Abstract: An improved open-cycle cooling apparatus in which a cooling chamber holding a device to be cooled is coupled with a cold fluid delivery system and, in which the cold fluid delivery system includes a delivery tube which directs a stream of cold fluid to strike the device and a return which vents the expended cold fluid from the cooling chamber. The improvement comprises a rigid enclosure formed within the chamber and configured to adaptively engage one end of the cold fluid delivery tube. The device to be cooled is disposed within the enclosure. The enclosure also includes a return to remove expended cold fluid from the cooling chamber to the return of the cold fluid delivery stystem. The improvement further comprises an alignment guide disposed within the enclosure between the device to be cooled and the one end of the cold fluid delivery tube engaged to the enclosure.