any moving parts in the embodiment of fig9 fig1 provides flow paths similar to the embodiment of fig9 except that the heat transfer surface 32 and cold plate 34 are not directly connected to the throttle device 35 these elements of a closed cycle refrigeration system would be connected by copper tubing 36 at p1 whereby the throttle device 35 is adaptable for many different cooling applications in fig1 a throttle device 38 includes a fixed orifice 22 arranged in parallel with a parallel pair of porous material elements 16 16 39 the porous material 16 16 39 may be of the same or different pore sizes and cut off temperatures so as to tune the device 38 to a desired cool down time an integrated valve body 40 holds the three throttle elements 16 16 39 22 but two independent bodies could be used preferably held together with a highly conductive wire such as copper for good thermal contact between all elements in each instance the fixed orifice that is used for steady state operation is dimensioned for a low refrigerant flow velocity thus the vibrations delivered at the cold interface with the object to be cooled are vastly reduced over the conventionally sized capillary tube that.