LHC Programme Coordination

A draft summary of the filling schemes for the 2017 ramp-up

These filling schemes are candidates for the 2017 ramp-up. Where possible the maximal phase shift has been minimised by equally distributing the injections. This is also welcome by ATLAS due to their IBL veto. The actual filling schemes to be used are variations on those mentioned below, and can be found in the filling scheme editor/viewer tools. The current expected list is:

Single_3b_2_2_2.csv for the first 2 fills
Multi_12b_8_8_8_4bpi_3inj_2500ns.csv for the 12b fill(s) (the same scheme was used in 2016; 4 Single bunches per injections, 3 injections)
25ns_75b_63_30_60_12bpi_9inj.csv for the 72b ramp-up step. The scheme has 3 INDIVs at the beginning, requested for studies in experiments.
25ns_313b_301_228_240_48bpi_9inj.csv for the 300b ramp-up step: The scheme has a colliding INDIV, 2 trains of 12b and trains of 48b.
25ns_409_397_350_365_96bpi_7inj.csv for the 300b ramp up step with longer trains: The scheme has a colliding INDIV, 2 trains of 12b and trains of 96b (2x48b)

The schemes feature a colliding (IP1&5) INDIV at the start of the orbit followed by 2 trains of 12b which makes the steering and the checks on the steering easy. One of the 12b trains is not colliding in IP 1&5 to make various background studies possible in ATLAS and CMS. The second train of 12b will be dropped at a later stage when it starts to reduce the number of colliding bunches in the experiments.

These schemes are for discussion with the the Experiments, the MPP and the LHC experts.

The AGK has been calculated for trains of 288b with a batch spacing of maximal 225ns. The value 31261 resulted from 7.935us (beam with 225ns MKP gap and 160ns rise time) and 3us of the abort gap itself. It would be good if machine experts could confirm the correctness of the calculated value.

For comments please contact the LPC.

Name	rampup step	AGK	max phase shift	Remarks
Single_3b_2_2_2	3		very small	First steps with nominal bunches
Single_12b_8_8_8	12		very small	Next to first steps...
25ns_73b_73_38_49_12bpi_7inj_800ns	72	31261	+/- 7.5 ps	6 trains of 12b and one INDIV in the witness zone
25ns_73b_61_30_60_12bpi_7inj_800ns	72	31261	+/- 7.5 ps	6 trains of 12b (on non-colliding in IP1&5) and one INDIV in the witness zone
25ns_313b_301_228_240_48bpi_9inj_800ns	300	31261	+/- 29 ps	6 trains of 48b, 2 trains of 12b (one non-colliding) and one INDIV in witness zone
25ns_409b_397_350_365_96bpi_7inj_800ns_bs200ns	300	31261	+/- 30ps	4 trains of 2x48b, 2 trains of 12b (for the last "300b" step with longer trains). One 12b train non-colliding in IP1&5, one INDIV in the in the witness zone.
25ns_601b_589_524_545_96bpi_11inj_800ns_bs200ns	600	31261	+/- 30 ps	4 trains of 2x48b, 4 trains of 48b and 2 trains of 12b (one non colliding in IP 1&5). One INDIV at the start. Train of 96 injected in last bucket before AGK, INDIV injected in bucket 1.
25ns_601b_589_526_550_144bpi_7inj_800ns_bs200ns	600	31261	+/- 40 ps	4 trains of 3x48b, 2 trains of 12b (one non colliding in IP 1&5). 1 INDIV at the start. Train of 144b injected in last bucket before AGK, INDIV injected in bucket 1.
25ns_937b_925_820_851_144bpi_14inj_800ns_bs200ns	900	31261	+/- 36 ps	4 trains of 3x48b, 7 trains of 48b, 2 trains of 12b (one non colliding in IP 1&5). 1 INDIV in the witness zone. Train of 144 injected in last bucket before AGK.
25ns_1177b_1165_1052_1100_144bpi_11inj_800ns_bs200ns	1200	31261	+/- 44 ps	8 trains of 3x48b, 2 trains of 12b (one non colliding in IP 1&5). 1 INDIV in the witness zone. Train of 144 injected in last bucket before AGK.