KEK beam test

H. Sakamoto

Purpose

To optimize a concentration of the second dopant for scintillating fibers KEK beam test to study light yields for various conc

entrations

Summary

Purpose for the beam tests

We tested the light with two difference tests to study the light yield with realistic components of 3HF concentration dependence

First time (T553-1): calibrated the gain of pmt with 1 p.e. Second (T553-2) : 〃 with more p.e. ( ～ 20p.e.)

T553 (this time) T542 (last year) SciFi length 40cm 20cm Mirror aluminized mirror aluminized mylar Connection MICE connector acryl board Clear fiber w/ and w/o 4m no PMT R7411U-40MOD R7899-MOD

Scintillating fibers tested

Kuraray SCSF-3HF ; 0.35mm-phi, multi-clad, s-type In this beam test, pT(2%) scifi was also tested.

pT(1%) + 3HF(5000ppm) pT(2%) + 3HF(5000ppm) pT(1%) + 3HF(3500ppm) pT(1%) + 3HF(2500ppm) pT(1%) + 3HF(4500ppm) pT(1%) + 3HF(7500ppm) pT(1%) + 3HF(10000ppm) pT(2%) + 3HF(10000ppm)

Attaching SciFi with MICE conn.

Attached the SciFi and clear fibers with MICE conn. Clear fibers for pmt’s gain calibration

Clear fiber (1.05mmΦ)

SciFi (0.35mmΦ): 14fibers

SciFi

Clear fib

Scintillating fiber

• Connecting the SciFi into the hole of MICE connector

Fixing by optical cement

• Fixed the SciFi with optical cement

Q.E. of VLPC & 3HF emission spectrum

3HF emission spectrum

520nm

Quantum efficiency of VLPC

520nm

Quantum efficiency

VLPC vs PMT QE

01020304050607080

200 300 400 500 600 700 800

Wavelength [nm]

Quan

tum

Efficie

ncy [

%]

00.020.040.060.080.10.120.140.16

PMTQE [%]VLPCQE [%]ZD43233HF

Photo multiplier tube

We used the photo multiplier tube instead of VLPC.

Hamamatsu R7411U-40MOD GaAsP (Gallium-Arsenic-Phosphorous) 8mm diameter 10 stage Head-on Type HV= -850V

Set up T542 (last year)

•Side view

PMTSci-Fi

Aluminized tape

22mm

20 fibers

These were in a dark box

•Front view

PMTSci-fi

KEK beam test set up Ⅰ

D1 TOF2D2Sci-Fi

Trigger coincidence of all counters

Data we took ADC & TDC of all counters and Sci-Fi

1.5m4m

•0.6 GeV/c•1.2 Gev/c

TOF2 Sci-Fi TOF1D1

Dark box

D2

• p+　•π+ 　　

Beam

D3

Set up (T553) Beam area

Dark box

Set up (T553)

In the dark box

D1D2 SciFi and support

Setup (T553)

mirrorpmt

SciFi

•SciFi and its support gide before setting in the dark box

Aluminized mirror

SciFi

Mirror

PMT (R7411U-40MOD)

SciFi

PMT

Close up of SciFi 14 fibers were arranged into 420um bitch

Arrangement of Scifi

For single layer : 14 fibers

For double layer : 3 fibers for up and 4 for down

420um

T553-1 (first test) Gain calibration -1

calibrated the PMT’s gain by 1 p.e. Injected the LED light adjusted as 1 p.e. to the cathode surface of the PMT.

1 p.e. was determined with the ratio of 0 p.e. and 1 p.e.

But this measurements was not worked Not good S/N To the second test with higher p.e.#

The result : Light yield

T553-1 (first time)

These are not p.e. but the relative values are meaningful. 5000ppm has the highest light yield in tested fibers.

1. 5000 -1%2. 4500 -1%3. 10000 -1%4. 2500 -1%5. 5000 -2%6. 3500 -1%7. 7500 -1%8. 10000 -2%

T553-2 (second test)

Gain calibtion -2 Adjusted the LED to

about 20 p.e. P.e.# was estimated

by ((MEAN)/(RM

S))^2

Beam stability

Stability of beam momentum by Time of flight of 0.6 (Gev/c) proton

Monte Carlo

•Simulated 1.2 (GeV/c) data for proton and pion• Histgram (red) = MC • Plot w/ err = data

Pion

Proton

Result of light yield

P.e.# (estimated by MC)

Light yield of 5000ppm-(1%)

•Light yield (5000-1%) = 8 p.e. @MIP

Result of light yield Light yield of 2500ppm-(1%)

P.e.# (estimated by MC)

• Light yield (2500-1%) = 6.5 p.e. @MIP

The result

•Single layer && 4m clear fiber

5000ppm-1% 2500ppm-1%

The result

•Double layer && NO clear fiber

5000ppm-1% 2500ppm-1%

The result

•Double layer && 4m clear fiber

5000ppm-1% 2500ppm-1%

Conclusion from the beam test

We tested scintillating fibers of different 3HF concentration.

We used green sensitive PMTs in stead of VLPC.

The result of light yield test Single layer

5000ppm-1% : 8 p.e. (3 p.e.) 2500ppm -1%: 6.5 p.e. (3 p.e.)

Double layer 5000ppm-1%: 10 p.e (4.5 p.e.) 2500ppm-1%: 8 p.e. (4.5 p.e.)

Summary

We studied the light yield of scintillation fibers mixed with 3HF as a secondary dopant with realistic component .

We studied the light yield with some conditions. w/ and w/o 4m clear fiber Single and double layer

The result of light yield pT(1%) + 3HF(5000ppm) 　 has the highest light yield in any conditions.