Abstract: Various embodiments are directed to pulse tube coolers having flow resistance devices that are variable within the thermodynamic cycle of the pulse tube. An example pulse tube may comprise a compressor, a regenerator, a reservoir and a pulse tube. A working fluid may be positioned within the regenerator, pulse tube and reservoir. Further, a variable phase control device may be positioned in a fluid path between the pulse tube and the reservoir. The pulse tube cooler may also comprise a control circuit. The control circuit may be programmed to vary a characteristic of the variable phase control device based on the position of the pulse tube cooler in its thermodynamic cycle.

Abstract: Various embodiments are directed to pulse tube coolers and components thereof. A pulse tube cooler may comprise a compressor, a regenerator, a pulse tube and a reservoir. A network of phase control devices may be placed in a fluid path between a hot end of the pulse tube and the reservoir. The network of phase control devices may have at least one flow resistance device and at least one inertance device.

Abstract: Various embodiments are directed to pulse tube coolers and components thereof. A pulse tube cooler may comprise a compressor, a regenerator, a pulse tube and a reservoir. A network of phase control devices may be placed in a fluid path between a hot end of the pulse tube and the reservoir. The network of phase control devices may have at least one flow resistance device and at least one inertance device.

Abstract: Various embodiments are directed to pulse tube coolers having flow resistance devices that are variable within the thermodynamic cycle of the pulse tube. An example pulse tube may comprise a compressor, a regenerator, a reservoir and a pulse tube. A working fluid may be positioned within the regenerator, pulse tube and reservoir. Further, a variable phase control device may be positioned in a fluid path between the pulse tube and the reservoir. The pulse tube cooler may also comprise a control circuit. The control circuit may be programmed to vary a characteristic of the variable phase control device based on the position of the pulse tube cooler in its thermodynamic cycle.

Abstract: A pulse tube cryocooler including a heat exchanger and a pulse tube is modified with an in-line inertance gap attached to the pulse tube for gas phase shifting of gas pressure in the cryocooler for improving the efficiency and temperature range of pulse tube cryocoolers.

Abstract: A displacer cryocooler including a multistage heat exchanger is modified with a phase shifting device connected between stage volumes for gas phase shifting of gas pressure in the cryocooler for improving the efficiency and temperature range of expander cryocoolers.

Abstract: Cryocoolers, including coolers, heaters, and heat pumps each having a first stage and a second stage, are modified with controlled and variable gas phase shifting devices for controlling gas pressure and mass flow between volumes of the first and second stages for improving the efficiency and temperature range of expander cryocoolers such as displacer cryocoolers using controlled valves as flow impedance devices and pulse tube cryocoolers using inertance gaps as flow inertia devices, for maximizing cooling between the first and second stages.