Measuring Ion Temperature in Plasma: Why Use Tungsten/Molybdenum Probes?

[mkbh_10]

I am nt able to understand why we are not able to measure ion temperature in plasma using single probe method ?

Why tungsten or molybednum probes are used ?
The book says due to their refractory properties but i am nt getting it .



TO mod , i didnt find a plasma related section so posted this here so please move it if there is one .

 

[Astronuc]

Unfortunately we don't have a plasma physics forum, so other than HEP, one could probably post in Gen Phys or Classical Physics.

What type of plasma?

Here are some papers that might be of interest.

http://www.ktu.lt/lt/mokslas/zurnalai/medz/medz0-91/16%20Testing...(pp.346-350).pdf

http://epsppd.epfl.ch/Hersonissos/pdf/P2_142.pdf

http://www.terrapub.co.jp/journals/EPS/pdf/5112/51121309.pdf

http://depts.washington.edu/rppl/presentations/APS2009/2009-APS-poster-24.pdf

In the last reference (poster), look at Table 2. A Comparison of Material Sputtering Threshold, and note the ranking of W, Ta, and Mo compared to other materials. The refractory metals have high melting temperature and high sputtering threshold, so they are ideal for certain high temperature applications.

I believe a single Langmuir probe can be used for temperature measurement - at least electron temperature - but perhaps ion temperature is of interest.

http://www-ferp.ucsd.edu/boedo/Diagnostics/Te_Fluctuations/Rudakov_htpd_00.pdf