Energizing charged particles by an orbit instability in a slowly rotating magnetic field.

The stability of charged particle motion in a uniform magnetic field with an added spatially uniform transverse rotating magnetic field (RMF) is studied analytically. It is found that the stability diagram of a single particle's orbit depends critically on the chosen boundary conditions. We show that for many boundary conditions and wide regions in the parameter space, RMFs oscillating far below the cyclotron frequency can cause linear instabilities in the motion which break μ invariance and energize particles.

Evaluation of a collisional radiative model for electron temperature determination in hydrogen plasma.

A collisional-radiative (CR) model that extracts the electron temperature, T, of hydrogen plasmas from Balmer-line-ratio measurements is examined for the plasma electron density, n, and T ranges of 10-10 cm and 5-500 eV, respectively. The CR code, developed and implemented in Python, has a forward component that computes the densities of excited states up to n = 15 as functions of T, n, and the molecular-to-atomic neutral ratio r(H/H). The backward component provides n and r(H/H) as functions of the Balmer ratios to predict the T.