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Advanced Implantation Detector Array (AIDA): Update & Issues. presented by Tom Davinson on behalf of the AIDA collaboration (Edinburgh – Liverpool – STFC DL & RAL). Tom Davinson School of Physics The University of Edinburgh. DESPEC: Implantation DSSD Concept.
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Advanced Implantation Detector Array (AIDA): Update & Issues presented by Tom Davinson on behalf of the AIDA collaboration (Edinburgh – Liverpool – STFC DL & RAL) Tom Davinson School of Physics The University of Edinburgh
DESPEC: Implantation DSSD Concept • SuperFRS, Low Energy Branch (LEB) • Exotic nuclei – energies ~ 50 – 200MeV/u • Implanted into multi-plane, highly segmented DSSD array • Implant – decay correlations • Multi-GeV DSSD implantation events • Observe subsequent p, 2p, a, b, g, bp, bn … decays • Measure half lives, branching ratios, decay energies … • Tag interesting events for gamma and neutron detector arrays
AIDA: DSSD Array Design courtesy B.Rubio • 8cm x 8cm DSSDs • common wafer design for 8cm x 24cm and 8cm x 8cm configurations • 8cm x 24cm • 3 adjacent wafers – horizontal strips series bonded • 128 p+n junction strips, 128 n+n ohmic strips per wafer • strip pitch 625mm • wafer thickness 1mm • DE, Veto and up to 6 intermediate planes • 4096 channels (8cm x 24cm) • overall package sizes (silicon, PCB, connectors, enclosure … ) • ~ 10cm x 26cm x 4cm or ~ 10cm x 10cm x 4cm
ASIC Design Requirements Selectable gain 20 100020000 MeV FSR Low noise 12 60050000 keV FWHM energy measurement of implantation and decay events Selectable threshold < 0.25 – 10% FSR observe and measure low energy b, b detection efficiency Integral non-linearity < 0.1% and differential non-linearity < 2% for > 95% FSR spectrum analysis, calibration, threshold determination Autonomous overload detection & recovery ~ ms observe and measure fast implantation – decay correlations Nominal signal processing time < 10ms observe and measure fast decay – decay correlations Receive (transmit) timestamp data correlate events with data from other detector systems Timing trigger for coincidences with other detector systems DAQ rate management, neutron ToF
AIDA: Current Status • Prototype ASIC design • final design review this week • submission October 27 • Prototype FEE design • engineering concepts established (specification v.1 available) • detailed engineering underway • liquid cooling required (cf. AGATA digitiser module) • Prototype testing • fully instrumented 8cm x 8cm DSSD • in-beam commissioning tests mid-2009
Oustanding Issues: Time Jitter • Transient signal analysis currently underway (realistic comparator design) • Preamplifier risetime ( Cf=0.6pF ) tr=110ns LLD threshold 0.26% 20MeV FSR • 20MeV signal • jitter ~0.13ns rms ( ID=1nA ), ?ns rms ( ID=100nA ) • 0.2MeV signal • jitter ~2.7ns rms ( ID=1nA ), ~4.0ns rms ( ID=100nA ) • b events will normally trigger multiple strips ‘simultaneously’ • S/N improves as n1/2 • Highlights importance of • minimising detector – instrumentation separation • reduces noise and risetime • radiation damage mitigation • detector cooling • Evaluate prototype & review
Oustanding Issues: Threshold • Detailed simulation (with realistic component tolerances and behaviour) • shows random comparator offset variations in excess of minimum threshold • specification (0.25% of 20MeV FSR) • - design optimisation and minimisation • - design incorporates per channel offset correction via 6bit DAC • - evaluate prototype & review
Outstanding Issues: AIDA Enclosure • Design study by E.Reillo et al. (CIEMAT) • http://www.ph.ed.ac.uk/~td/AIDA/Meetings/12May2008/AIDA%20chamber.pdf • Comparison of s/steel, Al and C fibre materials • ‘Best’ option Al • 0.5mm entrance window (path to ToF n-detectors) desirable • Presumed satisfactory choice for Ge detectors • TAS? 4p neutron detector?
AIDA Project Information Project web site http://www.ph.ed.ac.uk/~td/AIDA/welcome.html Design Documents http://www.ph.ed.ac.uk/~td/AIDA/Design/design.html Project Technical Specification ASIC Project Specification v1.3 FEE Specification v1.0 The University of Edinburgh (lead RO) Phil Woods et al. The University of Liverpool Rob Page et al. STFC DL & RAL John Simpson et al. Project Manager: Tom Davinson
Acknowledgements This presentation includes material from other people Thanks to: Ian Lazarus & Patrick Coleman-Smith (STFC DL) Steve Thomas & Davide Braga (STFC RAL) Dave Seddon & Rob Page (University of Liverpool) Berta Rubio (IFIC, CSIC University of Valencia)