ELOG DESPEC

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

DESPEC

Fields marked with * are required
Entry time:	Sat Mar 29 11:37:48 2025
Author*:
Subject*:
<p><strong>To do:</strong></p> <p>1) <strong>Disconnect ribbon cables from p+n junction FEE64 adaptor PCBs of upstream DSSSD, apply c. 100V bias and check leakage current is zero i.e. eliminate shorts in PCBs</strong></p> <p> - When the p+n ribbon cables were disconnected for both the upstream and downstream AIDA, the pins and ribbon cables did not appear to have any blemishes.</p> <p>- Both sets of adaptor PCBs were biased to 100 V and only had an apparent fluctuation in current at c. 0.01 uA. At low voltages (~10V) the current cycled between 0 and 1 uA.</p> <p>2) <strong>Check that all ribbon cables are properly seated in the adaptor PCBs</strong></p> <p>- When inspected all ribbon cables seemed to be properly seated. A decent press was applied to confirm the seating. The PCBs themselves were inspected and no noticeable damage was observed.</p> <p>3) <strong>Check all adaptor PCB connector pins are OK: will need to remove ribbon cables</strong></p> <p>- Done for the p+n side, can decide if this is needed for the n+n side.</p> <p>4) <strong>If/when you open check seating of all Kapton PCBs in the DSSSD connectors and carefully check that ribbon cable and Kapton PCB connectors are aligned and not out by 1 or 2 rows say.</strong></p> <p>-  Will have to decide further.</p> <p>5) From email discussion: <strong>Check the SHV connector is grounded if one unplugs the cable from the back of the HV module. If yes: We are touching a ground somewhere. If no: it's via the HV (fine).</strong></p> <p>- When HV#0 was disconnected from the HV module, we used a multimeter on the SHV connecter and frame and read zero resistance 0L on the meter. While when completing the circuit for HV#1 (still) plugged into the HV module we read a resistance of > 1.7 Ohm.</p> <p>- The HV is touching ground somewhere. This should not be a problem however as the snout is isolated, and this was observed by connecting the SHV to the snout and reading 0L.</p> <p>6) <strong>Properly cover snout with black cloth and bias upstream.</strong></p> <p>- Snout was covered with black cloth and a black bag. The downstream detector p+n side was biased at 50V and charging/discharging was observed. This is probably due to a short connection somewhere.</p> <p>Summary: from the p+n side test the voltage-current break down appears to come from inside the snout.</p> Encoding: HTML ELCode plain Suppress Email notification

Attachment 1:
Drop attachments here...

ELOG V3.1.4-unknown