P4 2 Kawagoe

Review of Calorimeter R&D: 

Review of Calorimeter R&D The 7th ACFA LC Workshop November 9-12, Taipei, Taiwan K. Kawagoe / Kobe University

Introduction: 

Introduction Requirements for LC calorimeter Good energy resolution for single particles (both for electrons/photons and hadrons) Good linearity (from 1 GeV to a few 100 GeV) Good hermeticity (no cracks) Operational in strong magnetic field (~3Tesla) Good energy resolution for jets Essential to find W/Z/top in multi-jet final states

Two-jet mass resolution: 

Two-jet mass resolution A benchmark is two-jet mass resolution to separate W and Z. Right figures: nnWW and nnZZ events with different resolutions. Jet energy resolution of ~30%/sqrt(E) is required. Note: In many physics analyses, not only the jet energy resolution but also jet-finding algorithm will be equally important. 30%/sqrt(E) 60%/sqrt(E)

Traditional approach: compensation : 

Traditional approach: compensation Main contribution of hadron energy resolution : fluctuation of EM component in hadronic showers. Good energy resolution for single hadrons is achieved if signals from EM component and hadron component are equivalent (compensation). Compensating sampling calorimeter is realized by optimizing the ratio of absorber and sensitive material. So far achieved ZEUS (U+Scinti.): ~35%/sqrt(E) for single hadrons, ~50%/sqrt(E) for jets JLC test module (Pb+Scinti.): ~47%/sqrt(E) for single hadrons Note: Jet energy resolution can be much improved if track information is combined.

Compensating HCAL (Pb+Scinti.): test beam result: 

Compensating HCAL (Pb+Scinti.): test beam result Test beams: 1-4 GeV at KEK (1998), 10-200GeV at FNAL (1999). Energy resolution degraded by fiber-routing acryl plates. Good linearity thanks to hardware compensation. Still a good candidate for a LC calorimeter.

New approach: Particle flow: 

New approach: Particle flow Reconstruct each particle in a jet with Tracker+ECAL+HCAL Charged particles by Tracker: ~64% of jet energy Photons with ECAL: ~25% of jet energy Neutral hadrons with HCAL: ~11% of jet energy

Particle flow algorithm (PFA) : 

Particle flow algorithm (PFA) Ejet=S|P|ch+SEph+SEn.h s2jet=s2ch.+s2ph.+s2n.h.+s2confusion As the contribution of neutral hadrons is small, the HCAL energy resolution may be moderate for single hadrons. Particle flow (Energy flow) algorithm was used already at LEP, but the LEP detectors were not optimized for PFA. sconfusion is large and must be minimized. Track-cluster matching Separation of overlapping clusters

Optimization for PFA: 

Optimization for PFA Magnetic field to bend charged particles Large ECAL inner radius for particle separation Small ECAL Moliere radius for small lateral spread of EM shower Fine segmentation of ECAL/HCAL in 3-D MC truth After reconstruction MC by CALICE

Another new idea: Digital HCAL: 

Another new idea: Digital HCAL Digital HCAL is proposed and studied for PFA. Super fine segmentation (~1cm x 1cm, ~40 layers)  Huge number of readout channels Digital readout with cheap electronics (1bit/ch, no analog data). Number of hits is proportional to hadron energy. Asymmetry of energy response due to Landau fluctuation may be removed (better than analog HCAL?).

Analog vs. Digital HCAL Linearity Response: 

Analog vs. Digital HCAL Linearity Response Showers in a sampling calorimeters are characterized by their spatial development in terms of “track length” : Track Length (T) = sum of tracks of all charged particles in a shower – Analog sampling calorimeters sum energy, Digital sampling calorimeters sum hits T  E (particle energy) – what about spread in energy? (S. Magill@Victoria)

Analog vs Digital Energy Resolution: 

Analog vs Digital Energy Resolution GEANT 4 Simulation of SD Detector (5 GeV +) -> sum of ECAL and HCAL analog signals - Analog -> number of hits with 10 MeV threshold in HCAL - Digital Gaussian Landau Tails + path length Digital Analog E (GeV) Number of Hits /mean ~22% /mean ~19% (S. Magill@Victoria)

Current direction: 

Current direction Traditional approaches (Compensation, AHCAL, …) Well understood and established. May work a backup. New approaches (PFA, DHCAL, …) All detector concepts take the new approaches. More attractive and challenging… need much more effort Optimization should be made by Simulation studies Hardware studies Performance should be evaluated by Test beam studies

ECAL R&D studies: 

ECAL R&D studies

CALICE (CAlorimeter for LInear Collider with Electrons): 

CALICE (CAlorimeter for LInear Collider with Electrons) A big international collaboration (3 regions, 8 countries, 28 institutes) CALICE prepares beam test series ECAL: SiW HCAL: Analog and Digital

CALICE SiW ECAL: 

CALICE SiW ECAL ECAL system tests: 2004 October~ DESY electron beam test: 2004 November~ Beam tests with higher energy electron beams and hadron beams in combination with HCAL: 2005~

Slide16: 

Results from Cosmics/Single Slab DAQ Wafer 10 Wafer 12 ADC’s counts Calice SiW Cosmic signal response

What’s New: Silicon/W, SLAC-Oregon-BNL: 

What’s New: Silicon/W, SLAC-Oregon-BNL

Slide18: 

Dynamically switched Cf Much reduced power Much better S/N Allows for good timing measurement Silicon/W, SLAC-Oregon-BNL

LCcal Test beam results: Linearity and Energy Resolution: 

EE Cern TB 2003 Ebeam (GeV) 11.1%E Ecal (GeV) e- pm saturates Ebeam (GeV) Ecal (GeV) 15 GeV e- Const. term compatible with beam p 30 GeV 30 GeV e- E Si pad Layer 1 Si L1+L2 =1.76 mm y pad –y telescope (cm) 30 GeV electrons LCcal Test beam results: Linearity and Energy Resolution

Slide20: 

What’s New: Scintillator/W ECal, Colorado (cont’d) U. Nauenberg

Asian activities on ECAL: 

Asian activities on ECAL Beam test studies of fine-granularity lead-scintillator ECAL prototypes (strip-array and small-tile) Readout: clear fibers and MAPMT (only for beam test) Talks by Yamauchi, Nagano, Ono.

New design for Large detector: 

New design for Large detector Lead/scintillator  Tungsten/scintillator for smaller Moliere radius Scintillator segmentation to be optimized for PFA Readout by SiPMs, directly attached to WLS fibers.

SiPM, MRS, AMPD, …: 

SiPM, MRS, AMPD, … Micro-APD cells operated in Geiger mode, developed in Russia Number of cells up to ~ 1000 Effective area ~1mm x 1mm (very compact) High gain (~106); No AMP needed. Photon counting capability Cheap (a few $/device in future ?) Significant noise rate (~1MHz) CALICE AHCAL will use 8000 SiPMs. Some varieties (at least 3 groups in Russia) SiPM (Silicon photomultiplier) MRS (Metal-resistive silicon diode) AMPD (Avalanche multi-pixel photodiode) A talk on SiPM performance by R. Nakamura

HPK’s new device under development: 

HPK’s new device under development Samples being tested by T. Takeshita

HCAL R&D studies: 

HCAL R&D studies

CALICE Tile (Analog) HCAL: 

CALICE Tile (Analog) HCAL MiniCAL A small prototype (15cm x 15cm cross section Readout: APD, SiPM, and PMT (reference) Already tested with DESY electron beam New prototype A large prototype (1m x 1m cross section) Readout: ~8,000 SiPMs To be tested 2005 onwards with hadron beam MiniCAL

Calice Tile HCAL (minical): 

Calice Tile HCAL (minical)

Calice Tile HCAL (new prototype): 

Calice Tile HCAL (new prototype) 38 layers 30 * 220 tiles SiPMs with coax cables 8 * 145 tiles ~ 8000 analogue channels in total 1 m2 with 220 tiles Aim at common design for HCAL and tail catcher (~350 channels) SiPM

Calice Tile HCAL (new prototype): 

Calice Tile HCAL (new prototype)

Digital HCAL: 

Digital HCAL R&D of active layers GEM-based (talks by A. White) RPC-based Scintillator-based R&D of readout electronics

Progress on understanding prototype signals and associated crosstalk.Progress on large-scale GEM active layers. Working with ANL/Fermilab on readout electronics (GEM mods to RPC design). Working with 3M Corp. on GEM foil production. Issue now is the funding/timescale for test beam stack.: 

Design for DHCAL* using Triple GEM *J. Yu On behalf of the HEP group at UTA. Progress on understanding prototype signals and associated crosstalk. Progress on large-scale GEM active layers. Working with ANL/Fermilab on readout electronics (GEM mods to RPC design). Working with 3M Corp. on GEM foil production. Issue now is the funding/timescale for test beam stack.

Slide32: 

AIR4 is a 1-gap RPC built with 1.1mm glass sheet 1.2mm gap size Resistive paint layer is about 1MΩ/□ Running at 6.8 KV Avalanche signal ~5pc Efficiency >97% Total RPC rate from 64 channels <10 Hz Very low noise! Pad array Mylar sheet Mylar sheet Aluminum foil 1.1mm Glass sheet 1.1mm Glass sheet Resistive paint Resistive paint (On-board amplifiers) 1.2mm gas gap -HV GND What’s New: DHCal with RPCs, ANL L. Xia @Victoria

ANL RPC R&D Plan: 

ANL RPC R&D Plan R&D with chambers Essentially completed Electronic readout system Design and prototype ASIC Specify entire readout system Prototype subcomponents Construction of m3 Prototype Section Build chambers Fabricate electronics Tests in particle beam Without and with ECAL in front

Digital HCal with Scintillator (NIU)Stack & Tile Fabrication: 

Digital HCal with Scintillator (NIU) Stack & Tile Fabrication ~15pe/mip

Scintillator-based DHCAL: 

Scintillator-based DHCAL Study of small scintillator blocks started in Niigata. Shape and size White-paint or Al-evaporation

Plan of combined beam test studies: 

Plan of combined beam test studies Worldwide-effort (Asia, Europe, North America) CALICE is the biggest group ECAL (SiW) test with electron beam at DESY (2004/2005). Start ECAL+AHCAL test with high energy hadron beams at FNAL/Protovino (2005/2006). Then ECAL+DHCAL (funding problem ?) Other R&D groups will join with their detectors. A document (MoU?) for test beam needs to be sent to FNAL (meeting at ANL in September).

Slide37: 

Test Beam MoU Writing Meeting Argonne National Laboratory, September 23 – 24, 2004 I Welcome and introduction II Review of calorimeter projects ECAL HCAL Tail catcher Silicon – Tungsten (CALICE) Scintillator – Steel (CALICE) Scintillator – Steel (NIU) Silicon – Tungsten (US) RPC – Steel (Russia) RPC- Steel (Frascati) Scintillator – Tungsten (Japan) RPC – Steel (US) Scintillator – Silicon – Tungsten (Kansas) GEM – Steel (Texas) Scintillator – Silicon – Lead (Italy) Scintillator – (Colorado) III Discussion of requests to MTBF Presentation by E Ramberg V Writing of MoU Rate and length of spills Rate and energy range of electrons Energy range of pions VI Visit to Fermilab IV Discussion of the MoU Seminar by Holmes and Mishra (16:00) Visit of MTBF Outline Rôle of CALICE Assign writing tasks

Summary: 

Summary R&D studies on new appraoches/technologies Particle flow algorithm Digital hadron calorimeter SiPM for scintillator-based calorimeter They are very attractive and should be verified by simulation studies and test beam studies. Many different activities are on-going all over the world Combined test beam 2005 onwards: a world-wide effort I wish to thank speakers at Victoria and Durham workshops for their slides I used