LHC beams in the SPS in 2014

H. Bartosik, G. Rumolo, G. Iadarola

With the help from K. Kornelis, V. Kain and SPS OP crew

LHC beams during the startup

• Started the machine setup with LHC filling cycle• 12 bunches

• Acceleration needed for combined orbit correction (SFTPRO + LHC cycles) at top energy quadrupole alignment campaign (2 iterations)

• Correction may be beneficial for closed orbit stability during LHC extraction …

before alignment: hrms/vrms = 10.9/4.7 mm

after alignment: hrms/vrms = 2.3/1.6 mm

LHC beams in parallel to physics

• LHC beam on flat bottom cycle (3.2 s store) for vacuum conditioning of• MKP4

− During LS1 the MKP4 module was exchanged with a new one (E. Carlier) + intervention due to problem on water manifold in August

− High static pressure level (~1e-7 mbar) since the beginning, not significantly improving

MKPAMKPBMKPCMKP4

SW interlock

HW interlock

LHC beams in parallel to physics

• LHC beam on flat bottom cycle (3.2 s store) for vacuum conditioning of• MKP4

− During LS1 the MKP4 module was exchanged with a new one (E. Carlier) + intervention due to problem on water manifold in August

− High static pressure level (~1e-7 mbar) since the beginning, not significantly improving− Dynamic pressure rise with LHC beams already some conditioning for 72 bunches for 3.2s

(in parallel to SFTPRO)

LHC beams in parallel to physics

• LHC beam on flat bottom cycle (3.2 s store) for vacuum conditioning of• MKP4

− During LS1 the MKP4 module was exchanged with a new one (E. Carlier) + intervention due to problem on water manifold in August

− High static pressure level (~1e-7 mbar) since the beginning, not significantly improving− Dynamic pressure rise with LHC beams already some conditioning for 72 bunches for 3.2s

(in parallel to SFTPRO)− Software interlock at 2e-7 mbar can we increase it? (TE-ABT is investigating)− Hardware interlock at 1e-6 mbar … could be serious limitation for scrubbing

LHC beams in parallel to physics

• LHC beam on flat bottom cycle (3.2 s store) for vacuum conditioning of• MKP4

− During LS1 the MKP4 module was exchanged with a new one (E. Carlier) + intervention due to problem on water manifold in August

− High static pressure level (~1e-7 mbar) since the beginning, not significantly improving− Dynamic pressure rise with LHC beams already some conditioning for 72 bunches for 3.2s

(in parallel to SFTPRO)− Software interlock at 2e-7 mbar can we increase it? (TE-ABT is investigating)− Hardware interlock at 1e-6 mbar … could be serious limitation for scrubbing

• ZS

− Accidentally vented during LS1− Intervention next to ZS to repair vacuum leak on bellow for Miniscan, no limitation so far− Sparking no limitation so far, new spark monitor available

LHC beams in parallel to physics

• LHC beam on flat bottom cycle (3.2 s store) for vacuum conditioning of• MKP4

− During LS1 the MKP4 module was exchanged with a new one (E. Carlier) + intervention due to problem on water manifold in August

− High static pressure level (~1e-7 mbar) since the beginning, not significantly improving− Dynamic pressure rise with LHC beams already some conditioning for 72 bunches for 3.2s

(in parallel to SFTPRO)− Software interlock at 2e-7 mbar can we increase it? (TE-ABT is investigating)− Hardware interlock at 1e-6 mbar … could be serious limitation for scrubbing

• ZS

− Accidentally vented during LS1− Intervention next to ZS to repair vacuum leak on bellow for Miniscan, no limitation so far− Sparking no limitation so far, new spark monitor available

• New TIDVG

− No limitation so far (e.g. outgassing), since only 5% of 1e13 p SFTPRO beam dumped regularly

− New software interlock for dumped intensity in place (V. Kain)

Impressions so far

• Conditioning of sensitive elements• up to now we were not limited at all by e-cloud in the arcs

• would not have been better with coated magnets!!

• Beam instrumentation• Some key instruments were not calibrated/working at the beginning

• Debugging required some time and iterations

• Setup of transverse damper and longitudinal feedback• Requires also beam time …

• LHC beam available from PS• Up to now not in stable (i.e. constant) conditions extraction conditions incl. extraction bumps

changed many times in the last weeks

• Had lower priority than other CPS physics users …

• Scrubbing run right after startup probably not efficient?

Present status

• Beam from the PS • low energy part needs optimization (some instability)

• 72 bunches up to 1.3e11 p/b

• Transverse emittance below 4 um (measured with TT2 fils, S. Gilardoni)

• Extraction bump set to include dummy septum

• LHC beam on SPS short flat bottom cycle during nights• 72 bunches up to 1.3e11 p/b with good life time (>98% transmission for 3.2s)

Beam instrumentation

• Wire scanner• Bunch-by-bunch was working, presently software problem on frontend (followed up by BI)

• BWS 519 presently not working

• Standard equipment• BCT Checked (incl. SDDS logging)

• FBCT Checked

• BPMs

• BBQ

• Mountain range (incl. SDDS logging)

• Vacuum gauges• Will be logged during scrubbing run (M. Taborelli taking care, meeting on Thursday)

• Ecloud monitors

• Headtail monitor• Can be used, but only through FESA navigator manual saving (V. Kain is working on application)

• Transverse high bandwidth pick-up• Operational, application is being finalized (incl. SDDS logging)

• BGI• Not operational, but could be could moment to work on that … (BI is aware)

• LHC BPMs not working

Schedule

• Monday (3.11.)• Inject 25 ns beam on scrubbing cycles (18 bp, 33 bp) and perform basic checks

• Take reference measurements of emittance and beam lifetime with 25 ns beam (as many batches as allowed by MKP and vacuum)

• Check with B. Bahlan that ZS sparking interlocking works

• Move COLDEX in

• Start scrubbing run on 18bp flat bottom cycle

• Setup acceleration of 72 bunches (transverse damper + longitudinal feedback) in parallel

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Week 45

Schedule

• Tuesday – Sunday (4-9.11.)• Scrubbing with increasing number of batches and increasing store time on flat bottom

• E-cloud measurements on dedicated equipment

• Beam qualification in parallel, also on acceleration cycle (emittances along train, lifetime, …)

• a-C coated half cells

• COLDEX measurements in parallel

− Goal is to study COLDEX with different beam intensities and types− Measurements at 2 different beam screen temperatures− Measurements during acceleration

• Wednesday (5.11.)• 8h MD on 800 MHz LL-RF (on acceleration cycle)

• Monday (10.11.)• Move COLDEX out

• Return to physics

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Week 45

Operational procedures

• Accelerator mode to No Extraction• All extraction elements off

• Leave extraction channel in (we want to condition it in operational position)

• ZS voltage to -30 kV

• Septa off (including cooling circuits)

• Power converters in NA off

• Block fast interlock valves• Make sure Septa cooling circuits off!

• Interlock on integrated beam dump intensity • to be masked if using only flat bottom cycle

• Need to monitor carefully• Kicker temperatures (in particular MKP)

• Septa temperature

• Vacuum level of MKP1 (next to TIDVG)

Summary

• Up to now• 72 bunches with up to 1.3e11 p/b, good transmission on flat bottom

• Transverse feedback is setup on flat bottom

• Played LHC beam on short flat bottom cycle in parallel to physics for vacuum conditioning

• MKP4 is main limitation so far• New module installed during LS1 + problem on water manifold in August

• High static pressure level ~1e-7 mbar and no significant conditioning

• Dynamic pressure with LHC beam improving slowly

• Open question about increasing SW interlock (presently at 2e-7 mbar)

• Preparation for scrubbing run• Additional time between startup and scrubbing was very useful for beam setup

• Most of the beam instrumentation ready, remaining issues are followed up

Thank you for your attention!