850 camera Splinter discussion

Monday 19th May

Link to Dan's talk

Cryogenics

ADR (Adiabatic demagnetization refrigerator) vs Dilution refrigerator

ADR beneficial if you want it in the cabin (where it would tilt). However, on the nasmyth this is not necessary. Also the magnetic field issue is a problem. Any 'pro's' for an ADR? Cheaper. Anything else?

Chase fridge (CARDIFF) - for Muscat. Miniature dilution fridge (with paired continuous sorption fridge at 350mK, and continuous 1K sorption fridge) - sustained 150mk (five to six days). Can survive brownouts... but still need pulse tubes. Cool down time is 48 hours... full 80 hours to get down to 150mK. Uses 9L of He3.

Liquid cryogenic sourcing on Hawaii islands is difficult, and increasingly so. This might be an issue if we need cold traps. The new closed systems should not require this however neither was this in the original SCUBA-2 design.