L0 Status

1
L0 Status

• New prototype is in hand.
  ? Noise study has been resumed.
• Wire bonding.
• Pull strength 810 gram. (cable to cable)
• Assembly issues. ? has to be solved.

2
Pedestal and its sigma (no bias)
Fixture wrapped by aluminum foil connected to gnd.
HDI and HV(sensor) gnd connected
default
The source of noise seems to be dominated by
pick-up.
3
Pedestal and its sigma (fixture in Aluminum foil)
30V bias
0V
Small effect of depletion.
4
Size of total noise
Because two cables separated by enough space.
? 16 pF (cable)
10(?) pF (Si) ? 1500 e
If no load, 500 e.
Assuming 1 ADC 1000 e
? expect 1.0 ADC
counts of increase
Noise increase 0.8 ADC counts
5
Random noise (30V bias)
Common mode subtracted
Random noise 0.8 ADC counts total noise
6
Where the pick-up comes from?
Only around the cable shielded
Around cable and sensor shielded
Around cable and HDI shielded
? Main effect from cable (as expected!) plus
minor effect from HDI.
7
Assembly issues

• Last time, the problem on the sensor-cable
  bonding.
• This time, chip-cable.
• Alignment of two cables.
  ? Need to fix the configuration for better
  bonding, and may need to have the vendor two
  cables laminated.

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10
In case two cables are laminated together
Pads are 150 x 60 mm. ( the same as before)
100mm
100mm
200mm
100 150 200 mm shorter at the one end. ?900
mm shorter in total.
The shorter cable is laminated on top of the
longer one.
11
In case two separate cables
Pads are 150 x 60 mm. ( the same as before)
200mm
200mm
300mm
200 150 300 mm shorter at the one end. ?1300
mm shorter in total.