09:00

Leakage currents this morning again appear to have lowered during the night. Current plot shows a day/night variation but I think the minimum is decreasing ever so slightly.

This morning DSSD1=15.1uA and DSSD3=14.4uA, this is ~0.3-0.4 uA lower than yesterday. DSSD4 is still fluctuating in its leakage current and looks to have been all night. See attachment 1.

Will now proceed to systematically check all grounds before restarting AIDA.

Several cables have been re-routed this morning to clean up the area, allow us to see clear what cable goes where, and are avoid any unwanted interference. E.g. ion pump cables have been re-routed to not be near the bias cables, one ion pump cable was running between the power and hdmi on one of the FEEs, this was been sorted.

All grounds have been checked, some loose cables have been tightend up. Current ground configuration has all the adaptor cards (nn and pn) on a single detector connected together. One grounding cable then goes from each detector to the right coolant pipe which all the other detectors are also grounded to. This was the configuration for the previous beamtime. Will start pulser tests after lunch. Bias back on, leakage current slowly increasing again, DSSD3 current no longer fluctuating.

13:00

Ground config 1 - attachments 2-7 (described above)

Ground config 2 - attachments 8-10 (grounds now go to the CRYRING ground cable not the coolant pipe and jumper removed form bias module)

pulser widths 1.8L worse pretty much across the board. No sig impact on rates

Ground config 3 - attachments 11-14 (grounds returned to coolant pipe)

pulser widths 1.8L better than config 2 but still worse than config1

Ground configuration returned to first configuration. Pulser widths consistent with that seen before.

Additional bias tests.

Disconnected the pn bias cable (core) from DSSD1 but left nn bias cable connected. Biased. Observed bias ramp up but no leakage current was seen.

Reconnected pn bias cable but now disconnected nn bias cable. Biased. Observed bias ramp up, leakage current was seen to increase during ramp to ~8uA. Once fully ramped, leakage current started to slowly decrease and eventually went to zero.

Repeated same tests with DSSD2. Same behaviour observed as with DSSD1.

Have removed motors pins and tried some movement again. No effect on leakage current. Checked pulser widths before movement and after movement (with pnuematic IN). No change in pulser widths.

End of day status FEEs off, bias on and monitoring. Motor pins out to allow for last movement check, motors code running in screen session.