R2E impact of TCL settings: input for 2017 operation LHC Collimation Working Group #216, 10 Apr 2017 Rubén García Alía, on behalf of the R2E project

LHC Collimation Working Group #216 Introduction Quick overview of 2016 radiation levels related to TCL6 settings in P1 and P5 Projections for 2017 and impact on relevant equipment R2E recommendation for 2017 TCL6 settings April 10, 2017 LHC Collimation Working Group #216

TCL setting R2E impact: general overview w/o TCL6 with TCL6 FLUKA studies on the radiation in the Point 5 Q6-Q7 area:Roman Pots, TCL6 and RR, L. Esposito et al, LHC Collimator Working Group #168, January 2014 April 10, 2017 LHC Collimation Working Group #216

TCL setting R2E impact: general overview TCL6 effective in reducing losses in DS cell 9 Impact from collision debris: comparison of ATS and nominal optics, F. Cerutti et al, 3rd ATS optics preparation and validation meeting –December 7, 2016 April 10, 2017 LHC Collimation Working Group #216

TCL setting R2E impact: general overview TCL6 open: larger levels in DS, beginning of cell 9 Normalized Losses (Gy/fb-1) TCL6 closed: larger levels in RRs 2016 BLM measurements, proton-proton run (O. Stein, 25th MCWG, Feb 17) April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 Levels in RR: 2016 2016 settings agreed with R2E input (174th LMC meeting, Feb 2014) – failures in the ARC were expected to dominate Different scenario due to lower ARC levels and FGC sensitivity (and now FGClite deployment) Similar levels per TCL operation mode and luminosity are expected for 2017 Point 1 (TCL6 open): ~5·107 HEH/cm2/40fb-1 Point 5 (TCL6 open): ~2.5·107 HEH/cm2/40fb-1 Point 5 (TCL6 closed): ~2.5·108 HEH/cm2/40fb-1 P1 & P5 UJ, RR and DS levels: 2016 measurements M. Kastriotou et al, MCWG #25, February 2017 April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 Levels in DS: 2016 P1 RadMON cell 9 location: L1: Between MBB9 and MQ9 R1: between MQ9 and MBB9 P5 RadMON cell 9 location: L5: between MQ9 and MBB9 R5: below MBB9 No visible impact of TCL settings on radiation levels RadFET dose levels (40 fb-1): 9L1: 30 Gy 9R1: 4.2 Gy 9L5: 33 Gy 9R5: 5.4 Gy Cell 8: visible impact of TCL settings, but low absolute values (<1 Gy/40 fb-1) Analysis: Maria Kastriotou, Corinna Martinella April 10, 2017 LHC Collimation Working Group #216

Impact on equipment: EPC Sensitive systems and SEE cross sections in RRs (P1 and P5): FGC2: 120A (x72), 600A (x56) and 4-6-8 kA (x60): 1.5·10-10 cm2/unit Power: 600A (x56): 3.0·10-10 cm2/unit Roughly 17 R2E events estimated for 2017 (10x FGC2 + 7 power part) expected for 2017 with TCL6 closed settings (factor ~10 less for TCL6 open) Uncertainty related to equipment SEE cross section and count statistics Input from Yves Thurel and Slawosz Uznanski, TE-EPC April 10, 2017 LHC Collimation Working Group #216

Impact on equipment: QPS DS area mainly affected by open TCL6: between MQ8 and MBA9 Possibly sensitive equipment: nQPS crate, underneath MBB Therefore, hardly impacted by TCL6 settings And shown to be robust during 2015 ion-ion run Therefore, OK for TCL6 open settings Input from Reiner Denz, TE-MPE-EP April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 Conclusions From an R2E perspective, operating with TCL6 open is preferred due to: The reduced radiation levels in the RRs and therefore reduced number of EPC failures leading to dump The acceptable increase in the DS radiation levels, mainly impacting MBA9 April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 Extra slides April 10, 2017 LHC Collimation Working Group #216

Impact of TCL on DS cell 8, IP5 TCL6 closed April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 DS levels in IP5 - left Symmetric as to what is seen in right side April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 DS levels in IP1 - left Similar to P5, TCL6 in (as expected) April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 DS levels in IP1 - right DS BLM peak around MBA9 not visible for P1 right April 10, 2017 LHC Collimation Working Group #216

LHC Collimation Working Group #216 Fill 5020 example TCL6 in roughly 30 min before luminosity start April 10, 2017 LHC Collimation Working Group #216