3.5 KiB
3.5 KiB
title, description, template
| title | description | template |
|---|---|---|
| Critical Beam Dumps | Here a list of all uncontrolled / critical beam dumps is kept | main.html |
8 - Thu 25-Sep-25 22:58
- Root cause: vacuum / ID gap / ion instability
- Repetition of Nr. 7
- Vacuum Interlock threshold now reduced
- Filling pattern gap increased from 30 to 50 buckets
- https://elog-gfa.psi.ch/SLS/62484
7 - Thu 25-Sep-25 18:04
- Root cause: vacuum / ID gap / ion instability
- Beam dump seems to be caused by an initially slow-rising vacuum spike inside the X02SA U15 undulator
- Lifetime went down from 8 hours to <2 hours slowly in the last 5 minutes before the beam dump simultaneously with the pressure going up
- The observed vacuum spike could be a classical ion instability
- Vacuum Interlock unfortunately was not triggered
- ID gap is stuck at minimum value and cannot be opened which would improve the vacuum
- https://elog-gfa.psi.ch/SLS/62480
- https://elog-gfa.psi.ch/SLS/62482
6 - Tue 23-Sep-25 15:56
- Root cause: FOFB writes bad values to correctors
- Happened during BPM Sector reboot, i.e., overall reliability issue with BPM/FOFB system
- Beam dump controller only triggered by RF stations
- Post mortem data clearly shows that beam was lost before dump kicker was fired
- Communication issue between machine experts concerning disabling the orbit deviation beam dump seems irrelevant
- It would be good if the disabling and reenabling of the orbit deviation beam dump for sector reboots could be automized in a safe way
- https://elog-gfa.psi.ch/SLS/62451
- https://elog-gfa.psi.ch/SLS+RF/2121
5 - Thu 07-Aug-25 20:31
- Root cause: misfiring of one individual beam dump kicker stage
- it seems one stage of the beam dump kicker misfired, partially killing the beam and triggering an RF interlock which requested a beam dump which led to a intended firing of the beam dump kicker that failed for the only just misfired stage
- https://elog-gfa.psi.ch/SLS/61987
- https://elog-gfa.psi.ch/SLS/62030
4 - Tue 29-Jul-25 16:43
- Root cause: Fast change of quadrupole setpoints (MD shift)
- Fast orbit detection might prevent this in future but not if tune moved to 0.5
- https://elog-gfa.psi.ch/SLS/61837
3 - Tue 29-Jul-25 15:51
- Root cause: Fast change of quadrupole setpoints (MD shift)
- Fast orbit detection might prevent this in future but not if tune moved to 0.5
- https://elog-gfa.psi.ch/SLS/61836
2 - Wed 23-Jul-25 16:32
- Root cause: FOFB wrote NAN to corrector magnets
- Automated testing clearly shows the bug of the EPICS ringbuffer record in EPICS 7.0.8 leading to the regular appearance of huge numbers about every 5 seconds when writing a new value to the ringbuffer with 10 Hz. The bug is not observed at all for EPICS 7.0.9
- https://elog-gfa.psi.ch/SLS/61782
- https://elog-gfa.psi.ch/SLS/61768
1 - Tue 13-May-25 09:36
- Root cause: Misfiring of individual kicker during turning off 4 Kicker Bump at 400 mA
- EPICS procedure to prevent this is implemented
- https://elog-gfa.psi.ch/SLS/60877
- https://elog-gfa.psi.ch/SLS/60878