An improved He3-He4 mixing chamber for single-cycle experiments.

A new type of mixing chamber is described with which any dilution refrigerator, capable of reaching 30 mK continuously, can now attain temperatures below 3 mK when operating in the single-cycle mode.In a preliminary experiment this mixing chamber used in a dilution refrigerator with an additional superfluid He⁴ circulation of 2 × 10^?3 moles s^?1 reached a temperature of 4 mK continuously.