LHC progress report Week 7 2013 Coordination: Jan Uythoven, Mike Lamont Quench tests coordination: Mariusz Sapinski

Overview of the week Monday Tuesday Wednesday Thursday Finished 1.38 TeV loss maps First 100b fill – VdM attempt abandoned Tuesday 500b 1347b fills 3557, 3558, 3559 Wednesday Fill 3560 Evening: start VdM(s) Thursday Finish VdM, quick fill for ALFA & TOTEM, dumped at 07:24 Switch to quench tests Thursday morning – Saturday morning: quench tests Saturday morning – Sunday morning: powering tests 18-02-2013 LHC status

Precursor - change to pp run at 1.38 TeV Last Sunday at 6:04: dump of last Pb-p fill Configure machine for high intensity proton operation Access for BPMS attenuators, ADT, ATLAS, CMS Change RF and ADT settings, BLM thresholds back, BBQ, Head-tail monitor settings reverted ALICE polarity to negative Tests with beam Cycles with probes, testing of interlocked BPMS, loss maps Injection (Inj. Prot. IN) Injection (Inj. Prot. OUT) Flat-top separated Un-Squeezed Collision (with RP IN?) Betatronic-H Validated OK CHECK Betatronic-V Neg. off-mom -- Pos. off-mom Asynch dump Just OK 18-02-2013 LHC status

Laurette and Markus special 3556 (500b) 3557 3558 3559 ALFA TOTEM 3555 (100b) 3560 Van der Meer scans 18-02-2013 LHC status

Same - luminosity 18-02-2013 LHC status

Proton-proton at 1.38 TeV Fill Nb Nc Stable Peak L Int L [pb-1] 3555 Dump 3555 100 mix 46 1h47m 2.7e30 .001 Loss map 3556 510 504 5h28m 5.6e31 0.59 OP 3557 1374 1278 1h28m 1.28e32 0.39 missing frame packet on the BLM optical link 3558 1h9m 1.48e32 0.50 RF crow bar 3559 8h18m 2.06 3560 5h12m 1.14e32 1.6 SIS interlock on orbit tolerances when starting length scale calib 3562 39 29 2h12m 0.008 3563 4h31m 2.4e30 0.002 Loss maps 3564 48m 1.24e32 0.27 18-02-2013 LHC status

Roman pots – late request At the end of the upcoming 1400 bunch fill we briefly insert the pots to the validated position of 22 sigma, just as a necessary condition for proceeding further in the plan. I remind that last night's insertion to 22 sigma from the 500 bunch fill was without any problem. At the end of a low-intensity fill, possibly the VdM fill, we insert the pots to 13 sigma (where we would have physics acceptance) and do a quick loss map at dumping time. If this loss map is ok, we insert to 13 sigma in the remaining fills. Mario Deile Only partially achieved 18-02-2013 LHC status

Beam size etc Emittance at injection were 1.1-1.2 um for the 50 ns beam Emittance from luminosity: 1.4 um with essentially nominal intensity (1.15e11 ppb) going into collision NB less ramp, no squeeze 18-02-2013 LHC status

End of Run 1 (2009 - 2013) 18-02-2013 LHC status

BSRT heating test We filled B2 in two major steps (690 bunches, waited ~30min, filled the rest up to 1338 bunches). Intensity per bunch ~1.5e11p. With the machine full we increased few times the RF voltage to reduce the bunch length. During the whole period we observed the temperature with probes in vacuum (installed during TS4). See the attached plot, from which: The 3 couples of probes (close to the mirror, close to the ferrite tiles and close to the mirror arm vacuum bellow) clearly show that the ferrite is absorbing most of the RF power (as expected) and likely heating the rest. We need to recalibrate the probes after dismantling the system in LS1… 18-02-2013 LHC status

BSRT heating test 18-02-2013 LHC status

BSRT heating test Even with the machine full for several minutes, the B2 mirror (glass bulk with dielectric coating, installed in TS4) didn't show any coating deformation --> image distortion, as observed in B1 (glass bulk + metallic coating) during 2012 high intensity fills and reproduced today in parallel to the B2 studies. The test was very useful to us, for understanding the system and take the appropriate actions during LS1. 18-02-2013 LHC status

TIM As agreed we are currently doing the RP survey of the LHC with the TIM while the beam is on (survey started at 10h23 - now arrived in point 4 – 3km of survey in total). Up to now the train is fully operational and controllable from surface with stable vision feedback. On the RP side we had a maximum of 1mSv when exiting UL55 with an average of 0.3µSv along the machine. Bruno Feral 18-02-2013 LHC status

Somewhat hampered on Friday by the change of power converter limits… Quench tests 18-02-2013 LHC status

QT: 1MW on to collimators During collimation quench test with protons, 1 MW losses over several seconds were generated on collimators using ADT excitation. No magnet quenched in such conditions while signal on BLMs exceeded the assumed signal at quench by factor 3.5. 18-02-2013 LHC status

QT: steady state with orbit bump 2. During steady-state loss with orbital bump a loss lasting about 20 seconds was generated directly on cold aperture. Quadrupole 12L6 quenched in with BLM signals approximately at the expected level. Results of this exercise confirm what was achieved during the test in 2010 and are in disagreement with collimation test result, pointing probably to a large dependence of BLM signal from the loss scenario. 18-02-2013 LHC status

QT: Fast losses 3. During fast loss quench test we have tried to address quench limit at UFO timescale. We have achieved longer loss (about 10 ms instead of ~1 ms) and quenched the magnet at the BLM signal level more than 5x higher than current estimation of quench limit. That is a very good news for UFO-related worries for LHC operation after LS1. 18-02-2013 LHC status

QUENCH! With 8.2e8p (bunch 1092) and 200% ADT gain 23:45 Friday evening QUENCH! With 8.2e8p (bunch 1092) and 200% ADT gain 18-02-2013 LHC status

QT: Q6 4. During Q6 test the magnet was quenched with current corresponding to beam energy of ~4.5 TeV. Unfortunately we had no time to repeat this test with current corresponding to higher beam energy. 18-02-2013 LHC status

Message from Mariusz This success is thanks to your efforts, careful planning and preparations, which started with the first QSTW meeting on March 13th 2012. We had in total 6 meetings. Slides and minutes can be found here: https://indico.cern.ch/categoryDisplay.py?categId=1537 I would like to thank you all. And thanks to OP for breakfast with champagne on Saturday morning! The data which were collected are very important to assess LHC limits during 7 TeV run. The analyses will continue over next weeks and results will be discussed and presented, at MPP, LSWG and Collimation meetings. & Daniel Valuch! 18-02-2013 LHC status

And near permanent presence during quench tests Special thanks… Many thanks to the collimation team (Stefano, Gianluca, Belen et al) for coming the last 4 weekends (pPb, PBp, polarity changes, pp) setting-up and verifying the loss maps And near permanent presence during quench tests 18-02-2013 LHC status

Saturday 16th February – early morning 08:08 Quench End Run 1 Ramp-down 16-02-2013 LHC status

Incoming 18-02-2013 LHC status