development of a vertex chamber with using gem yutaka mizoi osaka electro-communication university...
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Development of a Vertex Chamber with using GEM
Yutaka Mizoi
Osaka Electro-Communication University
Colleagues; Tomokazu Fukuda, Shizu Minami, and Wataru Imoto
Workshop for MPGD at Kyoto University, 2004.Dec.3-4.
Contents
1) Experiments2) Cylindrical Drift Chamber System3) Design of Vertex Chamber4) Schedule and etc.5) Other Cylindrical GEM Detectors
1) Experiments
I) Study of Double- Hypernuclei @ J-PARC a) Confirm the existence of 4H
b) Search for 5H
II) p + n p + @ RCNP
)114.3MeV/c~( HeH
p)HHe(
104MeV/c)~( HeH
33
3*4
*44 ΛΛ
p
p
-
-
π
π
97MeV/c)~( pHeHe
116MeV/c)~( HeH34
44 ΛΛ
p
p-
-
π
π
MeV/c)99~( pHeHe
134MeV/c)~( HeH-45
55
p
p-π
MeV/c)9.132~( HeH
100MeV/c)~( pHH-44
45
p
p-π
p +
High vertex resolution is required for tracing two- tracks.
High counting rate from background.
2) Cylindrical Drift Chamber System (CDS)
Vertex Chamber
Cylindrical Drift Chamber
Hodoscopes
Solenoid Magnetk-
k+
Vertex DeterminationMomentum AnalysisParticle Identification
3) Design of Vertex Chamber
Development History
E906@BNL in 1998:Previous CDS designed by J. P. Nakano, et al. for experiments.No Vertex Chamber, Z-Chamber outer of CDC did not be used due to...
E961@BNL accepted in 2002:A newly developed vertex chamber will be installed in the previous CDS,but .......
Recently, design study of a new CDS has been started for J-PARC.
E961 E906
Target (density) LiH (0.83 g/cm3) 9Be (1.85 g/cm3)
Target size 5.08x1.225x20 cm3
5.08x1.225x15.24 cm3
Target position (0, 0, 27.3) cm (0, 0, 0)
CDS acceptance 62% of 4 55% of 4 (60<<146) (71%)
K+ acceptance 69 msr 29 msr *
Z 0.8 mm rms 3 mm rms
p 2.4 MeV/c rms 4.3 MeV/c rms
* The upper 4 elements of FP were excluded from trigger in E906.
Results of GEANT simulationsResults of GEANT simulationsHotchi
w/o vertex chamber w/ vertex chamber
deca
ys
Dou
ble
s
ign
als
Distance of Closest Approach (cm)
DCA<2cm DCA<0.8cm
Hotchi
Required dimension : ~ 100 mm x 315 mm
New z-vertex chamberNew z-vertex chamber
Two Promising Designs - Anode wire or GEM ?
Read-out Strip Electrode
Anode Wire
Field WireGEM foil x 2~3
-
-Anode
Strip
Z position
Strip
GEM
Z
R
Anode-wire configuration;Well known structure,One-dimensional tracking,Wire-tension stress... GEM-foil configuration;
Two-dimensional tracking,No mechanical Stress,High counting rate,Unknown structure,Mass density......
(Inner or Outer is another option.)
Design of the Read-out Strip-Electrode SheetPolyimide 25m+Cu 18m X 3 layers, 3mmX129.3mm Strip with 0.2mm gap X 96 strips
322.2(ストリップ両端間)
ストリッフ長゚
129.
3
GN
D幅
139.
3
ストリップ1番ヒ ン゚ ストリップ
96番ヒ ン゚10 20 30 40 50 60 70 80 90
GNDS1
S49
S51
S95
GND
GND
GND
奇数ピン番のみ 昇順配置
偶数ピン番のみ 降順配置
48 51~ ヒ ン゚はNC
1 4 NC~ ヒ ン゚はGNDS96
S52
S50
S2
GND
GND
GND
外形-取付穴 3.0(マイナス公差要)
352.0〔=GND寸=チェンバー寸法355.0 ×-(0.5 2)〕
外形全長 470.0
チェンバー取付用スルホール×P15.0 22(23個)=330.0
0.50.5
Required Design for GEM
i) Gas gain ? 103~4 ~ achievable with single GEM foil.ii) Multi GEM ? for safety margin; two or three GEMs, but thickness is another problem.iii) Size ? 30cm X 15cm ~ available in CERN workshop.
4) Development Schedule1) Anode-wire configuration Test in a planer geometry will start soon. A test bench with anode wires will be ready at KEK in December. Thanks for Sekimoto-san.
2) GEM-foil configuration Three 10cm2-GEM foils made in CERN have just arrived. A test bench in a planer geometry is now under designing.
Prof. Sauli gave us a large-area (junk) GEM foil with 31cmX31cm. A mechanical test for forming a GEM foil into cylindrical shape will be performed in this FY.
5) Other Cylindrical GEM Detectors
I) BoNuS Detector@Jefferson Lab. Howard Fenker, et al.
100MeV/c)( pnede -- ppBoNuS=Barely off shell Nuclear Structure
Radial TPC 20cm x 8-12cm
http://www.jlab.org/~hcf/bonus/
II) TACTIC@TRIUMF, Pierre-André Amaudruz, et al.
pBepBe
BnHeLi77
1148
TACTIC=TRIUMF Annular Chamber for Tracking Identification of Charged particles
Nuclear-Astrophysical Reactions
http://tactic.triumf.ca/
Summary
Which is better for the present purpose,GEM or Anode-wire configuration?We will continue study to resolve it.
Anyway, we will develop a cylindrical GEM detector.It is a very attractive challenge itself.
A CDC will be replaced by a cylindrical GEM TPC !?