1. Technology Department MKP status L. Sermeus, L. Ducimetière TCM 18 November 2014

2. Technology Department Contents 18 November 2014L. Sermeus2 System layout Operational observations to date including Scrubbing Spares status and preparation Short-term improvements and longer-term outlook

3. Technology Department MKP Status LSS1 layout 18 November 2014L. Sermeus3 MKP-S MKP-L MKP-S: 2 tanks (1 & 2) with 5 S-magnets and 1 tank (3) with 2 S-magnets MKP-L: 1 tank (4) with 4 L-magnets

4. Technology Department MKP Status 18 November 2014L. Sermeus4 MKP-L (tank 4) Aperture: width: 141.5 mm height: 54 mm length ~700 mm (22 cells) Impedance: 12.5 Ω Ground conductor: Be (36 nΩ.m) MKP-S (tanks 1,2,3) Aperture: width: 100 mm height: 61 mm length ~500 mm (17 cells) Impedance: 16.67 Ω Ground conductor: Ti6Al4V (1.78 µΩ.m) Magnet apertures

5. Technology Department MKP Status 18 November 2014L. Sermeus5 During scrubbing run, the magnet ground conductor temperature went up to 45 °C in tank4. The vacuum pressure went up to ~5·10 -7 (~interlock limit) Operational observations after LS1 PT100

6. Technology Department MKP Status 18 November 2014L. Sermeus6 Why is the vacuum so bad in the presently installed magnet? - what parts are outgassing? Mainly aluminium plates (very large area) then ferrite, difficult to say in which proportion. The ferrite are clean but it is the first time they experience the beam scrubbing. The ferrite blocks are also compressed between the plates. - what process was used on these parts, and is this something new or was it always used? Aluminium plates treated with sodium hydroxide and not hot-dried under vacuum (vacuum part of VSC oven appear to be out of order ?) - was the tank OK in the lab tests (vacuum wise) or not (same behaviour as in machine)? Very long (months) to reach acceptable vacuum in the lab test. Nevertheless VSC approved the installation of the tank with the observed performance because there was no leak and the second pumping was expected to be faster. Operational observations after LS1

7. Technology Department MKP Status 18 November 2014L. Sermeus7 The currents in TMR7A (trace 1) and B (trace 2) are delayed by ~15 ns. Same observation for TMR8A (trace 3) and B (trace 4). No real explanation. It seems to be due to magnet construction. Magnets B might have less capacitance than A. Operational observations after LS1

8. Technology Department MKP Status 18 November 2014L. Sermeus8 Spare status and preparation All spare tanks are under N 2 atmosphere Tank 5 modules is operational. Tank 2 modules status is unclear. It is though to be operational but this has to be confirmed. Tank 4 modules removed during LS1 is operational (stored in radioactive area) but : Not equipped with PT100; No transition pieces between tank and magnets and also between magnets; No capacitive pick-ups for field measurements;

9. Technology Department MKP Status 18 November 2014L. Sermeus9 Short term “improvement” Reinstall tank 4 spare as it is. Planning: Bring back to Lab (room to find or delay the PS 100 ns ion test). vacuum pumping to check that the dismantling has not degraded the vacuum performance. If ok: Installation ( disconnection HV, transport + installation + alignment + vacuum connection) : 3 to 4 days mini Pumping + leak detection (in parallel with HV disconnection of other MKPs: 1 week DC conditioning (3 parallel bench if working) : 3 weeks mini (with access during week-end) Reconnect all MKP’s HV equipment (entrance boxes, HV cables, terminating resistors) : 3 days EC Check after reconnection : 2 days Pulsed conditioning : 1 week mini Time: ~7 weeks after lab test.

10. Technology Department MKP Status 18 November 2014L. Sermeus10 Short term “improvement” Move the MKP4 4 mm inwards to be nearer the ground conductor Ion beam with present configuration and kicker misfire (source J. Uythoven)

11. Technology Department MKP Status 18 November 2014L. Sermeus11 Short term “improvement” Move the MKP4 4 mm inwards to be nearer the ground conductor Estimation of the beam induced power loss reduction factor as a function of the horizontal beam position ( x beam ) at flat bottom (sigmarms ~20-22 cm) for the 25 ns beam. Similar values have been found for the 50 ns beam. Therefore, the simulations predict a significant improvement in terms of beam induced power loss approaching the ground conductor (positive x beam ). (C. Zanini) With 4 mm, the gain is very small!

12. Technology Department MKP Status 18 November 2014L. Sermeus12 Longer term outlook Bake-out of the aluminium plates under vacuum at +/- 200°C before assembly (already done on ferrite at 1000°C under vacuum). Bake-out of the magnet module under vacuum in a test tank (AA test tank should be ok) before installation in the final tank (not bake-able) – magnet construction to be checked. Vacuum valve for each MKP tank (à la MKI). Rebuild magnet with electro-polished stainless steel plates rather than Al and bake at ~300°C (needs a complete redesign). Having a radioactive storage place with permanent ionic pumping (means having enough pumps and power supplies; having regular access to check that the pumps are ON, or having a remote control) Redesign magnets with beam screen – will require more modules / tanks / generators