title: Improved density profile measurements in the C-2U advanced beam-driven Field-Reversed Configuration (FRC) plasmas.
abstract: In the prior C-2 experiment, electron density was measured using a two-color 6-chord CO2/HeNe interferometer. Analysis shows that high-frequency common mode phase noise can be reduced by a factor of 3 by constructing a reference chord. In the system upgrade from C-2 to C-2U a 4-chord far-infrared laser interferometer was developed, which demonstrated superior sensitivity (1 × 1016m-2at >1 MHz bandwidth) and solved the under spatial sampling issue of the C-2 interferometer system. Improved density-profile measurement results are presented in this paper, including evidence of fast-ion modified density profile and stabilization of the n = 1 plasma wobble mode.
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: M
authors.initials: M
authors.lastname: Beall
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: B H
authors.initials: BH
authors.lastname: Deng
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: H
authors.initials: H
authors.lastname: Gota