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LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 1 Summary of Calorimetry sessions at ECFA-DESY ‘02

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1 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 1 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

2 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 2 Distributions discussed at LCD-Soft workshop at NIU, Nov 2002. Deposited energy by 400 GeV electron in VFE News CALICE ECAL silicon-tungsten study (J-C. Brient, CALICE)

3 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 3 Impact from dead wafers Impact from non-uniformity (inter-calibration) Response non-uniformity in ECAL (%) Fraction of dead wafers in ECAL (%) ECAL silicon-tungsten study CALICE

4 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 4 400 GeV electron Simulation of the maximum energy deposited by e.m. shower in a (10  m) 3 of silicon (input transistor of preamp. in VFE) Discri. cut Following this crude estimation, VFE inside seems possible Definite conclusion with VFE in beam !!! ECAL silicon-tungsten study CALICE

5 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 5 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 ECAL silicon-tungsten study End 2003 – ready for first cosmics test Summer 2004 – ready for first test beam

6 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 6 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.

7 RPC design for DHCAL

8 R&D plans 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 IHEP Apr03

9 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 9 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.

10 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 10 Energy resolution Response for K 0 L

11 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 11 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.

12 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 12  E/E = 6% + 101% /  E  E/E = 0% + 160% /  E Energy resolution for different Cell sizes

13 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 13 Some resolution improvement when increasing the efficiency The improvement has almost the same order of magnitude for different energies Read-out efficiency

14 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 14 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

15 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 15 Number of additionally fired cells is calculated through Poisson distribution Energy resolution practically does not depend on signal overlapping

16 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 16 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.

17 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 17 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.

18 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 18 Prototype description (Slightly reduced to cope with budget:45) Pb/Sc + Si Scintillation light transported with WLS σ tail fibers: Cell separation with grooves in Sc. plates with Tyvec strips inside Coupled with clear fibers (to PM): (Reduced to cope with budget:252)

19 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 19 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)

20 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 20 Test beam * results Set up: 2 planes Si μstrip telescope 2 trigger Scintillators Calorimeter first segment (2 X 0 ) read by PM 1 Si pad detector *CERN SPS H4 beam cal e - 40 / 50 GeV π 50/150 GeV (used as m.i.p.)

21 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 21 Test beam results CALORIMETER (2.1 X 0 ) 4 layers m.i.p.→check light output and uniformity in Light collection: Ratio signal/sigma →lower limit for photoelectrons N phe >5.1 /layer → cal(45layers):>220 phe/m.i.p. ± 20% good uniformity: Simulated Light collection disunifority(20%)

22 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 22 Test beam results: Si pad detector (Energy Measurement) No saturation! m.i.p. Signal >4 sigmas (coherent noise subtraction not optimized) Pedestals e/  behaviour clearly different 50 GeV electrons 150 Gev  50 GeV electrons

23 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 23 Test beam results: Si pad detector (Position Meas.) 10 GeV simulated electrons Position resolution < 2mm in agreement with Monte Carlo 50 GeV electrons 40 GeV electrons

24 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 24 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(?)

25 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 25 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)

26 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 26 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.

27 New Results and further Plans for the TESLA Tile HCAL What did we establish so far ? 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

28 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 28 New Results and further Plans for the TESLA Tile HCAL 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 What did we establish so far ?

29 New Results and further Plans for the TESLA Tile HCAL What are the next steps ? 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

30 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 30 more on scintillators Best scintillator: is BC-408 on base of Poly-Vinyl-Toluene >>> 25 pe/tile(5x5 cm 2 ) measured in Hamamatsu MA-PM >>> about 600 photons on photocathode but BC-408 is rather expensive, need 6950 m 2, ~ 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

31 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 31 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

32 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 32 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. TFS wrapped with 3M-Superreflector a b c

33 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 33 Detailed investigation of available photodetectors: APD’s: gain 300-500 CMS-type, 5x5mm 2 S5344, 3x3mm 2, S5355, 5x5mm 2 S8664-55, 5x5mm 2 S8550, 32 pixels of 1.6x1.6mm 2 Si-PM’s: gain 10 5 MEPHI, 1x1mm 2, MA-PM’s: gain 10 6 H8711-10, 16 pixels of 4x4mm 2 R5900-00M16, 16 pixels of 4x4mm 2 800-1200 Photodetectors needed (APD or MA-PM’s) 3200-4800 Si-PM’s of 1x1mm 2 needed alternatively More on photodetectors

34 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 34 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 mm 2 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

35 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 35 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 cm 2, 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 The MINICAL studies, 1

36 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 36 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  T and  U shift To study: LY (>15pe) Uniformity (<3-4%) Gain Noise separation from MIP peak (>4  ) Stability (<1%) Calibration precision with MIP’s (< 2%) Useful rates (> 0.1Hz?) The MINICAL studies, 2

37 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 37 The MINICAL studies, via web Install in minical: different scintillators fibres photodetectors preamps supply voltages trigger conditions Look for: gain stability signal width signal noise separation calibration with MIP’s run parameter file LED monitoring Study the results of up to 64 channels with MIP’s ITEP LPI MEPHI Prague Protvino DESY.... At DESY: via web: Start run with new components or new settings all 24 hours. very similar later during prototype running in

38 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 38 The structure (from top to bottom): plastic air bag layer, 500  m ? 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 Tile-Detector-Cassette a a= 6.5 cm b=1.12-1.67m c= 2.75 m b c The structure:

39 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 39 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 m 2, 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 ?)

40 LC-cal mtg, 09-12-02ECFA-DESY 2002 ws summary Dhiman Chakraborty 40 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

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