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 SiVTX pixel (cold version)  HCAL (Pb(Fe)/scinti or digital) W/Scinti ECAL TPC (Jet chamber as option) Si intermedi.-Trk SC-coil SiVTX pixel  Pb/scinti HCAL Pb/Scinti ECAL Jet chamber Si intermedi.-Trk SC-coil “GLC” design (ACFA) “Huge” (world-wide)

Area of EM CAL (Barrel + Endcap) –SD: ~40 m 2 / layer –TESLA: ~80 m 2 / layer –Huge: ~100 m 2 / layer –(GLC: ~130 m 2 /layer) Huge ~2.1m Comparison of size of EM CAL surface

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).

Common layout for ECAL and HCAL

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= cm). –Total radiation length ~26X 0. 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= cm). –Total Pb thickness 90cm ~ 5.3 I. –Add ECAL (1.0 I )  6.3 I (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~10 6 (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: ~1mm 2 ) 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/cm 3, 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) –Design optimization –R&D of SiPM (DPPD) –R&D of readout electronics –Construction of an ECAL test module –Tests with cosmic-rays –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 !!