By Topic

CO2 laser imaging interferometer for high spatial resolution electron density profile measurements on LHD

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

The purchase and pricing options are temporarily unavailable. Please try again later.
9 Author(s)
Akiyama, T. ; Tokyo Institute of Technology, 2-12-2 O-okayama, Meguro-ku, Tokyo 152-8550, Japan ; Tanaka, K. ; Vyacheslavov, L.N. ; Sanin, A.
more authors

Your organization might have access to this article on the publisher's site. To check, click on this link: 

A CO2 laser (λ=10.6 μm) imaging interferometer was developed for detailed and precise electron density profile measurements and was installed on the large helical device in 2001. A CO2 laser is adopted to avoid fringe loss due to the short wavelength. An imaging scheme is employed that uses three slab-like beams and multichannel detector arrays to measure with fine spatial resolution. As an initial trial we used one slab-like beam that passes through the plasma edge. Phase distributions were measured without fringe loss even after pellet injection. Density profiles can be obtained by the slice and stack method with a spatial resolution of 16 mm (about 3% of the plasma minor radius). The electron density was found to rise to about 6×1019 m-3 just after pellet injection even near the last closed flux surface. Mechanical vibration effects would be negligible in such a case. A bench top experiment of a coaxial YAG laser (λ=1.06 μm) interferometer for vibration compensation was carried out. © 2003 American Institute of Physics.

Published in:

Review of Scientific Instruments  (Volume:74 ,  Issue: 3 )