1. FCC Infrastructure & Operation Update on the cryogenics study Laurent Tavian CERN, TE-CRG 28 October 2015

2. FCC cryogenics studies FCC Cryogenics Studies Cryoplants (~50-100 kW @ 4.5 K including 10 kW @ 1.8 K) Ne-He cycle for refrigeration above 40 K TU-Dresden Innovative He cycle CEA Grenoble Cooling scheme and cryo-distribution PhD student C. Kotnig Specific studies (CD, WU, Transients…) Fellow H. Correia Rodrigues Design pressure impact on heat inleaks Wroclaw-TU MoU signed Addendum signed MoU signed Addendum 1 signed Addendum 2 signed MoU signed Addendum to be signed In steady-state

3. FCC-hh cryogenic layout CryoplantL Arc+DS [km]L distribution [km] 2 x 4 = 82 x 4.7 = 9.4 8.4 CryoplantL Arc+DS [km]L distribution [km] 44.7 4.45.1 44 4.46.5 10 cryoplants 6 technical sites 20 cryoplants 10 technical sites No cryoplant redundancy at Point A and G No cryo-distribution in ESS (8.4 km) The baseline The alternative

4. FCC-hh cryogenic capacity Cryoplant40-60 K [kW] Tcm [kW] 40-300 K [g/s] 59211135 6161299 10 cryoplants 6 technical sites 20 cryoplants 10 technical sites Cryoplant40-60 K [kW] Tcm [kW] 40-300 K [g/s] 2965.767 3256.267 2935.667 3316.467 Without operational margin ! The baseline The alternative

5. FCC-hh: Magnet temperature D. Tommasini

6. FCC-hh: Magnet temperature T_sc < ou = 4.5 K T_he must be fixed at a lower temperature to guarantee T_sc – T_he max depends on the thermal conduction of the heat through the coil – And depends on the temperature increase due to the heat integration along the magnet string. Subcooled He circuit must be considered Q T_he T_sc T_he ?

7. FCC-hh: Magnet cooling scheme À la HERA for normal He À la LHC for superfluid He

8. Cryogenics architecture

9. Process flow diagram CWU Ne-He WCS He WCS 300-40 K UCB 40-4 K LCB Sector BS cold circulator (CC) BS warm circulator (WC)

10.  s = 0.7 (cold compressor)  s = 0.83 (warm compressor) Nelium cycle and BS circulators Shield 1M Shield 4M Shield 7M Bypass 7M Basic 7M 1 MW ≙ 36 MCHF in 10 years of FCC operation Cooling channels @ 50 bar (40-60 K) C. Kotnig

11. Nelium cycle and BS circulators Cooling length: 7 magnets (105 m, 800 valves) or 4 magnets (60 m, 1600 valves)?: -Cost of 800 additional valves (including integration and controls): ~8 MCHF -With warm circulators: gain of 0.25 MW, i.e. ~9 MCHF of operation cost saving -With cold circulators: gain of 0.6 MW, i.e. ~22 MCHF of operation cost saving (but increase (x2) of the valve failure rate)

12. Cold compressor for He subcooling Nominal operation Thermal shields in series with the BS (~600 kW) NeHe cycle at ground level CL cooling @ 40 K, 1.3 bar (~140 g/s) CC vs CW: Overall efficiency  in favour of CC if low pressure ratio, (OK up to 7 magnets) Capacity adaptation during energy ramp  WC? (factor 7 in 15 min !) (~12 kW)

13. New type of Nelium compressors

15. Cool-down (warm-up) 300-80 K

16. H. Rodrigues 2.5 MW LN2 precooler (~4 x LHC) Up to 25 LN2 trailer per day per sector ! (2 t/h) ~5000 t of LN2 per sector (~8 MCHF for 1 FCC cooldown)  1 spherical storage of 23 m diameter (to be filled in advance to ease the logistics) 2.5 MW of heating power: electrical heater or recovery of compression power? (Saving of 360 kCHF per FCC warmup)

17. Half-cell cooling loop Superfluid He cooling “à la LHC” -Separate circuit for indirect cool-down and warm-up (no impact on the CM design pressure) -Bayonet heat exchanger for Liquid-liquid LHe II -Thermal shield and heat intercepts on the return header -Safety/quench valve spacing : ~100 m (to be validated)

18. Half-cell cooling loop Normal He cooling “à la HERA” -Separate circuit for indirect cool-down and warm-up (no impact on the CM design pressure) -Thermal shield and heat intercepts on the return header -Safety/quench valve spacing : ~100 m (to be validated)

19. Main cryogenic transfer lines (He II) (He I)

20. Electrical power to the refrigerators ?

21. FCC-ee RF straight section 2 main-ring and 1 booster-ring RF module strings

22. FCC-ee: RF data : 120 GeV, 12 mA 1-cell2-cell4-cell RF voltage [MV]5500 SR power per beam [MW]50 Synchronous phase [deg]162.3 Gradient [MV/m]10 Active length [m]0.3750.751.5 Voltage/cavity [MV]3.87.515.0 Number of cavities1467734367 Total cryomodule length [m]256914681012 Q 0 [10e9]3.0 Heat load per cavity [W]53.9110.9241.9 Total heat load per beam [kW]79.081.488.8 R/Q [linac ohms]87169310 RF power per cavity [kW]34.168.1136.2 Matched Qext4.7E+064.9E+065.3E+06 Bandwidth @ matched Qext84.381.975.1 Optimal detuning [Hz]-132.6-128.8-118.1 A. Butterworth Static heat inleaks: 5 W/m, i.e. [kW] Heat load for 2-main and 1-booster rings Dynamic load of 2-main rings Dynamic load of booster ring (~10 % of one main ring) [kW] Total

23. FCC-ee cryogenic capacity (2 main + 1 booster rings) CryoplantQ stat [kW] Q dyn [kW] Qtot [kW] 54550 Total FCC-ee20180200 -RF-cavity modules installed in the long straight sections (Points J and D) -Bending field adapted to the beam energy loss (SR) along the 50 km half-turn. -Operating temperature still to be optimized (4 K, 2 K, 1.8 K, 1.6 K) 4.2 km Magnetic refrigeration?

24. FCC cryogenics study schedule FCC weeks (Next in Rome 11-15 April 2016) FCC cryogenics days (Next October 2016, where?)