卒業研究発表『J-PARCでのハイペロン陽子散乱実 …ndip.in2p3.fr/tours14/AGENDA/AGENDA-by-DAY/Presentations/...glued each other 4 0 0 m m Construction of CFT prototype

“ Development of a cylindrical tracking detectorwith multichannel

scintillation fibers and PPD readout ”

7th International Conference on New Developments In Photodetection

Yuya AkazawaTohoku University

for the J-PARC E40 collaboration

2

Contents Motivation for development

– Requirements Construction of Cylindrical Fiber Tracker

– Fiber construction– PPD Read-out

Performance evaluation

– Response for cosmic ray and proton

– Linearity

– Energy resolution

Summary

Liquid H2 target

BGO calorimeter

CFT

Σp scattering experimentΣp scattering experiment @J-PARC , Japan ⇒⇒ ΣN interactionMeasurement of dσ/dΩ of Σp scattering with high statistics

※ It is difficult to use Σ as a target or a beam ∵ lifetime (~10-10s) 　　　　⇒ need to produce Σ in a target

event identification by reconstructing kinematics

from θ and Ep'

of scattered protons

dEで粒子識別します

π±

beam

K+

S±

①Production

Liquid H2 target

BGO calorimeter

CFT

①Production π± + p → Σ± + K+




from θ and Ep'


p


NDIP2014 poster Honda Ryotaro

π±

beam

K+

S±

①Production

②ScatteringLiquid H

2 target

BGO calorimeter

CFTCylindrical Fiber Tracker(CFT) ・ Trajectory ・ Energy deposit PID⇒

BGO calorimeter・Kinetic Energy

S±'①Production π± + p → Σ± + K+

②Scattering Σ± + p → Σ±' + p'




from θ and Ep'

p'of scattered protons

p



π±

beam

K+

S±

①Production

②ScatteringLiquid H

2 target

BGO calorimeter



S±'①Production π± + p → Σ± + K+





from θ and Ep'

n

p±p'of scattered protons

p



Liquid H2 target

BGO calorimeter








from θ and Ep'



π Beam

K+

S'n

pp'

S

Liquid H2 target

BGO calorimeter








from θ and Ep'

Measurement of energy deposit by CFTwith combination of scintillation fibers & MPPCs


Main topic ~development of CFT~


π Beam

K+

S'n

pp'

S

Requirements– Energy resolution

• 35% for 70MeV proton for 1 layer

– Angular resolution : σθ=0.77deg

– Surround the target• Cylindrical shape• Long active region ・・・ 400mm

– 2 types of fiber configurations ⇒⇒ Track finding 3 dimensionally

• Φ layers ( straight layer )• UV layers ( spiral layer )

ビーム軸をz軸と定義

get z position using “Φ”

Φ layer measure “Φ”

U・V layer

Cylindrical Fiber Tracker (CFT)

• Acceptance for scattering events

Energy deposit depends on the MMassass↓↓

Resolve proton and π

300mm

400mm

Requirements– Energy resolution

• 35% for 70MeV proton for 1 layer

– Angular resolution : σθ=0.77deg

– Surround the target• Cylindrical shape• Long active region ・・・ 400mm

– 2 types of fiber configurations ⇒⇒ Track finding 3 dimensionally

• Φ layers ( straight layer )• UV layers ( spiral layer )

ビーム軸をz軸と定義

get z position using “Φ”

Φ layer measure “Φ”

U・V layer

Cylindrical Fiber Tracker (CFT)

• Acceptance for scattering events

Energy deposit depends on the MMassass↓↓

Resolve proton and π

・ Fiber construction➢ Special fiber configuration

・ Many channel operation ➢ Photon readout fiber by fiber

Prototype

Some challenges to overcomeSome challenges to overcome for development of CFTfor development of CFT

300mm

400mm

CFT prototype

MPPC – S10362-11-050P　HPK– MPPC size : 1×1mm2

– Pixel size : 50×50μm2 – 400 pixels/MPPC

r = 60

Scintillation Fiber – Kuraray SCSF-78M– Diameter：0.75mm

– MPPCs are operated and read-out by EASIROC boards

EASIROC boardsMPPCs are operated and read-out by

➢ 3layers2 straight layers + 1 spiral layer

➢ 1,100 fibers➢ Read fiber by fiber

400mmReadout frame

Reflector – ESR

EASIROC board – Specialized for

multi-MPPC readout – ADC, TDC

Read & operate

12






– Linearity


Summary

Construction of CFT prototype

Straight layer

Fiber fixing frame

Fixed to only frame hole Fiber was not glued each other

400 mm


Straight layerSpiral layerUU層層

Fiber fixing frame


400 mm

400 mm


Straight layerSpiral layerUU層層

Fiber fixing frame

• Number of fiber : ~1100 channels


400 mm

400 mm

400400mmmm

100100mmmm3 layers were combined. 3 layers were combined.

Φ1+U+Φ2Φ1+U+Φ2

Readout ~photon sensor~• Number of fiber : 1100 channel• Photon sensor

： MPPC fiber by fiber A circuit mounting 32 MPPCs

Readout　frame

Edge of fibers

64mm

30m

m

1×1mm2

6mm間隔 100μm精度ゴムシート 0.8mm

MPPC

• Contact between fiber and MPPC– by connecting PCB and readout

frame



Readout　frame

Edge of fibers

spacer(rubber sheet)

0.8mm

attach

64mm

30m

m

1×1mm2


Readout frame

MPPC

fiber

MPPC


framecontact

　　Ref EASIROC chip : proceedings of NDIP 2011 Omega/IN2P3EASIROC board : R. Honda PD12



Readout　frame

Edge of fibers

spacer(rubber sheet)

0.8mm

attach

64mm

30m

m

1×1mm2


Readout frame

MPPC

fiber

MPPC

EASIROC board


framecontact

ADC , TDC , bias adjustment etc...

MPPC operation

• For uniformity of MPPCs– Each MPPC's gain was adjusted

by changing bias voltage.

– 1,100 MPPCs were adjusted.

• Operation voltage– Over Voltage ≈ 1.4V

ADC [ch]

pedestal

1 photon

2 photon

MPPC output

– Fittingしてない絵

EASIROC20mV/bit, 0~4.5Vfor each channel

y[m

m] Measurement of cosmic ray

• Mean value = 19 p.e. – sufficient to distinguish hit

Photon Num oftypical fiber

p.e.

p.e.

Fiber No.

Light yield was almost uniform.

Uniformity for all fibersDistribution of p.e. for cosmic ray

Uniformity for all fibers

coun

t

21






– Linearity


Summary

Performance evaluationMeasurement of energy deposit

➢ Linearity ➢ Between energy deposit and light yield

➢ Energy resolution➢ Require σ/Mean = 35% for 70MeV proton for 1 layer

in order to resolve proton and pion with 4σ

Σ decay product

π±

beam

K+

S±S±'

n

p±p'

pcosmic ray

MIP particle

Test experiment in CYRIC

Behavior for proton

　　　　　 θp beam

CFT

CH2target

– Angular resolution

Performance evaluation for protonΔE-E relation PID⇒

⇒⇒ angular resolution was acceptable

・ pp scattering experiment– 80MeV proton beam from

cyclotron @CYRIC in Tohoku Univ.σ

E(BGO) =1.2%

for 80MeV p beam

Test experiment in CYRIC

Behavior for proton

　　　　　 θp beam

CFT

CH2target

energy deposit:dEScattering angle : θ

　kinetic energy:E

– Angular resolution

Performance evaluation for protonΔE-E relation PID⇒

⇒⇒ angular resolution was acceptable

・ pp scattering experiment– 80MeV proton beam from

cyclotron @CYRIC in Tohoku Univ.

– Ep is selected by θ

σE(BGO)

=1.2% for 80MeV p beam

Kin

etic

en

erg

y E

[M

eV

]

Scattering angle θ [degree]

response for proton 20~70 MeV

Linearity of light yield• Separating angles corresponds to select Ep.selecting θ

SimulationEstimated energy deposit

Experimental datap.e.

comparecompare

Linearity of light yield

Estimated energy deposit [MeV]

MPPC covering area to fiber : 400pixel*(covering ratio) ≒ 180pixel

1mm

0.75mm

dete

cted

p.e

.

cosmic ray

Response function

Nout = Neff*{1- exp(-B*dE/Neff)}

Neff = effective pixel number of MPPC

= 197 pixels

• dE from proton is higher than that of MIP

• Separating angles corresponds to select Ep.selecting θ



comparecompare

※ For each layer

PreliminaryPreliminary



MPPC covering area to fiber : 400pixel*(covering ratio) ≒ 180pixel

1mm

0.75mm

dete

cted

p.e

.

cosmic ray

Response function

Nout = Neff*{1- exp(-B*dE/Neff)}

Neff = effective pixel number of MPPC

= 197 pixels

• dE from proton is higher than that of MIP

• Separating angles corresponds to select Ep.selecting θ

How much does non-linearity affect to energy resolution ?



comparecompare

※ For each layer

PreliminaryPreliminary

Energy resolution


Ene

rgy

reso

lutio

n [%

]

• Resolution was worse than simulation. <-- to be calibrated for each channel• Energy resolution of CFT = 28%28% for 70MeV proton (dE = 0.7MeV)

satisfied our requirement (35% for 70MeV)

Energy resolution of one layer

PreliminaryPreliminary • Simulation – Cylinder Shape of fiber– Fluctuation of Photon

number– MPPC Saturation

suggests that resolution will become worse at high dE region.

SimulationData

summary We plan to perform Σp scattering experiment at J-PARC

CFT(Cylindrical Fiber Tracker) will measure the trajectory and the energy deposit

Construction –– a Prototype consists of 3 layers• Scintillation Fiber + MPPC• 2 straight layers +1 spiral layer ≈ 1,100 fibers• MPPCs which read each fiber were operated by EASIROC board

Performance evaluation • Measured cosmic ray and pp scattering

– Cosmic-ray ・・・ Mean detected photon number = 19 p.e.• Linearity ・・・ MPPC saturated in high energy deposit region.• Effective pixel number of MPPC = 197pixels

⇔ consistent with fiber covering area• Energy resolution

– worse than that of simulation ← to be improved

– σ/Mean = 28% for 70MeV proton(dE=4.7MeV)

satisfied our requirement

Back up

To improve the energy resolution


dete

cted

p.e

.

cosmic ray

1mm

0.75mm

• Calibration method– Response function

➢ Layer by layer (now)contain the effect of the deviation of MPPC' gain

➢ ⇒⇒ fiber by fiber Energy resolution should be improved.

• Expand MPPC effective area– Inserting a spacer between fiber and MPPC– MPPC saturation will become weaker.

• etc... fiber

MPPC

fiber

Spacer

MPPC

32

A design of actual type Actual detectors

The design have almost finished

Just now constructing

CFT BGO

CFT+BGO

・BGO calorimeter ・・・

24 BGO(30×25×400mm3) will be placed cylindrically

・CFT ・・・

4 Φ layers,4 U・V layers ~5,000 fibers

x[mm]

y[m

m]

Φ1U

Φ2

Efficiency• Efficiency for Φ layer

(actual hit) / (expected by other 3 hit track)Φ1-①

Φ1-③

Φ2-①

Φ2-③

actual hit

expected byother 3 hit

?

・ Number of photon is sufficient・ Position dependence

⇒ suggest that there were some space between some fibers

efficiency = 87%Position dependence of efficiency– Each fiber position

– to be improved

{

Φ=0

Φ

Φ

h


Estimated dE for pp scat.

•

Detected p.e.

en

erg

y d

ep

osi

t [M

eV

]

• Linearity between energy deposit(simulation) and p.e.(actually detected)

energy deposit [MeV]

de

tect

ed

p.e

.

Comparevia scattering angle

cosmic ray

considering air gap (0.8mm) between fiber edge and MPPC

• 176 pixel

angular resolution

Target peak13.7mm(σ)13.7mm(σ)

・estimated from σvertex

=13.7mm13.7mm

σΔθ

=1.0°

・Ideal resolution (Geant4)σ

Δθ=0.77° , σ

vertex=9.4mm

vertex

proton beam　　　　　　　　　　　

Prototype nearly realized the simulated performance ⇒ to be better by improving position precision

Vertex (beam line) [mm]

Ep'calc (pC scattering)

Ep'calc (pp)

Ep'

mea

sure

(BG

O+

CF

T)

[MeV

] Angular distribution of Ep'

Scattering angle [degree]

　　　　　　　　　　　　　　CH2target(200μm t)

Trajectory was reconstructed by CFT ----> vertex ( beam line × trajectory)

Documents

卒業研究発表 『J-PARCでのハイペロン陽子散乱実 …ndip.in2p3.fr/tours14/AGENDA/AGENDA-by-DAY/Presentations/...glued each other 4 0 0 m m Construction of CFT prototype

卒業研究発表『J-PARCでのハイペロン陽子散乱実 …ndip.in2p3.fr/tours14/AGENDA/AGENDA-by-DAY/Presentations/...glued each other 4 0 0 m m Construction of CFT prototype