2. Capacitive pick-up on MKP: why, when, who, resources, others
M.J. Barnes, N. Magnin, V. Namora, L. Sermeus
Outline:
Why use capacitive pick-ups (CPUs) on installed kicker magnets?
Present status of CPUs on MKP magnets
What is required to have functional CPUs?
Recommendations
21/8/2017
MJB - nTCM

3. Why use capacitive pickups (CPUs) on installed kicker magnets?
CPUs originally installed on all MKIs:
Cabling/digitizers envisaged for locating breakdowns in magnet & calculating delay (for magnet heating);
Cables run during YETS 15-16;
Digitizers installed during EYETS
BUT… during recent synchronization of MKIs (historically done with TMR waveforms)….
4 MKI8 TMRs showing good synchronization:
3 MKI8 CPUs: B&C on top of one another (D not working):
Reason for differences between MKI TMR and CPU not understood – which is best ???
Maybe CPUs on MKPs, in BA1, could allow better synchronisation adjustment ????
21/8/2017
MJB - nTCM

4. Present status of CPUs on MKP magnets
MKP-S. T#2
MKP-L. T#4
Beam
MKP-S. T#1
T#3 1A 2A 3A 3B 4B 5B 6B 7A 8A
Each MKP module is resistively terminated.
Two modules pulsed, in parallel, from one PFN.
MKP-S
Magnets previously upgraded;
Capacitive pickups on i/o and o/p of modules: 1A, 2A, 3A, 3B, 4B, 5B, 6B
MKP-L
Upgrade of spare planned to start in Nov. 2017, for installation during LS2 (see minutes of nTCM of 19/6/2017)
Capacitive pickups on i/o and o/p of modules: 7A, 8A (and same planned for spare).
21/8/2017
MJB - nTCM

5. What resources are required for functional CPUs?
No additional work presently foreseen for EDS, KSC or PPE (spare MKP-L is already planned for upgrade, including CPUs, starting Nov. 2017);
Cabling required, from tunnel, for CPUs (EN\EL);
16 coaxial cables, each of ~200m;
CERN type CC50 cable (low-loss): ~2 CHF/m  ~6.4 kCHF;
Acquisition cards (EC): ~40 kCHF
Long-term: IPOC analysis of waveforms (EC)
Others ???
200 m cable length will cause dispersion of signals – shouldn’t be a problem provided that all signals are equally influenced.
21/8/2017
MJB - nTCM

6. Recommendations
Request 16 cables to be installed for MKP (all of identical length) – can be cancelled at a later date if necessary.
Note: as per MKIs, CPUs on MKP could potentially be used to monitor when (8 of 16) magnets approach their Curie temperatures….
In parallel investigate differences between synchronization of TMR and CPU signals, for MKIs (NM, EC, MJB).
21/8/2017
MJB - nTCM