VISION ON DETECTORS Subhasis Chattopadhyay VECC Kolkata V
VISION ON DETECTORS Subhasis Chattopadhyay VECC, Kolkata V. Balagi BARC, Mumbai
Detectors in DAE: - Present status Detectors are being developed and used from the inception for detecting particles ranging from thermal neutrons to cosmic rays Nuclear physics, Solid State Physics, High energy physics, Medical diagonesis Neutrons, photons, charged particles (light or heavy), muons, neutrinos… Underground to nuclear physics labs, India, Europe, USA Special areas of interest for DAE Reactor safety and control Health physics instrumentation Basic research Based on this bright present we built our vision for luminous future
Detectors for tomorrow Discussion based on: Gross material properties of the media Ø Solid State Detectors Ø Gas Detectors Ø Scintillators and special detectors R&D Continues to improve any or all of these areas. Vision on detector development: àImprovement by newer detector materials/ technique. àNew uses of the detectors for the society.
Solid State Detectors Various types of solid state detectors are used: Surface Barrier Si, Si(Li), HPGe, Si-pad, Si-strip, CCD based Handling Si technology for making detectors is itself a challenge Achievements so far: Low energy to URHIC, X-ray to high-energy charged particles Proposals for future (one step ahead): Nuclear physics: Large BARC charged particle array (108 modules) Si-strip detectors (1000 modules) for CMS experiment High Energy Physics: at CERN Inner tracking with compact double • Industrial participation sided Si-Microstrip. BEL, Bangalore CBM@GSI (big challenge next 10 -15 yrs). SAXS/WAXS: CCD camera for study of anisotropy in materials.
Solid State Detectors: - New materials CVD Diamond and Silicon-Carbide: (Radiation hard, Fast, Low noise, Rugged) CVD technique is tested at various labs in DAE Applications: Inner tracking in HEP Experiment, Reactor incore flux monitoring, Medical Imaging Si. C: Wide dynamic range, high temp. operation (To be developed) Si-pixel detector with amorphous Si (Pixel detectors are to be used in ALICE) Challenges ahead: Deposition of amorphous silicon on ASIC readout: new technology for pixel sensors (low cost, radiation hardness, thin films) Technological issues: Deposition of high quality (low defects) thin film. Applications: Medical Imaging, HEP Experiment.
Gas Detectors Achievement so far: • High granularity gas proportional array • 100, 000 cells (STAR experiment, BNL) • 250, 000 cells (ALICE experiment, CERN) • Large area position sensitive pad chambers (ALICE experiment, CERN) • Experience in underground experiments with gas detector. (6000 proportional counter built) • Silver proportional counter: Pulse neutron flux monitoring Proposals for future: Tissue equivalent ion chambers: Total REM dose for X-rays and neutrons Large area detectors o Multi-wire proportional chamber(MWPC) o Microstrip detector o Resistive plate chamber(RPC) o Gas Electron Multiplier (GEM) based detector
SANS/SAXS/WAXS Focus Areas Microstrip Built in BARC Less sample scanning time, Solve parallax problem using curvilinear MWPC INO: • RPC Neutrino observatory: Fast, good position resolution detector (RPC) GEM: Wireless, flexible geometry, fast dimension: 3 m X 2 m • No of chambers: 11 K • Eff > 90% achieved Rigorous R&D worldwide Used in One HEP experiment. Pos res: 57 micron, timing: 12 nsec
q TLFC configuration: Special detectors 233 U fission counters (up to 1 cps/nv) LEU fission counters (up to 3 cps/nv) q Al 2 O 3 based phosphor, KMg. F 3: Ce 3+, Si. O 2: Cu, Al. N, Dosimetry for gamma, fast and thermal neutrons q Gamma compensated Pt-Bi SPNDs : Overcomes anomalous behaviour of Pt SPNDs q Inconel SPNDs: Fast, low burn-up, long life. Coiled detectors for future reactor applications to be developed q Bubble detector: Personal dosimeter, Measurement of pulsed neutrons, On-line neutron area monitor
Discussions: detector vision Two clear areas emerge from DAE perspective: Radiation monitoring: Reactor program (with very stringent specifications) Beam monitoring and other diagnostics (accelerators) Materials study (material research is a thrust area in DAE) Plasma monitor reduces import component significantly (e. g. Si), Industry collaboration is crucial. Quest of knowledge (NP, SSP, HEP, Astrophysics): We started with smallest scale: next decades will see DAE participating as a core member in these experimental program. INO will be project of next decade. A dedicated detector research facility (institute? ) for DAE need alone. Next decade should see detectors for DAE from DAE, given the strong base we have, not a distant dream
Detector Vision: need of the society Common theme: need of the society. 9 ke. V absorption radiography using GEM Medical diagonesis. X-Ray imaging: GEM, a-Si-films with scintillators, PSDs. PET: RPC Precision radiography setup using Si. 2 -D Dosimetry: GEM, RPC. Worldwide in large accelerator centres dedicated facilities are being built for development of detectors for medical applications eg. Medpix@CERN. We must have dedicated facility for R&D on Detectors for medical applications.
“ My very modest contribution to physics has been in the art of weaving in space thin wire detecting the whisper of nearby flying charged particles produced in high-energy nuclear collisions. It is easy for computers to transform these whispers into a symphony understandable to physicists. But the whispers can also be produced by radiations widely used in biology or in medicine, such as electrons from radioactive elements or X-rays. In this last case it is possible to reduce, by a large factor, the doses of radiations inflicted on the patients. ” Georges Charpak, Banquet speech, Nobel Academy (1992)
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