Laser-induced fluorescence of phosphors for remote cryogenic theromometry
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, noncontact, cryogenic-temperature measurements in electrically hostile environments, such as high dc electric or magnetic fields. The National Aeronautics and Space Administration is interested in using 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 ultraviolet laser, provide fluorescence lifetimes having logarithmic dependence with temperature from 4 K to above 125 K. A calibration curve for both La{sub 2}O{sub 2}S:Eu and Mg(F)GeO{sub 6}:Mn is presented, as well as emission spectra taken at room temperature and 11 K. 4 refs., 13 figs.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- Sponsoring Organization:
- DOE/ER; NASA
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6558487
- Report Number(s):
- ORNL/ATD-44; ON: DE91001733
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400102 -- Chemical & Spectral Procedures
440500* -- Thermal Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
CONTAINERS
CONTROL EQUIPMENT
CRYOGENICS
CRYOSTATS
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
EQUIPMENT
FLUORESCENCE
LANTHANUM COMPOUNDS
LASER RADIATION
LUMINESCENCE
MANGANESE COMPOUNDS
MEASURING INSTRUMENTS
PHOSPHORS
RADIATIONS
RARE EARTH COMPOUNDS
REMOTE SENSING
SPECTRA
TANKS
TEMPERATURE DEPENDENCE
TEMPERATURE MEASUREMENT
THERMOMETERS
THERMOSTATS
TRANSITION ELEMENT COMPOUNDS
WALLS