Page 13 - Two-chord Interferometry using 3.39 µm He-Ne Laser on a Flux-Coil-Generated FRC

13
HTPD2010, Wildwood, NJ, 5/17/2010
Presenter: Hiroshi Gota
Privileged and Confidential
Phaseshiftinducedbyplasma: Line-integrated electron density:
Δφ=tan−1 sinφ cos φ
sinφ, cosφ: signals from QPD L: path length along chord
Averaged electron density:
Total temperature (using pressure balance):
B2 B2 p+ z =pmax= e
kTB2 B2⎛x2⎞ total=e =e ⎜1−s⎟[eV]
2μ0 2μ0 n=nβ
e 2μ0nmaxe2μ0nee⎝2⎠
max e
Density Measurement
& Temperature Estimation
∫L n dl = 4πc2meε0 Δφ 0 e e2λ
ne = ∫L nedl 0
L
λ ~ 3.39 μm ≈1.047×1020Δφ [m-2]
β =1− r−r
xs=so si rFL −rFC
x2 s
2