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U.S. Department of Energy
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Laser-induced fluorescence of phosphors for remote cryogenic thermometry

Conference ·
OSTI ID:6762176

Remote cryogenic temperature measurements can be made by inducing fluorescence in phosphors with temperature-dependent emissions and measuring the emission lifetimes. The thermographic phosphor technique can be used for making precision, non-contact, cryogenic temperature measurements in electrically hostile environments, such as high DC electric or magnetic fields. NASA is interested in utilizing these thermographic phosphors for mapping hot spots on cryogenic tank walls. Europium-doped lanthanum oxysulfide (La{sub 2}O{sub 2}S:Eu) and magnesium fluorogermanate doped with manganese (Mg{sub 4}(F)GeO{sub 6}:Mn) are suitable for low-temperature surface thermometry. Several emission lines, excited by a 337 nm UV laser, provide fluorescence lifetimes having logarithmic dependence with temperatures from 4 to 125 Kelvin. A calibration curve for both La{sub 2}O{sub 2}S:Eu and Mg{sub 4}(F)GeO{sub 6}:Mn are presented as well as emission spectra taken at room temperature and 7 Kelvin.

Research Organization:
Oak Ridge National Lab., TN (USA)
Sponsoring Organization:
NASA
DOE Contract Number:
AC05-84OR21400
OSTI ID:
6762176
Report Number(s):
CONF-9009274-1; ON: DE91001221
Country of Publication:
United States
Language:
English