-
Unstable injection after
recycling, cannot reproduce machine
- Causes: PC decay effects,
FiDeL prediction inaccuracies
- Diagnostic tools:
trajectory analysis, lifetime, beam losses at absorbers
- Remedies: De-Gauss cycle,
longer waiting times, FiDeL modification, orbit/energy feedback, …
-
Calibration of
BPMs vs. correctors not possible
- Causes: bad optics, not
acquiring properly, not triggering
- Diagnostic tools:
BI-expert tools for pick-up calibration, kick-response -> LOCO,
YASP, check longitudinal structure of beam, call expert
- Remedies:
optics: compare with
signals on screens where possible; trigger problems: increase
lifetime, increase intensity per bunch (if with pilot)
-
Impossible to
increase lifetime
- Causes: field errors ->
very small dynamic aperture, poor shot-by-shot reproducibility
-> difficult to tune
- Remedies/diagnostic tools:
dampers, chromaticity - until lifetime good enough to
commission BI, check whether unstable (turn-by-turn data),
measure and adjust tunes, chromaticity, check blow-up of beam,
...
-
Impossible to
extract
- Causes: kicker timing wrong (e.g. if bunch in bucket
1), energy tracking wrong, kicker wrong polarity
- Diagnostic tools: OASIS for beam signal + kicker
waveform, dump line instrumentation (screens, BLMs,...)
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