Semi Digital HCAL Data analysis results Robert Kieffer Institut de Physique Nucléaire de Lyon 10/02/2016 1

Outline Test beam periods summary. Small chambers studies Large chambers studies Power pulsing Conclusions 10/02/20162

Test beam periods summary 10/02/20163 Beam LineDateAim CERN PS T10July 2008 (7 days)Small chambers Studies CERN PS T9August 2008 (6 days)Mini SDHCAL setup CERN PS T9Nov (5 days)Small chambers Coating tests CERN PS T9June/July 2009 (22 days)Large Chamber + Small chambers High rate CERN SPS H4August 2009 (7 days)Large chamber studies CERN PS T9May 2010 (11 days)Large chamber homogeneity CERN SPS H2June 2010 (7 days)PowerPulsing CERN SPS H4Sept 2010 (10 days)Large chambers tracking More than 1400 kEvts taken using pion beams A lot of complementary cosmic data taken at lab.

Tracking analysis principle Offline reconstruction:  Clustering in chambers  Track fitting in small setup  Alignment (σ±1 cm)  Projection in large chamber.  Check if there is a cluster.  Compute local efficiency Distance: point réel /point attendu (cm) XY alignment ( small setup Vs Large chamber) 10/02/20164 Small Setup (cm) Large chamber

10/02/20165 Small chambers studies using HARDROC1

Time selection on Small chambers data All events (Sig+Noise) Out of time (Noise) Events in time (Signal) Previous spill Actual spill noise 10/02/20166 Trigger (ms) Scintillators coincidence was used to trig the readout

10/02/20167 High voltage scan Resistive coating comparison: Results obtained using tracking

We didn’t see any angle effect on detection efficiency 10/02/20168 Angle scan Results obtained using tracking

10/02/20169 Performance maps in small chambers Efficiency Map (1cm binning) Multiplicity Map (0.33cm binning to see interpad effect) PAD Linked cells causes higher multiplicity Results obtained using tracking

Eudet Telescope Table XY with 4 GRPCs Photogrammetric spots for alignment Tracking with EUDET pixel telescope 10/02/ Beam

Black (Trigger): spatial prediction of hits in GRPC, from EuTel. Red : matched digital hits (EuTel + GRPC) Efficiency: Efficiency: Red/Black Interpad efficiency 10/02/ No efficiency loss on interpads (500 μm) Tracking resolution σ±10μm

Large protype studies using HARDROC 2 10/02/ ASICs = 9216 channels/1m 2 1m 2 Cassette BeamBeam

Beam profile in a Large chamber (1m 2 ) 10/02/ Very low noise contamination. Result obtained using time selection only

Efficiency homgeneity Vs HV scan 3 differents areas HV scan on 3 differents areas. Statguard coated chamber. 10/02/ Top-Right Top-Center Down-Left Results obtained using tracking DIF6 DIF9 DIF10

 HV: 7.5 kV  Threshold: 144 DAC  Position scan area limited by the movable table. 1m 2 GRPC map Efficiency homogeneity studies 10/02/ Results obtained using time selection only

Multiplicity homogeneity studies 10/02/  HV: 7.5 kV  Threshold: 144 DAC  Multiplicity highly related to threshold level but quite homogeneous. Results obtained using time selection only 1m 2 GRPC map

Beam conditions: High Rate Aim: PowerPulsing tests using B field. Beam Beam 32x48 cm 2 GRPC field B field 3T Magnet Power Pulsing Test Beam 10/02/201617

no impactefficiency B field has no impact on efficiency. B field effect on chamber efficiency No Power Pulsing 10/02/ Results obtained using time selection only

B fielda bit multiplicity B field increase a bit the multiplicity. B field effect on chamber multiplicity No Power Pulsing 10/02/ Results obtained using time selection only

Principle of power pulsing Power On Period: 10ms (100 Hz) DutyCycle: 2/10 2 ms Enable Acquisition Trigger for chip readout Injecting on falling edge through a 2pC build in capacitor Scintillator Coincidence « In Spill » Signal & Veto From Acquisition DIF Trigger Power On ASU Busy Trigger Enabling Power Pulsing: consumption goes from 2A to 0.7A 10/02/201620

Timing of power pulsing Trigger taken in the same power-cycle (2ms) Trigger taken in two consecutive power-cycles (10ms) One cycle without trigger (20ms) Two cycles without trigger… Up to 11 power- cycles acquiring during a spill !!! Gaussian fit sigma: ±0.84 ms Power on 2ms 10/02/201621

Efficiency with power pulsing About 4% efficiency loss! 3T B field 10/02/201622

Analysing efficiency loss internal delay (Δt=100 μs)  Can’t change the internal delay (Δt=100 μs) during test beam (DIF’s Firmware). second part  I applied a time selection offline, to keep only event taken during the second part (1 ms) of the 2 ms power-on time. 1 ms Δt 10/02/201623

Analysing efficiency loss Waiting 1ms after power-ON is mandatory to avoid efficiency loss Waiting 1ms after power-ON is mandatory to avoid efficiency loss. Actually Hardroc2 can be ready in 0.1ms - >Studies are still ongoing 3T B field 10/02/201624

Conclusions Efficiency more than 95%. Multiplicity < 1.3Pad/MIP (could be re-defined less using the 3 thresholds) Detection rate: Steady up to 100 Hz/PAD Noise rate: ~0.1 Hz/cm² No angle effect on efficiency Detector still working in a 3 Telsa field Good efficiency/multiplicity homogeneity on large chamber Validity of power pulsing concept proven. 10/02/201625

Thank you for your attention. 10/02/201626