1
Readiness of Forward Muon Arms for W Detection
Itaru NakagawaFor the PHENIX Muon Trigger
Upgrade Collaboration
22
1. Muon Tracking Chambers– 3 stations of Cathode strip
chambers– Each station has multiple planes
for redundancy– Slow read out -> No trigger
2. Muon Identifier– 5 layers of Iarocci tubes in x and y– 80 cm of steel plate absorber
(total)– Provides trigger p > 2 GeV
St#1
St#2
St#3
MuTr
Same configuration in SouthSame configuration in South
MuID
B
Current Muon System
3
Observed in Run9 pp
B
p,k
n
mfake High PT m
Study done by Yoshinori Fukao (RIKEN)
4
Efficiency Measurement with Cosmic Ray
cosmic High Efficiency underClean Circumstance!
Study done by Yoshinori Fukao (RIKEN)
MuTRG System Run09 performance
5
•MuID Algorithm•Track Matching w/ MuID•Timing cut w/ RPC•Track Matching w/ RPC•Neutron Backgrounds• Yoshimitsu Imazu’s Talk
•etc ..
MuTrg-FEE x MuID
Study done by Yoshinori Fukao (RIKEN)
6
Rate Dependence of MuID Rejection Power
•Can RPC substitute MuID?•Does RPC give better Rejection Power?
7
Road Map to Run11 Production Run
MuTRGMuTRG
RPC3
Run11
RPC3
absorber
Completed Installation of Absorbers
8
North Station-1
New Hadron Absorber
North South
35cm thickSUS310(2 interaction Length)
9
Final Muon Trigger Configuration
MuTRGMuTRG
RPC3
Run12
RPC3
absorber
RPC1
10
MuTr X-Talk
11
MuTr Cross Talk
HV (1800 V)
1 MWAnode wire
1 MW
100 pF ....
Cathode strips (96 strip)
~0.1 pF/strip
Rise time of anode signal ~ 10 nsec
Removed to reduce HV trips
Anode Readout
100mV
3V
Serious Issue for Big Pulse
Pointed out by Tsutomu Mibe@KEK
Decap
Doesn’t exist.
12
ADC
MIP
MIP
Event Display of ADC Distribution
Strip
Gap 1Stereo
Gap 2Stereo
Gap 3Stereo
Gap 1NonStereo
Gap 2NonStereo
Gap 3NonStereo
Origin of Big Pulse -> Neutrons?
13
Can be serious issue at high rate
x2 (Run 11?) x5 (design)
Current set up
Recap (1/10? cross talk)
Luminosity
Rate
per
strip
(kH
z)
Run 9, 500 GeV data
10ms Pileup at 100kHz
14
SolutionHV (1800 V)
1 MWAnode wire
100 pF ....
Cathode strips (96 strip)
~0.1 pF/strip
Rise time of anode signal ~ 10 nsec
R<<1M W1 MW
Additional Circuit to let anode current escape to ground.
15
Pads for surface mount capacitorsLeft over Solder + Coating
To Anode Wire
MuTr Station-3 Anode Card
Capacitor (Removed)
16
North Station-3 Anode Gap
25mm28mm
Geometrical Constraint
Anode cards are only accessible from their back. Front pattern can only be visible using an inspection mirror.
17
Recap Clamp PrototypesR&D byYoshinori Fukao (RIKEN) Yoshimitsu Imazu (RIKEN)Kentaro Watanabe (Rikkyo)
18
Effect of Recap
19
Test Bench Setup
90Sr Source
Anode wire
Strip
#22
w/ and w/o Clamp
20
Comparison w/ .vs w/o Terminator
22
27
17
Trigger
w/o Clamp
Strip#
22
27
17
w/ Clamp w/ Clamp
Trigger
w/o Clamp
Comparison w/ .vs w/o Clamp
w/o Clamp
With Clamp
Strip Number
Aver
age
ADC
[cha
nnel
]Conductive Rubber
21
22
Neutron Absorber
23
The full muon arm again• Only 1/20 of all PYTHIA
events• Only MuTr St1• Y-scale is from old macro• Only neutrons from
upstream of St1
Neutrons in St1 Current setup SS310 absorber +SWX207HD5 Only SWX207
Thermal Neutron
• Origin of Big Pulse
• Thermal Neutron Absorber
Thermal Neutron photonAbsorber Borated Poly 2.5cm Pb 1cm + Fe 1cm
Attenuation ~10-2 ~5x10-2
€
11B + n→7Li* +α7Li*→7 Li + γ (478keV )
€
A + n(thermal) → (A +1) + γ(≤ 8MeV )
478keV
B 25mm Pb 1cm MuTr
25meV neutron
(e,g)
Fe 1cm 24
25
Summary• High Momentum Muon Trigger (MuTrig-FEE &
RPC3) is to be commissioned in Run11• Sufficient Rejection Power can be achieved, but
trade off of efficiency.• 99% Efficiency with Cosmic at High PT • Thermal Neutron is suspect degrades MuTr
performance– Neutron Absorber Partial Install– Recapacitation Clamp Prototypes to be tested in Run11
26
Backup Slides
27
Towards Successful Installation
28Fiber Scope
Alignment
Spacer determines Transversedirection within ~ 300mm.
Possible misalignment can be found by visual inspection using a fiber scope
Fiber scope shot
29
Electrical Contact
Readout socket
Readout BoardElectrical Contact will be confirmedby measuring Voltage using temporaryreadout tool.
To be removed after the measurement.
30
Installation Proposal
To be installed North Bottom Octants
31
Clamp Coating Max Current Average Current
w/o w/ <1uA <1uA
w/ w/o >100uA Tripped after 2 min.
w/ w/ 1uA 1uA
w/ w/o >100uA Tripped after 1min.
w/ w/ 2uA 2uA
Extreme Breathing Test
HV=1900VDuration 2min
32
MuTr Station-3
33
Recapacitation (Station-3)
Capacitorはすべて取り外し済み。Station-3 Chamberを取り出すの実質的に難しい。簡易的に取り付けられるクリップでグラウンドに落とす。
34
Coating
Anode CardParylene CPrint Kote
remover
Takes time, but removable
化学的に溶かすには 175℃でクロロナフタレンに反応して溶解(1時間以上)。事実上ムリ。
De-Capacitation(コンデンサーの取り外し)の際にパリレンが溶けてるのでは?
35
DAQによる測定
ADC>1000ch以上の事象
ADC>1000以上の大きなパルスを観測したとき、周辺のストリップには逆電価のシグナルが観測される。
…,13,14 31,32,……21,22,23…
90Sr線源
ストリップ番号
ストリップ番号
ストリップ番号AD
C [c
hann
el]
ADC
[cha
nnel
]
Anode wireを共有していない
Anode wireを共有していない
線源直下のストリップ
36
Low energy neutrons• Low energies• Fluctuation before
SWX needs investigation
• Suppression of very low energies might depend on input neutrons
behind SWX207HD5
before SWX207HD5