Thermal Load Budget and Helium-3 Circulation Requirement for a Dilution Refrigerator Stage Reaching Ten Millikelvin

This paper presents a computed design for a dilution refrigerator stage intended for millikelvin refrigeration, with its performance, resource budgets and margins derived from stated assumptions rather than asserted. The headline results are: heat conducted down the supports of 3.6 microwatt; heat conducted along the wiring loom of 0.384 microwatt; radiative load from the still-temperature shield of 2.32e-05 microwatt; total steady load on the mixing chamber of 4.38 microwatt; helium-3 circulation needed to hold 10 mK under the full load of 461 micromol per second. 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.