CERN Accelerating science

Prepare for ramp

We will be able to spend an indeterminate length of time on the injection plateau.

Model and experience will be used to update the ramp functions to take care of a varying depth of snapback.

On the injection plateau, the power converters driving the correctors will have been driven through and will still be driving through pre-determined functions. They will have also received trims from the RMS. They will also have received trims from the operators and/or from feedback systems.

Let us assume that the required beam has been successfully injected. This might be simply a pilot for tests or the full complement of 12 batches per ring. In any case the decision is made to ramp, presumably by the operator.

Need to:

1. Establish length of time on injection plateau
2. Reference model or measurements to establish depth of snapback.
3. Calculate required corrector functions
4. Incorporate any trims made via Harmonic factory, operator or feedback loops.
5. Load functions to hardware

Note: some collimation will be required when attempting to ramp pilot bunches, as the energy goes up so does the quench potential.

Functions loaded to:

• Power converters
• RF - frequency, voltage
• Tune feedback [?]
• Energy compensation with horizontal orbit correctors [?]
• BLM thresholds up the ramp - check
• Experiments' dipole compensation.
• Separation bumps
• Crossing angle