Design and Prototype Test ofSCINTILLATING FIBER TRACKER

Zhihong Ye

Duke University

JLab User Group Meeting, 06/03/2014

Supported by 2014 JSA Postdoc Prize

High resolution, large acceptance, hybrid HyCal calorimeter (PbWO4 and Pb-glass)

Measure GEp within Q2 range of 2x10-4 – 2.0x10-2 GeV2 (lower than all previous (e,p)

experiments)

Simultaneous detection of elastic and Møller electrons

Windowless H2 gas flow target

Spokesperson: A. Gasparian, D. Dutta, H. Gao, M. Khandaker

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Original Motivation: The Proton Charged Radius Experiment (PRad) in Hall-B

To increase the resolution at the lowest Q2

points, we decied to add a new position

detector with additional features:

Thin Not too much space between

Vacuum Box Exit and HyCal

Minimum radiation materials Control

the background events at a small level.

Allow a hole at the center for the

electron beam to go through

Add a new position detector here

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Possible Candidates of Position Detectors (or Tracking Devices):

o Drift Chambers (DC)

• Provide <100 um position resolution; Thin; Widely used;

• No enough time to design, built and test a 1.2 meter x 1.2 meter large DC;

• Hard to produce a hole at the center;

GEM current selection

High tracking resolution (<100um) and good timing (~ 10ns); High rate; Insensitive

to EM field

UVa (Nilanga Liyanage’s group) can produce 120cm x 60cm plates;

A hole can be produced;

Can be ready before the experiment; Readout electronics are available;

Scintillating Fiber Tracker (SFT) as a backup due to the lack of time, man-power and

experience

• Good position resolution: e.g. 1mm fibers can give as good as ~300um;

• Thin, e.g. 1 mm plastic fiber gives only <0.3% radiation length;

• Replace Veto-Counter to perform precise time-measurement at the same time

• A hole can be easily produced.

• And more advantages!

Original Motivation: The Proton Charged Radius Experiment (PRad) in Hall-B

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Scintillating Fiber Tracker: Advantages

Scintillating Material: emits visible lights via de-excitation when a charged particle

deposits its energy through ionization process;

Scintillating Fiber (SciFi): A core of scintillating materials with one or several layers

of thin cladding with lower index of refraction;

Good Time Response: SFT can provide better timing measurement than DC and

GEM;

Without Gas Systems: Unlike GEM and DC;

Easy Handling: Easily installed, stored and transported; can be used in vacuum or

high EM field;

Easy Analysis: We just need to determine which SciFi is fired (“YES/NO” algorithm).

This new SFT can have a wide application in many projects!

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Scintillating Fiber Tracker: Previous Developments Existing similar detectors (since 1990s):

Mainly applied in Medical Imaging (small size):

e.g., Proton Computed Tomography Scanner (FERMILAB-PUB-12-067-E), INFN

D0 in Fermi Lab: 0.84 mm SciFi + Visible Light Photon-Counter (VLPC)

Four concentric cylinders (Nucl. Phy. B 61B (1998) 384-389)

KAOS in Mainz: 200cm wide 50cm long 0.25mm SciFi + Multi-Anode PMT

200cm x 50cm, only the vertical plane (C. Ayerbe Gayoso, PhD thesis) by INFN

New detectors under developing:

LHCb: 300cm long 0.25mm round SciFi+ Silicon Photon

Multiplier

250cm x 300cm, 5 super layers, only the vertical plane

COMPASS, HERMES, SONTRAC, etc …

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Scintillating Fiber Tracker: Our Design The new SFT proposed for PRad:

120cm x 120cm active area

SciFi would be about 1.5m long

X&Y position tracking on electrons

Two perpendicular planes, each has two layers of

SciFi

Time measurement on electrons

replacing veto-counter to reject photons

A hole at the center allowing the beam pipe to go

through

What we should know before we build:

What type of SciFi? How many layers?

How to assemble the SciFi?

How to mount the SciFi on the supporting structure?

What type of photon-detector?

Silicon Photon Multiplier (SiPM) or Multi-Anode PMT (MaPMT) ?

What Read-Out system?

How to reduce the cost?

For 1mm SciFi (300um resolution), ~4800 fibers and ~2400 output-channels!(If combining two-fibers and reading out signal from one-end)

Detector Frame

Photon-Detectors on one side only

Two fibers as one readout

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Prototype Test Project:https://wiki.jlab.org/pcrewiki/index.php/Prototype_Test

Propose the project

The Plan

Prepare Setup

Test SciFi Test SiPM

Purchase Samples

Purchase & Assemble

SciFi

Design Mounting

Frame

Purchase / Make(Detectors, PS,

PreAmp)

Test Tracking Performance (with beam?)

Here we are!

Read-Out System (FastBus, fADC, others?)

The SFT Prototype:

5 cm x 5 cm active area

50 (X) and 50 (Y) read-out channels

200 1.5 meter long SciFi

100 SiPMs

Mounting Frame and Supporting

Struecture

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Prototype Test Project: The Hall-a Laser Lab shared with SoLID-EC test

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Prototype Test Project: SciFi Test

Selection of

SciFi:

Option 1 ---Square Fiber

12D

Charged Particle Direction

Option 2 ---Round Fiber

Good: Smaller Gaps (maximize the detection efficiency), Easier Align&Assembling

Bad: Shorter Attenuation Length

Numbers about SciFi claimed by manufactures:

~8000(?) photons/MeV for each MIP within a 1mm fiber;

~3.1% Trap-Efficiency for Single-Clad (~5.4% for Multi-Clad);

~ 3 ns Decay Time;

~4 m Attenuation Length (for blue light);

Position Resolution: , where D is the diameter

of the fiber

Good: Longer Attenuation Length

Bad: Larger Gaps, Poor Trap-Efficiency (position dependence)

We look for one type of SciFi that has: Strong Light-Yield, Mechanically Strong, and

High Detection Efficiency.

For our SFT with 150 cm fibers, square fiber may be better.

Multi-Clad

Single-Clad

Considering the quantum efficiency of photon-detector (<30%), 1-mm SciFi gives <50 p.e. on each end, but it should be much lower in reality .

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New Fiber-Samples from Kuraray:

1, x2 SCSF-78MJ , 1mm, Round, 3meters, Multi-

Clad

2, x2 SCSF-78MSJ , 1mm, Round, 3meters,

mechanics stronger, Single-Clad (30% less

light yield)

3, x2 SCSF-78J, 1mm, Square , 3meters

4, x2 SCSF-78J, 1.5mm, Square , 3meters

From Hall-D: x8 SCSF-78MJ 1mm, Round, 2

metersGoal: Measuring the Light-Yield and Attenuation Length for different types of SciFi.

SciFi Testing Setup:

The SciFi being testing:

SciFi Polishing Tools

Prototype Test Project: SciFi Test

3um2um 1um

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Scintillator (HallC)

1-inch PMT (Hall-C)

SciFi

Ru106 Radiation Source

Mounting Block

We built a 200cm x 20cm Black-Box !

SciFi Testing Setup:

Thank you! Walter Kellner @Hall-C Machine Shop!

Prototype Test Project: SciFi Test

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Checked the signals with

Oscilloscope;

Will take data with DAQ this

week;

Hall-D has done many tests with

78MJ which gives ~ 8 p.e.;

~20 p.e. would be a good

number to get high detection

efficiency (add two fibers);

The fibers are needed to be

polished with better tools

(borrowing a polishing-machine

from Hall-D).

Hall-D’s experiences and test

results can be adopted!

SciFi Testing Setup: Quick check1mm 78MJ-Round

1mm 78J-Square 1.5 mm 78J-Sqaure

1mm 78MSJ-Round

~8 p.e.~5 p.e.

~7 p.e. ~10 p.e.

Prototype Test Project: SciFi Test

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Assembling & Mounting: Just a plan.

Carl Zorn and Brian Kross, etc. in the Detector Group have

given many suggestions

Will learn from Carlos Ayerbe who built the SFT for

KAOS@Mainz:

http://wwwa1.kph.uni-mainz.de/A1/publications/doctor/ayerbe.p

df

Mark Emamian from Duke is helping the Mounting Frame

design.

Rohacell Foam+Carbon Fiber Foil

Solution: Glue them on a plane with Rohacell

foam+carbon fiber foils

Problem: Adding more dense materials (potential

radiation background)

Optical Glue

Rohacell Foam

Aluminum Frame

Fibers

The plan is divided into groups

Mounting Cookie on each end (Scheme Draw)

Screw

Challenge for us– How to avoid the horizontal SciFis to

bend down?

Prototype Test Project: SciFi Test

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Photon Detectors: 1, SiPMs: Silicon Photon Multiplier

Cheap ~$10 per SiPM+~$10 power supply+~$10

Pre-Amp;

Large Gain ~~ x106 ;

Insensitive to magnet field

Need a Pre-Amp Design Hall-D has a very good

design

Gain is temperature-depended

Relatively larger dark current;

Radiation damage by the neutron background;

Cross-Talk

Hamamatsu Multi-Pixels Photon Counter (MPPC)

Used in Hall-B & Hall-D for testing

We newly purchased

Hamamatsu MPPC S12572-100P/50P

Prototype Test Project: SiPM Test

One photon only fire one pixel (unless cross-talk or dark-current)

SiPM Avalanche Photodiode (APD) pixels working in Geiger-mode

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Photon Detectors:

2, MaPMTs (possible candidate)

From Carlos Ayerbe’s thesis

More commonly used;

Multi-channels outputs

Much cleaner background;

High radiation tolerance;

Degraded performance in strong

magnet field;

Cross Talk

Expensive;

Our Duke group has a 64ch H8500 MaPMT for test

We will borrow a 16ch MaPMT from SBS

Prototype Test Project: SiPM Test

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SiPM Test Setup:

4mm Scin. Strip+SiPM

Goal: Understand the performance of the SiPM --- Gain, Noise Level, Stability with Temperature, ADC & TDC spectra.

Fiber+SiPM Mounting Block

SiPMs with Pre-Amp (Hall-D)

SiPMs with Pre-Amp (Stepan@Hall-B)

High Precision Power Supply (Hall-D)

x2 Low Voltage Power Supplies (Hall-A&-D)

Black Box (from Simona Malace) Temperature Sensor

Thank you, Walter Kellner!

Prototype Test Project: SiPM Test

Fan

Sr90

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SiPM Test Setup: (Stepan’s SiPMs+Pre-Amp)

1 p.e.

2 p.e.

3 p.e.Hamamatsu

Measurements(what we

expect to see)

Not yet seen pretty pattern from

scope

More to learn about SiPM

Data taking with DAQ will be

proceeded soon;

1 p.e.2 p.e.

3 p.e.

Prototype Test Project: SiPM Test

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Read-Out System of >2400 Output

Channels:1, SiPM (or MaPMT) + FastBus ADC + TDC

Requires a large amount of NIM modules and long

delay cables

2, SiPM (or MaPMT) + fADC

Need >20 fADC & VME64 which are rare and

expensive

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3, A “Cheaper” Solution EASiROC for SiPM or MaROC for MaPMT

Developed by OMEGA@IN2P3;

Pre-Amp integrated with adjustable Low/High Gains;

ADC outputs and TDC outputs;

One “OR” logic output for triggering; One “SUM” analog output;

~$130 for each chip (or <$5 per channel);

Need an additional readout board (“expensive”)

Prototype Test Project: Read-Out System

OMEGA Test Board (USB readout)

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SiTCP read-out board designed at KEK (TCP/Ethernet 1Gbps )

32ch Inputs with adjustable High/Low Gain

32 ADC Outputs

32 TDC Outputs

Logic Output

EASIROC (or the new version called CITIROC)

NIM-based Read-Out Board designed by I. Nakamura (KEK) for J-PAC

A new MaROC3 with a read-out

board (USB port) has been

purchased for SoLID-EC test; We

will study its performance with

SULI students’ help.

Read-Out System of >2400 Output

Channels:

With EASIROC+SiPM or MaROC+MaPMT,

the SFT will be “portable”!

Prototype Test Project: Read-Out System

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Summary:

SFT provides a great option to improve the PRad experiment and can be applied to many

other projects.

Prototype Testing Project is undergoing:

(1) It took a few months to prepare the setup due to very limited resources.

(2) Received and receiving many helps from colleagues in Hall-A/B/C/D, Detector Group,

Duke Univ, etc.

(3) We have almost everything set up and will have some serious results very soon.

Near Term goals (not working n full-time):

Test and choose SciFi;

Test SiPM and MaPMT

Design and build the mounting structure

Assembling the 1.2m x 1.2m SFT is challenging but practicable.

Three options of the read-out systems are available.

Highly appreciate your suggestions and helps, and welcome to join.

I hope one day the full size SFT can be built!

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I am grateful to receive many helps from:

Hall-A: Alexandre Camsonne, J-P Chen, Jack Segal, etc

Hall-B: Sergey Boyariov, Stepan Stepanyan, Youri Sharabian, etc.

Hall-C: Joe Beaufait, Mark Jones, Walter Kellner, Simona Malace, Brad

Sawatzky, etc

Hall-D: Elton Smith, Yi Qiang, etc

Detector Group: Brian Kross, Wenze Xi, Carl Zorn, etc.

RadCon: Adam Hartberger

Many other colleagues and friends

Special Thanks are given to:

• JSA User Board that give me the Postdoc Prize and offer me such a

precious opportunity

• Hard working Graduate Student: Chao Peng (Duke), Li Ye (Mississippi

Statue)

• Brad Sawatzky and Yi Qiang who lend me many instruments and help

me to complete the setup

• Prof. Haiyan Gao, Yi Qiang and Stepan Stepanyan who give me many

advices to design and

carry out this project.

• Prof. Donal Day, Prof. Haiyan Gao and Doug Higimbotham who provide the

reference letters.

• And the PRad collaboration & SoLID collaboration.

Acknowledgement:

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BACKUP SLIDES

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Cost Estimation of the Full-Size SFT:

• Each Fiber: 1mm width ( round or square ) is $1 per meter.

for 1.2m x 1.2m, we need roughly 2400 1.5m-long fibers for each plane to cover the

gaps.

for x-y two planes, 4800 fibers ~ $7.2 K

• Photo-Detector: SiPM module $10 for each channel quoted from Hamamatsu.

Amplifier used in Hall-D: $10 for each channels ( plus Design Fee $???)

Power Supply (~$10 for each channel)

For one-end read-out: 2400 channels x $30 per channel ($72K + engineer design of the

Pre-Amp)

• Mounting Frame and Supporting Structure ($???)

• Connectors + Cables + Tools + Supplies ($???)

• ReadOut+DAQ:

From SiPM to raw data: Discriminators, FastBus ADC & TDC (40 cards for each) (or fADC

)

OR: EASIROC --- $100 for 32 channels

+ Read-Out Board ( we need to borrow designs and make all by ourselves ~$1500 per

board or cheaper)

Total Read-Out: ~$120K

~~$80K