Monday 6th August & night

Slides:



Advertisements
Similar presentations
Monday 29 October 08:48 V/dM scan CMS end of fill #3236. Check of “fast scan”. 10:06 V/dM scan finished, start of RF studies, reducing RF voltage. 11:10.
Advertisements

Thursday 27 th October 00:57 fill 2257 dumped during squeeze (RQTF.A67B1) 03:52 stable beams fill #2258 4:33 Dumped, problem of LBDS dilution kicker power.
Tuesday 7 th August - morning 07:10 Reinjection after loss of fill 2920 to UFO near ALICE  26 pb -1 in 1h16m; peak lumi 6.4e33 cm -2 s -1 08:10 dump at.
LHC Status Fri Morning 3-June
Monday – Morning L. Drosdal: Injection line TI8: IQC threshold for BPM H from 2mm to 2.5mm to avoid unnecessary latches due to variations.
Wednesday
Wednesday :06 Dump fill 3533: interlock BPMS in IP6
Friday 15th June 01:11 Injection.
Luminosity lifetime – fill 2932
Monday :00 Stable beams 9_6_6_6 13:40 Access.
Friday 07:00 Power glitch on the EDF network. Point 8 affected.
Tuesday 11th September LHCb dipole presently fault off
Monday fill with 1092 bunches (6 h stable beams)
Wednesday 17th August Rocky, short fills, initial luminosities are good LHCb polarity change to negative seems ok 18/08/2011 LHC 8:30 meeting.
LHC summary week 32 Coordination: Mike Lamont & Jan Uythoven
02/08/ :35: Lost access chain in point 2 (PX24 PAD)  Dump after ~14.5 hours ~100 nb-1.
LHC Morning Meeting - G. Arduini
Week 46 Week 46: Machine coordinators: Roger Bailey – Gianluigi Arduini Main aims of the week: Stable beams with ions Scheduled stop for ion source refill.
Coordination: G. Arduini, E.B. Holzer
Tue :25 Beams dumped due to RF vacuum interlock
Wednesday /Thursday 09-11:00 Verification of the LSS6 interlocked BPMs: took longer to fill due to some problems with RF cavities in the PS. In the mean.
LHC Morning Meeting - G. Arduini
Monday – recovery from MKI flashover
Wednesday Morning 8: :30 end of fill study - octupole polarity inversion (Elias, Tatiana, Alexey, Georges, …): Goal: study the effect of the.
Thursday 17th May 01:11 Fill #2633 dump in squeeze arc circulator load channel Ad1B 03:16 Fill #2644 Stable beams, lumi 5.2e33 cm-2s-1 04:38 Dumped by.
Wednesday 31 October: Morning
Summary of Week 16 G. Arduini, J. Wenninger
Friday 31st August & night
Friday day 00:51 Fill #1862 Beams lost to inner triplet skew quad power converter fault. Delivered lumi 33 pb-1 Access required for repair RQSX3.L1 converter.
Mike Lamont, Jorg Wenninger
Wednesday 8th August & night
Summary of Week 26 Main aims: G. Arduini, B. Holzer, M. Lamont
04-05/08/2010 End of physics at ~11:00 after 18.5 hours ~120 nb-1.
Saturday – Morning 7:36 beams dumped
Not the most productive 24 hours on record
Friday Morning 7:30 injection for fill 2908
Sunday
Wednesday 03/11 – The Plan Finish electron-cloud program:
Wednesday 9:08 Fill 3214 dumped by OP after 5:26 hours in stable beams
Wednesday 10/5 Cryo recovery until 18:30
Aims for the week Recover from technical stop and precycle at 10A/s
Wednesday 10:00 test of the un-squeeze to 90 m at 4 TeV.
Rocky last 24 hours Losses Q6.R5 Orbit SIS TCDQ OK! Power converters
LHC Morning Meeting - G. Arduini
Thursday 26th July 13:21 Fill 2880 beam dumped
Monday 6th 07:39 Dump fill #1854, RQ6.L2 tripped, followed by access
Monday 11th June 08:10 Beam dumped in the ramp by OP. OFB did not start its function and kept the injection orbit. 08:50 Switch LHCb polarity to negative.
Saturday :42 stable beams fill 3541
Saturday 12 March Morning: problem on RSD1.A12B2 – flow rate problem on the cooling water for the converter. 14:00: Loss map -500 Hz (positive energy offset)
LHC Morning Meeting - G. Arduini
Thu 04:00 Fill #2729 Stable Beams. Initial lumi 6.5e33 cm-2 s-1.
Tuesday In the morning test cycle with probe for Q’ measurement.
Saturday 06/11 Triplet R8 tripped during ramp for collision setup.
Wednesday h18: 228b fill lost just before start of ramp.
LHC Morning Meeting - G. Arduini
Friday 15th February - morning
Another Immortal Fill….
Tuesday 24/5 Fill # :00 Stable beam fill # bunches
Monday 27th August & night
Wednesday 26 October 2011.
Thu :00 Dumped beams, refill for Pb-Pb physics. No more protons in 2011… Some changes: Increase of flat top total voltage to 14 MV. Feed-forward.
Saturday 6th October 05:38 STABLE BEAMS # :06 OP dump
Monday 14th May 00:03UFO at BLMQI.06R8.B2E10_MQML. Beam dump Re-steering required for TI2 03:28 STABLE BEAMS # e11 ppb, 4.11e33 cm-2s-1 13:36.
31/3/2010 Difficult day… but at the end stable beams.
Wed 12/10 09:30 – 10:30 Ramp down of ALICE solenoid to 50% nominal field on request of ALICE. Increase of the vacuum (e-cloud in this area that has not.
Friday During the night from Thursday to Friday: by mistake, SPS longitudinal blow-up was not active  Smaller transverse emittance from the.
Saturday 26 November 2011.
Tuesday
Wednesday 8th (I) 09:22 Fill #1855. Beams dumped by Alice dipole trip Stable beams for 10.5 hours; int. lumi 31 pb-1 After investigation EPC could not.
Tuesday
Presentation transcript:

Monday 6th August & night 04:20 SPS extraction kicker problem - access in the mean time. ALICE solenoid fixed. 13:00 Pre-cycle by running nominal ramp with reduced octupole currents in the ramp. 15:00 Injecting physics beams fill #2917. 16:21 With squeeze finished, beams dumped due to ALICE interlock. ALICE BCM dumped with values 300 % of threshold. Expect UFO. 17:48 Injecting for physics, fill #2918 19:07 Stable beams. Low initial lumi's of about 4.5e33 cm-2s-1 due to blow-up of bunches at the end of ramp with octupoles at 150 A. 00:24 Operator dump. Integrated lumi around 68 pb-1. 02:41 Fill #2919. Beams unstable throughout the squeeze. Lost on HV BLM 05:05 Fill #2920 Stable Beams. Lumi’s around 6.3e33 cm-2s-1 (!), although some losses in squeeze. 06:20 Dump due to ALICE BCM. UFO… 08:10 Fill #2921 Dumped start of ramp.UFO: BLMQI.03R8.B2e10_MQXA 07/08/2012 LHC 8:30 meeting

SPS Extraction kicker MKE4 – 9 h 21 min From Laurent Ducimetière and Volker Mertens: MKE4 system #1 was switching on with an unstable delay of up to 2 µs, which had activated the interlock of the fast pulse surveillance. All stages from the timing to the thyratron main switch were checked; the latter was finally diagnosed as causing the fault. The normal procedure foresees exchanging the faulty switch against the spare. The spare switch is presently used in 867 for the conditioning of the spare MKE magnet; its preparation and transport to ECA4 had been launched. Acknowledgements to EN-HE for the handling efforts. In parallel the faulty switch was opened in situ for in-depth investigations. A bad contact was found on a soldered resistor on the thyratron bias circuit. After redoing the soldering the switch was successfully tested and put back in operation. 07/08/2012 LHC 8:30 meeting

Access in the morning Vacuum: repaired TPG at Pt 4 Cryo: replaced magnetic bearing box at pt 8 EPC: replaced RD2.R5 sub-converter ATLAS: Access for intevention on muon system gas distribution ALICE solenoid: problem idendified on thyristor, and corrected (polarity issue) 07/08/2012 LHC 8:30 meeting

Fill #2917 Different from last night: Result Octupoles reduced to 150 A at end of energy ramp, compared to 300 A. Test to prepare for octupole polarity change. Damper gain brought up again in Adjust, as the low damper gain caused beam losses while going into collision in the previous two fills. Average bunch intensity 1.49e11 p/b. Result Up to 10 % losses at the beginning of the squeeze, most likely due to the lower octupole strength. At end of squeeze, before going into Adjust beam dumped by ALICE BCM – 3 x above threshold Categorize this as a UFO in ALICE 07/08/2012 LHC 8:30 meeting

Losses at the beginning of the squeeze 07/08/2012 LHC 8:30 meeting

Fill #2918 Repeat with same setting as the previous fill to get certainty about the observations Again beam unstable end of energy ramp with the octupole current at 150 A. Beam saved by increasing chromaticities. Especially B1 V, in total +5. Decide to increase octupole current to 200 A at end of energy ramp for the next fill. Now more beam losses during squeeze, possible due to blown up bunches during the ramp and very large chroma’s Low initial lumi’s due to blown up beams, mainly B1 according to BSRT scan. 07/08/2012 LHC 8:30 meeting

End squeeze Start squeeze 07/08/2012 LHC 8:30 meeting

Start of Stable Beams: low lumi’s 07/08/2012 LHC 8:30 meeting

Fill #2919 Some small losses en of energy ramp Tune trims look at QT currents – improved lifetime Beam unstable throughout squeeze This time octupoles were higher at start of squeeze (200 A) and are kept high in squeeze Lost end of squeeze on BLM HV IP7 07/08/2012 LHC 8:30 meeting

BSRT scan: B1 blow up in squeeze 07/08/2012 LHC 8:30 meeting

Fill #2920 .... But beam was also unstable, some bunches, during the squeeze. Start of squeeze Flat top 07/08/2012 LHC 8:30 meeting

06:20 Lost because of ALICE BCM interlock – like Monday. Fill #2920 06:20 Lost because of ALICE BCM interlock – like Monday. 07/08/2012 LHC 8:30 meeting

ALICE UFO – well possible 07/08/2012 LHC 8:30 meeting

The Plan Do Physics, while preparing the octupole polarity change Plan for the octupole polarity change Understand stability problem end of ramp / start of squeeze Today: test injection with many bunches and high bunch intensities (>1.5e11) with negative octupole polarity. Followed by physics with original octupole polarity. In parallel prepare functions with negative octupole polarity. Wednesday: Test ramp with two pilots and negative octupole polarity to check tune and chroma all the way up to collision. Pilots not to collide anywhere. Correct chroma functions following the findings. Stable physics runs with negative octupole polarity, if all goes well. 07/08/2012 LHC 8:30 meeting