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

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct 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 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 25*25 mm 2 sensors), discrete readout via fanout, electronics mounted on PCBs - Soon switched to 4” technology: 50*50mm 2 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 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 SILICON DETECTORS IN H1 - OVERVIEW CST (strips) BST (strips, pads) FST (strips) electron beamproton beam proton direction = forward direction

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct SILICON DETECTORS IN H1 - DETAILS - Three different sensor types: R-Strip, Phi-Strip, Pad - Two different readout hybrids: S-Hybrid, Pad-Hybrid Mechanical design: Carbon fiber reinforced plastic VERTEX - Modular design of all components - Design as a “plug in” device with remotely operated contact ring (including all media connections for N 2 and H 2 O) - 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 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) modules (spares included) produced for both FST and BST

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct 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 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 -> detector module -> repeater (pre-processing) -> H1 readout

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct BST PAD DETECTOR MODULE 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 AC coupled sensors with 32 (4 * 8) pads

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct PERFORMANCE PAD MODULE - Tuning of all modules under HERA conditions with no beam -> ‘noise counts’ - Threshold scale calibrated with MIPs in a test beam - Most critical part after design: depletion voltage of sensor -> careful decoupling and grounding mandatory - nearly 100% trigger efficiency with tuned system -> 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 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 RESULTS (continued) - spatial resolution  FST alignment before alignmentafter alignment

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct 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 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 HERMES RECOIL DETECTOR - REQUIREMENTS 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) MHz readout to match the HERA frequency. - Prefer a chip already used in HERMES (Lambda Wheels - HELIX 128). REQUIREMENTS ON Silicon Sensors - Detection area about 200*100mm 2 - Spatial resolution in ‘phi’ about 1mm - low quantities needed (two layers) therefore look for sensors available - TIGRE Sensors (MICRON Ltd. UK)

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct HERMES RECOIL DETECTOR - R/O TECHNIQUE (1) 1 “MIP” = 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 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 HERMES RECOIL DETECTOR - PROTOTYPE ZEUS hybrid Sensor

Wolfgang Lange, DESY Zeuthen: Silicon Detector Projects Kraków, 10-Oct 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: N 2 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)