Calorimeters Design Issues and Simulation Needs

C.Woody

Physics DepartmentBrookhaven National Lab

EIC Simulation Workshop

Oct 9, 2012

C.Woody, EIC Simulation Workshop, 10/9/12 2

Design Issues for a Calorimeter System for an EIC Detector

• Must cover the phase space and kinematic range necessary to carry out the suite of physics measurements at EIC

• The requirements are different in different regions of phase space

• Must work in conjunction with the tracking system of the EIC detector to provide the necessary energy/momentum resolution to carry out the physics measurements

• The calorimeters must cope with the backgrounds produced by the machine and surrounding materials, and must survive the radiation environment

• The detectors must work in the presence of a strong magnetic field

C.Woody, EIC Simulation Workshop, 10/9/12 3

EIC Detector – Conceptual Design Central Detector Forward/Backward Detectors

• Large acceptance: -5 < h < 5• Asymmetric• Nearly 4p tracking and EMCAL coverage• HCAL coverage in central region and hadron direction • Good PID • Vertex resolution (< 5 mm)

• Electron is scatted over large range of angles (up to ~165˚)

• Low Q2 → low momentum (~ few GeV)• Requires low mass, high precision

tracking

EM

EM

EMEM

EM

HAD

HAD

HAD

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Momentum and Angle ResolutionFrom the sPHENIX MIE Proposal (T.Hemmick)

electron direction

proton direction

5 x 100 5 x 250

Measurement of FL(x,Q2)Assumption: To measure yield to 1% requires 20%

uncertainty due to bin shifts

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Kinematic Coverage and Resolution - DISFrom the sPHENIX MIE Proposal (S.Bazilevsky)

h<-1 |h| < 1

e ep

pg

g

Energy resolution is especially important at low y

Defines “reach” in y (→ higher x)

h<-1 |h| < 1 Ee vs hNote: Cutting out low momentum electrons (E<1 GeV) does not loose much in x and Q2

C.Woody, EIC Simulation Workshop, 10/9/12 6

Kinematic Coverage and Resolution - DVCS

h<-1h>1 |h| < 1Eg vs h

From the sPHENIX MIE Proposal (S.Bazilevsky)

DVCS photon is mainly in central region and fairly low energy

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Energy Resolution vs Tracking ResolutionS.Bazilevsky, FSU PHENIX Collaboration Meeting

EMC = Track a=5% E ~ 2.7 GeVa=10% E ~ 4.2 GeVa=20% E ~ 7 GeV

Tracking: p/p = 0.01p + 0.01

EMCal: E/E = a/sqrt(E) 0.02

= Track, if Track < EMC

= EMC, if EMC < Track

Tracking only

a=10% a=20%

Resolution on x and Q2 (5 x 250)

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HCAL Outer

HCAL InnerEMCAL

Solenoid

VTX

Coverage ± 1.1 in h and 2p in f

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sPHENIX CalorimetersTungsten-Scintillating Fiber

“Optical Accordion” EM Calorimeter

Scintillating Tile WLS Fiber HCAL

SiPM+ Mixer

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sPHENIX Calorimeter Simulations (GEANT4)

resolution = (14.0 0.2)%/E

10 GeV electron shower 10 GeV pion shower

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STAR Forward Calorimeter

C.Woody, sPHENIX Review - EMCAL, 10/5/12 11

Spacal/SpacordionTungsten Powder/Epoxy/SciFi

Results from beam test at Fermilab (Jan 2012)

O.Tsai, H.Huang (UCLA)

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STAR Forward Calorimeter Simulations O.Tsai (UCLA)

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PWO Crystal Calorimeter for PANDAEndcap3864 crystals

R. Novotny, CALOR12

11360 PWO-II crystals200 mm long

Barrel

15 GeV Positrons

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P.Adzic et.al., JINST Vol.5 (2010) P03010

Radiation dose after 500 fb-1 (~ 10 yrs)

CMS Crystals

Radiation Effects on Detectors

JLAB SiPMsY.Qiang et.al, arXiv:1207.3743v2,17 July 2012

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Needs for Monte Carlo Simulation(not an all inclusive list…)

• Further refinements are needed on the calorimeter requirements for energy resolution, segmentation, etc over the required kinematic range.

This needs to be integrated with the requirements on the tracking system for momentum resolution, vertex capabilities, etc over the same kinematic range.

The calorimeters and tracking detectors should be considered as a combined system when looking at these requirements. • Improve simulation models of some of the proposed detector designs (e.g., include

realistic geometry of absorber and active material, effects of light collection, dead material, etc). This is important to study the non-uniformities that may exist in the proposed designs and could lead to important systematic effects.

• Improved simulations of machine backgrounds that generate backgrounds in the various detectors (particularly soft electrons, gammas and neutrons)

• Compute radiation levels and neutron fluences over the solid angle subtended by the various detectors. This needs to include a realistic model of the IR design and the overall detector itself.

• ….C.Woody, EIC Simulation Workshop, 10/9/12