1. R&D Towards a Linear Collider Detector DOE Site Visit Wednesday July 27, 2011 Senior: Fadeyev, Schumm, Spencer Students: Bogert, Carman **, Chappelletvolpini *, Cunnington, Gomez, Key, Khan *, Maduzia, Mallory, McFadden, Michlin, Mistry, Moreno, Newmiller, Ramirez, Schier **, Taylor *, Thompson * * Senior thesis completed ** Campus award for senior thesis

2. Areas of Activity Generic Studies Charge division Long-ladder noise Electronics Development LSTFE readout KPIX readout Radiation Damage High-dose electromagnetic irradiation Simulation Beamline calorimeter reconstruction Non-prompt track reconstruction

3. Charge Division Can a longitudinal coordinate be measured with microstrip sensors? Explore with PC-board microstrip mock-up and PSpice simulation

7. Areas of Activity

8. Long-Ladder Readout Noise Probe conventional notions about dependence of readout noise on distributed capacitance and series resistance

9. Standard Form for Readout Noise (Spieler) Series Resistance Amplifier Noise (series)Amplifier Noise (parallel) Parallel Resistance F i, F v are signal shape parameters that can be determined from average scope traces. Dominant term for long ladders (grows as L 3/2 )

10. Expected Noise vs. Ladder Length Series noise expected to dominate for narrow (50  m) pitch sensors above ~25 cm long “Lumped element” Load

11. Sensor “Snake”: Read out up to 13 daisy-chained 5cm sensors (with LSTFE-1 ASIC) Sensor “Snake” LSTFE1 chip on Readout Board Can read out from end, or from middle of chain (“center-tap”)

12. Naïve Prediction vs. Observation “Lumped” Load Observed

13. Exploring Long-Ladder Noise Results To explore/understand difference between expected and observed, a full network simulation was developed in SPICE by Aaron Taylor (  UNM physics Ph.D. program) and Khilesh Mistry

14. Comparison with Full Network Model Full network simulation

15. Further Reduction: “Center-Tapping”  NIM paper in preparation Center-Tap Observed Center-Tap Simulated

16. The LSTFE Microstrip Readout ASIC Designed at SCIPP by Spencer, Schumm et al.

17. Time-Over-Threshold (TOT) Readout: the LSTFE Pulse-development simulation  no loss of accuracy for TOT readout (relative to direct ADC conversion) Targets low-complexity, long-ladder tracking solution Real-time readout stream favorable for forward tracking also LSTFE-I prototype relatively successful; LSTFE II under testing. Upgrades relative to LSTFE-I include Improved environmental isolation Additional amplification stage to improve S/N, control of shaping time, and channel-to-channel matching Improved control of return-to-baseline for < 4 mip signals (time-over-threshold resolution) 128 Channels (256 comparators) read out at 3 MHz, multiplexed onto 8 LVDS outputs

18. FIFO (Leading and trailing transitions) Low Comparator Leading-Edge-Enable Domain Proposed LSTFE Back-End Architecture Clock Period  = 400 nsec Event Time 8:1 Multi- plexing (  clock = 50 ns)

19. Some early results: TOT respone Time over Threshold (  s) Minimum ionizing region Very uniform response for large pulses; increased sensitivity in min-i region

20. More early results: Noise v. Capacitive Load Result at 100 pF (optimization point): 1375 electrons noise, but without detector resistance (distributed RC network)

21. Use of the SLAC KPiX Chip for Tracking SCIPP charged with looking at KPiX in the one-few fC range (tracking regime)

22. 0-Charge Input Offset (mV) by Channel (x10) Offset in mV for no input charge Four mis-behaving channels KPiX 7

23. Window of operating thresholds  Very narrow! Need to consider for further KPiX versions… Number of channels with occupancy greater than 0.1% Number of channels with efficiency less than 99.9% KPiX 7 Use SCIPP pulse- development simulation to assess impact of offset variation

24. The ILC BeamCal: Radiation Damage Studies Reconstruction Studies

25. 25 The Issue: ILC BeamCal Radiation Exposure ILC BeamCal: Covers between 5 and 40 miliradians Radiation doses up to 100 MRad per year Radiation initiated by electromagnetic particles (most extant studies for hadron – induced) EM particles do little damage; might damage be come from small hadronic component of shower?

26. 26 Irradiation Plan Use existing Micron sensors from ATLAS R&D n-type and p-type Standard float-zone and Magentic Czochralski Runs of 0.1, 0.3, and 1 GRad for each sample Runs with samples far from radiator (no hadronic effects)  Total integrated dose of ~10 Grad Will assess the bulk damage effects and charge collection efficiency degradation. Sensors Sensor + FE ASIC DAQ FPGA with Ethernet

27. Charge-Collection Modularization Activity Can connect multiplicity of Sensor Board modules to PMFE w/out wire-bonding Requires development of 6 PCB/litho components (Donish Khan; accepted to Stanford Ph.D. program)

28. BCAL Simulation Alex Bogert: Geometry and virtual segmentation Overlay Mean pair background subtraction Developing high-energy electron pattern recognition

29. Average Deposited Energy per Layer Background Signal

30. Pair Background Energy Fluctuations

31. Non-Prompt Tracking with the SiD Explore performance via explicit signature: Metastable stau NLSP (Gauge-Mediated SUSY)

32. Reconstructing Metastable Staus w/ SiD Gauge-Mediated SUSY Large tract of parameters space as stau NLSP Metastable (  c  stau ~ centimeters) is in cosmologically preferred region Process is with

33. Reconstructing Metastable Staus w/ SiD Started with: 5+1 layers for inside track 4 layers for outside track New result: Include VTX-only inside track

34. Measuring Staus with the SID Stau sample: 11.1 fb -1 of e + e -  stau pairs with m stau = 75 GeV E cm = 500;   = 90 fb  c  = 23 cm Background sample: 5.3 fb -1 combined SM background

35. Reconstructing Metastable Staus w/ SiD Focus initially on r decay = 22-47 cm… Reconstruct decays by requiring: - Outer hit of inner trk on last VXD or 1 st tracker layer -  1 missing layer between inner & non-prompt trks - Both tracks on the same side of the Barrel (in z) - Tracks have a geometric intersection in the x-y plane And: When inside track has  1 Central Tracker Hit - The sign of the track curvatures match - Non-prompt track curvature larger than the primary Of 897 staus with 6cm < r dec < 47cm, 642 staus are reconstructed, of which 592 truth-match

36. Stau Reconstruction Efficiency Truth-Matched Staus

37. Signal to Background for 10 fb -1

38. Signal to Background (10 fb -1 ) Good separation between signal and background for #prompt tracks/event and inside track p t  Require, e.g., fewer than three prompt tracks #Prompt Tracks/event p T of inside track

39. Reconstructing Metastable Staus w/ SiD Started with: 5+1 layers for inside track; 4 layers for outside track New result: Include VTX-only inside track Next step: Try to use cal- assisted tracking to get three-hit kinks (dedicated recon- struction by Mallory, Michlin, Bogert)

40. Wrap - Up Many projects underway: Charge-division study published Ladder noise study in preparation for publication Electronics development proceeding Simulation studies bearing fruit New BeamCal contribution in full swing Meaningful research experience for many undergraduates; 8 theses in past three years, including two campus-wide thesis awards

41. Backup Slides

43. Areas of Activity