Power Converters for Magnets. Introduction Specification Magnet characteristics SPS supercycles Design optimization Generalities Power converters characteristics BB4 building Power converter renovation Provisional budget Vacuum chamber protection
The second cycle is very restricting because we have to change the TI8 cycle to a CNGS cycle very quickly and it is foreseen to use the same power converter to feed both main bend chains (TI8 and CNGS) one after the other.
The power converters will be installed in an existing building. It will need to be cleaned and the false floor will be adjusted to receive the power converters (this cost is in ST budget).
The old power converters coming from SPS and LEP need refurbishing to improve their reliability
For the power parts of the power converters, the price of the refurbishment is about 30% of new converters.
17 old converters + 2 spares + 18 MDGV/H (15 + 3 spares) + 1 New
To comply with the SPS supercycle specification, we must use an electronic switch. Since it is not a safe element, if we want to give access in TI8 while CNGS is running, we will need mechanical switches to disconnect the MBI.
With more time between LHC cycle and CNGS cycle (~20s) and a number of operations limited (a few per day), it would be possible to use an easier and cheaper design. With only one mechanical switch, we can gain ~ 100 kCHF.
The initial estimate was 60% of the flat top value but with optimized current references, we can assure 55%.
we have to study, design and manufacture the switch for MBI and MBG supply:
- More difficult and expensive with electronic switch but runs with supercycle.
- Easier and cheaper with mechanical switch only (gain ~ 100 kCHF) but waste of time during change of cycle (~ 20s) and number of operations limited (a few per day). If this solution is chosen, it will be possible to add the electronic switch in the future without problem (just money wise).