SCIPP R

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SCIPP RD on the International Linear Collider
Detector
SCIPP Review May 18, 2006 Presenter Bruce Schumm
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• RD Activity is increasing, with studies now on
  four fronts
• Physics and machine studies for e-e- running
• Detector resolution standards from physics
  simulation
• Reconstruction capabilities of all-silicon
  tracking
• Hardware proof-of-principle of low-noise silicon
  strip readout

Current involvements (all very much part time)
3 senior physicists, 1 post-doc (looking for a
second), 8 (current) undergraduate students, 1
engineer, 2 technical staff, one bored spouse of
a Silicon Valley engineer.
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International Linear Collider Activity on the
e-e- Front

• Clem Heusch is the SCIPP participant in e-e-
  studies
• Leading international effort in the use and
  application of e-e- beams at the ILC
• Continuing series of workshops hosted by SCIPP
  proceedings published in World Scientific
• Heusch is a member of ILC Subcommittee on
  International Collaboration.

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Detector Resolution Standards from Selectron
Production
Participants Senior Physicist Bruce
Schumm Undergraduate Thesis Students Sharon
Gerbode, Heath Holguin, Troy Lau, Paul Moser,
Adam Perlstein, Joseph Rose, Matthew
Vegas Community Member (on hold before Grad
School) Ayelet Lorberbaum Recipient of two
Undergraduate Research Awards grad school at U.
Michigan.
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Motivation To explore the effects of limited
detector resolution on our ability to measure
SUSY parameters in the forward region (benchmark
process study).
SiD Tracker
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Determine the selectron mass accuracy in both the
central (0 lt cos? lt .8) and full (0 lt cos? lt
1) region
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(No Transcript)
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Simulation of SiD Tracking System (and SiD
variants)
Participants Senior Physicist Bruce
Schumm Recent Graduate Students Christian
Flacco, Michael Young Undergraduate
Students John Mikelich, Tyler Rice, Lori
Stevens, Eric Wallace Supported primarily
through department (TA) funds SLAC paid for ½ of
his support this summer.
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Simulation of SiD Tracking System, continued
Three areas of work Fast MC Simulation Billior-
based LCDTRK.f (B. Schumm) provides covariance
matrices for fast MC simulation and resolution
plots. SiD Tracking Capabilities Explore
tracking performance of SiD tracker and
variants Microstrip Pulse Development
Simulation Provides simulation of pulse
development and amplification for designing and
detector layout
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LCDTRK.f comparison of SiD options with TESLA
(LDC) design, from Snowmass 2005
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CURVATURE ERROR vs. CURVATURE
Standard (Original) Code
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Pattern Recognition Capabilities of an
All-Silicon Central Tracker
Can one do pattern recognition with only five
central tracking layers? Might more layers
improve performance to an extent that justifies
the extra material?
SiD Tracker
Current code Nick Sinev, U. Oregon
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EFFICIENCIES FOR QQBAR EVENTS
Doesnt look that spectacular what might be
going on here?
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Of course! The requirement of a VXD stub means
that you miss anything that originates beyond r
3cm. This is about 5 of all tracks.
With current VXDBasedReco algorithm, we wont
get the 5 of tracks that originate beyond 2cm.
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Outside-in Tracking (Eric Wallace)
Circle-fit tracker (Tim Nelson, SLAC) developed
at Snowmass Eric has optimized this algorithm
for finding non-prompt tracks after hits from
VXDBasedReco tracks are flagged
Essential tool for SiD track parameter
optimization.
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Pulse Development Simulation
Long Shaping-Time Limit strip sees signal if and
only if hole is col-lected onto strip (no
electrostatic coupling to neighboring strips)
Include Landau deposition (SSSimSide Gerry
Lynch LBNL), variable geometry, Lorentz angle,
carrier diffusion, electronic noise and
digitization effects
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Result S/N for 167cm Ladder
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Electronics Simulation
Detector Noise From SPICE simulation,
normalized to bench tests with GLAST electronics
Analog Measurement Employs
time-over-threshold with variable clock speed
lookup table provides conversions back into
analog pulse height (as for actual data)
RMS
Gaussian Fit
Essential tool for design of front-end ASIC
Detector Resolution (units of 10?m)
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The SCIPP/UCSC ILC HARDWARE GROUP
Faculty/Senior Alex Grillo Hartmut
Sadrozinski Bruce Schumm Abe Seiden
Students Greg Horn Glenn Gray Bryan Matsuo
(Comp.Sci.)
Post-Docs Gavin Nesom Jurgen Kroseberg
Lead Engineer Ned Spencer Technical Staff Max
Wilder, Forest Martinez-McKinney Recently lured
away by the sirens of Silicon Valley
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The LSTFE-2 ASIC
Process TSMC 0.25 ?m CMOS
3 ?s shaping time analog readout it
Time-Over-Thres-hold with 400 nsec clock
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128 mip
1 mip
Operating point threshold
Readout threshold
1/4 mip
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INITIAL RESULTS
LSTFE-2 chip mounted on readout board
FPGA-based control and data-acquisition system
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0.80 fC
0.46 fC
Comparator S Curves Vary threshold for given in
put charge Read out system with FPGA Get
1-erf(threshold) with 50 point given
response, and width giving noise
1.42 fC
1.11 fC
1.73 fC
2.04 fC
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Gain and Noise Results (Load 150 pF, or about
a 115 cm detector) Noise referred to input is
in equivalent electrons Result 5300 electrons
noise Expectation 1400 electrons
noise Picoprobe studies isolate problem to
shaper stage ? Redesign getting underway
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DIGITAL ARCHITECTURE FPGA DEVELOPMENT
Digital logic should perform basic zero
suppression (intrinsic data rate for entire
tracker would be approximately 50 GHz), but must
retain nearest-neighbor information for accurate
centroid.
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Proposed LSTFE Back-End Architecture
Low Comparator Leading-Edge-Enable Domain
81 Multi-plexing (?clock 50 ns)
FIFO (Leading and trailing transitions)
Event Time
Clock Period ? 400 nsec
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DIGITAL ARCHITECTURE VERIFICATION
ModelSim package permits realistic simulation of
FPGA code (for now, up to signal propagation
delay)
Simulate detector background and noise rates for
500 GeV running, as a function of read-out
threshold. Per 128 channel chip 7 kbit per
spill ? 35 kbit/second For entire long
shaping-time tracker 0.5 GHz data rate (x100
data rate suppression)
Nominal Readout Threshold
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LONG LADDER CONSTRUCTION
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OVERALL SUMMARY

• Linear Collider RD at SCIPP is
• Directly benefiting from SCIPP expertise
• Focused on central issues for the ILC
• Supporting leadership roles (international
  cooperation, oversight of tracking RD)
• Creating synergies with other SCIPP programs
• Providing key educational opportunities,
  undergrad through postdoc, with a good placement
  record