Abstract: This specification discloses a cryostat assembly for a refrigerated infrared detector unit which includes an interior recess having therein a coolant conduit. The recess is partly bounded by a cylindrical wall and the coolant conduit has an exit nozzle which releases coolant tangential to the wall so that the noise of the coolant impact against the walls of the recess is reduced. Further, the coolant conduit is electrically conductive and has sufficient surface area to remove electrostatic charge from the coolant. The reduction of acoustical noise of the coolant impact against the recess walls and the discharge of an electrically charged coolant permits elimination of an electrically conductive coating on the walls of the recess and greatly simplifies production. Still further, the positioning of the coolant conduit and coils abutting the recess boundary serves to support and position the conduit exit nozzle.