Injection STATUS – TOWARDS 144 bunches

1. Injection STATUS – TOWARDS 144 bunches W. Bartmann, C. Bracco, L. Norderhaug-Drosdal, B. Goddard, W. Hofle, D. Jacquet, V. Kain, M. Meddahi, J. Uythoven, D. Valuch, J. Wenninger

2. Injection Quality Status TCDIs • 24 bunch injection clean: • Loss maxima from uncaptured beam • TCDI loss maxima: fill 1646 – 200 bunches filling, 24 bunches per inj • beam 2 3 % maximum, beam 1 8 % maximum • Beam 1 trajectory not perfect in H, pointing to HiRadMat switch magnet

3. Fine tuning of some thresholds required Threshold of BLMQI.06L2.B2I20 From time to time: low losses “seem” high BLMQI.06L2.B2I20 threshold too low

4. Transverse losses - observations Beam 2: 8 bunch injection, no scraping on • Scraping in the SPS needs to be well under control and switched on • SIS surveillance will come • Correcting back to reference trajectory works well • Still more statistics needed for consistency between pilot and nominal intensity corrections • Need to be able to compare steering settings for 2 users and task in nominal sequence for copy • Then steering to be done by OP • For the time being no issues for increasing intensity from transverse losses

5. Longitudinal Losses Max loss in percentage from dump thershold downstream of TDI • Larger capture voltage seems to pay off: • But also some filters changed (e.g. TCTVb) • Losses at the end of filling: 200 bunch fillings • …need to check losses on TCLIA/TCTH for beam 1 – losses on D2 on other side are higher than on triplet • More analysis needs to be done. If possible would like to re-calibrate

6. Abort Gap Cleaning @ Injection Available now: • Sub-Sequence to move abort gap cleaning to injection settings • Sub-sequence to stop and start abort gap cleaning: • start abort gap cleaning in prepare for filling sequence • …and stop before starting the ramp (tune feedback) • Status: • Tested with beam: first bucket, NOT with last possible bucket • Sub-sequences are not part of nominal sequence yet • MCS checks need to be re-enabled and tested

7. Injection Cleaning – not tested with beam • Injection Cleaning – modus operandi: • Injection sequencer requests next injection + configures and switches on cleaning • No injection event: injection cleaning switched off with injection sequencer time-out or internal time-out of injection cleaner • If injection arriving: automatic switch off cleaning • injection forewarning – details still to be discussed • With beam-in • At the end of filling: cleaning amplitude and excitation mode set to zero through sequence • Sequences: prepared, not in nominal sequence • Sub-sequence to prepare cleaning before filling • Sub-sequence to disable cleaning after filling

8. Injection Cleaning in Injection Sequencer Implemented as part of the injection sequencing

9. Towards 144 bunch injections • Quantify effect of TI8 shielding installed during TS (1 hour) • Check aperture TI2 and TI8 after vacuum intervention Shutdown – needed before injection of >24b (0.5 shift) • 75 ns spacing, up to 96 bunches (0.5 – 1.5 shifts) • Check losses in the line, oscillations, scraping SPS • Re-steer if necessary, re-optimise collimators if needed (unlikely...) • 50 ns spacing, up to 144 bunches (1 – 3 shifts) • Start with 12b • Check losses in the line, oscillations, scraping SPS • Re-steer if necessary, hope not to have to re-optimise collimators (can open to +/-5 sig if needed) • Increase intensity injected in steps (36, 72, 108, 144) • Checks in SPS extraction, TLs and in LHC at each step (losses, trajectories, oscillations, damping, capture, cleaning, vacuum, ...) • 25 ns only after experience • Have to obtain more operational experience with up to 144 bunches before increasing the injected intensity • Including experience with abort gap and injection gap cleaning

11. Beam 2 – 24 bunches