Barrel PID upgrade

K. Inami (Nagoya)Ljubljana, Hawaii, Cincinnati

and PID group

- R&D status- Structure design- Prototype study

- Beam test- Photon detector- Electronics

- Design study- To do, cost estimation

2

Barrel PID upgrade

2.6m

1.2m

e-

8.0GeVe+

3.5GeV

Focusing DIRC / fTOP / iTOP Aerogel RICH

- PID () detectors; Focusing DIRC, fTOP, iTOP- Cherenkov ring imaging detectors with quartz- Locate in the current TOF region

3

Barrel PID options

Converging the detector design Wide bar (40~50cmW x 2cmT), focus mirror (R=5~7m) Shape of readout plane depends on the choice of photon detector

By A.Schwartz-san

(Nagoya) (Cincinnati)

(Hawaii)

4

Structure Quartz: 255cmL x 40cmW x 2cmT

Focus mirror at 47.8deg. to reduce chromatic dispersion

Multi-anode MCP-PMT Linear array (5mm pitch), Good time resolution (<~40ps) Measure Cherenkov ring image with precise timing information.

MCP-PMT

(TOP counter, Nagoya)

18 counters in

5

Structure design

Can locate iTOP standoff inside sBelle structure

(iTOP, M.Rosen-san, Hawaii)

CU

RR

EN

T

FU

TU

RE

TOP

iTOP16 modules in

6

Structure design Just started structure

design With KEK workshop engineer

Need optimization Use honeycomb plates etc.

(M.Rosen-san)

Deflection ~250um

Barrel Deflection with full Quartz Load ~1,150kg

Barrel Deflection with full Quartz ~1,230kg

Deflection ~300um

7

Prototype development Demonstration of the performance

Quartz radiator (Fused silica)　・ Flatness:<1.2m/m　・ Roughness:0.5nm

Photon detector　・ Time resolution　・ Efficiency

Filter (>400nm)　・ Suppression of chromatic dispersion

PMTquartz

Prototype overview

915mm400mm

20mmquartz

915mm400mm

20mm400mm

Glued Glued

20mm

(Nagoya)

8

Quartz radiator Check the quality for

time resolution Single photon pulse laser

=407nm MCP-PMT Several incident position

No degradation of time resolution

Enough quartz quality

Propagation length [mm]

Tim

e re

solu

tion

[ps]

Line 1Line 2Line 3<40ps

Quartz

MCP-PMT

47.2 deg. MCP-PMT

9

At Fuji beam line in June and Dec. Using real size quartz and MCP-PMT

MCP-PMT: Multi-alkali p.c., C.E.=60%

Check Ring image Number of photons Time resolution

Beam test

MWPC 1 MWPC 2

Lead glass + Finemesh PMT

Timing counter10mm quartz + MCP-PMTt0 < 15ps

MCP-PMT (56ch)

TOP counterQuartz bar(1850×400×20mm)

Trigger counter

Quartz + support jig

10

Beam test results Ring Image

Similar with Simulation Number of photons

Ave. number of photons; 15.7as expected

Time resolution

1st 2nd

3rd 1st 2nd

3rd

[1count/25ps] [1count/25ps]

Data Simulation

Resolution(1st peak)

Data 76.0±2.0 [ps]

Simulation

77.7±2.3 [ps]

11

Propagation length [mm]

Tim

e re

solu

tion

[ps]

Simulation

Check time resolution For several incidence condition and channel

Data agrees well with simulation expectation. Confirmed the level of chromatic dispersion effect

Time resol. vs. propagation length

12

Photon detector R&D Square-shape multi-anode MCP-PMT

Multi-alkali photo-cathode Gain=1.5x106 @B=1.5T T.T.S.(single photon): ~35ps @B=1.5T Position resolution: <5mm

Semi-mass-production (14 PMTs)

σ=34.2±0.4ps

QE： 24%@400nm

Ave. QE： 17%@400nmTTS＜ 40ps for all channelsTDC [1count/25ps] Wavelength [nm]

QE

[%]

13

Lifetime issue Lifetime test

Multi-alkali p.c. with Al protection With square-shape MCP-PMT Short lifetime, position dependence

Difference with round-shape PMT Enough lifetime (>10 super-B year)

Need to confirm the lifetimeof round-shape MCP-PMT

Need to confirm the difference Internal structure

QE before againg

QE after againg

14

Lifetime with round shape MCP with 10m pore Multi-alkali p.c. Aluminum protection on 1st

MCP

Initial Q.E.; 20% at 400nm Initial Gain; 4x106

TTS keeps <40ps. Need to improve for initial

Q.E. and initial aging Slope seems to be

manageable. Can expect to improve during

R&D in next year Output charge (mC/cm2)

Relative QE

Relative Gain

~3 super-B years

?

15

MCP-PMT R&D status Multi-alkali p.c. SL10

Added ceramic shield To protect gas feedback

Improved lifetime Obtained normal Gain and TTS Still need to irradiate more photons

and study detail Need to improve correction efficien

cy (~35% ~60%) Put Al protection layer on 2nd MCP Deliver April and May

GaAsP p.c. SL10 Change the process method

To improve yield rate Will add ceramic shield

Preliminary result from HPK

Old

New

16

Readout elec. R&D (Hawaii)

6.4 ps RMS

(4.5ps single)

Waveform sampling Comparable performance

to best CFD + HPTDC MUCH lower power, no

need for huge cable plant!

Using full samples significantly reduces the impact of noise

Integrated module

17

Readout elec. R&D

16k channels2k BLAB3128 SRM

128 DAQ fiber transceivers

32 FINESSE8 COPPER

All pieces have prototypes in existence or in fabrication

-- present performance results in July

Already~10% system

Fabbed

(Hawaii)

18

Design study Simulation studies

Handmade + Geant3 (K.Inami, Nagoya) Geant4 + ROOT (K.Nishimura-san, Hawaii) Mathematica, Handmade? (Cincinnati) Analytical calculation (M.Staric-san, Ljubljana)

Reconstruction program for gsim study

Standoff

2 readout

1 readout

19

Design study with ring image

Calculation with Mathematica Prefer to use wide bar and standoff, in order to obtain clear difference

of ring images

(Cincinnati)

20

Comparison btw. iTOP and fTOP For initial comparison purposes all assumptions are same… except

fTOP: No expansion length, 2 cm by 44 cm detector plane (SL10* PMT). iTOP: 3.6 cm expansion length to a 10 cm x 44 cm detector plane (SL10* PMT)

Separability comparable, slightly better with imaging. iTOP geometry optimization just started! Results may improve with optimization of

bar width/thickness, focusing length, chosen photon detector, etc.

20

iTOP fTOP

(Hawaii)

21

Performance check GaAsP, CE=35%, >400nm

10ps jitter

(Nagoya)

22

Performance checkWith 10ps jitter

GaAsP, CE=35%>400nm

Multi-alkali, CE=60%

>350nm

23

Simulation study

Similar results with Nagoya’s simulation

For B case, 2-readout type shows better results.

(M.Staric-san)

24

Cost estimate & Production time

Quartz bars 16~18 modules (2x40x91.5cm3 x3 + mirror, standoff) Okamoto optics (by Nagoya)

1800x18+2700 万円 ~ 3.6M$, 2 years Zygo (by A.Schwartz-san, Cincinnati)

$72k x 3 x 16 + alpha ~ 3.7M$ From Taiwan (by C.H.Wang-san and P.Chang-san)

?? Photon detector (increasing gradually)

MCP-PMT by Hamamatsu; 600 pieces for TOP, 3 years Multi-alkali photo-cathode; ~2.7M$ GaAsP photo-cathode; ~4.2M$

MCP-PMT by Photonis; ??? (expect cheaper price) Electronics

LABRADOR; <$10/ch Structure

25

Summary Barrel PID based on TOP/DIRC

Cherenkov ring imaging with position and precise timing (<50ps) using Quartz + MCP-PMT

Wide bar (40~50cmW x 2cmT), focus mirror (R=5~7m) Shape of readout plane depends on the choice of photon detector Started structure design

Prototype study Expected performance by beam test Readout electronics with BLAB3 ASIC will be tested soon.

Photon detector Lifetime test with round shape and square shape MCP-PMTs

Seems manageable lifetime. Need to establish production reliability and lifetime

Design study With several simulation programs Need to obtain consistent result first

26

What to do Prototype study

Check ring image with focus mirror, quality of quartz radiators Electronics prototype performance

Design study Simulation programs showing consistent results

Design choice and optimization Robustness against multi-track events, beam BG

Effect to outer detector, again Material of standoff, structure Distance btw. radiator and ECL

Photon detector choice Lifetime for MCP-PMT

Test with square-shape MCP-PMT from Hamamatsu and Photonis Performance and production reliability

Hamamatsu vs. Photonis Determine the size Photo-cathode (GaAsP/Multi-alkali) By next

summer

27

Backup

28

Performance Full simulation with

GaAsP photo-cathode + Focusing mirror >400nm filter, CE=35%

29

Barrel PID detector Cherenkov ring in quartz bar

Reconstruct ring image using ~20 photons reflected inside the quartz radiator as a Babar’s DIRC.

Utilize 3D information Arrival position

(x,y) Arrival timing (t)

Difference of propagation time for is ~100ps