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

FCC cryogenics studies FCC Cryogenics Studies Cryoplants (~ K including 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

FCC-hh cryogenic layout CryoplantL Arc+DS [km]L distribution [km] 2 x 4 = 82 x 4.7 = CryoplantL Arc+DS [km]L distribution [km] 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

FCC-hh cryogenic capacity Cryoplant40-60 K [kW] Tcm [kW] K [g/s] cryoplants 6 technical sites 20 cryoplants 10 technical sites Cryoplant40-60 K [kW] Tcm [kW] K [g/s] Without operational margin ! The baseline The alternative

FCC-hh: Magnet temperature D. Tommasini

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 ?

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

Cryogenics architecture

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

 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 50 bar (40-60 K) C. Kotnig

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)

Cold compressor for He subcooling Nominal operation Thermal shields in series with the BS (~600 kW) NeHe cycle at ground level CL 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)

New type of Nelium compressors

Cool-down (warm-up) K

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)

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)

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)

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

Electrical power to the refrigerators ?

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

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] Voltage/cavity [MV] Number of cavities Total cryomodule length [m] Q 0 [10e9]3.0 Heat load per cavity [W] Total heat load per beam [kW] R/Q [linac ohms] RF power per cavity [kW] Matched Qext4.7E+064.9E+065.3E+06 matched Qext Optimal detuning [Hz] 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

FCC-ee cryogenic capacity (2 main + 1 booster rings) CryoplantQ stat [kW] Q dyn [kW] Qtot [kW] Total FCC-ee 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?

FCC cryogenics study schedule FCC weeks (Next in Rome April 2016) FCC cryogenics days (Next October 2016, where?)