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

2. 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
LHC status

3. 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
LHC status

4. Laurette and Markus special
3556 (500b)
3557
3558
3559
ALFA TOTEM
3555 (100b)
3560
Van der Meer scans
LHC status

5. Same - luminosity
LHC status

6. 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
LHC status

7. 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
LHC status

8. Beam size etc
Emittance at injection were 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
LHC status

9. End of Run 1 ( )
LHC status

10. 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…
LHC status

11. BSRT heating test
LHC status

12. 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.
LHC status

13. 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
LHC status

14. Somewhat hampered on Friday by the change of power converter limits…
Quench tests
LHC status

15. 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.
LHC status

16. 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.
LHC status

17. 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.
LHC status

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

19. 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.
LHC status

20. Message from Mariusz
This success is thanks to your efforts, careful planning and preparations, which started with the first QSTW meeting on March 13th We had in total 6 meetings.
Slides and minutes can be found here:
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!
LHC status

21. 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
LHC status

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

23. Incoming
LHC status