proton, nuclei spectra measurement indirect search of Dark Matter Galaxy gamma ray source Launch time : 2015.12.17 Altitude: 500 km Orbit type: solar ‐ synchronous Orbit period: ~95 min PSD: Charge measurement, Anti ‐ coincidence STK: Track reconstruction, Charge measurement BGO: Energy measurement, E ‐ p separation, Trigger NUD: E ‐ p separation 7/15/2017 ICRC 2017 Busan, Korea 3

DA DAMP MPE Tr Trigger Syste System (D (Desig esign Id Idea ea) Decreasing Trigger rate & Data Size Dead time: 3ms Sub ‐ triggers: High Energy Electrons (HE Trigger) Basic e ‐ p separation Shape of cascade shower Detector Calibration (MIPs & Unbiased) 100 GeV e Minimizing Ironizing Particle Unbiased events Gamma ~ 500 MeV (LE Trigger) Lower threshold Electronics Calibration (Periodical) Pedestal 7/15/2017 ICRC 2017 Busan, Korea 4 100 GeV proton

The The Tr Trigger Syste System (“H (“Hit” Signal) Signal) 14 Layer, 22 BGO/layer 2 side, 3 dynodes readout; Top 4 and Bottom 4 layers, 5, 8 dynode for trigger DM032 C. Feng IDEAS VATA 160: VA: Pre ‐ amplify, shaping, S/H TA: fast Shaping, Comparator 1 TA process 22 channel, output “or ‐ ed” as “hit” signal TA signal determining SAA CRD124 W. Jiang et al. 7/15/2017 ICRC 2017 Busan, Korea 5

The The Tr Trigger Syste System (G (Glo lobal Tr Trigger Signal) Signal) Trigger decision logic of DAMPE Logic coincidence on “Hit” signal to generate sub ‐ trigger Sub ‐ trigger Pre ‐ Scaled before Global trigger decision Sub ‐ trigger : Enable/Disable according to physical requirements Periodical trigger for electronics calibration 7/15/2017 ICRC 2017 Busan, Korea 6

The The Tr Trigger Syste System (T (Trigg rigger Logic) Logic) Sub ‐ trigger Settings L1_P_dy5 denote “Hit” signal of Layer1, P side, dynode 5 7/15/2017 ICRC 2017 Busan, Korea 7

DA DAMP MPE Tr Trigger Ra Rate Pole Equator Trigger rate varies with latitude Pre ‐ scale suppress the trigger rate SAA, Unbiased and LE trigger rate high. 7/15/2017 ICRC 2017 Busan, Korea 8

Calibr Calibration ion of of Tr Trigger Thr Threshold shold Trigger thresholds : important in trigger related study. Count Layer_4_N8 Layer_4_N8 Threshold MIPs Calibration DM044 S. Wen et al. Trigger Threshold Calibration Calibrate every channel for the thresholds and corresponding energy 7/15/2017 ICRC 2017 Busan, Korea 9

Thr Threshold shold .v .vs. Te Temperature Threshold (ADC) Temperature Time(Day/Month/Year) Thresholds has negative correlation with temperature ‐ 1chn/C° 7/15/2017 ICRC 2017 Busan, Korea 10

MC MC ‐ Da Data Com Comparison arison of of Tr Trigger Efficiency ficiency MC: GEANT4 with calibrated thresholds Data: pure electron sample HE Trigger Efficiency MC and Data match quite well for Electrons 7/15/2017 ICRC 2017 Busan, Korea 11

Sum Summar ary • DAMPE Trigger: energy trigger, energy information from BGO Calorimeter • Sub ‐ trigger specialized according to physics motivation, pre ‐ scaled to decrease trigger rate. • Trigger rate varies with particle flux, as expect • Trigger threshold calibrated, (ADCs) negative relation with T . • Trigger efficiency for high energy electrons is stable and high. 7/15/2017 ICRC 2017 Busan, Korea 12