title: Advanced spectroscopic analysis of 0.8-1.0-MA Mo x pinches and the influence of plasma electron beams on L-shell spectra of Mo ions.
abstract: This paper presents a detailed investigation of the temporal, spatial, and spectroscopic properties of L-shell radiation from 0.8 to 1.0 MA Mo x pinches. Time-resolved measurements of x-ray radiation and both time-gated and time-integrated spectra and pinhole images are presented and analyzed. High-current x pinches are found to have complex spatial and temporal structures. A collisional-radiative kinetic model has been developed and used to interpret L-shell Mo spectra. The model includes the ground state of every ionization stage of Mo and detailed structure for the O-, F-, Ne-, Na-, and Mg-like ionization stages. Hot electron beams generated by current-carrying electrons in the x pinch are modeled by a non-Maxwellian electron distribution function and have significant influence on L-shell spectra. The results of 20 Mo x-pinch shots with wire diameters from 24 to 62 microm have been modeled. Overall, the modeled spectra fit the experimental spectra well and indicate for time-integrated spectra electron densities between 2 x 10(21) and 2 x 10(22) cm(-3), electron temperatures between 700 and 850 eV, and hot electron fractions between 3% and 7%. Time-gated spectra exhibit wide variations in temperature and density of plasma hot spots during the same discharge.
authors.affiliation: Physics Department/220, University of Nevada, Reno, NV 89557, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Shlyaptseva
authors.forename: S B
authors.initials: SB
authors.lastname: Hansen
authors.forename: V L
authors.initials: VL
authors.lastname: Kantsyrev
authors.forename: D A
authors.initials: DA
authors.lastname: Fedin
authors.forename: N
authors.initials: N
authors.lastname: Ouart
authors.forename: K B
authors.initials: KB
authors.lastname: Fournier
authors.forename: U I
authors.initials: UI
authors.lastname: Safronova