from outside Europe: 27 CERN

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1 WORKSHOP HIGHLIGHTS RICH2007 summary in short: great VITALITY of Cherenkov Imaging Detectors! 1

2 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing p and pursuing novel approaches for Cherenkov Imaging g detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects exotic applications not discussed relevance of exporting RICH techniques and technologies for different ionizing i i particles detectors t for basic research and applications 2

3 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing and pursuing novel approaches for Cherenkov Imaging detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects 3

4 RICH2007 in FIGURES Attendance: more than 120 registered participants from 17countres countries + CERN from 4 CEI countries: 45 Argentina from outside Europe: 27 CERN 10 invited talks Israel 69 contributions 50 talks 19 posters Czech R. France Germany Greece Italy Japan Mexico Russia Slovakia Slovenia South Corea Sweden Switzerland United Kingdom USA 4

5 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing and pursuing novel approaches for Cherenkov Imaging detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects 5

6 PHYSICS & Cherenkov Imaging Detectors 1/3 particle and nuclear physics experiments based on RICH detectors (concluded experiments not included) field of Physics experiment where status presented at RICH2007 heavy and light BABAR SLAC active quark spectroscopy superbelle KEK proposal X CLEO III CORNELL active COMPASS CERN active X COMPASS2 CERN proposal future superb X PANDA GSI preparation X MIPP FERMILAB active X K physics P326 CERN proposal X B physics BABAR SLAC active superbelle KEK proposal X future superb X LHCb CERN starting X Longitudinal and transverse spin structure of the COMPASS CERN active X nucleon, generalized parton distribution function COMPASS2 CERN proposal HERMES DESY just concluded X PANDA GSI preparation X PHENIX upgrade BNL proposal quark-gluon fusion ALICE CERN starting X ALICE upgrade CERN proposal X heavy ion physics BRAMHMS RHIC active PHENIX RHIC active ALICE CERN starting X hadron properties in normal and heigh density CBM GSI preparation X nuclear matter HADES GSI active X hypernuclei PANDA GSI preparation X 6

7 PHYSICS & Cherenkov Imaging Detectors 2/3 messages: the future of a large variety of particle and nuclear physics fields strongly depends on the progress in Cherenkov Imaging Detectors Ubiquity it of the RICH detector t (D. Websadle, 16/10/07) (a part: Tevatron, LHC GPDs) the high rate capability and the high resolution demands are central High resolution & high rate demands ALICE upgrade superbelle / future superb CBM COMPASS2 PANDA NA62 This workshop series is the reference forum for the RICH community 7

8 PHYSICS & Cherenkov Imaging Detectors 3/3 Astroparticle : Cherenkov detectors are fundamental in 3 sectors, all 3 RICH Cherenkov Imaging detectors for ion identification in CR (satellite and baloon-borned borned experiments) Flying RICH2007: CREAM 2. (Solar and) cosmic ν telescopes high mass targets ( 10 9 t) use large masses of transparent media available in RICH2007: Tunka, Antares, Nemo, KM3Net 3. High energy gamma-ray astonomy Issue size versus improved photon RICH2007: MAGIC, LAGO These experiments are totally based on the detection of the Cherenkov radiation! To improve sensitivity: the size cannot grow unlimited improved photon detectors guarantee the progress in this field 8

9 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing and pursuing novel approaches for Cherenkov Imaging detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects 9

10 NOVEL APPROACHES In operation Aerogel coupled to wavelength shifter (DIRAC) Not for imaging For future applications Multiple refractive index Aerogel for proximity focusing RICH (FARICH, BELLE upgrade on ~10 ps resolutio equired: t re COMPLEMENTING or ALTERNATIVE possibilities with TOF The new concepts of DIRC family 10

11 TOF: NEW OPPORTUNITIES 11

12 the DIRC family after the pioneering experience with BABAR DIRC now DIRC detectors regarded as favourite scheme for the future of B-factories Panda the upgrade of the DIRC concept is via time measurements with unprecedented resolution TRENDS TOP concept: save on the number of photon detector channels Focalised TOP: include chromatic correction Focusing DIRC; push resolution via chromatic corrections PROVEN! Schemes derived from TOP and focusing DIRC proposed for Panda RELATED TECHNICAL ASPECTS Photon detectors t allowing t resoultion 50 ps see later the t 0 quest development of adequate high rate electronics to preserve the t resolution figures in extended systems ( 10 5 ch.s) 12

13 TO LIMIT CHROMATIC DISPERTION ocity (m/ /ns) Light propagation velocity inside quartz QE(%) 40 Bi-alkali Multi-alkali 35 GaAsP G roup vel Wave length (nm) photon lambda(nm) HAMAMATSU MCP-PMT,, 4 ch.s GaAsP photo-cathode ( alkali p.c.) Higher quantum-efficiency at longer wavelength less chromatic error Prototype shows the enough performance Gain = 0.64x106, TTS = 35ps for single photon High Q.E. (>40% at 500nm) (K. Inami) 13

14 FOCUSING TOP y Virtual readout screen: TOP photon detector remains a compact one PMT Fo ocus Mirro r 14

15 FOCUSING DIRC A general upgrade of the DIRC concept: Future DIRC needs to be smaller and faster Focusing and smaller pixels can reduce the expansion volume by a factor of 7-10 Faster PMTs reduce sensitivity to background. Photon detectors Hamamatsu H-9500 MaPMTs Burle-Photonis MCP-PMT Αll pixels: Correction off: Correction on: mineral oil 3mm pixels only: Correction off: Correction on: σ=10.4mrad σ=6.9mrad σ=7.5mrad σ=5.5mrad Position 1 Lpath 10m θ c (mrad) θ c (mrad) θ c (mrad) θ c (mrad) 15

16 PANDA schemes mirro ors 20mm fused silica radiator disc FOCUSING LIGHT GUIDE TIME OF PROPAGATION dichroic mirrors as colour filters allows two wavelength bandshigher photon statistics small wavelength bands minimise dispersion effect + optimised photocathodes mirrors give different path lengths self timing design single photon resolution σ t ~30-50ps required 16

17 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing and pursuing novel approaches for Cherenkov Imaging detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects 17

18 SINGLE PHOTON DETECTORS 1/2 single photon detectors the CENTRAL QUESTION since the beginning of the RICH era established single photon detectors t (used in experiments): PMTs (HERMES, NA62, MIPP), MAPMTs (COMPASS), hybride PMT with ihsidid diodes and dluminescent screens (*) (Tunka) MWPCs with CsI photocathodes (COMPASS, ALICE) starting now to be used: HPDs (LHCb) (*) GEMs with CsI (HBD in Phenix) Also considered: Hamamatsu flat pannels (CBM) hybride detectors (*) 18

19 SINGLE PHOTON DETECTORS 2/2 R&D the requests: QE: high QE (above standard PMT photocathodes having peak-values of %) r: rate capabilities (> 100 khz/ mm 2 ) t: time resolution below 100 ps B: insensitivity to high magnetic fields (B=1T and more) $: reasonable costs to make large systems affordable L: Large area and wide angular acceptance of each single sensor the approaches: Poly- and nano-crystalline diamond-based photocathodes (QE) Hybrid avalanche photodiodes HAPD (B) Si photomultipliers (QE,r,t,B) Microchannel plate (MCP) PMTs (B,t) THGEMs + CsI (r, B, $) Resistive GEMs and THGEMs + CsI (r, B, $) ARCALUX ($) Large, wide aperture (hybride) PMTs (L) 19

20 SINGLE PHOTON DETECTORS Comparison criteria PDE better than QE LHCb HPD production PDE = E GEOM x QE x E by DEP pe also folding with effective Cherenkov spectrum <QE> per delivery batch 270 nm (per batch) essential! nevertheless increased QE remains a central goal average QE [%] <QE> per batch running <QE> (batch 0-25) 27 - Which margin for the improvements of standard 25 photocathodes in vacuum devices? 23 - The necessity of deeper contacts and positive 21 feedback loops with industry - Exceptional QE in Si-PMs; parameter optimization to preserve it in PDE QE [%] RMS of batch spread batch no. Batch number 270nm> = 30.8% 20

21 MAPMTs COMPASS RICH-1 upgrade second MAPMT RICH after HeraB Hamamatsu 16 anode PMTs (R7600) NEW:UV extended glass coupled to quartz optics NEW: Ratio 1:7 = photocathode s. / telescope entrance s. ($!) wide angular acc. (± 9.5 degrees) NEW: high sensitivity pre-amplifier and fast electronics NEW : dead zone: 2% even with 46 mm pitch 56 ph.s / ring at saturation time resolution better than 1 ns Cost: 1 M / m 2 in spite of the large angular acceptance, not adequate for large transverse size detectors which would require higher angular acceptance SUCCESSFUL UPGRADE, BUT NOT THE ULTIMATE SOLUTION FOR RICHES WITH LARGE TRANSVERSE DIMENSIONS 21

22 LARGE SENSITIVE AREAS GASEOUS PHOTON DETECTORS photoconverting vapours are no longer in use, a part CLEO III (rates! time resolution!) the present is represented by MWPC with CsI the first prove (in experiments!) that coupling solid photocathodes and gaseous detectors works Severe recovery time (~ 1 d) after detector trips Aging ion feedback! Moderate gain: 10 5 The way to the future: ion blocking geometries Future started t with HBD in PHENIX windowless!!! GEM/THGEM allow for multistage detectors With THGEMs: High overall gain pe det. efficiency! Good ion blocking (up to IFB at a few % level) MHSP: IFB at 10-4 level: opening the way to the physicists dream (Philosopher s Stone): Gaseous detectors with solid photocathodes for visible light 22

23 THE RELEVANCE OF HIGH GAINS Polya functions Gain 10 4 Gain 10 6 Threshold always critical! Limited pe detection efficiency With good electronics: threshold no longer critical good pe detection efficiency 23

24 HBD GEM-based photon detectors scheme invented and proved at Weizmann Operation in CF4 also proven in lab windowless detector substantial increase in λ range: down to 120 nm (10 ev) HBD first application noise performance: pedestal rms 0.15 fc or 0.2 p.e. at a gain of 5000 Photon detector 1 m 2 EXPECTED: ~36 photoelectrons at saturation N0 = 840 cm -1 looking forward for results! Mylar window Honeycomb (paper) panels Sealing frame Side panel Service panel FEEs 100ns PA Readou t plane HV terminals Triple GEM module with mesh grid 24

25 TRENDS in PHOTON DETECTION More and more hydride devices HPDs, focalized and proximity focus HAPDs QUASAR 370 photon counting! Si- PMTs Characteristics and status see J. Haba s review spectacular results when the experimental challenge is not imaging based on single photoelectrons (MAGIC) classical Cherenkov imaging principle proved noise control still a central issue! Radiation hardness and noise Environmental conditions and noise pattern identification resolution S/B ~ effective number of pe decreased by this factor 25

26 Si-PMs in MAGIC 26

27 Si-PM studies for BELLE PID upgrade Si-PM Handles: Light guides Smaller t window 27

28 OUTLINE OUTLINE RICH2007 figures the key role played by Cherenkov Imaging detectors in a variety of fields in particle, nuclear and astroparticle physics proposing and pursuing novel approaches for Cherenkov Imaging detectors the numerous R&D studies for single photon detectors the variety of skillful proposals and solutions for RICH related technological aspects 28

29 TECHNOLOGICAL ASPECTS Radiator materials aerogel material (BELLE upgrade, super B factory) radiation hardness of fused silica (future DIRCs in PANDA) gas systems (C-F gasses: DIRAC, LHCb) Mirrors & optics construction of light mirrors (LHCb) Mirror reflectivity (MAGIC) fl ( G ) Mirror alignment monitoring (COMPASS, LHCb) Mirror alignment adjustment (COMPASS) (Dichroic) mirrors for focusing DIRC and TOP approaches Detector control (LHCb) Patter recognition and PID algorithms Making use of tracking information (ALICE, COMPASS, LHCb) w/o tracking information (HTA, ALICE) HL trigger capabilities (LHCb) calibration software (LHCb) for specific applications for the TOP concept for the focusing aerogel RICH El t Electronics i Self-triggered read-out electronics (CBM) Fast electronics (COMPASS) RICH2007,, Trieste 15RICH /10/

30 TECHNOLOGICAL ASPECTS Radiator materials aerogel material (BELLE upgrade, super B factory) radiation hardness of fused silica (future DIRCs in PANDA) gas systems (C-F gasses: DIRAC, LHCb) Mirrors & optics construction of light mirrors (LHCb) Mirror reflectivity (MAGIC) Mirror alignment monitoring (COMPASS, LHCb) Mirror alignment adjustment (COMPASS) (Dichroic) mirrors for focusing DIRC and TOP approaches Detector control (LHCb) Patter recognition and PID algorithms Making use of tracking information (ALICE, COMPASS, LHCb) w/o tracking information (HTA, ALICE) HL trigger capabilities (LHCb) calibration software (LHCb) for specific applications for the TOP concept for the focusing aerogel RICH Electronics Self-triggered read-out electronics (CBM) Fast electronics (COMPASS) 30

31 RADIATOR MATERIALS the low momentum domain <10 GeV/c: Aerogel vs quartz Aerogel Separation up to higher momenta (but Rayleight, transmission ) Lower density smaller perturbation of particle trajectories, limited number of photons (variable index of refraction to partially overcome) Progresses in aerogel production Quartz θ saturation ti at lower momenta (but removing chromaticity ) it high density large number of photons, trajectory perturbation excellent transparency, excellent mechanical characteristics detectors of the DIRC family the high momentum domain > 10 GeV/c: gas radiators low density gasses for the highest momenta or the best resolutions (NA62) Still a major role played by C-F gasses; availability of C4F10 Gas systems for purity (transparency) and pressure control 31

32 AEROGEL NEWS 1/2 News from NOVOSIBIRSK PRODUCTION STATUS ~2000 liters have been produced for KEDR ASHIPH detector, n= blocks mm have been produced for LHCb RICH, n=1.03 ~200 blocks mm have been produced for AMS RICH, n=1.05 n= aerogel lfor SND ASHIPH detector n=1.008 aerogel for the DIRAC 3-4 layers focusing aerogel High optical parameters (Lsc 43mm at 400 nm) Precise dimensions (<0.2 mm) 32

33 AEROGEL NEWS 2/2 News from JAPAN 3rd generation:2002- A-RICH for Belle upgrade (new solvent) Home made! largely improved transparency very good homogeneity both density and chemical comp. 2-layer samples 4 th generation: high density aerogel n = 1.22 n = prototype result with 3 GeV/c pions 2005 sample 2001 sample n~1.050 photon yield is not limited by radiator transparency up to ~50mm 160mm n = x35x10mm 3 transmission length: 18mm at 400nm transmission length(400nm): 46mm 33

34 MIRRORS & OPTICS No longer a pure high momentum need! Focusing TOP High momenta and large acceptances Mosaic-type mirror wall Poor effectiveness of the off-line corrections the quest for monitoring and remote corrections of the mirror alignment Low momenta, focalised DIRC and TOP approaches NEW! 40cm 2cm Spherical mirror (R=5m) Optical elements to enlarge the effective area of the photocathode PMTs (COMPASS, NA62) Si PM 34

35 ELECTRONICS for RICHes a central question NOW and more in the FUTURE: read-out electronics with high resolution time measurements in extended systems MAPMT read-out upgraded COMPASS RICH-1: 10 k ch.s, DEAD TIME free, σ t = 107 ps trigger rates up to 100 KHz 1 TDC ch = ps ANALOGIC READ-OUT In the past: threshold control in low gain gas detectors almost exponential shape of the Polya distribution for low gains In the future: Larger use of Si photon detectors (pure Si or hybrid ones): photoelectron counting implies analogic read-out 35

36 MIRROR ALIGNMENT THE PROBLEM mirror wall, 21 m 2, 116 mirrors parallel photons are reflected by different mirrors, not identifiable It can marginally be corrected off-line 5 pixel shift is equivalent to 0.7 mrad tilt 36

37 WAYS OUT 1. monitor misalignments CLAM: on-line monitoring of mirror alignment MIRROR ALIGNMENT 5 pixel shift is equivalent to 0.7 mrad tilt LHCb: Laser monitoring system 2. correct for misalignments remote angular regulation compatible with gas purity using PIEZO ACTUATORS mirror rear side regulation: 2 orthog. movements 37

38 Patter recognition and PID good software packages are essential elements of a detector particularly p y true for RICH detectors from the review and the contributions, 2 messages 1. pattern and PID based on tracking information a al Ypsilantis-Seguinot widely used essential in crowded environments 2. best PID algorithms are based on both Likelihood k l h d algorithms l h and d Hough Transforms by product: easy handling of odd patterns COMPASS 300 TOP (ch/25ps) 250 TOP STAR BABAR DIRC RICH2007,, Trieste 15RICH /10/ x 0 50 (mm)

39 WORKSHOP HIGHLIGHTS Vitality is there! The vitality of Cherenkov detector discipline is due to the enthusiastic work of all of us Thank you for this common effort! 39