ELOG AIDA

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

AIDA

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Sat Dec 12 02:12:17 2015

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Stripped down contents of AIDA NIM bins to only what is required by AIDA.
Now have BNC PB-5 pulser, sum and invert module, single and quad Caen HV supplies in the top crate and the MACBs in the bottom crate.
Removed were FIFO, leading edge discriminator and a quad coincidence module, all used in the DAQ integration.
Smallest dial on pulser potentiometer was round at an unlikely number, seems to have been knocked.
&nbsp; &nbsp; &nbsp; &nbsp; - connected to scope and consecutive values on the biggest dial does not produce integer multiples of the lowest setting -&gt; needs sorting out for future pulser walkthroughs.
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Tested tripped detector from Apr/May (BB18-1000 3131-11) with kaptons connected to nnaida1,3,5,8 (GND to nnaida1), +ve HV with braid to front strips via nnaida5 and core to back strips via nnaida3.
&nbsp; &nbsp; &nbsp; &nbsp; - biased to +150V with a stable leakage current of 9.5uA in a very warm room.
&nbsp; &nbsp; &nbsp; &nbsp; - stable for ~2mins then I_L jumped to 20uA and detector tripped.
&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;- subsequently unable to successfully bias the detector. Trips on ramping up around 15-20V every time.
&nbsp; &nbsp; &nbsp; &nbsp; - no visible damage or broken bond wire.
Initial conclusion is this detector is broken (but see bellow). Then tried with another (BB18-1000 2977-15, pre-prod)
&nbsp; &nbsp; &nbsp; &nbsp; - encountered similar problems in that the detector tripped once at ~+50V and then kept tripping around +12V thereafter.
This was all carried out with the jumper combination already present from the end of the run in May - Lk1,3,5+7 had jumpers on on all FEEs, but we were unable to bias detector.
Removed all jumpers and 2977-15 biased successfully to ~75V (with 10.12 uA leakage current). Pulser resolution ~700 ch FWHM for NNAIDA 1 (p-side); 20 ch for NNAIDA2 (no DSSD connected)
Setting1:
&nbsp; &nbsp;- Add jumpers LK1 to nnaida1 (w/grounded Kapton cable), LK3 to nnaida3 (+75 V), LK1 and LK3 to nnaida5 (ref. 0V), and LK3 to nnaida8 (revB PCB). See attachment 1.
&nbsp; &nbsp;- Biased with 10.44 uA leakage current @ 75V
&nbsp; &nbsp;- About half of the Cu-braids with ground connections across FEEs are loose (clamps had snapped while moving table/mounting DSSD).
&nbsp;&nbsp; - Using 2015Apr30-diode-mod2 ASIC settings.
&nbsp; &nbsp;- Resolution of sample channels (FWHM): nnaida1: 320 ch, nnaida3: 500 ch, nnaida5: 280 ch, nnaida8: 180 ch.
Tried a couple more jumper settings:
&nbsp; &nbsp;- nnaida1: LK1+LK3, nnaida3: LK3, nnaida5: LK1+LK3, nnaida8: LK1+LK3: overcurrent with a couple of volts (short circuit, likely LK1 in nnaida8).
&nbsp; &nbsp;- nnaida1: LK1+LK3, nnaida3: LK3, nnaida5: LK1+LK3, nnaida8: LK3: detector trips (I&gt;20uA) at about 18 V, and after tripping first time there is a steeper increase of I vs V (~20uA at ~ 9V).
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Setting2:
&nbsp; &nbsp;- Same jumpers as setting 1: nnaida1: LK1, nnaida3: LK3, nnaida5: LK1+LK3, nnaida8: LK3.
&nbsp; &nbsp;- Connect all Cu-braid cables to ground the Cu blocks of first two rings of FEEs.
&nbsp;&nbsp; - The resolution in all FEEs improved to about 170ch FWHM, except for nnaida1 (with grounded Kapton cable): nnaida1: 310 ch, nnaida3: 170 ch, nnaida5: 180 ch, nnaida8: 160 ch. See attached sample spectra and waveforms.
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