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!