title: Measurements of electron density and temperature in the H-1 heliac plasma by helium line intensity ratios.
abstract: Electron density and temperature distributions in the H-1 heliac plasma are measured using the helium line intensity ratio technique based on a collisional-radiative model. An inversion approach with minimum Fisher regularization is developed to reconstruct the ratios of the local emission radiances from detected line-integrated intensities. The electron density and temperature inferred from the He I 667.8/728.1 and He I 728.1/706.5 nm line ratios are in good agreement with those from other diagnostic techniques in the inner region of the plasma. The electron density and temperature values appear to be a little high in the outer region of the plasma. Some possible causes of the discrepancy in the outer region are discussed.
authors.affiliation: Plasma Research Laboratory, Australian National University, Canberra ACT 0200, Australia. shuiliang.ma@anu.edu.au
authors.forename: Shuiliang
authors.initials: S
authors.lastname: Ma
authors.forename: John
authors.initials: J
authors.lastname: Howard
authors.forename: Boyd D
authors.initials: BD
authors.lastname: Blackwell
authors.forename: Nandika
authors.initials: N
authors.lastname: Thapar