Recap Clamp for MuTr Station-3 Itaru Nakagawa For the PHENIX Muon Trigger Upgrade Collaboration Especially credit to: Tsutomu Mibe (KEK) Yoshinori Fukao (RIKEN) Yoshimitsu Imazu (RIKEN) Kentaro Watanabe (Rikkyo) 1

MuTr Cross Talk 2 HV (1800 V) 1 M  Anode wire 1 M  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 3V3V 3V3V Serious Issue for Big Pulse Pointed out by Tsutomu Decap Doesn’t exist.

Solution 3 HV (1800 V) 1 M  Anode wire 100 pF.... Cathode strips (96 strip) ~0.1 pF/strip Rise time of anode signal ~ 10 nsec R<<1M  1 M  Additional Circuit to let anode current escape to ground.

Pads for surface mount capacitors Left over Solder + Coating Pads for surface mount capacitors Left over Solder + Coating To Anode Wire MuTr Station-3 Anode Card Capacitor (Removed) 4

North Station-3 Anode Gap 5 25mm 28mm Geometrical Constraint Anode cards are only accessible from their back. Front pattern can only be visible using an inspection mirror.

Mounting A Clamp on Anode Card Probe 6 Gap-1 Station-3 Anode Card Screw Station-3 Chamber Capacitor Pad Gap-2 Station-3 Anode Card 28mm MuID Side IP side Anode card Clamp

Recap Clamp Prototypes 半田の残りかす (C) ShinEtsu Rubber Co. ： EC-BM300 (2.5  cm) (A) 4 pin probes (B) single pin probe 7

Advantage/Disadvantage of Different Prototypes Single Pin Probe Low resistivity. Strength against stress is not too strong 4 Pin Probes Stronger against stress More Chances to make contact. Uncontacting pin can behave as unwanted capacitor between pad Conductive Rubber Probe Absorb surface structure. Stable Contact Removing Anode Coating Required Resistance depends on stress of rubber volume Advantage Disadvantage 8

Effect of Recap 9

Test Bench Setup 90Sr Source Anode wire 10 Strip #22 w/ and w/o Clamp

Comparison w/.vs w/o Terminator Trigger w/o Clamp Strip# w/ Clamp Trigger w/o Clamp

Comparison w/.vs w/o Clamp w/o Clamp With Clamp Strip Number Average ADC [channel] Conductive Rubber 12

Towards Successful Installation 13

14 Fiber Scope Alignment Spacer determines Transverse direction within ~ 300  m. Spacer determines Transverse direction within ~ 300  m. Possible misalignment can be found by visual inspection using a fiber scope Possible misalignment can be found by visual inspection using a fiber scope Fiber scope shot

Electrical Contact 15 Readout socket Readout Board Electrical Contact will be confirmed by measuring Voltage using temporary readout tool. Electrical Contact will be confirmed by measuring Voltage using temporary readout tool. To be removed after the measurement.

ClampCoatingMax CurrentAverage Current w/ow/<1uA w/w/o>100uA Tripped after 2 min. w/ 1uA w/w/o>100uA Tripped after 1min. w/ 2uA 16 Extreme Breathing Test HV=1900V Duration 2min

Installation Proposal Single Pin Probe x 20 4 Pin Probes x 20 Conductive Rubber x To be installed North Bottom Octants

Summary We have developed prototype clamps for re- capacitation to MuTr St-3. Good Contact was established more than 90% channels with present design in North MuTr. We propose to install 3 different prototypes (each 20) to North bottom Octants for Run11. They can be uninstalled during Run if they cause trouble in HV operation. 18

Backup Slides 19

20 ADC MIP Event Display of ADC Distribution Strip Gap 1 Stereo Gap 2 Stereo Gap 3 Stereo Gap 1 NonStereo Gap 2 NonStereo Gap 3 NonStereo