Week 22 - Injector Long MD (From Wednesday 02/06 08:00 to Thursday 03/06 08:00 in dedicated and from Thursday 03/06 08:00 to Friday 04/06 08:00 in // to LHC)


- Wednesday 02/06 (08:00 - 12:00) - Coasts preparation in the SPS (decoupled) while the MD beam is prepared in the PSB and PS (+ another MD in the PS)

- 08:00 - 10:00 => MD beam preparation in the PSB (Bettina and Giovanni) + MD in the PS for PS injection tests with the LHCPROBE bunch and the kicker KFA45 in short-circuit mode (the aim is to measure the transverse emittance blow-up as a result of the increased ripple on the kicker flattop, Rende). This beam was already produced in the PSB on the users MD3/LHC25B: ~ 250-260E10 p/ring within the correct (requested by the PS, to avoid the creation of satellite bunches) longitudinal parameters (i.e. 180 ns and 1.3 eVs) and transverse emittances (total, sum x and y) of ~ 8 microm (rings 3 & 4) and ~ 10 microm (rings 1 & 2).

- 10:00 - 12:00 => MD beam preparation in the PS (Heiko and Rende). This beam was already produced in the PS on the user TSTLHC25 (3 BP): ~ 1.7E11 p/b with an average bunch length of ~ 4.1 ns (or even ~1.9E11 p/b with an average bunch length of ~ 4.3 - 4.4 ns). Measurements of transverse emittances on Wednesday 26/05 revealed values of ~ 4 microm (in both planes) at injection and ~ 5 microm (in both planes) at top energy. Some transverse optimization is still ongoing (at the time of writing, i.e. Wednesday 26/05).


- Wednesday 02/06 (12:00) to Thursday 03/06 (07:00) - ~ Ultimate intensity studies in the SPS (for the 1st time!), using the beam prepared in the PSB/PS (see above)

- Change of SPS supercycle: LHC_4Inj_FB10860_FT500_2010_V1 => It is the nominal LHC cycle for the 25 ns beam: 451.19 GeV/c (new momentum), 18 BP = 21.6 s, already taken in week 17 with the ~ nominal LHC beam.

- SPS user = LHC1

- RF MMI target = LHC25NS

- Timing sequence in the CBCM = LHC1-0/1/3(1)

Contact persons: E. Shaposhnikova and E. Metral

Pre-requisites:

- The interlock threshold on the temperature of the MKE kickers should be ~ 90º C (it should be ~ 70º C when there are extractions) => No need to call Etienne Carlier anymore as it is done in SIS.

- In the past, during (the scrubbing run and) the LONG MDs with LHC beam the ZS were RETRACTED / HV to 0 kV / ION TRAPS ON (the ZS expert was informed). During this MD the ZS experts will participate.

- The cooling circuit for the septa magnets (circuits 214, 414 and 614) should be switched OFF (by TI from the CCC).

- Block the fast vacuum valves OUT in the injection and extraction areas (LSS1, LSS2, LSS4 and LSS6) => Giovanna Vandoni (TE/VSC, 163269 => ~ 20 min) takes care of this (also after the MD to come back to the initial situation). The list of the 11 valves VVFA and VVFB to be blocked during the MD are:

BA 1 : VVFA 11901

BA 2 : VVFA 21701, VVFB 21877, VVFB 21802

BA 4 : VVFA 41638

BA 6 / TT 60 : VVFA 610213, VVFA 61957, VVFA 61637, VVFA 61460, VVFB 61802, VVFB 61877

- The magnets with the e-cloud monitors are 4 dipoles: MDHW51832, 51836, 51838, 51853, all with 0.12 T (MDHW51832 with 25 A). In addition, there is a C-magnet (MDPH51753 with 28.5 A, in series with 754 to compensate) which contains a sample which can be inserted and removed.

- Detailed planning:

- 12:00 - 14:00 => Inject 12 bunches in the SPS and check orbit, tune, chromaticity etc. (OP, RF, ABP).

- 14:00 - 16:00 => Transverse dampers adjustment with 12 or 24 bunches (Wolfgang).

- 16:00 - 20:00 => Longitudinal adjustments (feedforward etc.) with 72 bunches, and then we will try and add a 2nd batch (RF).

- 20:00 to Thursday 03/06 07:00 => Ecloud (and instability including TMCI) studies with the maximum number of batches (Mauro, Wolfgang, Benoit).

- ZS in the SPS => Usual issues (outgassing) followed up by experts (Bruno). Some stable conditions for few hours would be required during the night.

- MKE kickers => Usual issues (temperature increase) followed up by experts. The setting-up of the beam should be done as fast as possible and with the minimum number of bunches. Mike Barnes will closely follow the outgassing of MKE4 (with the interlock for extraction still set at 70 deg, as per last MD) and he will react if the outgassing gets to uncomfortable levels (the interlock level is set to 5E-7 mbar).

- Possible BI issues with higher intensity than nominal in the SPS => Marek Gasior is informed about the intensities which could be used during this MD (up to ~ 1.9E11 p/b and up to 4 batches of 72 bunches...) and he will check that the instrumentation will work normally for these intensities (and bunch lengths).

 

- Thursday 03/06 07:00 to 08:00 - Check the ZS HV conditioning + change the SPS supercycle: LHCFAST1 + LHC1 + MD1 (30 BP, 36 s)


- Thursday 03/06 (08:00 - 17:00) - Continue the studies on the ~ ultimate intensity beam in the SPS in // to LHC, with the aim to accelerate the maximum number of batches and identify the bottlenecks

 

- Thursday 03/06 (17:00 - 20:00) - Come back to nominal LHC beam in the PSB, PS and SPS (RF specialists needed in the PS)

 

- Thursday 03/06 (20:00) to Friday 04/06 (07:00) - Ecloud studies with the nominal intensity beam in the SPS in // to LHC


- Friday 04/06 (07:00 - 08:00) - Recovery from MD (OP)

Unblock the vacuum valves in the injection and extraction areas (Giovanna Vandoni, TE/VSC, 163269 => ~ 20 min)

Ask TI to restart the cooling circuit for the septa magnets (circuits 214, 414 and 614)

J. Borburgh should verify the conditioning of the septa

L. Ducimetiere and Viliam Senaj should verify the conditioning of the MKDV

- Change of supercycle

- Send beam to physics at 08:00



Author: Elias Métral - AB/ABP
Last update: Wednesday, May 26, 2010 08:17:22 AM
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