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Calorimetry: a new design. 2004/Sep/15 K. Kawagoe / Kobe-U. Introduction. Our previous studies Pb/Scinti optimized for compensation ~45%/sqrt(E) resolution for single hadrons ~15%/sqrt(E) resolution for electrons/photons Fine granularity ECAL (strip-array & small tile) New design
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Calorimetry: a new design 2004/Sep/15 K. Kawagoe / Kobe-U
Introduction • Our previous studies • Pb/Scinti optimized for compensation • ~45%/sqrt(E) resolution for single hadrons • ~15%/sqrt(E) resolution for electrons/photons • Fine granularity ECAL (strip-array & small tile) • New design • To be optimized for Particle Flow Algorithm (PFA) aiming at 30%/sqrt(E) resolution for jets • ECAL: W/Scinti with SiPM analog readout • HCAL: Pb(Fe)/Scinti with SiPM (semi-)digital readout • Other options ?
Typical “Huge” models under consideration “Huge” (world-wide) “GLC” design (ACFA) m m SC-coil SC-coil HCAL (Pb(Fe)/scinti or digital) Pb/scinti HCAL W/Scinti ECAL Pb/Scinti ECAL TPC (Jet chamber as option) Jet chamber Si intermedi.-Trk Si intermedi.-Trk SiVTX pixel (cold version) SiVTX pixel
Comparison of size of EM CAL surface • Area of EM CAL (Barrel + Endcap) • SD: ~40 m2 / layer • TESLA: ~80 m2 / layer • Huge: ~100 m2 / layer • (GLC: ~130 m2 /layer) Huge ~2.1m
Layout of scintillators • We have an experience of strip-array ECAL. • Array of 1cmx20cmx2mm-thick strips • Advantages : • Fine granularity (1cmx1cm effective cell size) • Reasonable cost • No WLS fiber bending • Disadvantages : • Ghost rejection needed
New: Strip & Tile CAL • We have an experience of small tile ECAL, too. • Ghost clusters would be easily removed with additional small-tile layers. • This idea SHOULD be well confirmed by full simulation studies. • Strip & Tile CAL can be achieved with SiPM readout (directly attached to WLS fibers) .
ECAL structure • An ECAL super-layer consists of • W 3mm + X-strips 2mm +cable 1mm • W 3mm + Y-strips 2mm +cable 1mm • W 3mm + small tiles 2mm + cable 1mm • Effective Moliere radius 18mm • 10 super-layers (30 layers) • Total thickness 18cm (r=210-228cm). • Total radiation length ~26X0. • Dimensions (to be optimized) • Strips (1cm x 20cm) • Small tiles (4cm x 4cm)
HCAL structure • An HCAL super-layer consists of • Pb 20mm + X-strips 5mm +cable 1mm • Pb 20mm + Y-strips 5mm +cable 1mm • Pb 20mm + small tiles 5mm + cable 1mm • Pb is good for compensation, but may be replaced by Fe. • Is this sampling fine enough ? (need simulation) • 15 super-layers (45 layers) • Total thickness 117cm (r=230-347cm). • Total Pb thickness 90cm ~ 5.3lI. • Add ECAL (1.0lI) 6.3lI (thick enough?) • Dimensions (to be optimized for PFA) • Strips (1cm x 20cm) • Small tiles (4cm x 4cm)
Number of readout channels • With 20cm x 1cm strips and 4cm x 4cm tiles • ECAL prototype • 650 analog readout channels • Calorimetry for the real detector • ECAL: ~2.0M analog readout channels. • HCAL: ~5.5M (semi-)digital readout channels • A big challenge !! • Number of channels could easily change the order depending on the strip/tile size.
SiPM • next talk by T. Takeshita • Micro-APD cells in Geiger-mode. • Developed in Russia. • Good for fiber readout • Gain~106 (No amplifier needed) • ~1000 pixels in small area (~1mm x 1mm) • Further R&D is needed for • Better quantum efficiency (now: ~20%) • Lower noise rate (now: ~1MHz) • Larger effective area (now: ~1mm2) for other applications • CALICE Analog HCAL will use ~8000 Russian SiPMs. • Hamamatsu started to develop a similar device.
W plates • Contact with a Japanese company (A.L.M.T. corp.) • W alloy is easier to handle than pure W. • W:Ni:Cu=95:3.4:1.6, density=18g/cm3, no magnetism. • For ECAL prototype • We need 30 W plates (20cm x 20cm x 3mm-t) . • Rough cost estimate ~1.5MYen (or ~25Yen/g). • For real ECAL detector • We need ~200ton W plates. • Mass production may reduce the cost: ~10Yen/g. • Very rough cost estimate ~ 2 BYen. • Production in 3 years is possible.
R&D issues • Design optimization (scintillator shape and size) • to remove “ghost” clusters • to match tracks and clusters for particle flow algorithm • Photo-sensors (SiPM) • Readout electronics • Gain monitoring system • Mechanical structure
Possible schedule (very very preliminary) • 2004-2005 • Design optimization • R&D of SiPM (DPPD) • R&D of readout electronics • 2005-2006 • Construction of an ECAL test module • Tests with cosmic-rays • 2006-2008 • Test beam studies of the ECAL test module “standalone” • Test beam studies in combination with CALICE HCAL
Institutes/staffs • Japan • KEK (J. Kanzaki) • Kobe U. (K. Kawagoe) • Konan U. (F. Kajino) • Niigata U. (H. Miyata) • Shinshu U. (T. Takeshita) • Tsukuba U. (S. Kim, H. Matsunaga) • Korea • Kyungpook National U. (D. Kim) • Russia • Joint Institute for Nuclear Research (D. Mzhavia, P. Evtukhovitch, et al.) • Good relation with CALICE, especially with Analog HCAL group at DESY (V. Kobel et al.).
Conclusions • New calorimeter design • ECAL W+Scinti+SiPM, analog readout • HCAL Pb(Fe)+Scinti+SiPM, (semi-)digital readout • R&D issues • Design optimization • SiPM • Readout electronics • Gain monitoring • Mechanical structure • Schedule • Test beam for ECAL prototype in 2006 ? • Of course, any other ideas / activities are welcome !!