韓国におけるDSSDの開発
ソウル大学所属

木内 隆太
2012年7月17日@KEKContents・ Introduction
・ DSSD sensor
・ Test of DSSD・ Summary

E07 experiment @ J-PARC and DSSD
(from nakawaza-san’s slide)# 103 (E373) ==> 104 X-stops{L-L Interaction,
H-dibaryon,
X-Nucleus Interaction,
Inside Neutron Stars (Quark-star?)<==> 3-dimensional Nuclear chart

Strangeness

Strange matter

S = -2S = -1

S=0

neutronExperimental Setup
Target ～ DSSD (x2) ～ Emulsion

We aim to set Silicon detectors close to the emulsion plate !

DSSD sensor

DSSD building• By Double Silicon StripDetector(DSSD), we candetect X-Y position with
one circuit board.
• We are now
collaborating withProf.Hwanbae Parkin Kyungbook
university toproduce DSSDDetector
・ Layout
・ Sensor Cost-- Masking :total ~30,000,000 won-- 6’’ Wafer (x 18) :3,000,000 won-- processing cost : ~15,000,000 won～350万円・ APV25 chip & APVDAQ VME module

・ Assembly configuration by REPICFrom Dr. Kah’s slideFrom Dr. Kah’s slideDimensions of the AC-DSSD
Dimensions

n-sideSensor sizep-side
73620 μm x 37760 μm

Strip length

71630 μm

35770 μm

Strip width

20 μm

40 μm

Number of strips

5121024

AC pad256 μm x 72 μm

256 μm x 72 μm

DC pad136 μm x 36 μm

98 μm x 48 μm

Biasing pad

240 μm x 100 μm

Guard-ring pad

240 μm x 100 μm

Designed values
Biasing resistance
Coupling capacitancen-sidep-side8.8 MΩ

8.8 MΩ

247 pF/strip
or 123 pF/strip

247 pF/strip
or 123 pF/strip

By Kha Dongha kah@knu.ac.kr

Wafer design~7cm
DSSD-1pitchadapter~3.5cmDSSD-3

DSSD-2

DSSD-3~70um pitch strip

p-siden-sideBy Kha Dongha kah@knu.ac.kr

pitchadapter

DSSD-2

Strip direction

DSSD-1

Strip direction

p-side2-N-sub pad(7150 x 60)
73620 μm

8x2-Guard-ring pad(240 x 100)
8x2-Bising pad(240 x 100)
1024-DC pad

Strip length : 35770 μm

37760 μm

(98 x 48)1024-AC pad(256 x 72)

1024x2-AC pad(256 x 72)

By Kha Dongha kah@knu.ac.kr

n-side37760 μm

73620 μm

Strip length : 71630 μm

2-N-sub pad

8x2-Guard-ring pad

8x2-Bising pad

1024-DC pad

1024-AC pad

1024x2-AC pad(7150 x 60)(240 x 100)By
Kha 100)
Dongha kah@knu.ac.kr(240x(98 x 48)(256 x 72)(256 x 72)

DSSD sensor produce
dicingsensors

By Korean venture company (SENS)DSSD leak current - estimate
V-I graph
1.20E-03

1A
1B

1.00E-03

1C
2A
2B

Current(A)8.00E-04

2C
3A

6.00E-04

3B
3C

4.00E-04

4A
4B

2.00E-04

4C
5A
5B

0.00E+00-2.00E-04 05C

50100

150

Voltage(V)Dep. voltage ~80 V – most are useless

200

6A
6B

DSSD leak current - estimate
V-I graph
1.00E-05

1A
1B
1C

8.00E-06

2ACurrent(A)2B
2C

6.00E-06

3A
3B
3C

4.00E-06

4A
4B

2.00E-06

4C
5A
5B

0.00E+00

5C

050

100
Voltage(V)150

Sensors 2A (1B ,6B) may be used

200

6A
6B

CapatitanceSensors 2A (& 1B) could be usedAPV25 chip・ Analogue pipeline chip for readout ofSilicon detectors developed by CMS・ Handle 128 channels
・Consists of CR-RC shaper (t:50nsec) ,amplifier, pipeline (192cells), multiplexer

・ Input : Clock, Trigger
Output : bi-directional current (multiplexed)“The APV25 Deep Submicron Readout Chip for CMS Detectors” , L.L. Jones et.al.

DSSDの写真
N-SideP-SideReadout Module・ “APVDAQ” VME module developed byBelle group
・ 128 ch multiplexed signals aretransferred by 30 m category 7 LAN cable( yellow cable in the right picture)

・ Readout by FADC on the board(10bit, 40MHz sampling)

SSD/ DSSD

Data acquisition with sampling mode: wave formafter shaper

APV25 chip has a function of data sampling
By fitting the data points , we can know
peaking time
We can exclude accidental hits by timing !

Raw Data (sample)
Raw Data from a APV25 chip which contains 128 ch’s information
128ch

128ch

0nsec

25nsecHeader
Structure

50nsec75nsec100nsec

125nsecSSD・(Single Side) Silicon Strip Detector
・Sensor-- ATLAS sensor-- Strip : 768ch , 80μm pitch-- effective area 64mm-- radiation tolerance >3*1014-- (typical operation voltage) ~ +70V

・Readout chip-- APV25-s1 chip (developed by CMS)-- Each chip has 128 ch of pre-amp and shaperand use serial transfer by multiplexer

64mm

Performance of SSD-- Beam rate dependence
Timing resolution

Efficiency

If the beam spot size is a few cm (φ) , SSD can work under 10 MHz .

Test of DSSDIV曲線

N側に＋の電圧を与えた場合 （P側の場合もほとんど同じ）

Comparison of Pedestal distribution
Non bias
Bias 80V
Case of SSD

P側読み出し時の“信号”イベント
宇宙線・線源トリガー
Clockトリガー

信号と思われるイベントは現在のところ単なるfluctuation …….

まとめ・ 韓国・慶北大学と共同してDSSDセンサーを開発した。
・ データの読み出しその他はこれまでのところ問題ない。
・ 但しセンサーの評価として、ノイズが大きく（リーク電流が大きい）、また有意な信号はまだ検出できていない。

・ 今後については慶北大学とも連絡をとりながらどうすすめるかを検討中。

Results of KEK-E373

6 / 16at FB19

• NAGARA event (1)Track data (lengths, angles and PID)

1. Single-L (TK#4)

H.Takahashi et al.,
PRL87 (2001) 212502

image of TK#7 in D-Block [gave K.E.]=> Both of charge for TK#7 and #8
should be an unit.
(exceeding Q-value of non-mesonic decay)=> Single-L = He nucleus
L

2. TK#6 was a p- by measurement of dE/dx andtopology of its end point (with Auger electron).

IV CurveN側読み出し時の“信号”イベント

Data Suppression
・ DAQ trigger accept rate ~ 20 Hz ( 4SSDs)~ 1Khz @ J-PARC K1.8 beamline

・ Most of data is null : a few hits
within 768 ch

Discard the null data before readout
Last year, we developed this data
suppression system,
And test it at RCNP experiments first time

DSSDの測定の様子
・DSSDの読み出し面に対してシンチを配置して宇宙線及び線源によるコインシデ
ンストリガーを生成
・ただしバイアスはGNDをその他から切り離したDSSDの下に線源(Sr90)を設置

読み出しAPVチップの領域
P-sideN-side