MPS Minutes 20210825

Present: MA, HH, RN, AD, MR, KL, AL

Commissioning status

Finished scans in medium energy section
Initial issues with EMBT:MB0 power supply stopped us from taking scan the week before
Taking scans at EINJ setpoint 950 - 975 ~10.5 MeV
- Higher EINJ setting increased dark current by factor of ~3. Spill levels in medium section ~factor of 2-3 higher compared to 2020 data. In high energy section as well.
- Still need to take dark current scan to add background to thresholds
- Should also have a study of energy dependence and dark current
10kW was reached at 25MeV (EINJ setting ~710). No issue with BLMs tripping
Problem really mostly with tuning procedure when beam is on view screens
- Is there a way one could implement interlock procedure that disables a particular detector when specific view screen is inserted and re-enables when the view screen is out of the beamline again?
- Presently, we're tripping when on view screens as beam is spilled and trip settings are for well-focused beam.
- We shouldn't sacrifice safety for convenience and just bump up thresholds
- Rod: This requires well specified changes
- In principle single channel can be disabled. Just have viewscreen status as trigger.
- Rod: Option for more detectors to discriminate between de-focused and focused spills? Might be to complicated for immediate solution.
- Should we have threshold settings depending on mode of operation? Need to discuss with Thomas.
- MA: Does cyclotron have monitors that are getting disabled from time to time? --> Unclear.

10kW was reached at 25MeV (EINJ setting ~710).
Next goal is 10kW at 30MeV.
Fields were measured by RPG outside of the ehall and didn't appear to increase with higher power
RPG measured fields at the dump afterwards. ~10uSvr/hr as usual.
On Wednesday evening energy was already increased to 27.8 MeV at 6kW. Tune wasn't ideal. Spills just at threshold limits in high energy section. AL slightly increased levels from 50nC to ~75nC to avoid trips. In high energy section we have factor of 2 safety margin before hitting 100nC in 100ms losses.

AL reached out to Thomas about meeting for global reset. Will arrange meeting time when Thomas is back from vacation
After MPS re-commissioning report, AL will write up LED calibration specs
Still need to get Post-Mortem data to analyse from BLM trips.
No update on fibre. Reflector has not arrived yet.