Direct measurement of energetic electron flow in Q-shu University experiment with steady-state spherical tokamak.
Rev Sci Instrum
; 82(11): 113509, 2011 Nov.
Article
en En
| MEDLINE
| ID: mdl-22128977
In magnetized plasmas, the presence of a significant number of energetic electrons has been observed but quantitative characteristics of these electrons are proving difficult to investigate. A Langmuir probe offers a means to provide quantitative measurement of these energetic electrons that takes into account electron emissions (secondary electron emission and electron reflection) from the probe tips and sheath expansion around the probe tips caused by a considerable negative potential. In this paper, these effects are experimentally confirmed and an analytical means to measure energetic electron characteristics are proposed. An analysis of plasmas produced by a high frequency wave is then applied leading to the successful detection of an asymmetric flow of energetic electrons. The estimated electron temperature and current density were approximately 4-5 keV and 2-3 kA/m(2).
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Rev Sci Instrum
Año:
2011
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos