SILICON DETECTOR PROJECTS

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SILICON DETECTOR PROJECTS _at_ DESY Zeuthen (up to
now) By Wolfgang Lange, DESY Zeuthen
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OUTLINE

• Early Silicon Detectors in Zeuthen
• Silicon Detectors in H1 (BST, CST, FST, BST-PAD)
• Silicon Detectors in ZEUS (Barrel Detector)
• HERMES Recoil Detector
• Facilities and Collaborators

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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EARLY SILICON DETECTORS

• Development together with Werk für
  Fernsehelektronik Berlin (WF)
• First silicon sensors in planar technology
  1987
• DC coupled, 50µm pitch on 2 wafers (up to
  2525 mm2 sensors),
• discrete readout via fanout, electronics
  mounted on PCBs
• Soon switched to 4 technology 5050mm2
  sensors
• DC coupled, 50µm pitch, development of the
  first thick film hybrid,
• use of the first readout ASIC (MX-2,
  Stanford University)
• first application calibration of the
  L3-central tracking chamber _at_ CERN
• Development together with Halbleiterwerk
  Frankfurt/Oder (HFO)
• and Institut für Halbleiterphysik
  Frankfurt/Oder (IHP)
• - May 1989 first own production of DELPHI type
  sensors (IHP FF/O)
• AC coupled, 25µm pitch (one indermediate
  strip, polysilicon resistors),
• sensors used successfully until 1993 in
  different experiments
• 1991 we started the development of our own
  sensor types (strip, pad).

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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SILICON DETECTORS IN H1 - OVERVIEW
FST (strips)
CST (strips)
electron beam
proton beam
BST (strips, pads)
proton direction forward direction
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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SILICON DETECTORS IN H1 - DETAILS

• Three different sensor types R-Strip,
  Phi-Strip, Pad
• Two different readout hybrids S-Hybrid,
  Pad-Hybrid

VERTEX
Mechanical design Carbon fiber reinforced
plastic

• Modular design of all components
• Design as a plug in device with
• remotely operated contact ring
• (including all media connections
• for N2 and H2O)
• Separate inner and outer shielding
• Cable- and media connections are
• pre-installed to the contact ring

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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S(tandard) - DETECTOR MODULE

• universal detector module
• for front and back side
• low cost design with included strip line
• and heat distributing Al bottom layer
• standard circuitry (using APC 128 /decoder)
• optimized for low common mode and
• low noise (including ground plane)
• 220 modules (spares included) produced for
• both FST and BST

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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CST BARREL (NOT ZEUTHEN ZÜRICH BUT H1)

• CST barrel consists of two layers
• completely covering the vertex
• (beam pipe)
• Ladders consist of 6 double sided sensors
• with hybrids on both sides
• hybrids are equipped with radhard readout
• chips APC128 (DMILL)

one ladder
CST hybrid
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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BST PAD DETECTOR

• For the measurement of deep inelastic scattering
• one needs to trigger on such events (vertex
  pointing)
• Background suppression for SPACAL hits
• (photon background)
• Four planes (disks) with pad detectors which are
• read out by the trigger system of H1 (trigger
  level 1)
• Pad detector supplies trigger patterns (masks
  or
• classified tracks, L1) as well as hit patterns
  (level 3)
• Measurement of normalized counting rates per
  area
• allows the use as radiation monitor

Readout chain sensor -gt detector module -gt
repeater (pre-processing) -gt H1 readout
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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BST PAD DETECTOR MODULE
AC coupled sensors with 32 (4 8) pads

• ASIC PRO/A
• 32 channels
• preamp / shaper / discriminator
• adjustable gain (four steps)
• subtraction of neighboring
• channels possible
• output monostable or
• time over threshold
• input current compensation
• optional
• over all test feature

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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PERFORMANCE PAD MODULE

• Tuning of all modules under HERA conditions with
  no beam -gt noise counts
• Threshold scale calibrated with MIPs in a test
  beam
• Most critical part after design depletion
  voltage of sensor
• -gt careful decoupling and grounding
  mandatory
• nearly 100 trigger efficiency with tuned system
• -gt tracks defined already with two hits in
  two planes

self triggered spectrum of MIPs (pedestal added
with external trigger)
Threshold scans for different depletion voltage
supplies
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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RESULTS - strip modules

• Excellent performance of strip modules
• (S-hybrid equipped with sensors from CIS
  Erfurt)

S/N 30 spatial resolution 12 µm
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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RESULTS (continued) - spatial resolution

• FST alignment

before alignment
after alignment
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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ACTIVITIES FOR THE ZEUS Micro Vertex Detector

• No development of real silicon but
  development of parts
• flex foils for the interconnection of sensors
  and r/o hybrids
• design, production and application of special
  glueing
• techniques for flex foils on top of silicon
  (tooling included)
• design and production of handling tools for
• double sided silicon
• DC measurement of a large quantity of sensors

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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HERMES RECOIL DETECTOR
Position of Recoil Detector
Recoil Detector Detection of low momentum
recoil protons
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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HERMES RECOIL DETECTOR - REQUIREMENTS

• REQUIREMENTS ON
• Silicon Sensors
• Detection area about 200100mm2
• Spatial resolution in phi about 1mm
• low quantities needed (two layers)
• therefore look for sensors available
• - TIGRE Sensors (MICRON Ltd. UK)

• R/O ELECTRONICS (R/O Chip)
• - An analog pipeline chip is needed to
• accommodate the HERMES trigger.
• - A dynamic range of 70 MIP ( 280 fC).
• - 10 MHz readout to match the HERA
• frequency.
• - Prefer a chip already used in HERMES
• (Lambda Wheels - HELIX 128).

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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HERMES RECOIL DETECTOR - R/O TECHNIQUE (1)
1 MIP 24 000 e-/h pairs /- MIP pos/neg
charge on preamp

• Conclusions
• - Linear response over /-10 MIP
• - Saturated at 15 MIP

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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HERMES RECOIL DETECTOR - R/O TECHNIQUE (2)
Solution charge division
charge division works nicely (and can be tuned to
the needs)
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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HERMES RECOIL DETECTOR - PROTOTYPE
Sensor
ZEUS hybrid
Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003
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FACILITIES AND COLLABORATORS

• At DESY Zeuthen we are able to perform (class
  10k clean room)
• Ultrasonic wire bonding (Au, Al, down to 17.5 µm
  wires)
• Glueing with high mechanical precision and/or
  special hardening procedures (silver epoxies)
• Measurements of single and double sided sensors
  on different probe stations
• long term measurements (darkness, special
  atmosphere N2 or similar)
• chip testing (delivered probe cards can be
  adapted)
• additional electronics workshop with
  automatic SMD placement and soldering tools
• mechanical workshop with NC machining/milling
• at DESY Hamburg a state of the art
  programmable wire bonder

• Companies / Institutions we are used to work
  with
• - Sensors CiS Erfurt (D), Micron Ltd. (UK),
  SINTEF Oslo (N), Hamamatsu (J)
• chip design IDE AS, Oslo (N) and ASIC
  Laboratory of University of Heidelberg (D)
• probe cards Wentworth Deutschland GmbH, München
  (D)
• high precision printed circuit boards Würth
  GmbH, Roth am See (D), Optiprint (CH)
• thick film hybrids Elbau GmbH, Berlin (D)

Wolfgang Lange, DESY Zeuthen Silicon Detector
Projects
Kraków, 10-Oct-2003