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HERMES: Forward RICH Detector

HERMES: Forward RICH Detector. Evaristo Cisbani / INFN-Rome Sanità Group Most of the slides from R. De Leo and D. Ryckbosch. EIC Detector Workshop JLab : 4-5/June/2010. Overview Performances Inheritance HERMES RICH in SBS HallA Aerogel RICH in CLAS12. HERMES Experimental Setup.

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HERMES: Forward RICH Detector

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  1. HERMES: Forward RICH Detector Evaristo Cisbani / INFN-Rome Sanità Group Most of the slides from R. De Leo and D. Ryckbosch EIC Detector Workshop JLab : 4-5/June/2010 Cisbani / HERMES RICH • Overview • Performances • Inheritance • HERMES RICH in SBS HallA • Aerogel RICH in CLAS12

  2. HERMES Experimental Setup e+N e’ + h +X in DIS Cisbani / HERMES RICH 2 identical RICH modules

  3. Hadron PID: HERMES RICH Identify p, K and p from 2 to >12 GeV/c 5.5 GeV K+ C4F10 gas REAL DATA from NIMA 479 (2002) 511 14.6 GeV e- 1.5 GeV p- Cisbani / HERMES RICH aerogel Two radiators: aerogel and gas PMTs as photon detector Focusing Optics gas Reference: NIMA 479 (2002) 511-530

  4. HERMES RICH module layout 147 63 101 180 48 Cisbani / HERMES RICH 126 281 unit is cm

  5. Radiators Aerogel Dirk Rickbosch – DESY07 (Absorb otherwise randomly reflected photons) (cut photons with l<300 nm) Cisbani / HERMES RICH Refractive Index n(633 nm)=1.03 Scattering//Absorption Length L(400 nm) = 2.3 cm C4F10 Gas at STP n(633 nm)=1.00137

  6. Optics not aligned Cisbani / HERMES RICH aligned

  7. Photon Detector plane ¾ inch diameter Cisbani / HERMES RICH + single PMT 100 mm mMetal sheet wrap up to 90 G magnetic field Size of the detector and diameter of the PMT defined by cost constraint

  8. Light Collection Nov 98 Dirk Ryckbosch – DESY07 Funnel collection efficiency Cisbani / HERMES RICH

  9. Electronics Cisbani / HERMES RICH • VME based, 20 MHz bus from front-end to VME • less than 30 ms to transfer data to VME • able to keep data up to 800 ns (selectable) since trigger • down to 50 ns gate width • No time information

  10. One RICH Module during installation Cisbani / HERMES RICH

  11. p K Rings and identification probability matrix Cisbani / HERMES RICH

  12. Reconstructed angle and number of photoelectrons electrons efficiency Rayleigh scattering ~l-4 aerogel aerogel saero=7.6 mrad Npe = 10 Cisbani / HERMES RICH sgas=7.5 mrad gas gas Npe = 12

  13. Exp. angle resolution (%) * Hamamtsu R7600 **Better aerogel transmittance, L(400 nm)~1 cm  reduced thickness (e.g. 4 cm) Cisbani / HERMES RICH HERMES: Largest error from pixel size; by design (cost-performance tradeoff)

  14. n qC ring n (e+>5GeV) plot vs day HERA shutdown Cisbani / HERMES RICH

  15. average n (e+>5GeV) Dn ~ 0.0003 Dn ~ 0.0003 Cisbani / HERMES RICH Very stable Dn ≈ 3 *10-4 in 10 years! Dn ≈ 1*10-4 in the last 5 years!

  16. one RICH module preserved @ UVa (thanks to G. Cates) HERMES RICH Cisbani / HERMES RICH Aerogel Spare Now stored at UVa under safe/controlled conditions + additional wall of spare Aerogel from the other module.

  17. SIDIS (Cond. appr. Exp.): Setup and parameters e+3He→e’+p(K)+X BB: e-arm at 30o  = 45 msr GEM Tracker Gas Cherenkov Shower  GMn/PR-09-019 SBS: h-arm at 14o  = 50 msr GEM tracker excellent PID / RICH Hadron CALO Cisbani / HERMES RICH Event rate: ~104×HERMES 60 days of production expected stat. accuracy: 10*better than HERMES on proton Beam: 50 A, E=8.8 and 11 GeV (80% long. Pol.) Target: 65% polarized 3He  GEn(2)/PR-09-016  Luminosity: 1.4×1037 cm-2s-1

  18. HERMES RICH in SBS (SIDIS Exp.) Cisbani / HERMES RICH (old GEM setup)

  19. RICH detector in CLAS12 • Main Requirements: • separation up to 8 GeV/c • from 5 to 40 degree polar angle • p/K rejection>100 (<1% p contamination) • minimize material budget Substitute 2 LTCC sectors with a RICH detector Possible option: aerogel + SiPM (with time correlation) RICH Cisbani / HERMES RICH • ratio K/ ~ 0.1-0.15 From. M. Contalbrigo

  20. Aerogel characteristics improvements Cisbani / HERMES RICH 2005 IEEE Nuclear Science Symposium Conference Record M. Tabata et al.

  21. Aerogel RICH with 2 x mirrors 35o Proximity between 5 and 10 degree Mirrors acts at polar angle above 10 degree Doubled detector area Focusing mirrors to reduce detector area to ~ 2 m2/sec Relax performance requests for the external half (lower p) Increase pad size Reduce channel number Standard PMTs 25o Focusing mirror 20o Photon detectors 10o 5o Target Beam Cisbani / HERMES RICH Similar to i.e. LHC-b !!! From. M. Contalbrigo

  22. Aerogel RICH with mirror & semi-reflective layer 35o 25o Proximity up to 15 degree Mirror above 15 degree High density of hits check with track multiplicity Too high absorption in aerogel semi-reflective mirror Reduced collection efficiency (bi-alcali q.e. 25 %) ultra bi-alcali q.e. 45 % cost increases by 50 % 20o 10o 5o Target Semi-reflective mirror Beam Photon detector Cisbani / HERMES RICH New concept !!! From. M. Contalbrigo

  23. Summary • HERMES RICH designed and built in ~2 years • Configuration: Mirror Focusing, dual radiator, with PMT readout • First RICH using aerogel radiator in a real experiment • Very stable performance in 10 years • HERMES RICH “inheritance”: • H-RICH for SIDIS physics in SBS/Hall A • CLAS12 p-K-p PID detector (work in progress!) • Presently available improvements (at reasonable price): • Better aerogel (higher transmission and reduced scattering) • Smaller photon detectors: multianode PMTs, SiPM (with time information) • Improved mirrors Cisbani / HERMES RICH Recent RICH 2010 conference: http://rich2010.in2p3.fr/

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