Abstract: A purity monitor is provided. The purity monitor includes a cryo-cooler and a piezo-electric crystal microbalance that may have a matte finish. The cryo-cooler includes a nozzle and plumbing components disposed to supply a fluid having a working pressure of up to 10,000 psig to the nozzle. The nozzle provides for locating substantially all of a pressure drop of the cryo-cooler near an exit thereof. The nozzle sprays fluid onto the piezo-electric crystal microbalance and the piezo-electric crystal microbalance measures a mass of non-volatile residue (NVR) left thereon by the spraying. Respective temperatures of the fluid and the piezo-electric crystal microbalance are controllable based on a type of the NVR.

Abstract: A purity monitor is provided. The purity monitor includes a cryo-cooler and a piezo-electric crystal microbalance that may have a matte finish. The cryo-cooler includes a nozzle and plumbing components disposed to supply a fluid having a working pressure of up to 10,000 psig to the nozzle. The nozzle provides for locating substantially all of a pressure drop of the cryo-cooler near an exit thereof. The nozzle sprays fluid onto the piezo-electric crystal microbalance and the piezo-electric crystal microbalance measures a mass of non-volatile residue (NVR) left thereon by the spraying. Respective temperatures of the fluid and the piezo-electric crystal microbalance are controllable based on a type of the NVR.

Abstract: A system includes a cryocooler configured to cool an object, a sensor configured to measure a temperature of the object, and a controller configured to generate an actuator drive signal to control the cryocooler based on at least one temperature measurement from the sensor. The cryocooler includes a heat exchanger and a needle configured to control flow of coolant gas through the heat exchanger. The cryocooler also includes a motion rod configured to move the needle and an actuator assembly configured to move the motion rod to thereby move the needle. The actuator could include a motor and a gear head configured to rotate a lead screw and a lead screw nut located around the lead screw and configured to translate rotational motion of the lead screw into linear motion. The actuator could also include a piezoelectric actuator or a linear actuator.

Abstract: A system includes a cryocooler configured to cool an object, a sensor configured to measure a temperature of the object, and a controller configured to generate an actuator drive signal to control the cryocooler based on at least one temperature measurement from the sensor. The cryocooler includes a heat exchanger and a needle configured to control flow of coolant gas through the heat exchanger. The cryocooler also includes a motion rod configured to move the needle and an actuator assembly configured to move the motion rod to thereby move the needle. The actuator could include a motor and a gear head configured to rotate a lead screw and a lead screw nut located around the lead screw and configured to translate rotational motion of the lead screw into linear motion. The actuator could also include a piezoelectric actuator or a linear actuator.

Abstract: An in-line valve flow controller for a Joule-Thomson cryostat. The controller has an in-line valve stem that is part of, and is collinear with, an actuation stem of the cryostat. Both the in-line valve stem and actuation stem sit in an orifice of the Joule-Thomson cryostat. This arrangement automatically positions the valve stem over its valve seat. The in-line valve flow controller integrates with a temperature dependent snap disk that is used to close the valve stem against the valve seat. Initial flow rate is determined only by the diameter of the orifice of the Joule-Thomson cryostat, and not by valve position. Bypass flow is aso set by the diameter of the orifice, which is not subject wear, and the valve stem prevents contaminates from clogging the orifice.

Abstract: A cryostat (10') with a heat exchanger (13'); a valve (25') for controlling the flow of fluid through said heat exchanger (13'); and a snap disk (30') for actuating the valve (25'). In a specific embodiment, the snap disk (30') is constructed of at least two different materials (32', 34'), each having a different coefficient of thermal expansion. The snap disk (30') is mounted upon an orifice block (38') and coupled to a needle valve (25') by a connecting rod (40'). The needle valve (25') engages an orifice (16') in the orifice block (38'). The orifice (16') is in communication with the tubing (14') of a heat exchanger (13') via a channel (44') in the orifice block (38'). The geometry of the snap disk (30') is such that when the disk changes state, it snaps due to the thermal properties thereof. This ensures fast response with abrupt closure characteristics and considerable travel. In addition, the snap disk (30') allows for a simplified cryostat design with minimal weight and cost.