D1 and MCBXC pressurized superfluid helium channels sizing for heat extraction Rob van Weelderen

Layout as used for quantifying necessary free space for heat extraction via the superfluid helium for D1 & MCBXC Q3 MCBXC D K (coil) HeIium Or 10 W + Q K 10 W + Q K 10 W K (non IP-end) K (collar nose) K (coil) ~ 12.9 m (including interconnects)~ 4.0 m Layout & dynamic loads based to be confirmed) Assumptions: - D1 is passively cooled via conduction through pressurized HeII - The inner triplet magnets are actively cooled with maximum T of K 1)MCBXC is actively cooled as well  12.9 m conduction cooling length 2)MCBXC is passively cooled ……….  16.9 m conduction cooled length -T cold mass D1 at IP end K  50 mK “budget” to extract heat longitudinally -T at D1 coil  220 mK “budget” to extract heat from D1 coil

Free conduction area as function of total power deposition 50 mK from 2050 K to K, 12.9 or 16.9 m conduction length