TAPERED PULSE TUBE FOR PULSE TUBE REFRIGERATORS

摘要

Thermal insulation of the pulse tube (78) in a pulse tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube (78). A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube (78) radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.