Transcript Multi-PM optical module progress

Optical module progress
P.Kooijman,Nikhef
Pylos april 2007
HV-supply
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Second version of the HV supply
Works ok
HV-adjust 1070 -1470V
Threshold 1.209-1.221V
Pinholes
1500V
via
PCB-a
5kV/
mm
gnd
Prepreg layer
PCB-b
High voltage design
HV supply
-1500V K
5mV/div
Artificial PMT pulse
D1
in
500mV/div
Comparator output
D2
out
Cable delay
Circuit delay = 3ns
D9
A
10ns/div
3V3 amp
+
LT1617-1
3V3
com
p
Q
Q\
Amplifier-TOT included
IT JUST FITS
Support of PMT’s in sphere
• Styrophoam
• Supports tube but allows
axial movement
• Contact with glass via
RTV silicon contactlens
shaped according to the
radius of the glass
PMT tests
• XP53x2 has a bit high darkcountrate
• Looking into other 3” tubes
• Maybe also slightly higher gain
(See talk by Herbert.)
Readout idea
Create
pulsetrain
TOT pulse
Photons arrive
Charge
capacitor
“slowly”
Every ns
discharge
Very fast
100 ps
Modulate
and
reflect
light in
fiber
Advantages
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Deadtimeless
There and back over same fiber
Time calibration simple
All electronics on shore
Power consumption ~200 mW
No loss of information
– Low pulseheights photon counting
– Large pulseheights – large TOT
Conclusions
• No show stoppers yet
• Power consumption per sphere less than
5W
• Bits show which PM is hit
• Can work at 20 Gb/s over 100 km
• All devices needed are available