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C.WoodyBNL

Summary of the Calorimetry Session

PHENIX Upgrade Workshop

Dec 14-16, 2010

PHENIX Collaboration MeetingJanuary 11, 2011

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Upgrade Workshop - Calorimetry SessionAgenda Start at 8:30 am •10’ – Introduction to the Workshop and Calorimetry Session (M.Leitch pptx, pdf; C.Woody ppt, pdf) •30’ – Overview of the PHENIX Decadal Plan (D.Morrison, pdf) •20’ – Physics with Calorimetry in the PHENIX Upgrade (M.McCumber, pdf) •20’ - Calorimeter Requirements – What’s in the Decadal Plan ? (N.Grau, pdf) •20’ - Technology Choices for Calorimetry in an Upgraded PHENIX Detector (C.Woody ppt, pdf) •30' - Status of Physics Analysis with the Current PHENIX EMCAL (T.Sakaguchi, pptx, pdf) •30’ - The ALICE FOCAL (T.Gunji pdf, pptx ) •30’ – ORNL Approaches to the ALICE FOCAL & Ties to Future PHENIX Upgrades (C.Britton ppt , pdf ) •20’ – Open mike (All) pdf Lunch 12:00 pm – 1:00 pm •30’ - Hybrid Calorimetry in an Upgraded PHENIX (E.Kistenev, ppt) •30’ - Scintillator Calorimetry for the PHENIX Upgrades (J.Frantz, pptx, pdf) •30' - New Technologies for SciFi Calorimeters (O.Tsai, pptx, ppt) •30’ - Use of SiPMs in the GlueX Barrel Calorimeter (E.Smith, pdf) •30' - The CALICE Calorimeters (F.Sefkow) pdf Physics Colloquium: 3:30 pm – 4:30 pm (P.Steinberg) •Open Discussion, Summary and Future Plans: 4:45 pm – 6:00 pm

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Ground Rules

1. Do not deviate from the Decadal plan design “too much”

2. Want a Compact Detector with specific physics capabilities that will be able to perform unique and important physics measurement in 5-10+ years at a “reasonable” cost

We are not aiming to build a new, large, multipurpose detector like ATLAS,CMS, or ALICE

3. Design based around a “small” solenoid magnet in the central region

However, things like the radius of magnet should be considered as a variable within reasonable limits

4. Focus on technology choices that will enable this type of design

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Basic Assumptions

• Inclusion of a Hadron Calorimeter covering 2 and || < 1 implies the need for a Compact Electromagnetic Calorimeter

• Both calorimeters need to be hermetic and projective

• To handle shower overlaps in central Au+Au collisions, a Compact EMCal implies: - Small Moliere radius (~ 2 cm) - High segmentation ( ~ .01, ~ .01)

• Identifying single photons from 0s up to pT ~ 40 GeV/c requires a preshower detector with () ~ .0005

~ 300 m at R = 60 cm

• At least part of the CEMC will be inside the magnetic field

• The hadronic calorimeter will be outside the field and will have have relatively low granularity ( ~ 0.1)

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Energy Resolution vs Occupancy

Assumed energy resolutions in the Decadal Plan: - Electromagnetic ~ 15%/E - Hadronic ~ 50%/E

The energy resolution requirements will determine the sampling fraction in a sampling calorimeter, which will in turn have an impact on the Moliere Radius, Radiation Length and Nuclear Absorption Length

RM, X0 and I will determine the transverse segmentation and longitudinal depth of the calorimeters.

Occupancy will be determined by how far the calorimeters are located from the interaction point

Simple calculation (A.Oskarsson) based on scaling our present Pb-Sc EMCAL at R=5m and RM=3 cm to a new Compact EMCAL at R=60 cm and RM=2 cm changes occupancy from 2% to 66% !

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Technology Choices

Material (g/cm3) RM (cm) X0 (cm) I (cm)

c (MeV)Sampling

W 17.50 0.93 0.35 9.6 8.0Pb 11.34 1.60 0.56 17.0 7.4Fe 7.87 1.69 1.76 16.8 22.0Si 2.33 4.80 9.36 45.5 41.0

Scint 1.05 9.60 42.40 79.5 94.0

HomogenousPbWO4 8.30 2.00 0.89 20.7

LSO 7.40 2.07 1.14 20.9PbF2 7.77 2.22 0.93 21.0

• Sampling vs Homogeneous

• Optical vs Ionization- Optical Scintillator (crystal, plastic), Wavelength Shifter, Cherenkov- Ionization Silicon, Noble Liquids (Ar, Kr, Xe)

• Readout Devices

“Apparent” RM ~ 1.8 cm due to Cherenkov

Reduced by sampling fraction

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FOCal 2011

2 mm W plates, ~5 X0 4 mm W plates, ~16 X0

22 layer of ~500 Si pads 15x15 mm2

8 layers of ~300 0.5 mm wide Si strips (4 X + 4 Y)

Segment - 0 Segment - 1 Segment - 2

-enhanced early shower measurements;

-reduced readout gaps to reduce shower

blow-up;

-resolved dynamic range problem.

E.Kistenev

0

Preshower separation

Provides good compactness due to thin sampling layers of silicon

9

CNS, India, ORNL, 7

• “Standard” W+Si (pad/strip) calorimeter (CNS)– Similar to the PHENIX FOCAL but 3.5m away from IP

• W thickness: 3.5 mm (1X0)

• wafer size: 9.3cmx9.3cmx0.525mm • Si pad size: 1.1x1.1cm2 (64 ch/wafer)

• W+Si pad : 21 layers• 3 longitudinal segments• Summing up raw signal

longitudinally in segments

• Single sided Si-Strip (2X0-6X0)

• 2 separation, 6 inch wafer• 0.7mm pitch (128ch/wafer)

Total 25kchannels

First segment Second segment Third segment

Si Strip (X-Y) Tungsten Si padCPV

ALICE FOCAL Taku Gunji +

Chuck Britton

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EMCAL Options - Decadal Plan Accordion

Projective Towers

Scintillator Accordion (E.Kistenev & colleagues from Russia)

Tungsten Scintillator Shashlik

ALICE Pb-ScProjective Shashlik

w/APD Readout

%7.1%12

EE

E

HERA-B had a non-projective W-Sc Shashlik

Composite tungsten plates can be formed into accordion shape

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Scintillating Tile Hadron Calorimeters

Scintillator tiles read out on edges with WLS fiber

Depth segmentation achieved by fiber routing

%5.5%4.56

EE had

E

WLS fiber

ATLASOther Tile-WLS

Fiber CalorimetersCMS Barrel Hadron

LHBb HCALSTAR EMCAL

D0HERA

CALICE (w/SiPMs)

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Scintillating Fiber Calorimeters

R.Wigmans, NIM A494 (2002) 277-287

1 mm plastic scintillating fibers

Other Sci-Fi Calorimeters

H1KLOE

JETSETCHORUS

E864 (BNL)

SPACAL

Embedding scint fibers in an absorber matrix (Oleg Tsai)UCLA Prototype 0.25x0.25, 0.3 mm fibers 0.8 mm spacing

“Spacardeon”

%2.2%33

EE Had

E

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Hybrid Option for PHENIX Central Calorimetry

-em energy resolution: 20% at 1 GeV

-em depth: 20 X0 or more;

-had. Resolution – better 50% at 1 GeV

-had depth: ~4 Labs

Si-Sc hybrid option

-Active preshower ~4 X0

-2 mm W (or equivalent) plates in preshower

-Si readout in preshower

-Pb & Sc in both E-sampling segments

-Optical readout in sampling segments

s-c magnet

EMC energy sampler Hadronic energy

sampler

Preshower

E.Kistenev

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Self supporting structure

Optical Readout AccordionE.Kistenev

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Shashlik W-Sc EMCal Module

square cross-section“a” slightly decreases from 15.0 mm to 14.9 mm as || increases

“b” slightly decreases from 16.8 mm to 16.7 mm as || increases

aa

bb

Thickness of W = 1.5 mmThickness of Scintillator = 1.0 mmRadiation length X0 = 5.8 mmuse 46 layers of W+ScDepth of the module = 20X0

Sampling fraction = 0.0569(rapidity independent)Position resolution = 2.8 mm at E = 1 GeV

= 0.9 mm at E = 10 GeV

Moliere Radius RM = 14.6 mm || x || segmentation = 0.0146 x 0.0146(Projective)~50 K ChannelsDon’t Need Preshower/SMD ?Energy resolution = 11.3 % / sqrt(E)Occupancy: 20 % (same assumptions for Pb)Price Quote: $8.2 M Total weight: 17.6 ton

J.Franz

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Barrel HCal Placed behind W-Sc Shashlik EMCal

38.60

38.6038.60

38.60

|| = 1.05 || = 1.05

|| = 1.05|| = 1.05

|| x || segmentation = 0.1 x 0.1 1054 readout channels

Boundaries ofrapidity cells in HCal are shown

J.Franz

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Issues and Questions

1. What is the real occupancy in the EMCAL and HCAL and how does it affect the physics ? EMCAL - Preshower identifies single s and 0s up to high pT, but overlapping showers from other particles in the event affects the ability to measure their energy HCAL - What is the affect of the underlying event on measuring the jet energy ? - Can we really live with very coarse segmentation if we want to correlate hadronic energy with charged tracks ?

2. What will be the radius of the magnet ? Increasing the radius of the magnet will:

reduce the occupancy in both calorimeters allow more space for tracking and increase BdL, improve momentum resolution

allow more space for particle id increase the cost

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Issues and Questions

3. What energy resolutions do we really want in the EMCAL and HCAL ?

4. Is ~ ±1 units of large enough to measure the jet given that we also want to measure soft fragmentation components ?

5. Should we try and identify muons behind the HCAL ?

6. Preshower needs to be inside magnet regardless of radius. Probably needs to be Si strips or pixels to achieve the required separation resolution

7. Remainder of EMCAL could be inside or outside the magnet. Could use PMTs if outside. However, cost due to increased size will be higher

8. Multiple technologies available for HCAL (tile-WLS, SciFi).

9. Need to look more carefully at the forward direction (pp + HI). There will be a lot of interesting physics to study in this region well into the future and

it connects well with the eRHIC program.

10. Additional detector R&D and simulations are needed

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Areas for Detector R&DIn building a Compact Electromagnetic Calorimeter, there is a tradeoff between Moliere radius and energy resolution

Si-W provides good compactness, but cost is prohibitive at larger radii

Need to study/develop a compact, low cost optical readout calorimeter Two options:

• W-shashlik • W-accordion

What is the optimal sampling fraction ?• Minimize Moliere radius• Minimize sampling fluctuations while preserving energy resolution• Provide enough light output to produce usable signals and minimize

fluctuations due to photostatistics

Choose readout device• APD• SiPM• PMT

inside magnetic field

outside magnetic field

need to develop low cost W absorbers (Tungsten Heavy Powder, Inc)

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Backup Slides

C.Woody, Calorimeter R&D Workshop Report, 1/11/11 21M.McCumber

C.Woody, Calorimeter R&D Workshop Report, 1/11/11 22M.McCumber

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M.McCumber

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M.McCumber

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|| = 0.9|| = 0.9

|| = 0.9|| = 0.9

44.30

44.3044.30

44.30

10.3010.309.90 9.90 9.409.408.60 8.60 7.707.70

|| x || segmentation = 0.015 x 0.015

50400 readout channels

1 m is the closest distance to the beamline from WSc material1 2 3 4 5 6 7 8 9 10

35 supermodules azimuthally

10 supermodules along the beam

for later review not to be discussed now

Barrel Shashlik W-Sc EMCal J.Franz

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E.Smith

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E.Smith

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CALICECalorimetry for the International Linear Collider

Analog Hadron Calorimeter (AHCAL)(one option being studied)

Scintillator tile –WLS fiber calorimeter read out with SiPMs7609 tiles, each with individual WLS fiber and SiPM (Pulsar)

38 layer 1 m3 prototype tested

First large scale deployment of SiPMs

R.Fabbri, 2009 IEEE NSS/MIC Conference Record

F.Sefkow

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CALICE Si-W EM Calorimeter

F.Sefkow