ELOG AIDA

AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40

AIDA

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Mon Dec 14 07:56:27 2015

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13/12/15
Current jumper setup:
&nbsp;&nbsp;&nbsp;&nbsp; - detector 2977-15 connected to nnaida1,3,5,8 with GND kapton to nnaida1
&nbsp;&nbsp;&nbsp;&nbsp; - bias of +75V to nnaida3 and nnaida5
&nbsp;&nbsp;&nbsp;&nbsp; - Jumpers:
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - nnaida1 &gt; Lk1. If Lk3 3 connected unable to bias detector
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - nnaida3 &gt; Lk3. if Lk1 connected unable to bias detector as the HV ground reference is connected at both p- and n-sides of detector.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - nnaida5 &gt; Lk1 + Lk3
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - nnaida8 &gt; Lk3
Powered system up as it was last night -&gt; 2977-15 connected to nnaida1,3,5,8 with only 4 FEE modules powered.
&nbsp;&nbsp;&nbsp;&nbsp; - n-side widths ~190-200 ch
&nbsp;&nbsp;&nbsp;&nbsp; - p-side widths ~100ch
&nbsp;&nbsp;&nbsp;&nbsp; - jumpers as above, ASIC setting as 2015Dec12_smallSetup, wav thresholds all at 500 apart from nnaida5 @ 250.
Spend remainder of day trying to fit mezzanine cables.
&nbsp;
14/12/15
Completed installation of mezzanine cables.
Resistance between all mezzanines and cooling crates still ~200 kOhms (up from ~2-5 Ohms on our arrival), apart from nnaida7+8, which is now at ~5 Ohms
However, all see resistance to main vertical copper pipe of ~3 Ohms.
As best as I can see, isolating tape in still in place for all FEEs &nbsp; &nbsp; =&gt; &nbsp; &nbsp; unknown point of contact.
&nbsp; &nbsp; &nbsp; &nbsp;&gt; LEMO cables to test inputs carry ground connection from NIM bin -&gt; NIM bin in electrical contact with support frame -&gt; coolant loop in electrical contact with support frame &nbsp;=&gt; electrical connection still present between FEEs and coolant loop, even in insulating guide pins are introduced
&nbsp; &nbsp; &nbsp; &nbsp;&gt; this problem is not observed at DL because the NIM bin in on the wooden table top and isolated from the coolant loop and any support structure
&nbsp; &nbsp; &nbsp; &nbsp;&gt; is it possible to isolate the NIM bins from the support structure?
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &gt; need to come up with some more systematic and fixed way/positions for measuring these resistances, i.e. always measure mezzanine to X.
Resistance between all mezzanines now ~ 0.5 Ohms.
n-side widths ~ 120ch and p-side widths ~ 120ch&nbsp;&nbsp;&nbsp; =&gt;&nbsp;&nbsp;&nbsp; peak widths almost halved in n-side, but increased by ~20% in p-side.
&nbsp;
Attempted to bias previously tripped detector.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - same jumper combination as other detector caused failure to bias &gt; leakage current jumps to 50uA at ~2V and trips shortly after, ramping back down from there.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - removed all jumpers and see same thing.
Will try again in the morning by attaching 3131-11 to cables currently on 2977-15, but it looks like 3131-11 really is defective somehow.

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