Discrete liquid/vapor detectors for use in liquid heliumSimple devices have been constructed and tested which can discriminate between liquid helium and its vapor. The devices are 0.25-mm doped silicon cubes suspended from 0.05-mm-diameter stainless steel and manganin wires. A small current is passed through the device heating it and lowering its resistance. The degree of self-heating is dependent on whether the device is immersed in liquid or is surrounded by vapor. The voltage across the device then indicates the presence of liquid or vapor. The devices are meant to operate in the milligravity environment of space. Tests simulating thick superfluid films which would be present in this case indicate less than 0.3 milliwatt per detector is sufficient to boil away these thick films. The detector response time under these conditions is less than 50 milliseconds.
Document ID
19920030793
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Dipirro, M. J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Serlemitsos, A. T. (NASA Goddard Space Flight Center Greenbelt, MD, United States)