Page 16 - Two-chord Interferometry using 3.39 µm He-Ne Laser on a Flux-Coil-Generated FRC
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⎡ ⎛r2 −r2 ⎞⎤ B(r)=B 1+ βtanh⎜ 0 ⎟
Bz as a function of r gives field- null point (r0) using fitting
z
0 ⎢ ⎜ r Δr ⎟⎥ ⎣ ⎝0 ⎠⎦
ni(r)=
β ≡ 2μ0 ∑j n0 jTj
B 02
R a w d a t a
ni0
⎛r2 −r2 ⎞ cosh2⎜ 0 ⎟
r Δr ⎝0⎠
B0 : External magnetic field
r0 : Null radius
Δr : Effective radial plasma width
Fitted line
Given derived parameters radial density profile can be calculated.
n0≈ 2μ0∑jn0jTj
If we can determine n0, then the temperature
Shot 2914, t=60 μs
can be estimated.
HTPD2010, Wildwood, NJ, 5/17/2010 Presenter: Hiroshi Gota
r0~17.57 cm and Δr~5.62 cm were used for fitting
Radial Profile Comparison (rigid-rotor model for Bz and n)
