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Message ID: 41     Entry time: Sat Apr 5 12:54:20 2025
Author: CG, MC 
Category: Detectors 
Subject: Bias curves 
Bias curves were completed for most detectors yesterday evening.

General news is that, due to the massively increased leakage currents, we were likely not fully depleting the detectors up until yesterday.
Generally, all detectors require much higher voltages to reach plateau than was expected.

For the inside pocket, this is +150V for the SiPads, -100V for the DSSD and -140V for the crystal PD.
The outside pocket may have different bias resistors in the MSI-8 (need to check at end of exp!) so they hit plateau at lower bias, but still higher than expected: +100V for SiPads, -100V for DSSD, -140V for 
crystal PD.

Bias curves are attached and can be found in the detector health spreadsheet at https://docs.google.com/spreadsheets/d/1Gt1tFHwn4XFrJ5_-nQvTi635UD0aHgN6gCdXDTHQdkI/edit?usp=sharing

Attachment 1: Bus 0, Mod 0. Inside pocket. Ch2 is uncabled at the MSI-8 so a bias curve couldn't be done for this detector, but was previously identified as likely having a short in Beavertail Elog 21.
Attachment 2: Bus 0, Mod 1. Inside pocket.
Attachment 3: Bus 1, Mod 0. Outside pocket. Ch3 is uncabled at the MSI-8 so a bias curve couldn't be done for this detector, but was previously identified as likely having a short in Beavertail Elog 21.
Attachment 4: Bus 1, Mod 1. Outside pocket. Ch3 is the crystal PD. Leakage current on this detector is slowly creeping up despite not being in the beam making a bias curve hard to do.
Attachment 1: biasCurvesBus0Mod0.png  70 kB  Uploaded Sat Apr 5 14:59:28 2025  | Hide | Hide all
biasCurvesBus0Mod0.png
Attachment 2: biasCurvesBus0Mod1.png  80 kB  Uploaded Sat Apr 5 14:59:41 2025  | Hide | Hide all
biasCurvesBus0Mod1.png
Attachment 3: biasCurvesBus1Mod0.png  48 kB  Uploaded Sat Apr 5 14:59:59 2025  | Hide | Hide all
biasCurvesBus1Mod0.png
Attachment 4: biasCurvesBus1Mod1.png  51 kB  Uploaded Sat Apr 5 15:00:13 2025  | Hide | Hide all
biasCurvesBus1Mod1.png
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