1 / 22

Digital Hadron Calorimeter (DHCAL)

Digital Hadron Calorimeter (DHCAL). José Repond Argonne National Laboratory. CLIC Workshop 2013 January 28 – February 1, 2013 CERN, Geneva, Switzerland. The Digital Hadron Calorimeter (DHCAL) I. Active element Thin Resistive Plate Chambers (RPCs) Glass as resistive plates

evonne
Download Presentation

Digital Hadron Calorimeter (DHCAL)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Digital Hadron Calorimeter (DHCAL) José Repond Argonne National Laboratory CLIC Workshop 2013 January 28 – February 1, 2013 CERN, Geneva, Switzerland

  2. The Digital Hadron Calorimeter (DHCAL) I Active element Thin Resistive Plate Chambers (RPCs) Glass as resistive plates Single 1.15 mm thick gas gap Readout 1 x 1 cm2 pads 1-bit per pad/channel →digital readout 100-ns level time-stamping Virtually dead-time free Calorimeter 54 active layers 1 x 1 m2 planes with each 9,216 readout channels 3 RPCs (32 x 96 cm2) per plane Absorber Either Steel or Tungsten J.Repond DHCAL

  3. The Digital Hadron Calorimeter (DHCAL) II DHCAL =Firstlarge scale calorimeter prototype with Embedded front-end electronics Digital (= 1 – bit) readout Pad readout of RPCs (RPCs usually read out with strips) Extremely fine segmentation with 1 x 1 cm2 pads DHCAL =World record channel count for calorimetry World record channel count for RPC-based systems 497,664 readout channels DHCAL construction Started in Fall 2008 Completed in January 2011 Test beam activities ~ 5 months in the Fermilab testbeam (Steel absorber) ~ 6 weeks in the CERN testbeams (Tungsten absorber) This is only a prototype For a colliding beam detector multiply by ×50 J.Repond DHCAL

  4. DHCAL Construction Fall 2008 – Spring 2011 Electronic Readout System 10,000 ASICs produced (FNAL) 350 Front-end boards produced → glued to pad-boards 35 Data Collectors built 6 Timing and Trigger Modules built Resistive Plate Chamber Sprayed 700 glass sheets Over 200 RPCs assembled → Implemented gas and HV connections Extensive testing at every step Assembly of Cassettes 54 cassettes assembled Each with 3 RPCs and 9,216 readout channels 350,208 channel system in first test beam Event displays 10 minutes after closing enclosure J.Repond DHCAL

  5. Testing in Beams Fermilab MT6 October 2010 – November 2011 1 – 120 GeV Steel absorber (CALICE structure) CERN PS May 2012 1 – 10 GeV/c Tungsten absorber (structure provided by CERN) CERN SPS June – November 2012 10 – 300GeV/c Tungsten absorber RPCs flown to Geneva All survived transportation A unique data sample J.Repond DHCAL

  6. First R&W Digital Photos of Hadronic Showers μ 120 GeV p μ Note: absence of isolated noise hits Configuration with minimal absorber 8 GeV e+ 16 GeV π+ J.Repond DHCAL

  7. Noise studies Several data sets Random trigger runs Trigger-less runs (all hits recorded) Triggered data (first 2/7 time bins) Average noise rate Depends on temperature and ambient pressure Impact on analyses/measurements Noise rate negligible for linearity/resolution Possible effect on shower shape measurements → Requires detailed studies Time → Nnoise =0.01 ÷ 0.1 hits/event in the entire DHCAL ~15 hits correspond to 1 GeV Time distribution of hits far from shower axis J.Repond DHCAL

  8. Measurements with Muons Performance of the chambers Established through measurement of response to muons Simulation RPC response tuned to reproduce signal from muons TCMT DHCAL J.Repond DHCAL

  9. Scan across a single 1× 1 cm2 pad x = Mod(xtrack,1.0) for 0.25 < y < 0.75 y = Mod(ytrack,1.0) for 0.25 < x < 0.75 Note: these features not explicitly implemented into simulation. Result of properly distributing charge over surface of readout pads J.Repond DHCAL

  10. Results - October 2010 Data CALICE Preliminary Fe absorber Gaussian fits over the full response curve Unidentified μ's, punch through

  11. Pion Selection CALICE Preliminary (response not calibrated) N=aE Standard pion selection + No hits in last two layers (longitudinal containment 16 (off), 32 GeV/c (effects of saturation expected) data points are not included in the fit. Fe absorber

  12. Pion Selection Fe absorber CALICE Preliminary (response not yet calibrated) B. Bilki et.al. JINST4 P10008, 2009. MC predictions for a large-size DHCAL based on the Vertical Slice Test. 32 GeV data point is not included in the fit. Standard pion selection + No hits in last two layers (longitudinal containment)

  13. Positron Selection B. Bilki et.al. JINST4 P04006, 2009. Fe absorber CALICE Preliminary (response not yet calibrated) N=a+bEm Data (points) and MC (red line) for the Vertical Slice Test and the MC predictions for a large-size DHCAL (green, dashed line). Correction for non-linearity Needed to establish resolution Correction on an event-by-event basis

  14. Positron Selection Fe absorber Correction for Non- Linearity

  15. CALICE Preliminary (response not calibrated) Positron Selection Fe absorber Uncorrected for non-linearity Corrected for non-linearity

  16. Transportation to CERN Transport fixture Specially built for transportation to CERN Shocks dampened with help of 9 springs Flown to CERN DHCAL cassettes Readout system Gas mixing rack Gas distribution rack Low voltage power supplies High voltage system RPCs Survived transportation to CERN Now back at Argonne (not tested yet) J.Repond DHCAL

  17. Response at the PS (1 – 10 GeV) W absorber Fluctuations in muon peak Data not yet calibrated Response non-linear Data fit empirically with αEβ β= 0.90 (hadrons), 0.78 (electrons) W-DHCAL with 1 x 1 cm2 Highly over-compensating (smaller pads would increase the electron response more than the hadron response) Remember: W-AHCAL is compensating!

  18. Resolution at the PS (1 – 10 GeV) W absorber Resolutions corrected for non-linear response Data fit with quadratic sum of constant and stochastic term (No systematics yet)

  19. Comparison with Simulation – SPS energies Data Uncalibrated Tails toward lower Nhit Simulation Tuned to Fe-DHCAL data (different operating condition) Rescaled to match peaks Shape surprisingly well reproduced

  20. Response at the SPS (12 – 300 GeV) W absorber Fluctuations in muon peak Data not yet calibrated Response non-linear Data fit empirically with αEβ β= 0.85 (hadrons), 0.70 (electrons) W-DHCAL with 1 x 1 cm2 Highly over-compensating (smaller pads would increase the electron response more than the hadron response)

  21. Contributors to the DHCAL Project J.Repond DHCAL

  22. Final Remarks DHCAL performed as expected and validates technical approach DHCAL is a novel detector Many studies ongoing on Calibration (response) Calibration (optimized for resolution) Noise Software compensation… Further R&D needed to design a ‘module 0’ LV/HV distribution Gas distribution and recycling 1-glass RPC design Development of semi-conductive glass (for high rate operation) RPC assembly techniques… J.Repond DHCAL

More Related