Precision Tracking Test Beams at the DESY-II Synchrotron. Simon Spannagel DPG 2014 T88.7 Mainz,

Transcription

1 Precision Tracking Test Beams at the DESY-II Synchrotron. Simon Spannagel DPG 2014 T88.7 Mainz,

2 Overview > Test Beams at DESY-II > Tracking with the DATURA Telescope Telescope Hardware Software Reconstruction & Analysis > CMS Pixel Testbeams with DATURA Resolution Studies Intra-Pixel Charge Collection Tracking Efficiency > Summary > Resources Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 2

3 Test Beams at the DESY-II Synchrotron > 1 GeV 6 GeV tunable electron/positron beam 4 GeV 0.95 mrad Beam generation from Bremsstrahlung Beam divergence ~1mrad > Three test beam areas with independent beams > Variety of users: LHC detectors (CMS, ATLAS), ILC detectors (Calice, FCAL) Belle II, Timepix, mu3e, DEPFET, SiPM, > DESY-II currently in shutdown till late summer Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 3

4 Tracking with DATURA - Telescope Hardware > Six planes of MIMOSA26 monolithic active pixel sensors (MAPS) 50 µm silicon, µm2 pixel size, with pixels Suited for low-momentum electron beams (multiple scattering) > Rolling-shutter readout, integration time of about 120μs > Four-fold coincidence scintillator trigger > Device Under Test (DUT) in the middle (3 planes up- and downstream) downstream arm cm REF scintillator triggers upstream arm cm 18 cm DUT CMS Pixel test beam setup GeV positrons scintillator triggers Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 4

5 Software DAQ, Reconstruction & Analysis > eudaq distributed data acquisition framework Allows integration of DUT DAQ, > EUTelescope Generic Pixel telescope Data Analysis Framework Provides set of processors with advanced algorithms for many tasks Under active development & use (CMS, ATLAS, DEPFET, Timepix, ) > General Broken Lines for track fitting Advanced track fitting algorithm including multiple scattering effects > Millepede II Fast linear least square fits for telescope & DUT alignment Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 5

6 Telescope Data Processing Strategy with EUTelescope Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 6

7 Application: CMS Pixel Phase I Upgrade Test Beams > CMS one of the most frequent users of DESY Test Beams Test beams already since 2011 In 2013 & 2014: 9 weeks, 640M events with more than 20 different DUTs > Setup with DATURA telescope for tracking and 1 CMS PSI46 Chip as DUT, to be characterized 1 CMS PSI46 Chip as timing reference detector to overcome track pile-up > Track resolution at DUT: σ ~ 4-7μm > Setup and analysis software used by many other CMS pixel detector groups: ETH Zürich (Planar sensors) US Groups (FPix detector, heavily irradiated devices) KIT (Irradiated sensors) Santander (3D pixel sensors) Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 7

8 CMS Pixel Test Beam: Resolution Studies > Resolution measurements Setup with rotation axes: resolution under different track inclination angles Resolution at different pixel threshold settings ( trim ) > Comparison with data from CMS pixel detector LHC σ = 7.4μm trim 80 trim 30 Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 8

9 CMS Pixel Test Beam: Intra-Pixel Charge Collection > Pixel sensor features ground-grid to avoid pixels with floating potential Cluster charge maps > DATURA tracks allow mapping of cluster charge to positions within pixel cells > Grid clearly visible due to high tracking precision (~5um track resolution on DUT) 50% charge loss at perpend. incidence Only 10% loss with charge sharing (tilt) Does not affect tracking efficiency at low threshold (1.5ke) Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 9

10 CMS Pixel Test Beam: Tracking Efficiency after Irradiation > Tracking efficiency: eff = psi46dig id203, D=13MRad, φ = 23, θ = 29 tracks linked to DUT cluster tracks with REF cluster > n-in-n sensor: type inversion w/ irradiation efficiency charge / Qmax partially depleted sensor volume, less charge collected (trapping, mobility) Efficiency still high, since charge is collected at the implant side After irradiation Before irradiation Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 10

11 Summary > DESY-II used for low momentum e test beams > DATURA telescope provides precise particle tracks > Software frameworks for DAQ and full reconstruction available > Application: CMS Pixel Phase I Upgrade test beams Resolution studies Intra-Pixel Charge Collection Tracking efficiency & Irradiated devices > Related talks: Radiation test of CMOS readout chips for the CMS pixel detector upgrade Ganna Dolinska, T Teststrahlanalyse bestrahlter Pixel Module für den Ausbau des CMS Detektors (Phase I) - Malte Hoffmann, T Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 11

12 > Backup. Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 12

13 Resources > DESY test beams - > DATURA telescope > eudaq - > EUTelescope - > General Broken Lines - > Millepede II - > CMS Pixel Detector - Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 13

14 Phase I Upgrade of the CMS (Barrel) Pixel Detector > Maintaining & extending tracking efficiency at higher luminosities > 3 end disks, 4 barrel layers > New readout chip (ROC) to cope with occupancy & data rates Additional buffer cells Reduced readout dead time Fully-digital 160MHz data transmission Reduced threshold CMS Pixel Phase I TDR > New ROC is incremental upgrade of present chip > Various flavors tested > Test beams use single ROC modules Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 14

15 Irradiated Samples > Two singe ROC modules CERN PS, 24 GeV protons psi46dig id202: Φ = 0.91*1014 p/cm2 (±7.4%) D = 3 MRad psi46dig id203: Φ = 3.77*1014 p/cm2 (±7.6%) D = 13 MRad after 500 fb-1 > Pixel detector dose: Layer 1: 100 MRad Layer 2: 40 MRad Layer 3: 20 MRad Layer 4: 13 Mrad > Bias voltage scans: Partially depleted sensor volume > Threshold scans Pixel upgrade TDR 2012 Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 15

16 Medium-η and Threshold Dependence > Spatial resolution depending on pixel threshold > Resolution at various positions of the pixel detector Various positions along the barrel; end caps psi46dig id205 tilt 20o psi46digv2 id305: turn 27.4 psi46digv2 id306: turn 28.3 η = 0.5 Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 16

17 Test Beam Simulation > Provides cross-check of test beam results > Using Pixelav simulation, used in CMSSW for template matching: > Output of the simulation: charge per pixel ROC parameters need to be simulated separately: Timing, threshold, buffer... Using TCAD E field grid and doping profile psi46dig 4.4GeV, φ = 20, -150V TCAD simulation of ¼ pixel cell psi46dig pixelav M. Swartz, , CMS Pixel General meeting Simon Spannagel DPG Mainz T88.7 Precision Tracking Test Beams at DESY-II 26 March 2013 Page 17