Project Title:

Remote, Wireless Monitoring of Positron Escape for Gauging Temperature and Strain

01.03-6000
900505
Remote, Wireless Monitoring of Positron Escape for Gauging Temperature and Strain

Abstract:

This project will investigate monitoring of strains and temperatures based on the
unique electrical properties of positrons at metal surfaces. Unlike bound electrons,
positrons are often actively expelled from metals due to a net negative work function
which can be sensitive to strain or temperature. Sources can be inexpensively created
inside a metal component by accelerator activation. The fraction of positrons leaving
the surface would be affected by a number of strain or temperature sensitive variables,
such as work function, defect density, grain-boundary size, and conductivity. Thus,
monitoring of annihilation gamma rays away from the activated surface will indicate
strain or temperature as in conventional sensors but at much higher temperature and
with none of the disadvantages which characterize electrical or optical fiber connections.
This would be ideal for operating high-temperature engines, particularly on rotating
parts. Refractory materials could be used at extremely high temperatures, over 2000oC.
Rapidity of measurement would be a function of source strength, but quite modest
sources which do not involve any hazard or special handling could produce reliable
measurements every 10 to 20 seconds.
Wireless, high-temperature gauges would have widespread application in advanced engine
testing and development.
strain, thermometry, radiometry, sensors, gauges, positron, transducer, wireless.
strain, thermometry, radiometry, sensors, gauges, positron, transducer, wireless