A Phase Shift Concept for Multistage Pulse Tube Coolers

A cryocooler may comprise a first stage, a second stage and a phase control device. The first stage may define a first volume. The second stage may define a second volume. The phase control device may be positioned between the first stage and the second stage to receive a flow of working fluid between the first stage and the second stage. The phase control device may comprise a flange and a plunger. The flange may be positioned along a longitudinal axis parallel a direction of the working fluid flow. The plunger may be translatable along the longitudinal axis at least partially within the flange. The plunger and the flange may be sized such that the plunger and the flange define a gap there between and a dimension of the gap is determined by a position of the plunger along the longitudinal axis.