1. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 1 Status of the Tile-HCAL for the Detector at TESLA 1. Actual project time planning 2. Groups involved 3. The milestones to the next PRC meeting 3. Actual R&D -- DESY-LPI -- DESY-H1 -- The minical array 4. E-flow studies -- The calorimeter prototype -- Testbeam at DESY -- Testbeams CERN,...? -- Collaboration with other groups

2. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 2 Groups involved: DESY-LPI, tile-WLS fibre optimisation, Photodetectors, simulation DESY FLC activity E.Devitsin, V,K., V.Kozlov, L.Popov, S.Potashov, A.Terkulov V. Morgunov, simulation and reconstruction strategies DESY-H1, Photodet, preamps, ADC-RO, calibration, prototype simulation V.Andreev, A. Fomenko, V.K., S.Reiche, P.Smirnov, Y.Soloviev ITEP, Moscow see presentation today MEPHI, Moscow see presentation today Prague, Univ. and Academy of Science see presentation today Imperial College London and Birmingham ADC-RO,together with ECAL P. Daunkey et al. Project time planing in 2002-2004: R&D in 2002: tile-fibre optimisation signal RO photodetectors preamplifiers and shapers ADC’s, FADC’’s buffering and DAQ studies with a ‘minical’ test array technical design studies: optimise the 1m 3 prototype for HCAL upgrade the TDR calorimeter design simulation studies to optimise the calorimeter structure PRC meeting in November 2002 2003, prototype construction envisaged 2004, prototype beam tests and data collection than presentation of realistic E-flow reconstruction

3. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 3 The milestones The R&D program as reaction on demands of PRC: agreed task list from 11.11.2001, DESY 1. Period: 11.-12.2001 -----------milestone: start minical test-array set up and - test operation at DESY, few channels 2. Period: 1.-2.2002 -----------milestone: LED stability monitoring, stable photo-detector operation possible, -----------milestone: start cosmic test with minical, with increasing number of active tiles, -----------milestone: finish construction design of 1m 3 -prototype (ITEP, Prague, DESY) 3.Period: 3.-4.2002 -----------milestone: optimal HCAL cell sizes defined from simulation (DESY), -----------milestone: final results from homogeneity TF-system measurements and simulation (Prague, ITEP), scintillator, WLS, reflector, clear RO fibres fixed.

4. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 4 The milestones,2 4. Period: 5.-6.2002 -----------milestone: TF radiation hardness and ageing studies completed (Tashkent) -----------milestone: definition of final TF-RO plate geometry and RO fibre routing (ITEP) -----------milestone: operation of appropriate final Silicon Pixel PM's with preamps (MEPHI) -----------milestone: operation of all 64 PD's (CAMAC-RO) in minical (ITEP, DESY) 5. Period: 7.-8.2002 -----------milestone: build a prototype of multiplexing +ADC RO (similar to ECAL) (DESY, LPI, ITEP, IC, U-BIR) -----------milestone: minical beam-tests at DESY, 1-6 GeV e-test beam 6. Period: 9.-10.2002 -----------milestone: build a prototype of Mplx +ADC RO, (DESY, LPI, ITEP, IC, U-BIR) -----------milestone: run a complete minical, 64 channels with appropriate PD's and RO as envisaged for 1m 3 PT (ITEP and DESY), MEPHI -----------milestone: beam tests with electrons, test: energy resolution, noise, linearity,..... (all institutes) -----------milestone: test minical in a 1.2 (4 T) magnetic field, needs inquiry

5. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 5 R&D studies on the tile-WLS fibre system at DESY and LPI/Moscow Green WLS fibre: attenuation length Scintillator light yield Scintillator : uniformity of RO Reflector foil: mirror or diffraction, light yield Reflector foil: uniformity of RO Tile-WLS system: optimal coupling, light yield, uniformity >>>> 5x5 cm 2, than:...7x7....16x16cm 2 tiles Scintillator : ~6600 m 2, costs! clear RO fibre: attenuation length R&D WLS fibre: bending in small radius WLS fibre: ageing, rad. hardness WLS fibre: fibre end mirroring R&D by: DESY-H1-LPI, ITEP, Moscow, Prague R&D by: DESY-H1-LPI, ITEP, Moscow, Prague

6. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 6 Find optimal WLS fibre Optimal WLS: -short abs. length for scintillation light -long atten. length of WLS shifted light

7. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 7 Tile-reflector studies So far studies with aluminised mylar white teflon foil Tyvek paper (Papierunion) best results with Tyvek ----several layers needed ----optimisation under way >>>tests with super-reflector (95-99%, 380 nm) 3M special, “3M Radiant Mirror Film” 20% more light collected!!!!

8. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 8 Scintillator/WLS fibre coupling Fibre end polished, open Tyvek coating of tile, air gap contact tile/WLS Look for cheaper scintillator from Russia, with similar performance! sensitive PM, number of photoelectrons from Gaussian fit to all individual N ph.e. contributions (poisson distrib.)

9. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 9 original fibre RO concept as described in the TESLA-TDR. Original concept of tile plate read out 1. layer Problematic are the small scintillator tile sizes to be read out Study other possibilities

10. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 10 Search for optimal WLS-Fibre arrangement 10 different TF configurations studied WLS fibre end polished, no reflector air gap contact to tile Tyvek reflector on tile tile irradiated with collimated Ru 106 source, simple current measurement for LY Ru 106 source,  ~ 2cm

11. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 11 Uniformity scan for optimal WLS-Fibre couplings 10 configurations studied: best LY: diagonal 1/4 c fibre, RO in groove best uniformity: straight fibre, RO outside tile All tiles: 5x5x0.5 cm 3  source =1.95 mm,

12. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 12 Best coupling shape for WLS fibres? Loops ph.e./tile ph./cell 1 7.7 184 2 10.5 256 3 10.0 240 unbent fibres: along edge, no groove: 7.0 168 along groove in centre 7.7 184 diagonal fibre, groove: 10.5 256 diagonal, minimal bend: 11.0 264 Other criteria to use unbent fibres: easy to insert, less risk of damage no bending stress, > less ageing

13. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 13 Inside magnetic field: HPD’s, expensive Silicon photodiodes, low gain, noise, n.c.effects APD’s, to study Si-photomultipliers (Si-PM), see MEPHI presentation Outside field: single small photomultipliers, logistic problem, Multi-anode photomultipliers (MA-PMT’s) Some details: ---APD’s: gain of 100-500 possible, extended noise? temperature stability, gain shift of 1-2% /°C low capacities 10-15 pF possible, >> lower amplifier noise tight packing in detector requires small sizes Hamamatsu: >> 4x8 channel Si-APD array, S8550, study started in Prague, 2 x 2 mm 2 photo-cathode pixels, specimen >>> common bias voltage, <500 V, gain 100-500 (?), peak ~600nm, >> work on integration with monolithic preamps, in collaboration with MPI Munich, Eckart Lorenz ITEP, Y. Guilitski Brookhaven, G. Woody Photodetectors ~1 x 2 cm 2

14. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 14 --- Si-PM’s: Studies at MEPHI (Moscow), B. Dolgoshein, See talk at International Conference on “Advanced Technology and Particle Physics”, Como, Italy, Oct. 2001 100-4000 pixels/mm 2 with common output, pixel size is 15-50  m, C pixel ~100 fmF each pixel consists of: --drift region in inner electrical field (10-500 V/cm) --Geiger region, ~0.7  m, electrical field of 500.000 V/cm gain 0.2..20*10 5 >> --output signal is proportional to number of pixels fired: S ~N pixel fired = m*(1-e -N ph *  /m ) with: M - total number of pixels, N ph - number of photons,  - photon detection efficiency. --sensitive to single photons, --problem is dark carrier rate (-40°C, ~200 kHz) >> --first selected samples available Nov. 2002, ---photomultipliers, properties known, have to be small, compact and cheap! Photodetectors

15. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 15 ---multi-anode photomultipliers (MA-PMT’s) >>> Hamamatsu, “Metal Channel Dynodes”, types: R5900-M16 >> H6568, 4x4 channels (4x4 mm 2 each) or R5900-M16 >> H7546, 8x8 channels (2x2 mm 2 each) New versions with less cross talk, at DESY enough available to equip fully the ‘minical’, 64 channels disadvantage: sensitive to small magn. field variations, dynamic range of MA-PMT’s is only a few times 10 2, sensitive to fields > ~100 G, light transport in ~7 m clear RO-fibres outside 4T field,  att  ~ 10 m >> 50% amplitude loss, gain uniformity between anodes: typ. 1.3 cross talk in MA-PMT’s (~ 1-2%), advantage: easy access, temp. stability, small noise, gain > 10 6 >>>>> will be used for minical test array studies as first option Photodetectors

16. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 16 The dynamic range of light signals: From V.Morgunov needs to be referred to events MIP in 3 layer cell deposes ~70 MeV maximal energy deposit ~ 15 GeV If MIP counted in channel 10 >>> 14.4 GeV >> channel 2048, >>> dynamic signal range: 11 bit 12 bit ADC’s would be excellent overflow problem to study: 1.correction methods using neighboured cells, 2.non linear ADCs

17. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 17 Calibration and monitoring of photodetectors Cell calibration with MIP’s ! ~250 000 cells, many calibration events needed off-line: some days during shut down online: between bunch trains, cosmic muon ~95% efficiency, useful ~2*10- 2 Hz, >> 1728 events/day/cell >> 2.4% calibration precision in one calibration day! in bunches (halo muons, endcaps only) 10 halos/BC, >> 1.1*10- 4 /sec/cell 14100 BC/sec, > 1.6 Hz/cell >> few minutes calibration time needed monitoring gain of PD’s: method A: pulsed LED,light split and send to all photodetectors, a stable photodiode, +/-1°C, dG/G < 1%o monitors LED gain via signal peak position method B: pulsed LED,stable gain from gaussian  of PM signal

18. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 18 The layer structure of the HCAL sandwich layers, lamination in: 38 in barrel, 45 in end caps, add. 4 in pole tips of end-caps with scintillator tiles: ~ 800 000 tiles sizes: ~5x5......~16x16 cm 2 cells: ~ 160 000 cells 9 (10) cell layers in barrel (end cap), grouped from 3,3,3,4,4,4,5,5,7 (3,3,3,4,4,4,5,5,7,7) s/w layers cell volumes: (0.22 ) 2 x0.36  (0.71 ) 2 x0.84  (1.6 R Moliere ) 2 x 3.5 X 0...(5 R Moliere ) 2 x 8 X 0 such a detailed structure to be studied in prototype HCAL granularity to be optimised for E-Flow reconstruction of jet energies, ~angles and jet-jet masses.

19. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 19 Assembled with up to 27 scintillator layers: 165 scintillator tiles of: 5x5 cm 2 >> 45 cells 10x10 cm 2 >> 8 cells 20x20 cm 2 >> 2 cells read out by WLS fibres to photo-detectors: 16 small PM’s 3x16 MA-PM’s, 1x32 APD array later: Si-PM’s (MEPHI, Moscow) Tile and S/w structure Cell structure Track cambers? A small pre-prototype : the „minical“-array Aim of this device is study of: stability, ageing and calibration with MIP’s

20. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 20 Beam tests with the „minical“-array Beam at DESY, “Strahl 22” reserved for 2 weeks in July, set up, cosmics 2 weeks in August, 1-6 GeV e- later in this year: test measurements in/between (?) solenoids >>> APD’s or Si-PM’s as photodetectors needed!

21. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 21 HCAL prototype for E-flow studies Required volume ~ 1 m 3 ~ 800-1200 calorimeter cells Fe-structure can accept analogue or digital HCAL 10 GeV pions 100 GeV pions 100 cm Leakage detector needed!

22. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 22 Studies with the prototype beam tests: --1m 3 structure made from Fe(ss) (or Brass?) --stack should be used for tile and digital HCAL studies --need electron, pion and proton test beam, muons for fast calibr? --different energies between 1-30 GeV performance studies: --linearity, --energy calibration and energy resolution, --position resolution, --measure containment of showers, leakage (sides and back) > --software compensation (e/  response  improvement  simulation tests and reconstruction studies: --verify shower shapes from MC simulation, tune MC --energy flow studies, establishment of real performance: --overlay of individual measured beam particles to jets >> --with entrance coordinates and angles as indicated from MC --include cell size and nonuniformity, calibration precision, noise... >>>> reconstruct objects as Z, W, top, Higgs in these studies collaboration with interested US groups agreed

23. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 23 Some first simulation results, reconstruction a la H1 V.Andreev pions in the 1m3 ss-prototype, resolution ~ 0.395/  E considerable leakage deteriorates this resolution tail catcher needed: with 0.8 dead Al coil and realistic Fe structure 1 cm 2 cell structure, RO of each layer >>>> 38 x 10 4 cells  /E ~ 0.395/  E mean leakage/incoming pion

24. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 24 Realistic event representation Strong bending in the magnetic field of 4T charged particle showers are not vtx pointing t-tbar production, 800 GeV, several W jets

25. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 25 Outcome of the meeting (27.3.02, Caltech, Pasadena, 19:30-21), page 1 R. Frey, V. Korbel, S. Macgill, V. Morgunov, D. Strom, H. Videau, V.Zutshi agreement on closer future co-operation in calorimeter studies: 1. Invitation to the regular E- and HCAL meetings, especially members from ANL/ZEUS. Connection via Video-Conference, thus meetings will start at 14:00 MEZ. The next monthly HCAL meeting at DESY is scheduled for 6.6.2002. 2. We keep CALICE web page up to date with E- and HCAL meetings, pointers also to minutes and interesting transparencies of weekly DESY internal HCAL meetings. 3. Information on schedule for minical studies at the DESY test beam. First 2 weeks in July are planned for set-up of minical in test beam. Detailed studies are foreseen in the 2 last weeks of August for MIPs and electrons (1-6 GeV). 4. V.K. will contact Michael Hauschildt, the test beam co-ordinator at CERN and try to get information on availability of beams (1-30 GEV, hadrons, muons and electrons) in 2004, CERN PS. 5. For other alternative test beams we have to look for at Serpuchov, Brookhaven,….? 6. Discussions on specification of 1m 3 HCAL prototype (absorber material, dimensions, tile sizes, equipped volume,..) and side leakage tagging and tail catcher requirements are under way. To optimise the prototype, simulation and reconstruction studies have started at DESY by the DESY-H1-PPI group. The US groups declared strong interest to contribute to such studies. 7. The Fe(ss)-HCAL stack is also foreseen for equipment with digital RO planes. 8. Study of the required tail catcher, structure and effective volume to fill (tile plates / digital planes).

26. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 26 Outcome of the meeting (27.3.02, Caltech, Pasadena, 19:30-21), page 2 9. Actual useable photodetectors, FE and RO electronics, all options have to be investigated for the prototype. A group of Imperial College, London has expressed strong interest to help with the design and implementation of the RO, starting from the ADC’s. So far DESY, ITEP, MEPHI, Prague are involved. 10. The beam test results will be used as input to - Shower size and energy resolution measurements for individual particles, - Leaking energy measurements, the improvement in resolution and reduction of missing energy tails, - Tune the software compensation a la H1 to improve further the energy measurement, - Realistic energy-flow studies with overlay and reconstruction of single particle clusters according to e.g. simulated W, Z, Higgs, t-tbar production....... 11. The effects of the magnetic field which changes significantly the charged track vectors in front of the calorimeter can be taken into account in a “realistic” energy flow simulation and reconstruction using measured prototype showers overlaid according to the simulated events in a cockeyed, non vertex pointing manner. 12. Aim is to find from such simulation and reconstruction studies all required beam test settings as: - Particle types and -energies, - Particle impact angles needed for overlays to jets and final states, - Number of particles to collect /data set. With these studies the useful prototype dimension, cell sizes and required volume fill (~4000 tiles combined to ~1000 electronic RO channels) and TC structure have to be optimised. Also we have to find out, which volume to fill with digital planes to draw a conclusive comparison. Probably, if 40 layers of digital RO will not be available at time for alternative test, as many tile layers as possible can be replaced with digital layers and consecutively shifted along the prototype depth. This can be studied in detail also!

27. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 27 Summary CDR >> TDR (2001) considerable improvement in concept straight fibre RO, at least for small cells, instead loops, >> ~25 ph.e. for calibration with PM for MIPs (~250 photons) further work on further improvement in light yield, lateral cell response uniformity seems ok (+/- 3-4%), but needs confirmation by simulation studies studies are underway for cell size optimisation s/w compensation (~ size of elm. cluster) E-flow measurement economy, costs minical-prototype is in operation, more channels soon prototype tests at CERN envisaged for 2004 wait for results from software prototype study group how to implement realistic tail catcher?

28. 13.4.02, V.Korbel, DESY II. ECFA-DESY LC workshop, St.Malo 28 Outlook Approved, final concept 2005 ? Approved, final concept 2005 ? Here we are 2002 Here we are 2002 Detector ready for first e-e interactions: 2012 ? Detector ready for first e-e interactions: 2012 ? Concept, design studies, R&D, prototype to be built for 2004 Minical design