VISION ON DETECTORS

Subhasis ChattopadhyaySubhasis Chattopadhyay

VECC, KolkataVECC, Kolkata

V. BalagiV. Balagi

BARC, MumbaiBARC, Mumbai

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

Based on this bright present we built our vision for luminous future

Special areas of interest for DAEReactor safety and controlHealth physics instrumentationBasic research

Detectors in DAE:- Present status

R&D Continues to improve any or all of these areas. Vision on detector development:

Improvement by newer detector materials/ technique.New uses of the detectors for the society.

Discussion based on:

Gross material properties of the media

Solid State Detectors

Gas Detectors

Scintillators and special detectors

Detectors for tomorrow

Solid State Detectors

Handling Si technology for making detectors is itself a challengeAchievements so far: Low energy to URHIC, X-ray to high-energy charged particles

Si-strip detectors (1000 modules) for CMS experiment at CERN

•Industrial participation BEL, Bangalore

Proposals for future (one step ahead): Nuclear physics:Large BARC charged particle array (108 modules) High Energy Physics:Inner tracking with compact double sided Si-Microstrip. CBM@GSI (big challenge next 10-15 yrs).SAXS/WAXS: CCD camera for study of anisotropy in materials.

Various types of solid state detectors are used:Surface Barrier Si, Si(Li), HPGe, Si-pad, Si-strip, CCD based

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.

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 in-core flux monitoring, Medical ImagingSiC: Wide dynamic range, high temp. operation (To be developed)

Solid State Detectors:- New materials

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 detectorso Multi-wire proportional chamber(MWPC)o Microstrip detectoro Resistive plate chamber(RPC)o Gas Electron Multiplier (GEM) based detector

Gas Detectors

Focus AreasSANS/SAXS/WAXS

Less sample scanning time, Solve parallax problem using curvilinear MWPCINO:

Neutrino observatory: Fast, good position resolution detector (RPC)

GEM:

Wireless, flexible geometry, fast

• RPC dimension: 3m X 2m

• No of chambers: 11K

•Eff > 90% achievedRigorous R&D worldwideUsed in One HEP experiment.Pos res: 57micron, timing: 12nsec

Microstrip Built in BARC

TLFC configuration:233U fission counters (up to 1cps/nv)LEU fission counters (up to 3cps/nv)

Al2O3 based phosphor, KMgF3:Ce3+, SiO2:Cu, AlN, Dosimetry for gamma, fast and thermal neutrons

Gamma compensated Pt-Bi SPNDs :Overcomes anomalous behaviour of Pt SPNDs

Inconel SPNDs: Fast, low burn-up, long life. Coiled detectors for future reactor applications to be developed

Bubble detector: Personal dosimeter,Measurement of pulsed neutrons,On-line neutron area monitor

Special detectors

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 reduces import component significantly (e.g. Si), Industry collaboration is crucial.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.

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 reduces import component significantly (e.g. Si), Industry collaboration is crucial.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 DAEfrom DAE, given the strong base we have, not a distant dream

Detector Vision: need of the society

Common theme: need of the society.Medical diagonesis. X-Ray imaging: GEM, a-Si-films with scintillators, PSDs . PET: RPC

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.

9 keV absorption radiography using GEM

Precision radiography setup using Si.

“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 aselectrons 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)