Direct measurement of cesium absorption isobars on polycrystalline tantalum
Journal Article
·
· J. Appl. Phys.; (United States)
A direct quantitative measurement of cesium adsorbed into polycrystalline tantalum has been made by a new technique involving radioactive cesium. Cesium vapor was admitted into a known control volume and adsorbed onto two adjacent parallel tantalum disk faces. The amount of adsorbed radioactive cesium was monitored with a sodium iodide crystal ..gamma.. detector. The surface and cesium reservoir temperatures were independently controlled. Tantalum surface temperatures of 500--1700 /sup 0/K and cesium arrival rates of 10/sup 15/--10/sup 21/ atoms/cm/sup 2/ have been investigated. Atom concentration is plotted as a function of temperature for various constant cesium arrival rates. The results follow theoretical predictions up to 0.5--0.75% of a monolayer. At higher coverages, the cesium adsorption increases rapidly to well over one monolayer. The cause of this rapid increase is determined to be the formation of cesium oxide on the surfaces resulting from a calculable diffusion of oxygen through the tantalum test chamber. Although the oxygen content is not measured, the qualitative behavior of the Cs-O system is shown. Surfaces with coadsorbed cesium and oxygen have a particular usefulness in improving performance of thermionic energy converters.
- Research Organization:
- College of Engineering and Applied Sciences, Arizona State University, Tempe, Arizona 85281
- OSTI ID:
- 5348090
- Journal Information:
- J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 49:1; ISSN JAPIA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Adsorption of cesium onto polycrystalline tantalum surfaces
Direct measurement of cesium adsorption on high-temperature surfaces using radioactive tracers
BASIC RESEARCH IN THERMIONICS. PART I. CESIUM PERMEATION THROUGH TANTALUM. Summary Report No. 1, November 1, 1961 to October 31, 1962
Technical Report
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Fri Sep 26 00:00:00 EDT 1975
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OSTI ID:7343640
Direct measurement of cesium adsorption on high-temperature surfaces using radioactive tracers
Journal Article
·
Sun Oct 31 23:00:00 EST 1976
· Nucl. Technol.; (United States)
·
OSTI ID:7317914
BASIC RESEARCH IN THERMIONICS. PART I. CESIUM PERMEATION THROUGH TANTALUM. Summary Report No. 1, November 1, 1961 to October 31, 1962
Technical Report
·
Mon Dec 31 23:00:00 EST 1962
·
OSTI ID:4640491
Related Subjects
30 DIRECT ENERGY CONVERSION
300402 -- Thermionic Converters-- Performance & Testing
36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ADSORPTION
ALKALI METALS
CESIUM
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
CRYSTALS
DIRECT ENERGY CONVERTERS
ELEMENTS
FLUIDS
ISOTOPE APPLICATIONS
METALS
NESDPS Office of Nuclear Energy Space and Defense Power Systems
NONMETALS
OXIDATION
OXYGEN
PERFORMANCE
POLYCRYSTALS
QUANTITATIVE CHEMICAL ANALYSIS
REFRACTORY METALS
SORPTION
TANTALUM
TEMPERATURE DEPENDENCE
THERMIONIC CONVERTERS
TRACER TECHNIQUES
TRANSITION ELEMENTS
300402 -- Thermionic Converters-- Performance & Testing
36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ADSORPTION
ALKALI METALS
CESIUM
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
CRYSTALS
DIRECT ENERGY CONVERTERS
ELEMENTS
FLUIDS
ISOTOPE APPLICATIONS
METALS
NESDPS Office of Nuclear Energy Space and Defense Power Systems
NONMETALS
OXIDATION
OXYGEN
PERFORMANCE
POLYCRYSTALS
QUANTITATIVE CHEMICAL ANALYSIS
REFRACTORY METALS
SORPTION
TANTALUM
TEMPERATURE DEPENDENCE
THERMIONIC CONVERTERS
TRACER TECHNIQUES
TRANSITION ELEMENTS