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Rigorous cycling procedure required to establish fully reproducible conditions etc. etc.
Put in picture of nominal cycle showing pre-cycle etc. After cycling, the ramp to the injection level will be performed by LSA sequencer.
Appropriate monitoring of all cycling will be implemented to make sure everything does what it’s meant to.
Cycling prescription strongly dependent on magnet type, options are:
Appropriate for main circuits (MB, MQ) with Rutherford cable.
Ramp magnets to top energy at maximum ramp rate (10 A/s), sit on flat top for something like 30 minutes, ramp down to pre-injection plateau.
Note that the MQ basically free fall down and the down ramp will follow the natural decay of the circuit.
Method: would anticipate performing this with pre-generated settings which are loaded as TABLEs into the power converter FGCs. This will allow explicit control of current levels etc.
For magnets for which zero remnant field is required, a de-magnetization cycle is possible. This cycle essential performs several cycles with diminishing amplitude to bring the magnet to the zero point of the B-I plot.
Method: would anticipate performing this with pre-generated settings which are loaded as TABLEs into the power converter FGCs. This will allow explicit control of current levels etc.
For magnets with simple cables, a simple cycle from minimum current, to maximum and back to minimum a number of times would be sufficient. This should of course respect magnet and power converter ramp rate limits.
Method: Simple database driven LSA command to perform the requisite PLPs between the min and max.
Some magnets are driven by power converters in the same circuit (e.g. MQMs, MQX). Cycling prescription for component magnets will need to be established. This has to be translated into power converter functions; the power converters will need to be driven synchronously. (The difference in current between power converters driving 2 in 1 quadrupoles, for example, has to be strictly controlled.)
Method: would anticipate performing this with pre-generated settings which are loaded as TABLEs into the power converter FGCs. This will allow explicit control of current levels etc.
Simply cycling of the nested magnets has to be performed; however, the cycling of the various magnets has to be performed one after the other in a strict pre-specified order.
Method: Database driven program or script to cycle, and monitor nested magnets in order.
Bear in mind Tevatron which used to unsqueeze and dry squeeze to reset
More convoluted possibilities are possible for magnets that are to be used at low currents.