LHC Performance Workshop (Chamonix 2016) Cryogenics Sessions 3 : LHC Hardware Performance G. FERLIN on behalf of TE-CRG group With contribution from K. Brodzinski, S. Claudet, D. Delikaris, L. Delprat, E. Rogez and L. Tavian

Agenda Hardware status and Availability 2015 Performance aspect 2016 Expected Hardware performance 2016 Improvement foreseen all along the year Cryogenic power studies BS thermal load IT movement investigation 26 Jan 2016 TE-CRG-OA

Hardware configuration 2015 Run2 configuration Two 4.5 K cold boxes + one cold pumping unit except P18/P2 w.r.t scenario for Run 1 (1 Cryoplant /2 sectors) Pro Additional installed capacity for BS scrubbing Better availability expected (less rotating component running). One parallel quench/sector could be recovered without delay Lower energy consumption (-2 MW) as collateral bonus Cons In case of multiple quenches in parallel (more than 3 cells !!!) , the recovery time should be affected. (never occurs during 2015) In case of 1.9 K trip, two sectors will be lost. (never occurs, as mostly seen in S12/S23 not concerned by this configuration) Tuning of this new configuration at P18/P2 not yet possible. More than 3 parallel quenches will increase the recovery delay 26 Jan 2016 TE-CRG-OA

Overall Availability 2015 [Cryo Maintain] Statistic for run 2 from April 5th to Dec 14, TS excluded Supply failures mainly during spring (Post LS1 effect Users failures mostly due to quenches @ 6.5 TeV Downtime in line with Run 1 despite higher beam induced heat loads 26 Jan 2016 TE-CRG-OA

Overall Availability 2015 [Cryo Maintain] Statistics in line with our Cryo monitoring Downtime is to be considered as average for each category. PLCs: average downtime = 18h12min /// frequency = 1 every 2 months Cold Compressors: average downtime = 6h34min /// frequency = 1 every 3,5 weeks OP / Human Factor: average downtime = 4h32min /// frequency = 1 per month Elec / Instrum / Tunnel: average downtime = 1h45min /// frequency = 1 every 10 days DFBMI: average downtime = 0h4min /// frequency = 1 every 2 days DFBAF: average downtime = 0h3min /// frequency = 1 every 4 days 4 contributors for 75% of total cryo downtime Most frequent contributors OP factor: Mostly new OP staff (<30% experienced with Run 1) and no more capacity margin 26 Jan 2016 TE-CRG-OA

Overall Availability 2015 [Cryo Maintain] Downtime per categories and mitigation action undertaken Most frequent CM losses: - DFBMI: 39 losses; Should be solved during YETS - DFBAF: 29 losses; Trigger origin should be discussed with stakeholders (thresholds, timer…) Most time-consuming CM losses: - 1.8 K units: 8 losses, Average equivalent to Run 1; should devrease if new configuration P18/P2 works well. - PLCs: 4 losses, should be solved with new firmware during YETS - OP/Human factor: 9 losses; should be partially solved by process optimization under high BS load - Elec/Instrum/Tunnel: 22 losses; Average equivalent to Run 1 26 Jan 2016 TE-CRG-OA

Hardware reliability 2015 2015 Hardware reliability for Cryoplants 0.7 0.8 0.3 2 1.5 1.8 1.6 Failure rate / unit / year 26 Jan 2016 TE-CRG-OA

Hardware reliability 2015 Hardware fault breakdown In line with 2012 good data + “Supply” in spring and Cryo PLC’s (Treated in TS or YETS) Multiple origins, less straight forward to improve Hardware fault in line with Run 1 26 Jan 2016 TE-CRG-OA

Hardware status 2015 Refrigeration Main hardware issue solved during YETS warm compressor degradation diagnosed preventively and replacement without damage nor impact Major leak on 18 kW plant 3 turbines failure, No impact, compensated by Liquid Nitrogen 26 Jan 2016 TE-CRG-OA

Hardware status 2015 Refrigeration: YETS improvement Distributed failures 16 valves for turbine Control 4 Cryo PLCs Activated charcoal replacement (P6/P4/P8); Risk identified with some oil removal systems, worth the effort and follow-up Software update all around LHC Partial Cold Compressor VFD & AMB exchange 24 VDC consolidation ……. 26 Jan 2016 TE-CRG-OA

Performance aspects 26 Jan 2016 TE-CRG-OA

Expected Hardware performance 2016 W/hc p+/bunch bunch number installed capacity limit for 4.5-20K installed capacity + margin form 1.9K unit at lower flow than designed limit S23 36 bunch trains 72g72 bunch trains 144 bunch trains 72 bunch trains cleaning s12, 23, 81, 78 85 Theoritical LHC nominal heatloads cleaning s34, 45, 56, 67 after 8b4e bunch train test In 2016 we will be able to provide at least the same capacity as in 2015 26 Jan 2016 TE-CRG-OA K.Brodzinski_6th Evian_2015.12.15

Expected Hardware performance 2016 Main improvement foreseen all along the year Software improvements to fulfill the cryogenic power increase (continued effort as in 2015 Automatic adaptation to follow the thermal load on BS (must be tuned online!) Tuning of installation to prepare a scheme for high load Anticipation of the thermal load before beam Smooth Decrease of the thermal load by electrical heating after dump For FDBAF, a new settings of the threshold (absolute value and timer) should decrease drastically the quantity of losses of the Cryo Maintain signal. … “Data mining” to anticipate possible issues on tunnel components (1st studies started last year with former EN-ICE); On & Off line tracking of process deviations and abnormal behavior. 12 Jan 2016 TE-CRG-OA

Expected Hardware performance 2016 Hardware configuration This configuration will be tested before the end of YETS 2015 The aim is to decrease the number of rotation machine to improve the global availability The second target is to boost the cooling power of the Cryoplant in P2 and consequently the BS cooling power for the S23(cooling capacity margin to be evaluated during tests, to be used in addition to previously defined actions for S23) Specific configuration with non symmetry 12 Jan 2016 TE-CRG-OA

Cryogenic power studies BS thermal load (Maximum plant power validation) Due to a limited margin for sector S23 the proposition consists to define a road map to increase the margin and to reach the ultimate power; A first step consists to perform a power survey of the Cryoplant unit not connected to sector in P2 (same power survey for the twin plant in P8). (already foreseen during the restart of the plants). The second step consists to Perform a maximum BS load on the sector by using electrical heater installed on BS circuits. In parallel, perform the same test on the twin plant installed in P8 This second step is not included in the YETS time schedule and should be included if confirmed (3 to 4 days) 12 Jan 2016 TE-CRG-OA

Cryogenic power studies BS thermal load (Process upgrade to reach higher power) Cryogenic power recovery by using cold bypasses and associated issue / propositions Theoretical interest: Recover cooling power for BS cooling A new test is foreseen at P2 (see slide above) Practical limitations of this scheme do not shows a high margin on measured sectors This operation scheme was not foreseen originally. Hardware modification are necessary to be able to use this configuration with higher effects on all points. A prototype should be installed during EYETS and after validation the 3 others installation should be updated during TS2 12 Jan 2016 TE-CRG-OA

Cryogenic power studies He storage Compression Compression Refrigerator (economizer) Refrigerator (liquefier) A B 1.9 K circuit 1.9 K circuit 4.5 K circuit 4.5 K circuit Magnets supply Magnets supply 12 Jan 2016 TE-CRG-OA

Cryogenic power studies ITR8 movement investigation In order to investigate the ITR8 oscilation, a step by step check sequence is proposed to identify concerned circuit if any This sequence should be: Adjust Pressure difference with DFBX to stop refilling Block all valves Validation the oscillations during a significative period. This sequence is not yet planned and needs 2 to 3 days to be done (possibly during powering test of the sector?) 12 Jan 2016 TE-CRG-OA

Summary For 2016, Cryo team expect a global availability in the range 93 to 95 % with CRG origin fault below 5% Beam Screen heat load mitigation Installed power ~110 W/h-cel, 160 W/h-cel already reached except S23 with plan to understand the lower margin Software optimization on going to fit with 2800 bunches Data mining to detect online smooth drift and anticipate possible issues. Proposition to test an upgraded cold by-pass, during EYETS, for recovering additional margin. 26 Jan 2016 TE-CRG-OA