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Summary of Calorimetry sessions at ECFA-DESY ‘02 http://www-hep2.fzu.cz/ecfadesy/Talks/Calorimetry. Dhiman Chakraborty dhiman@fnal.gov Northern Illinois University (NIU)/ Northern Illinois Center for Accelerator and Detector Development (NICADD) http://nicadd.niu.edu/
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Summary of Calorimetry sessions at ECFA-DESY ‘02 http://www-hep2.fzu.cz/ecfadesy/Talks/Calorimetry Dhiman Chakraborty dhiman@fnal.gov Northern Illinois University (NIU)/ Northern Illinois Center for Accelerator and Detector Development (NICADD) http://nicadd.niu.edu/ American LC calorimetry meeting 09 Dec, 2002 ECFA-DESY 2002 ws summary Dhiman Chakraborty
CALICE ECAL silicon-tungsten study (J-C. Brient, CALICE) Distributions discussed at LCD-Soft workshop at NIU, Nov 2002. Deposited energy by 400 GeV electron in VFE News ECFA-DESY 2002 ws summary Dhiman Chakraborty
ECAL silicon-tungsten study CALICE Impact from non-uniformity (inter-calibration) Impact from dead wafers Response non-uniformity in ECAL (%) Fraction of dead wafers in ECAL (%) ECFA-DESY 2002 ws summary Dhiman Chakraborty
ECAL silicon-tungsten study CALICE Simulation of the maximum energy deposited by e.m. shower in a (10m)3 of silicon (input transistor of preamp. in VFE) Discri. cut 400 GeV electron Following this crude estimation, VFE inside seems possible Definite conclusion with VFE in beam !!! ECFA-DESY 2002 ws summary Dhiman Chakraborty
ECAL silicon-tungsten study CALICE Tungsten in production at ITEP and IHEP Silicon wafers In progress at IP-ASCR (See Ondrej) and MSU (very good IY for the first 30 wafers) VFE in test for final design at Orsay LAL DAQ in design in UK (VME) some study on use of PCI (LLR) or even USB slot (SNU) !!! Mounting / final test bench in design in at LLR End 2003 – ready for first cosmics test Summer 2004 – ready for first test beam ECFA-DESY 2002 ws summary Dhiman Chakraborty
DHCAL R&D in Russia: status & plans(V. Ammosov) • Tuning of RPC performance • Decided to use glass for anode and cathode • Decrease the charge in the gas gap • Aim: minimize aging effects and maximize rate-handling capability. • Joint adjustment of detector and RO electronics. ECFA-DESY 2002 ws summary Dhiman Chakraborty
design and tests of approach-0 for RO electronics (step 1) Dec02 • tuning of RPC performance to Dec02 decrease the gap charge • design of a small RPC plane Dec02 • construction of this plane with a few hundred RO channels (step 1) Mar03 • beam tests of this plane in IHEPApr03 R&D plans
DHCal Energy Resolution(K. Beloous) • Each distribution is fitted by a Gaussian • Fit is iterative in the specified interval • / is used as E resolution • Some problems at low energies. • The results of the fitting procedure is not stable with respect to changing low limit of the fitting region. ECFA-DESY 2002 ws summary Dhiman Chakraborty
Response for K0L Energy resolution ECFA-DESY 2002 ws summary Dhiman Chakraborty
Cell size Number of hits strongly depends on the size of the cell. It reaches rather small value of 17 hits for cell size 5 cm. This leads to some dependence in energy resolution, more pronounced at low energies. ECFA-DESY 2002 ws summary Dhiman Chakraborty
E/E = 6% + 101% / E E/E = 0% + 160% / E Energy resolution for different Cell sizes ECFA-DESY 2002 ws summary Dhiman Chakraborty
Read-out efficiency • Some resolution improvement when increasing the efficiency • The improvement has almost the same order of magnitude for different energies ECFA-DESY 2002 ws summary Dhiman Chakraborty
Signal overlapping • Charge leakage - ionization produced by a particle could induce charge not only on the nearest Pad but on some of it neighbors • Crosstalk - read-out of the channel could cause other channels to be fired under assumption that signal overlapping does not depend on particle energy or position and therefore stays the same for each hit ECFA-DESY 2002 ws summary Dhiman Chakraborty
Number of additionally fired cells is calculated through Poisson distribution • Energy resolution practically does not depend on signal overlapping ECFA-DESY 2002 ws summary Dhiman Chakraborty
Conclusion • Some obvious dependencies of energy resolution • decreasing when the cell size increases • small improvement when the read-out efficiency increases • Energy resolution practically does not depend on signal overlapping • Choosing of the cell size can done after studying the reconstruction. ECFA-DESY 2002 ws summary Dhiman Chakraborty
The tile Scintillator-Si LC cal project(P. Checchia, INFN) • Prototype description • Production • Beam test results • Future plans • A lot of interesting material, see original slides online. ECFA-DESY 2002 ws summary Dhiman Chakraborty
Detector Assembly: 45 Layers calorimeter prototype completely built and ready for test Fibres grouped into 25x4 bundles making a 4-fold longitudinal segmentation. Slots for the insertion of the 3 Si pad planes (Motherboard). Mechanical support for photodetectors almost ready (Frascati) ECFA-DESY 2002 ws summary Dhiman Chakraborty
cal beam Test beam* results • Set up: • 2 planes Si μstrip telescope • 2 trigger Scintillators • Calorimeter first segment (2 X0) read by PM • 1 Si pad detector e- 40 / 50 GeV π 50/150 GeV (used as m.i.p.) *CERN SPS H4 ECFA-DESY 2002 ws summary Dhiman Chakraborty
4 layers m.i.p.→check light output and uniformity in Light collection: Ratio signal/sigma →lower limit for photoelectrons Test beam results CALORIMETER (2.1 X0) Nphe>5.1 /layer → cal(45layers):>220 phe/m.i.p. ± 20% good uniformity: Simulated Light collection disunifority(20%) ECFA-DESY 2002 ws summary Dhiman Chakraborty
Test beam results: Si pad detector (Energy Measurement) 50 GeV electrons m.i.p. Signal >4 sigmas (coherent noise subtraction not optimized) Pedestals No saturation! e/p behaviour clearly different 50 GeV electrons 150 Gev p ECFA-DESY 2002 ws summary Dhiman Chakraborty
Test beam results: Si pad detector (Position Meas.) Position resolution < 2mm in agreement with Monte Carlo 10 GeV simulated electrons 40 GeV electrons 50 GeV electrons ECFA-DESY 2002 ws summary Dhiman Chakraborty
Future Plans • insert Si planes (this month) • go to test beam (low energy Frascati, high energy DESY/CERN) • analyse two particle impact • substitute the absorber: Pb to W (next year)(?) • study new optical device (i.e. multianod PM’s) • combined test with HCAL(?!) • Why do not insert other (Prague) Si detectors(?) ECFA-DESY 2002 ws summary Dhiman Chakraborty
Conclusions • The proposed prototype is going to be completed (just insert Si planes) • A preliminar beam test at CERN with a partial set up gave reasonable and incouraging results • Tests with the complete detector are necessary to answer to all questions (be patient for some months) • …. but it they will be successfully answered, why do not include a calorimeter made following this technique into the general LC simulation and Pattern recognition? (this is also a PRC recommendation) ECFA-DESY 2002 ws summary Dhiman Chakraborty
TESLA tile Hcal: status and plans(V. Korbel, DESY) • Many interesting ideas and results, see original slides online. • Also another talk about Korbel’s findings from his visits to several industrial vendors in Russia. ECFA-DESY 2002 ws summary Dhiman Chakraborty
What did we establish so far ? New Results and further Plans for the TESLA Tile HCAL • Found: • scintillators with sufficient light yield • tile reflectors with >98% reflectivity • WLS fibres with acceptable secondary light production • TFS coupling geometry with good LY and response uniformity • a couple of photodetectors with good signal/noise ratio for MIP’s • a half dozen preamp prototypes are in design or available Documented in: V. Korbel, The Tile-HCAL Calorimeter for the TESLA Detector, a Status Report, CALOR2002, Pasadena, March 2002, http://3w.hep.caltech.edu/calor02 http://www.desy.de/~korbel/see/pasadena.ps V. Korbel, Status report on the TESLA Tile-HCAL, ECFA-DESY workshop, St. Malo, April 2002, http://www-daphnia.cea.fr/ecfadesy-stmalo/Sessions/korbel/ppt http://www.desy.de/~korbel/see/stmalo.ps
New Results and further Plans for the TESLA Tile HCAL What did we establish so far ? continued........ J.Cvach, Calorimetry at a Future e+e- Collider, ICHEP02, Amsterdam, July 2002, http://www.desy.de/~korbel/see/ichep02-cvach.ps V. Korbel, Progress Report on the TESLA Tile-HCAL, LCWS2002, Jeju Island, Korea, September 2002, Proceedings http://www.desy.de/~korbel/see/lcws2002_korbel.pdf The CALICE Collaboration, Progress Report on Calorimeter R&D for the Future Linear Collider, Memorandum from the CALICE Collaboration to the DESY-PRC, Oct. 2002 http://www.desy.de/~korbel/see/PRC_Oct2002_docu.pdf V. Korbel for the TESLA Tile-HCAL group, The Tile-HCAL Calorimeter for the TESLA Detector, a Status Report on the R&D-Studies for the DESY-PRC, Oct. 2002 http://www.desy.de/~korbel/see/tile-hacal-rd2002. 31 pages, with a lot of further references, a draft for a NIM or DESY paper ECFA-DESY 2002 ws summary Dhiman Chakraborty
What are the next steps ? New Results and further Plans for the TESLA Tile HCAL • Study: • performance and improvement of cheaper Russian scintillators • optimisation ideas for the optical transmission path • tile production technologies: casting, extruding, machining... • optimal tile sizes, arrangement in detector layers, granularity of cells • final design of the HCAL prototype structure • improvement of possible photodetectors in performance, package density and cost • appropriate preamps to be optimised for the different photodetectors • operation of a pre-prototype (mincal) at DESY
more on scintillators • Best scintillator: • is BC-408 on base of Poly-Vinyl-Toluene • >>> 25 pe/tile(5x5 cm2) measured in Hamamatsu MA-PM • >>> about 600 photons on photocathode • but BC-408 is rather expensive, • need 6950 m2, ~ 36 t • Russian scintillators: • (Protvino and Vladimir) • production factories and good experience available • scintillator is 5x cheaper than Kuraray, Bicron • LY is about 60-70%, • Cleaner material: Dow Chemical STYRON 663 (P-Nr 35886) • better surfaces ? • investigations to get ECFA-DESY 2002 ws summary Dhiman Chakraborty
more on fibres • ITEP: • Study again effect of varied fibre doting: • Y11(100), Y11(200), Y11(300) • find optimum • FH Friedberg: • Study 2 new Bicron fibres: • “DAYGLO”-experimental • BCF-99-06, red sensitive ECFA-DESY 2002 ws summary Dhiman Chakraborty
more on tile-fibre couplings This are the fibre coupling shapes finally selected from 10 different geometries. a,b preferred for BC-408 tiles, c for Russian PS tiles and large BC-408 tiles It turns out that proper fibre gluing in grooves is difficult, risk of deteriorating the smooth surface. b a c TFS wrapped with 3M-Superreflector ECFA-DESY 2002 ws summary Dhiman Chakraborty
More on photodetectors • Detailed investigation of available photodetectors: • APD’s: gain 300-500 • CMS-type, 5x5mm2 • S5344, 3x3mm2, S5355, 5x5mm2 • S8664-55, 5x5mm2 • S8550, 32 pixels of 1.6x1.6mm2 • Si-PM’s: gain 105 • MEPHI, 1x1mm2, • MA-PM’s: gain 106 • H8711-10, 16 pixels of 4x4mm2 • R5900-00M16, 16 pixels of 4x4mm2 • 800-1200 Photodetectors needed (APD or MA-PM’s) • 3200-4800 Si-PM’s of 1x1mm2 needed alternatively ECFA-DESY 2002 ws summary Dhiman Chakraborty
more on preamplifiers • CMS/DESY • APD’s: trans-impedance type, tested with APD’s, cheap • PM’s: voltage preamps, 10x gain, from H1 FPS, cheap • Minsk/Protvino: • 2 types tested with APD and MIP’s • 10 preamps available • 100 preamps in february 2003, ~ 3 Euro/channel • design of 16 channel multilayer PC: ~ 8000 Euro needed • OPERA/Orsay/Calice ECAL: • prototype: ~10 mm2 preamp chip, OPERA type for APD and PMs • Nov./Dec. specification of modifications, Prague/Orsay activity • than submission of test production order, ca 4000 Euro • delivery May/2003 about 15 boards with 16 preamps? • Prague: • for APD’s,see Ivos talk ECFA-DESY 2002 ws summary Dhiman Chakraborty
The MINICAL studies, 1 • MINICAL set up, November 2002 • Operation start up at 14.11.02 • Position in test beam area, • with connections from beam-test equipment • 2 trigger counters, 20x20 cm2, with own PM’s, • movable position in stack • 4 tile planes with individual TFS to insert • Tile plane: • millimeter paper to ease adjustment of TFS, • double side glue scotch to fix TFS • Connection to PD’s via ~50 cm long WLS fibres • 16 PM-channels, =1 Hamamatsu H8711-10 first • than ~ 10 APD’s with CMS/DESY-preamps • than 1 more Hamamatsu H8711-10 • also ~ 16 Si-PM’s • preamps from DESY, ITEP, Orsay, Prague ECFA-DESY 2002 ws summary Dhiman Chakraborty
The MINICAL studies, 2 • Calibration with LED pulses • Light pulses of a single LED distributed to PM’s • via additional calibration fibres • PM-masks (Prague) with 4mm hole, • to hold to 4 fibres at once: • (3 signal fibres from tiles, 1 LED fibre) • LED signal amplitude measured also • by a photodiode stable vs DT and DU shift • To study: • LY (>15pe) • Uniformity (<3-4%) • Gain • Noise separation from MIP peak (>4s) • Stability (<1%) • Calibration precision with MIP’s (< 2%) • Useful rates (> 0.1Hz?) ECFA-DESY 2002 ws summary Dhiman Chakraborty
The MINICAL studies, via web Study the results of up to 64 channels with MIP’s • Install in minical: • different • scintillators • fibres • photodetectors • preamps • supply voltages • trigger conditions At DESY: LED monitoring Start run with new components or new settings all 24 hours. via web: • Look for: • gain • stability • signal width • signal noise separation • calibration with MIP’s • run parameter file ITEP LPI MEPHI Prague Protvino DESY .... very similar later during prototype running in ECFA-DESY 2002 ws summary Dhiman Chakraborty
The Tile-Detector-Cassette c a b a= 6.5 cm b=1.12-1.67m c= 2.75 m • The structure (from top to bottom): • plastic air bag layer, 500 mm ? • support layer (steel or C-fibre) • long RO fibres • reflector layer • tile-WLS fibre arrangement • glue • reflector layer • glue • support layer (steel or C-fibre) The structure: ECFA-DESY 2002 ws summary Dhiman Chakraborty
time schedule for the HCAL prototype (2003/2004), I 1. Selection of appropriate photodetectors (APD’s and Si-PM’s) up to January, followed by ordering larger quantities for tests in minical (Febr.) 2. Selection of Russian scintillator to use, up to March 3. find optimal cell and tile sizes, from software and hardware studies, decision February 4. ordering Bicron BC-408 for the larger tile sizes, about 10 m2, up to February 5. studies and development of integrated preamplifier/shaper circuits, up to February 6. design of the PT stack, May 7. building of stack steel absorber structure > August (in ITEP ?) ECFA-DESY 2002 ws summary Dhiman Chakraborty
time schedule for the HCAL prototype (2003/2004), II 8. casting/machining of tiles or tile-plates up to September, (in factory ?, machining at DESY?) 9. a detailed tile-plate assembly concept has to be defined (July) 10. assembly of the TFS in detector cassettes, October 11. connection with photodet. and preamps, November-December 11. RO via CAMAC as long as British DAQ not available, end 2003 12. winter 2003/2004 operation studies with LED gain monitoring, and calibration studies with cosmic muons 13. setting up RO and reconstruction software up to spring 2004 14. transport to CERN in spring 2004 15. first test-beam runs at CERN in May/June 2004 ECFA-DESY 2002 ws summary Dhiman Chakraborty