PS-SPS days, January 18 th, 2006AB/BT Kicker and Septa status and expected performance at the 2006 start-up With input from: B. Balhan, E. Carlier, F

PS-SPS days, January 18th, 2006 AB/BT

Kicker and Septa status and expected performance at the 2006 start-up

With input from:

B. Balhan, E. Carlier, F. Caspers, L. Ducimetière, T. Fowler, E. Gaxiola, B. Goddard, M. Hourican, Y. Kadi, T. Kroyer, T. Masson, M. Meddahi, V. Mertens

K. Metzmacher, A. Prost, L. Sermeus

J. Borburgh


Outline

• PS kicker issues

• PS septa re-installation and spare situation

• SPS kicker issues and spare situation

• SPS septa status and spare situation

• SPS diluter (septa protection) limitations

• Conclusion

• SPS multi-cycling reservations


PS Ring Kickers

• Ion injection KFA28 becomes operational in 2006. System impedance will be reduced from 25 to 12.5. Control software will be integrated into the DSC also controlling KFA45 (dcpsk45.cern.ch).

• KFA45 & KFA71-79 vacuum tanks were vented to atmosphere owing to PS Main Magnet refurbishment. Both systems will require high-voltage reconditioning of the magnets.

• Modified all KFA71-79 HV transmission gas filled cable junctions

• Modified and recalibrated all KFA71-79 HV terminating resistors

• General fluid systems modifications Still a lot of work needs to be done to get

everything up and running, but no problems are envisaged


PS Complex Kickers

Major renovation of the B174 HV test area allows improved testing and preparation of spares with better security:

• BI.DIS spare pulsed power supply currently being recommissioned (inherited in 2003).

• Test system (spare KFA71 and KFA79 magnets and tanks plus two HV pulse generators) presently being rejuvenated.

• Development of new modular fluids system underway

• Development of switched HV load for ISOLDE target power supply dynamic response studies

• Construction of new HV cable shed provides improved protection and logistics


PS Complex KickersAD:

Planned removal of kicker tank K35 (p injection via the loop). This requires changes to the DSC control RTT for AD extraction (dadekik2.cern.ch). Two HV pulse generators and one vacuum tank containing two magnets become available as spares.

ISOLDE:Parallel operation of positive and negative 60kV power supplies requires controls RTT modification (disoht.cern.ch). Consequently increased voltage stress in HV changeover switch.


Septum Re-installation: PS SMH16

Installed: SMH16.1

The braze on the coil connection which leaked in July 2004 has been repaired (has served 6 weeks in 2004).

Spares: SMH16.2 (full spare): in PS from 19.7.2004 onwards

with 1 new coil and 1 coil with 6 years of service. 2 yokes with new coils. Consolidation budget

requested for additional vacuum vessel to complete the second full spare in 2006.


Re-installation of PS Electrostatic Septa Installed: SEH 23.2: overhauled as new SEH 31.1: overhauled as new New 3M FC-77 insulating liquid replaces

the SHELL Diala oil in feedthrough for SEH31

Conversion of SEH23 feedthrough for sd. 06/07 or sd. 08/09 depending on if and when the new MTE will be installed

Spares: SEH 23.1: to be overhauled in spring 2006 SEH 31.2: new, never installed before SEH 31.3: 2 yrs of exploitation, to be overhauled HV cable (pp300B); 160 m of old stock, and new replacement

cable being ordered (consolidation prog.)


Overview of Principal SPS Kicker Modifications

• LSS6 converted from slow extraction to fast extraction during 2005– 4 MKE’s installed

• Safety measures implemented on MKE’s in LSS4• MKP kicker rise time improvement to be completed before start-

up• Upgrade of the MKQ timing system for multi-cycling operation

Reminder:

Sparks observed during the 2004 run on the MKDV are still under investigation.


SPS Kicker Spare Situation Installed:LSS1: 4 MKP, 2 MKDV, 3 MKDH, 1 MKQH,

1 MKQVLSS4: 5 MKELSS6: 4 MKE

Operational spares: 2 spare MKP (1 type 5 modules, 1 type 2 mod.,

type 4 mod. to be rebuilt) 1 MKDV (but still to be pulse tested) 1 MKE


4 new MKE’s in LSS6

• 4 MKE magnets installed – System of short circuited type (instead of characteristically

terminated) (ref. LTC 16.11.2005)

– Advantage: despite doubling the rise and fall time (but still within spec, i.e. <10 µs) , the required kicker voltage is reduced → improves the reliability.

• 1 of 4 magnets is partially equipped with beam impedance reduction measures, which equally reduce the beam induced ferrite heating

• If such beam impedance reduction measures prove successful and workable in beam operation, this could be applied to all 9 MKE’s in LSS4 and LSS6 as from 2007 or later (depending on workload)


MKE Beam Impedance Reduction with Stripes Printed Directly on Ferrites

Interdigital comb structure 20mm spacing

Ref.: E. Gaxiola et al, “Experience with Kicker Beam Coupling Reduction Techniques”, PAC’05


SPS Extraction Kickers MKE LSS4• Safety measures implemented for extraction kicker

generators in SPS ECA4 • 4 silicon fluid self healing capacitors replace 52 mineral-

oil-filled capacitors• Fire retardant wall


SPS Injection Kicker MKPRise time improvements for MKP #4 started in 2004• Replacement of broken damping resistors of PFN #1 - #6• Final fine tuning to be completed on PFN #7 and #8

before start-up 2006• Goal: rise time of < 220ns


• LSS6 fast extraction installed: 1 TPSG6; 2 MST; 5 MSE (5 ZS moved to storage as spares for LSS2)

• Septa position definition changed: position refers to protection element position (most upstream component)

• Septa coil and yoke temperature sensors have been disconnected on MST/MSE in LSS4 and LSS6 in order to cure electro-magnetic coupling with LHC beam type.

• Interlock on girder position added for LSS4 and LSS6 extraction (Connection to the Extraction Permit)

Overview of Principal SPS Septa Modifications


SPS Septa Spare Situation Installed: LSS2: 5 ZS; 1 TPSN; 3 MST; 5 MSE LSS4: 1 TPSG4; 6 MSE LSS6: 1 TPSG6; 2 MST; 5 MSE

Spares: 5 ZS recovered from LSS6, plus additionally 1 spare for ZS1 or ZS2

(invar anode, 60 µm wires) and 2 spares for ZS4 or ZS5 (stainless steel anode, 100 µm wires).

4 MST 5 MSE No spare for TPSN Previous type TPSG4 to be upgraded to present design during

2006, but now serving as (low intensity) spare Spare TPSG6 to be built in second half of 2006


TPSG (Septa Protection) Elements

TPSG4 (LSS4)Improved design with

different absorbing materials, additional length and water

cooling installed

TPSG6 (LSS6)Newly designed, built and

installed


TPSG Diluter Performance

Diluter limit for CNGS type extraction

Diluter limit for LHC type extraction

MS protection limit

TPSG4 4.8 e13 2.2e13 4.9e13

TPSG6 n.a. 1.9e13 4.9e13

Maximum proton intensity equipment limits in case of full impact on diluter

Reminder:

LHC NOMINAL intensity in SPS: 3.3e13 protons total

LHC ULTIMATE intensity in SPS: 4.9e13 protons total

CNGS NOMINAL beam intensity: 2.4e13 protons / batch (2 batches in SPS in total)

CNGS ULTIMATE beam intensity: 3.5e13 protons / batch (2 batches in SPS in total)


TPSG Diluters Performance

• A beam sweep (as produced by a kicker failure) can be sustained without any damage and the diluter properly protects the downstream septa.

• Both diluters will be able to properly protect the downstream MS septa from full impact but the diluters themselves are likely to be irreversibly damaged by the LHC nominal intensity beam!


TPSG Upgrade

• Given the space constraints and due to the unavailability of the ultimately desired materials for the diluter during the construction period, more common and well specified materials are used for the time being, yielding the performance as mentioned before.

• Upgrading from graphite and Ti to C-C and γ-met should yield more robust diluters, although the resulting performance is still to be confirmed by calculations from CRS4.

• 2006 and onwards should see the validation and subsequently the construction of upgraded (spare?) TPSG’s


TPSG4 Behaviour in Case of Full Impact of Ultimate LHC Beam

Temperature rise of every diluter

block

Maximum Stassi ratio for a 250ms simulation


TPSG6 Behaviour in Case of Full Impact of Ultimate LHC Beam

Temperature rise of every diluter block

Maximum Stassi ratio for a 250ms simulation


Conclusions• PS kickers: Still a lot of work needs to be done to get

everything up and running, but no problems are envisaged

• PS septa: re-installation well under way. Installation of new type of HV feedthrough on SEH31 on critical path.

• SPS: New fast extraction channel at LSS6 nearly installed

• SPS kickers: MKP rise time improvements to be completed before start-up. MKE in LSS6 of short circuited type to improve reliability.

• SPS diluters: properly protect septa in all cases, but may likely be damaged in case of full impact by LHC nominal type beam on the diluters


Limitations on Multi Cycling (from MCSG)• Presently we cannot simply assume that the ZS, “as is”, in position

and with nominal HV on, is ready for fast multi-cycling.• More tests on the spark rate with high intensity beams are needed.• A potential solution may be to ramp down (t ≈ 8 s) the HV during

high intensity operation, but this is still a slow process that may not allow full & fast multi-cycling.

Outstanding issues:• Add interlock (BIC?) to prevent bumped beam if during CNGS or LHC

operation• Interlock on girder position• If ramping solution will be retained, additional interlocks are needed to verify

the absence/presence of Unom.• ROCS may be a suitable tool to manage the current/voltage settings• Interleaved mode operation with a slow extraction has to be studied for

LSS2 MST/MSE extraction (i.e. temperature sensors may heat-up due to LHC beams and stop the extraction channel)

• The new items will need careful commissioning before well functioning can be taken for granted.

Documents

PS-SPS days, January 18 th, 2006AB/BT Kicker and Septa status and expected performance at the 2006 start-up With input from: B. Balhan, E. Carlier, F