Cavity BPM systems work
Aim to provide long term stable BPM system operating at the best possible
resolution.
- Hardware measurements (related to BPM design, systematics etc)
- Operations (beam based measurements)
- First pulse operation
Hardware measurements
- Electronics gain (weekend measurement)
- Calibration tone (continuous measurement)
- Electronics noise figure (best possible resolution)
- Cavity coupling factor (x-y cross coupling)
Online measurements and tests
- Individual BPM calibrations (mover)
- Orbit bump calibrations (non-mover BPMs)
- Dynamic range, coupling strength (requires electronics gain), linearity
- Cross coupling (x-y)
- Resolution (simple, jitter removed)
- Tone calibration system (constantly updated gain measurements)
- Temperature monitoring system
- Long term position drift measurements
- Multi-bunch operation
- Use in "slow" feedback operation
- Electrical centre drifts/stability
First pulse operation (still useful test for ILC)
This is still useful as in a large system (
ILC, FEL) the BPMs cannot all be calibrated using a mover system. This would be the first test towards an ab-initio system, combined with careful gain/loss measurements would represent a test of the techniques that would have to be used at the
ILC.
- Measure precisely phase of each signal cable
- Local oscillator phase
- Phase difference for each BPM due to beam propagation