Status of R&D on Calorimetry for EIC

EIC Detector R&D Committee MeetingJune 5, 2013

The EIC Calorimeter R&D Consortium Contact Persons: H.Z. Huang huang@physics.ucla.edu and C. Woody woody@bnl.gov  

S.Boose, E. Kistenev, E.Mannel, S. Stoll, A. Sukhanov, and C. Woody(PHENIX Group, Physics Department)

E. Aschenauer, T.Burton, R.Darienzo and A.Kiselev(Spin and EIC Group, Physics Department)

Y. Fisyak(STAR Group, Physics Department)

Brookhaven National Laboratory

W. Jacobs, G. Visser and S. WissinkIndiana University

S. HeppelmannPennsylvania State University

C. GagliardiTexas A&M University

L. Dunkelberger, H. Z. Huang, G. Igo, K. Landry, Y. Pan, S. Trentalange and O. Tsai University of California at Los Angeles

Y. Zhang, H. Chen, C. Li and Z. TangUniversity of Science and Technology of China

C.Woody, EIC Detector R&D Committee, 6/5/13 2

Areas of Investigation

Tungsten Powder Epoxy Scintillating Fiber Calorimeter (W-SPACAL) • UCLA/IU/TAMU/PSU/BNL (STAR design)

Tungsten Scintillating Fiber Accordion Calorimeter• BNL (sPHENIX design)

SiPM readout system• BNL/IU (PHENIX + STAR)

BSO Crystal Calorimeter• USTC

Monte Carlo simulations (A.Kiselev’s talk)• BNL

C.Woody, EIC Detector R&D Committee, 6/5/13 3

Dedicated EIC Detector

ToRoman Pots

Upstreamlow Q2

tagger

HCAL HCALECAL ECAL

ECAL

RICHRICH

DIRC/proximity RICH

h-h

TPC/HBD

Planar GEM Tracker

C.Woody, EIC Detector R&D Committee, 6/5/13 4

Calorimeter Requirements• Endcap EMCAL at h < 0 (electron going direction)

• Needs to be high resolution (~ 1-2 %/√E) in order to measure electron energy well (solenoid field does not provide good momentum resolution in forward/backward directions)

• Best choice is scintillating crystals • PWO (similar to PANDA)• LSO/LYSO (excellent resolution but very expensive)• BSO (under development by this group)

• Barrel EM calorimeter• Need ~ 12%/√E when combined with tracking • Want to be compact (short X0 and small RM) in order to fit inside solenoid • Best achieved with tungsten absorber with scintillating fiber readout

• STAR design – tungsten powder epoxy with embedded scintillating fibers• sPHENIX design – tungsten metal plates with layers of scintillating fibers in between

• Forward EM calorimeter• Assumed to be similar to barrel design

• Forward and backward HCALs• Need ~ 40%/√E for single particles• sPHENIX HCAL (steel/scintillating tile with WLS fiber readout) • STAR forward HCAL (Pb/scintillator plates similar to ZEUS design)

C.Woody, EIC Detector R&D Committee, 6/5/13 5

Tungsten Powder Epoxy SciFi Calorimeter

Progress since last meeting (Dec 2012):

Short summary of what has been done

C.Woody, EIC Detector R&D Committee, 6/5/13 6

Slides from Oleg

C.Woody, EIC Detector R&D Committee, 6/5/13 7

Tungsten Scintillating Fiber Accordion Calorimeter

Progress since last meeting (Dec 2012):

We received 22 accordion shaped tapered thickness tungsten plates from Tungsten Heavy Powder (Phase I SBIR). Unfortunately they were the wrong thickness (~ 1.3 mm instead of 1.0 mm) due to a miscommunication between THP and the Chinese factory.

We nevertheless constructed a 2x7 tower prototype using these plates which allowed us to :

• Investigate different types of adhesives for gluing sandwiches and forming the absorber stack

• Develop a procedure for pre-forming scintillating fibers• Develop new tooling for assembly• Develop a procedure for gluing and assembling the absorber stack• Investigate white reflective epoxies for embedding fibers at readout end• Investigate white reflective paints and coatings for light collection cavities• Study the light collection efficiency and uniformity of light collection cavities • Produce a light collection cavity box for the prototype

C.Woody, EIC Detector R&D Committee, 6/5/13 8

Difficulty Controlling Shape and Tolerances on Accordion Plates

• Tungsten plates undergo “spring back” during cooling.

• Difficult to control shape to better than ~ 0.5 mm with current process

• However, can do post annealing which can restore the shape to much better precision. However, this will increase

the cost.• Can also achieve very high precision for

accordion shape with Electron Discharge Machining of pure tungsten metal. Can only do 20 cm wide plates, but cost should be much lower.

Not giving up on the accordion, but we are also now looking at flat tapered

plates that would be oriented at a small tilt angle to avoid channeling

Plastic mold made to same desired shape as accordion plates

C.Woody, EIC Detector R&D Committee, 6/5/13 9

Making Sandwiches

S.Stoll

• Fibers are glued together at ends to form ribbons

• Ribbons have considerable spring back to be flat

• Place ribbon in warm water bath (~ 80° C) to preform them into accordion shape

• Glue preformed ribbon between two tapered thickness accordion plates (each ½ the final absorber thickness) to form a sandwich

Fiber ribbon

Sandwich after gluing

Single plate with fiber ribbon on top

C.Woody, EIC Detector R&D Committee, 6/5/13 10

Correcting for the Attenuation Length along the Fiber

150mm long SCSF78MC fibers, preformed and epoxied with RHINO epoxy (no plates).readout ends treated with black latex paint, far ends wrapped with teflon.

source position scanning along ribbon (mm)

0 20 40 60 80 100 120 140

pe m

eas

ured

at

pm

t

0

20

40

60

80

100

epoxy, 38mm paintepoxy, no paintepoxy, 40mm paintepoxy, 25mm paint

region of epoxy

region of paint

S.Stoll

C.Woody, EIC Detector R&D Committee, 6/5/13 11

Assembling and Gluing the Stack

S.Stoll

Stack of 10 sandwiches before gluing Stack inside gluing fixture developed by THP

Tooling fixture allows for pitch of tapered plates Stack after gluing

C.Woody, EIC Detector R&D Committee, 6/5/13 12

Add a Diffusing Reflector on the Readout End

S.Stoll

• Want to cover ends of tungsten plates at the readout end of the stack with a diffusing reflector to improve light collection

• Pot ends of fibers with a mixture of white reflector and epoxy

• Opposite end is covered with a mirror reflector (Al mylar)

C.Woody, EIC Detector R&D Committee, 6/5/13 13

Towers are formed by Segmenting Readout End with Light Collecting Cavities

S.Stoll

22 mm

• Collector box is 3D printed from engineering drawing

• Cavities are coated with a white diffusing reflector

• SiPMs can be mounted to the sides of the cavities

14C.Woody, EIC Detector R&D Committee, 6/5/13

Light output from fibers embedded in glue(measured with PMT)

4% sampling fraction 40 x 103 g/GeV (Edep in cal)SiPM PDE ~ 0.25 10,000 x (Light Collection Factor) p.e./GeV in calorimeter

Light Collection Efficiency and UniformityLabsphere 6080 coated cavity

position (mm)

1.5 4.5 7.5 10.5 13.5 16.5 19.5

posi

tion

(mm

)

1.5

4.5

7.5

10.5

13.5

16.5

19.5 3.2 3.4 3.6 3.8 4.0 4.2

SiPM

percent of injected light collected by 3x3mm SiPM:

AVG efficiency: 3.5%MAX effic. : 4.2%min effic.: 3.0%MAX/min: 1.4

• Light collection efficiency is ~ 3.5% with a single 3x3 mm2 SiPM

• Non-uniformity is ~ 40% (max/min) with single SiPM

• Would expect ~ 14% efficiency and much better uniformity with 4 SiPMs (next on our list….)

~ 200 p.e./MeV 1000 g/MeV (Edep in scint)(PMT QE = 0.20)

15

Linearity and Dynamic Range

C.Woody, EIC Detector R&D Committee, 6/5/13

• Increasing the number of readout devices increases the number of photoelectrons and improves the light collection uniformity of a single tower, but does not help with linearity (each device sees the same flux)

• However, can lower flux and gain back p.e. yield by adding more devices, which does improve linearity

• Can add inputs passively into a single preamplifier or have a separate preamp for each device

• Is it necessary to have separate bias stabilization, temperature compensation and gain adjustment (for matching) for each device ?

measured and simulated photon distribution on 3x3mm MPPC s10931-025p14400 upixels, 25um upixels, pde=0.172 (@337nm)

incident photons

0 50x103 100x103 150x103 200x103 250x103 300x103

up

ixe

ls f

ired

0

2000

4000

6000

8000

10000

12000

14000

16000

simulation dataexponential fitlinear (pde)measured data

y = a(1-e-bx)

a = 14404b=1.1966e-5

Light Pulse Amplitude

16

SiPM Readout Electronics (PHENIX)

C.Woody, EIC Detector R&D Committee, 6/5/13

• Readout system being developed for sPHENIX• Preamp (voltage amplifier)• Temperature sensor (thermistor) for each SiPM• Feedback to bias voltage for temperature stabilization and control• Also developing 12 bit ADC

Setup for testing SiPMs• Bias control• Temperature stabilization• Linearity measurements

12 bit

12 bit

Compensation of gain variation with temperature of a Hamamatsu S10931-025P

See contribution to this year’s NSS/MIC by E.Mannel for details

C.Woody, EIC Detector R&D Committee, 6/5/13 17

SiPM Readout Electronics (STAR)• Readout system being developed for SPACAL and STAR FCS (proposed)

• Compact integrated module 22 × 22 × (25) mm3

• Four SiPM devices summed• Low power transimpedance amplifier (one for four SiPM)• Local bias voltage regulation from unregulated −90V input• Thermistor (one) compensates bias voltage with adjustable slope• Signal range >4000 pixel (for beam test)• Gain matching achieved by monitoring individual and summed single-pe signals

prototype board(“unfolded”)layout in progress

interfaces, DAC,cable driver

voltage regulators

MPPC’s, preamp

21 × 21 mm2 sections

G.Visser

C.Woody, EIC Detector R&D Committee, 6/5/13 18

Radiation Damage in SiPMs

GlueX CMS

C.Woody, EIC Detector R&D Committee, 6/5/13 19

Neutron Flux measurements from STAR

Slides from Oleg

C.Woody, EIC Detector R&D Committee, 6/5/13 20

New Hamamatsu SiPMs (MPPCs)

“Improved materials and wafer process technology” results in:

• Reduced after pulsing and cross talk• Lower noise• Higher PDE• Wider dynamic range and better linearity (10 mm and 15 mm micropixel

devices available)• Faster recovery time• Available in 1x1 mm2 and 3x3 mm2 devices

C.Woody, EIC Detector R&D Committee, 6/5/13 21

R&D on Crystal Calorimeters

Progress since last meeting (Dec 2012):

Short summary of what has been done

C.Woody, EIC Detector R&D Committee, 6/5/13 22

Slides from Yifei

23

Summary of R&D Over the Past 6 Months

• Continued development of the new W-SPACAL prototype

• Constructed a 2x7 tower prototype of the tungsten Scifi accordion. Plates were not ideal, but it allowed us to develop the procedure for assembling the absorber stack and test various calorimeter components

• Learned that current method for producing accordion plates will not allow achieving sufficient tolerances on larger plates. Will explore other methods for producing accordion plates and also investigate tilted tapered flat plate geometry

• Produced and studied a number of BSO crystals and determined that crystals of suitable quality could be produced.

• Developed circuitry for bias stabilization and temperature control of SiPMs and for reading out multiple SiPM in a single readout channel.

• Ordered 380 SiPMs (currently available Hamamatsu devices) for next prototype calorimeters as well as other long lead time tiems.

• Requested time for a beam test at Fermilab later this fall

C.Woody, EIC Detector R&D Committee, 6/5/13

24

Future Plans for the Next 6 Months

• Complete construction of new W-SPACAL prototype

• Construct a new 7x7 tower prototype tungsten SciFi accordion calorimeter with tapered flat plates which will have 0.5 X0 sampling ( 12%/√E).

• Complete BSO calorimeter prototype

• Develop SiPM control and readout electronics for both W-SciFi prototype calorimeters.

• Test all SiPMs for both detectors.

• Test both W-SciFi calorimeters in a test beam at Fermilab later this year

• Test BSO calorimeter in test beam (either Fermilab or Beijing)

• Order LYSO crystals for testing and comparison with BSO

C.Woody, EIC Detector R&D Committee, 6/5/13

C.Woody, EIC Detector R&D Committee, 6/5/13 25

Budget Requests for Year 2 Funding

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

BNL (same as in original proposal)

USTC (additional $75K)

Usage Cost (kUSD)

 

LYSO samples purchaseaim for a 3x3 prototype20x20x200mm each

40 Samples for R&D and testing, prototype design

Electronics, frame 15 PMT based read-out0.5 postdoc + 1 student 20 Labor for simulation and

testingTotal 75  

UCLA and other institutions – no additional request at this time

C.Woody, EIC Detector R&D Committee, 6/5/13 26

Backup Slides

C.Woody, EIC Detector R&D Committee, 6/5/13 27

Uniformity across the Fiber Ribbon

S.Stoll

150mm long SCSF78MC fibers, preformed and epoxied with RHINO epoxy (no plates).readout ends treated with black latex paint, far ends wrapped with teflon.

source position scanning across ribbon (mm)

0 10 20 30 40 50

pe

me

asu

red

at

pm

t

0

20

40

60

80

100

near edgefar edge

at far edge of glue (135mm)

at near edge of glue (8mm)

50 0

pmt

C.Woody, EIC Detector R&D Committee, 6/5/13 28

sPHENIX EMCAL and HCAL Prototypes

HCAL/EMCAL Prototype for beam test at Fermilab this fall

sPHENIX Hadron Calorimeter

C.Woody, EIC Detector R&D Committee, 6/5/13 29

Sampling Fraction of Accordion Calorimeter

GEANT4 simulation using approximate accordion geometry

50 tilt

11.50 tilt 1.25 cm

0.5 cm

2.4 mm2.1 mm1.0 mm 1.0 mm

W

scint

F 4.0% 3.6%

Simple answer based on dE/dx(for 0.6 X0 sampling)

Azimuthal dependence of radiation length seen by straight through particle

f

vs tilt angle(sPHENIX HCAL - flat wedge plates)

vs amplitude of oscillation of accordion

C.Woody, EIC Detector R&D Committee, 6/5/13 30

The PANDA PWO Calorimeter

Endcap3864 crystals

11360 PWO-II crystals200 mm long

Barrel

15 GeV Positrons

R. Novotny

C.Woody, EIC Detector R&D Committee, 6/5/13 31

Cost of LSO

From R.-Y. Zhu (Caltech), June 2012