R&D on W-SciFi Calorimeters for EIC at Brookhaven

E.Kistenev, S.Stoll, A.Sukhanov, C.WoodyPHENIX Group

E.Aschenauer and S.FazioSpin and EIC Group

Physics DepartmentBrookhaven National Lab

EIC Detector R&D Committee Meeting

May 17, 2012

Connection with other R&D Efforts at BNL on Calorimetry for EIC

C.Woody, EIC Detector R&D Committee, 5/17/12 2

• The PHENIX Collaboration is currently pursuing a major new upgrade effort → sPHENIX

• Main physics goal is to measure jets in heavy ion collisions

• Includes two new calorimeter systems Hadronic (first in any experiment at RHIC) Electromagnetic (W-SciFi accordion)

• R&D on calorimetry in general is an area of overlap with future interests at EIC, but primarily focus now is on an EMCAL

• Propose to combine parts of these efforts which would be of specific interest to EIC and not part of the PHENIX R&D plan into this proposal, along with simulation efforts on calorimetry for EIC from the BNL SPIN/EIC Group

C.Woody, EIC Detector R&D Committee, 5/17/12 3

HCAL Outer

HCAL InnerEMCAL

Solenoid

VTX

Coverage ± 1.1 in and 2 in EMCAL: Rinner=95 cm, T ~ 10 cm, L = 2.8m

sPHENIX EMCAL Requirements

C.Woody, EIC Detector R&D Committee, 5/17/12 4

• E/E ~ 18%/√E (~ 1 X0 sampling) - want much better resolution for EIC

• Need high segmentation for central heavy ion collisions - not as strong a requirement for EIC

• Energy range up to ~ 50 GeV in the central region for jets - may be similar for EIC, although generally lower E

• Must be compact (small Moliere radius, short radiation length) - small size low cost

• Tungsten scintillating fiber accordion satisfies these requirements - new technologies with tungsten materials makes this possible

• Readout must work inside a magnetic field - silicon photomultipliers are the preferred option

Optical Accordion Calorimeter

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Accordion design similar to ATLAS Liquid Argon Calorimeter

• Volume increases with radius

• Scintillator thickness doesn’t increase with radius, so either tungsten thickness must increase or the amplitude of the oscillation must increase, or both

• Plate thickness cannot be totally uniform due to the undulations

• Small amplitude oscillations minimize both of these problems

Want to be projective in both r- and

C.Woody, EIC Detector R&D Committee, 5/17/12

Sintered Tungsten Plates

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Variable thickness W-platesScintillating fibers in between

Density ~ 17.5 g/cm3

Problem is that cannot make sintered plates larger than ~ 20 cm

Phase I SBIR with

20 cm

C.Woody, EIC Detector R&D Committee, 5/17/12

Tungsten SciFi Epoxy Sandwich

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Scintillating fibers~ 0.5 – 1.0 mm

Pure tungsten metal sheet ( ~ 19.3 g/cm3) Thickness ~ 0.5-1.0 mm

Tungsten powder epoxy (~ 10-11 g/cm3)

Uniform thickness, thin pure tungsten metal sheets with wedge shaped SciFi + tungsten powder epoxy layer in between

Can be made into larger modules (> 1m)

C.Woody, EIC Detector R&D Committee, 5/17/12

Readout and Light Yield

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Want to have small photostatistics contribution to the energy resolution

Need sufficient light output from fibers to allow randomizing and collecting the light onto a small readout device

SiPM

ScintillatingFibers

Small reflecting cavity or wavelength shifting block

Possible Readout Schemes

C.Woody, EIC Detector R&D Committee, 5/17/12

SiPM direct readout of scintillating tile with “dimple”

F.Simon & C.Soldner, NIM A620(2010) 196-201

glued 6x6 fiber bundle

adc channels

0 100 200 300 400

coun

ts

0

100

200

300

400

500

bundle on pmtfit (mean=202ch ~ 100 pe/MeV)

Light output from fibers ~ 100 p.e./MeVConsistent with UCLA beam test measurement

Readout Devices & Electronics

9C.Woody, EIC Detector R&D Committee, 5/17/12

Considering two types of readout devices: SiPMs and APDs•SiPMs

• Higher gain (~106)• High noise (~ few MHz/mm2 at ~ 1 p.e. level)• Sensitive to temperature and voltage

G ~ (Vop-Vbr), Vbr varies with T (~50 mV/°C dG/dT ~ 10% /°C)

• Limitation on dynamic range due to finite number of pixels

Need to “tune” light level to stay within “linear” range New SiPMs being developed (AdvanSiD, Zecoteck,…) with more pixels/mm2 and (hopefully) high PDE

•APDs• Gain ~ 50-100 • Better linearity• dG/dV ~ 3%/V, dG/dT ~ 2% /°C

HamamatsuS10362-33-25C

3x3 mm2 14.4K 25 m pixels

Readout electronics must be designed to match• SiPM – high gain don’t need ultra low noise electronics (currently being developed within PHENIX)• APD – requires higher gain, lower noise front end

Both will require temperature stabilization and gain monitoring

R&D Goals for this Proposal

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• Develop W-SciFi technology that would allow building a high resolution electromagnetic calorimeter that is specifically optimized for EIC.

• Utilize parts of the R&D program within the PHENIX Collaboration, which is exploring similar technologies for sPHENIX, to leverage the effort on this design

Note: The R&D for EIC would focus only on work that would not be done within the context of the PHENIX effort.

• Study techniques to build modules with finer sampling and/or higher sampling fraction using the layered sandwich technique that would achieve the best possible energy resolution

• Study readout schemes to optimize the light levels for different readout devices (SiPMs and APDs) that would be most suitable in terms of gain, linearity and dynamic range for the energy range at EIC

• Develop the readout electronics that would best match the calorimeter design and readout scheme that would be optimized for EIC

• Generate simulation results to provide feedback and guidance on the calorimeter design

C.Woody, EIC Detector R&D Committee, 5/17/12

R&D Plan

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Year 1 Study and develop a high resolution EMCAL module design using the layered sandwich technique that is optimized for EIC applications

1. Fabricate and test module layers with finer sampling and/or higher sampling fraction (e.g., using thinner tungsten plates, smaller diameter fibers, etc.)

2. Study methods for embedding fibers that allow projective module construction3. Study light collection and mixing schemes that allow the use of either a single or

limited number of readout devices which provide sufficient photostatistics4. Develop the readout electronics to read out the device(s) used with the light mixer(s)5. Build several high resolution modules using the optimized designs from (1-4)

Year 2 Construct one or more full scale prototype modules with a high resolution design and fully characterize them in a test beam

• Modules ~ 20 x 20 cm2 x 10 cm deep (10 x 10 towers)• Build readout electronics for prototype modules• Carry out beam tests in collaboration with the UCLA/TAMU/PSU group

C.Woody, EIC Detector R&D Committee, 5/17/12

Simulation results and feedback are provided throughout years 1 and 2

Budget

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Note: Funding request is for items that would not be covered as part of the PHENIX R&D effort or the SBIR with Tungsten Heavy Powder

C.Woody, EIC Detector R&D Committee, 5/17/12

Item Year 1 Year 2Materials and supplies for testing fine sampling modules 10Materials and supplies light output studies 10Development of readout electronics and DAQ 5 10Technical support and designer 5 10Construction of full scale high resolution prototype module 40Test beam activities 15Total Direct 30 75Overhead (50%) 15 37.5Total (including overhead) 45 112.5