TY - JOUR AB - We describe the SPIDER flight cryostat, which is designed to cool sixmillimeter-wavelength telescopes during an Antarctic long-duration balloonflight. The cryostat, one of the largest to have flown on a stratosphericpayload, uses liquid helium-4 to deliver cooling power to stages at 4.2 and 1.6K. Stainless steel capillaries facilitate a high flow impedance connectionbetween the main liquid helium tank and a smaller superfluid tank, allowing thelatter to operate at 1.6 K as long as there is liquid in the 4.2 K main tank.Each telescope houses a closed cycle helium-3 adsorption refrigerator thatfurther cools the focal planes down to 300 mK. Liquid helium vapor from themain tank is routed through heat exchangers that cool radiation shields,providing negative thermal feedback. The system performed successfully during a17 day flight in the 2014-2015 Antarctic summer. The cryostat had a total holdtime of 16.8 days, with 15.9 days occurring during flight. AU - Gudmundsson,JE AU - Ade,PAR AU - Amiri,M AU - Benton,SJ AU - Bock,JJ AU - Bond,JR AU - Bryan,SA AU - Chiang,HC AU - Contaldi,CR AU - Crill,BP AU - Doré,O AU - Filippini,JP AU - Fraisse,AA AU - Gambrel,A AU - Gandilo,NN AU - Hasselfield,M AU - Halpern,M AU - Hilton,GC AU - Holmes,W AU - Hristov,VV AU - Irwin,KD AU - Jones,WC AU - Kermish,Z AU - MacTavish,CJ AU - Mason,PV AU - Megerian,K AU - Moncelsi,L AU - Montroy,TE AU - Morford,TA AU - Nagy,JM AU - Netterfield,CB AU - Rahlin,AS AU - Reintsema,CD AU - Ruhl,JE AU - Runyan,MC AU - Shariff,JA AU - Soler,JD AU - Trangsrud,A AU - Tucker,C AU - Tucker,RS AU - Turner,AD AU - Wiebe,DV AU - Young,E DO - 10.1016/j.cryogenics.2015.09.002 EP - 76 PY - 2015/// SN - 1879-2235 SP - 65 TI - The thermal design, characterization, and performance of the Spider long-duration balloon cryostat T2 - Cryogenics UR - http://dx.doi.org/10.1016/j.cryogenics.2015.09.002 UR - http://hdl.handle.net/10044/1/26308 VL - 72 ER -