Guidelines, Fresh Probes

  • RF injection phase (see procedure from YASP's help)

    • Need to correct with an empty ring, the phase is always averaged over all circulating bunches which biases the result (phase error smaller than in reality).

    • Add the same sign as the error reading to the Knob (non-multiplexed beam process).

    • If at the next injection the beam jumps into a different bucket, then it is necessary to reset the knob and correct the injection bucket (see procedure by Delphine).

  • RF synchro error (see procedure from YASP's help)

    • Up to 30-40 degres - ok.

    • If the error is larger, then one needs in principle to rematch the SPS-LHC energy difference with the LHC orbit correctors (YASP procedure). Please do not start this in the middle of the night, this has large impact on the tunes and requires a re-tuning of the ramp. Normally the energy is very stable - not corrected at all in 2017 !  - so a large change is suspicious.

  • Q': use the standard target value (15-20)

    • Modulation amplitude and frequency

      • For snapback measurement, then this amplitude and frequency.

  • Coupling

    • OK if < 0.004

    • Else use the coupling measurement usig the ADT.

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