Hold Time of a Cryogenic Dewar for Quantum Sensors: Multilayer Insulation Load, Neck Conduction and Boil-Off Budget

This paper presents a computed design for a sensor Dewar intended for cryogenic storage and transport, with its performance, resource budgets and margins derived from stated assumptions rather than asserted. The headline results are: heat load through the multilayer insulation of 0.044 W; heat conducted down the neck of 0.0801 W; hold time with the sensor powered of 2.92 days; hold time with the sensor unpowered of 11.2 days; boil-off rate with the sensor powered of 15.8 litres per day. Each figure was produced by the deposited computation from the inputs listed in the Methods, and the sensitivity of the conclusions to those inputs is examined in the Discussion. The design is a paper study: it is labelled, on its face and in this abstract, SIMULATED, NOT MEASURED, and no quantity reported here is a measurement of built hardware.