March 31 CALICE Collaboration meeting April 1 – 4 ECFA/DESY Linear Collider Workshop Amsterdam

Mostly repeat from previous CALICE meeting Additionally Japanese Italian ECAL Kansas Forward CAL Simulations }

CALICE ECAL Presented by J-C Vanel ECAL general view 3 rd structure (3×1.4mm of W plates) 370 mm 180 mm Silicon wafer 2 nd structure (2×1.4mm of W plates) 1 st structure (1.4mm of W plates) Detector slab 370 mm 8.5 mm mm mm Alveolus

Front End electronics (Cfi / W) structure type H Silicon wafer Shielding PCB Al. Shielding PCB (multi-layers) (  2.4 mm ) Silicon wafer (0.525 mm) Tungsten (1.4 mm, 2×1.4 or 3×1.4 mm) 8.5 mm Composite structure (0.15 mm / layer) Transverse view Detector slab PCB : - 14 layers - Thickness 2.4 mm

Chips PCB, Wafer, Chip : still in progress Wafer PCB board

Front end electronic : ASIC

Physic prototype  program is well advanced First test beam with electrons  mi 2004 First hadronic test beam  2005 Prototype in beam ~ summer 2004 –R&D (thermal et electronic) –Some part not so well covered Collaboration welcome http :// polywww.in2p3.fr/flc/calice.html

LCCAL LCCAL: Official INFN R&D project, official DESY R&D project PRC R&D 00/02 Contributors (Como, LNF, Padova, Trieste): M. Alemi, M.Bettini, S.Bertolucci, E. Borsato, A.Bulgheroni, M. Caccia, P.Checchia, C. Fanin, G. Fedel, J.Marczewski, S. Miscetti, M. Nicoletto, M. Prest, R. Peghin, L. Ramina, E. Vallazza. Presented by S Miscetti, A Bulgheroni Pb/Sc + Si 45 layers 25 x 25 x 0.3 cm 3 Lead 25 x 25 x 0.3 cm 3 Scintillator 3 layers of Silicon 1 x 1 cm 2 pads at 2, 6, 12 X 0

EEEE 11.5%  E Extensive Testing in Frascati Test Beam Electrons and positrons 50 – 850 MeV Energy selection 1 % Up to 10 3 electrons/s Energy resolution as expected Recently inserted Si-Pads E(MeV)

Conclusions and perspectives The LCCAL prototype is  fully working! - more Si Pads are under constructions - the third Si layer will be fully equipped - multianode PMs to be installed in late autumn Needs to start the simulation of this hybrid technique in LC software Succesfull test run with the whole prototype is under way at the BTF in Frascati Energy response and resolution as expected! Work is in progress to understand discriminating power of multiple hits by merging Silicon and Energy information. Two test beams at Higher Energy in preparation: PS (June 2003 ??) SPS (August 2003)

AHCAL: impressive progress Presented by V Korbel Tests of plastic scintillator Fiber routing optimization Selection of wavelength-shifting fibers Coupling of WLS-fibres to scintillator Clear fiber selection Connection of WLS and clear fibres Photodetectors: remaining candidates: APDs and Si-PMs

2 ns 2 mV Some features: Sensitive size 1x1mm 2 on 1.5x1.5 mm 2 Gain 2  10 6 at U bias ~ 50V Recovery time ~ 100 ns/pixel Nuclear counter effect: negligible (due to Geiger mode operation) Number of pixels: 576, now 1000/mm 2 Dynamic range > 200 R&D at MEPHI (Moscow), B. Dolgoshein, together with PULSAR (Russ. Industry) SiPMs, Silicon Photomultiplier For further details see: «Advanced study of SiPM»

Performance of SiPMs with 1 Scintillator Tile DESY e-test beam with various Si-PMs (MEPHI) 4-8 pe 576 px 53-55V 15 pe 1000 px Si-PM on tile 10 pe, 576 px 54V minical

Si-PM’s, dark rate and MIP detection Sum of 3 tiles in e-beam test at DESY 576pix/mm2 From Elena Popova, MEPhI

Minical array Assembled with up to 27 scintillator layers, of 9 tiles each, 5x5X0.5 cm scintillator tiles or 81 cells of 3 tiles read out by ~ 50 cm WLS fibres to photo-detectors: APD’s: 3 tiles/APD MA-PMs: 16fold, 3 tiles/pixel Si-PMs: 1 tile/Si-PM also:1x32 M-APD array (Pra Stack and Tile structure Aim of this device is: cosmics, study of: LY uniformity of response calibration with MIPs stability of MIP signals different photodetectors long term ageing LED monitoring: stability dynamic range e-beam, study of: energy resolution constant term

1. Enough LY from TFS (~200 photons at photodetector) 2. APD’s and SI-PMs are the photodetectors which do the task 3. Preamplifiers with low noise are essential (MIP-noise separation,calibration) 4. Minical test to establish calibration precision in summer 5. Now design of prototype boards for APD and Si-PMs, DUBNA 6. Photodetectors, large quantity to order in summer: 1000 APDs or ~ 5000 Si-PMs or both types in relevant quantities e.g. ~250/ Prototype stack (1m 3 ) will be build in summer 8. Assembly of PT-stack with TFS starts in Jan Spring 2004 is used to set up and calibrate all channels with cosmics. Outlook

DHCAL: Choice of Active Media Technologies investigated a) Scintillator Northern Illinois University b) Gas Electron Multipliers University of Texas at Arlington c) Resistive Plate Chambers IHEP Protvino JINR Dubna Argonne National Laboratory Boston University University of Chicago Fermi National Laboratory d) Short Drift Tubes IHEP Protvino Requirements Possibility of readout with fine segmentation of O(1 cm 2 ) Acceptable level of ‘cross-talk’ between channels Reliable, robust, long life of O(> 10 years) Affordable Presented by J Repond

GroupRussiaUS Resistive platesGlass Mode of operationAvalanche Number of gas gaps12 Number of pads1625 Tests withSources Cosmic rays Test beams Sources Cosmic rays MeasurementsCharge, efficiency and noise rates versus HV Pad multiplicity versus HVPad multiplicity Pad multiplicity for various t anode Comparison of various t gas gaps Rate capability Charge vs distance Resistive Plate Chambers RPCs

RPC: A few examples from the Russians… Efficiency versus rate for avalanche and streamer mode Pad multiplicity versus charge for different anode thicknesses

Conclusions about comparison of modes of operation

Name of chamberAIR0AIR1AIR2 Date of construction 11/20021/2003 Active area 20x20 cm 2 Number of gas gaps 222 Glass thickness 0.85 mm1.1 mm Thickness of gas gap 0.64 mm Resistive layer GraphiteInk Surface resistivity ~300 kΩ/□~200 kΩ/□~1200 kΩ/□ Streamer signal starting point 7.5 kV6.7 kV6.6 kV Pedestal width ~15 fC~8 fC Gas mixture Freon/Argon/IsoButane = 62:30:8 In future Freon/IsoButane/SulfurHexafluoride = 92:5:3 RPC: A few examples from the Americans…

Measurements of efficiencies Counting charges above Q 0 Counting events above V 0 Efficiency greater than 90% in avalanche mode (plateau ~200V) Small fraction of streamers Efficiency greater than 90% in avalanche mode (plateau ~300V) Small fraction of streamers Noise rate ~50Hz for avalanche mode This is low!

Central pad with maximum charge: select avalanches Looking at individual pads Charge on neighboring pads small!

Short Drift Tubes STDs Cell size 1 cm 2 x 3 mm Gas: IB:Ar:TFE = 80:10:10 Efficiency and Multiplicity As function of High Voltage Currently using flammable gas, exploring performance with other mixtures

DHCAL Readout schemes Real challenge…. 1 m 3 prototype: 400,000 channels! IHEP ProtvinoConditioning + FPGA + Serialiser JINR DubnaComparators + FPGA + VME US groupsCustom FE ASIC + concentrator + collector KoreaTesting entire chain of comparators and digital processing Imperial College London Adapting ECAL readout scheme to A/DHCAL

Readout at Protvino Conceptual design readout for 64 channels I Conditioning (analog) II FPGA (digital) III Serializer (readout of several FPGA)

May 6, 2003 Design of readout system in US… System overview I RPC ASIC located on the chambers II Data concentrators funnels data from several FE chips III VME data collector funnels data from several data concentrators IV External timing and trigger system

May 6, Conceptual design of readout pad Attempt to minimize cross-talk Overall thickness mm One ASIC for 64 (or 128) channels Will need 6250 (3125) ASICs for 1 m 3 prototype First version of boards being laid out ASIC: Analog signal processing Each channel has a preamplifier Needed for avalanche mode Can be bypassed (in streamer mode) Provides pulse shaping Provides polarity inversion

Modes of operation I Trigger-less operation Timestamp counter running inside chip (with external reset) Store timestamp and channel number when hit II Triggered operation Provide pipeline for temporary data storage Provide trigger input to capture data of interest (Provide trigger output: 1 bit) Timestamp to identify event Design of ASIC: Digital Processing Functions Attempt to implement features possibly useful for other detectors Significant overlap with what is needed for Off-axis detector Performance specifications being defined now…

Simulation Studies for DHCAL The NIU Report Presented by V Zutschi Progress with the Development of EFAs at Argonne Presented by J Repond for S Kuhlmann and S Magill Definition of a weight for CAL cells: W i = k Σ(1/R ij ) High weight cells chosen as seeds for clustering Tested on π 0 → γγ, Σ + → pπ 0 Implementation of jet algorithm First results on analog vs digital (different cell sizes) CAL only EF analog EF digital Development of track shower matching: TESLA Define cell weights depending on # of neighbors w/in 40 cells Cells with W > 1/40 treated as seeds for clustering Developed Photon Finder Perfect EFA Goal σ EM = 1.4 GeV Compare to h 0 σ h = 2.9 GeV σ EM = 2.8 GeV

Politics… Status and Plans of TESLA Presented by A Wagner

More information and upcoming meetings… Talks from DHCAL meeting in Paris on 28-February-2003 See

Next DHCAL meeting at DESY on June 30, 2003 Talks from CALICE meeting in Amsterdam on 31-March-2003 See Talks from LC workshop in Amsterdam, April 1 – 4, 2003 See Review of status of different DHCAL efforts First attempt to provide costing for different readout options Specifications for mechanical absorber structure: separate from AHCAL? stainless steel? gap thickness? variable? Co-operation on RPCs and readout with Russians? Date almost final