title: High sensitivity far infrared laser diagnostics for the C-2U advanced beam-driven field-reversed configuration plasmas.
abstract: A high sensitivity multi-channel far infrared laser diagnostics with switchable interferometry and polarimetry operation modes for the advanced neutral beam-driven C-2U field-reversed configuration (FRC) plasmas is described. The interferometer achieved superior resolution of 1 × 1016m-2at >1.5 MHz bandwidth, illustrated by measurement of small amplitude high frequency fluctuations. The polarimetry achieved 0.04° instrument resolution and 0.1° actual resolution in the challenging high density gradient environment with >0.5 MHz bandwidth, making it suitable for weak internal magnetic field measurements in the C-2U plasmas, where the maximum Faraday rotation angle is less than 1°. The polarimetry resolution data is analyzed, and high resolution Faraday rotation data in C-2U is presented together with direct evidences of field reversal in FRC magnetic structure obtained for the first time by a non-perturbative method.
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: 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: J
authors.initials: J
authors.lastname: Schroeder
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: G
authors.initials: G
authors.lastname: Settles
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: P
authors.initials: P
authors.lastname: Feng
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Kinley
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
authors.affiliation: Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Thompson