Calculation of finite-time ECRH power absorption using the method of characteristics

Summary form only given. An alternative method for computing nonrelativistic electron cyclotron resonance heating (ECRH) power absorption for systems in which the electron-RF-field interaction is limited to finite time-scales (i.e., inhomogeneous B-fields) is discussed. Formally, the approach computes the energy moment of the electron velocity distribution, using the method of characteristics and the RF perturbed electron orbits (approximated for finite resonance time). When applied to equilibrium systems, this technique benefits from an easy-to-follow derivation, as well as heating rate expressions that can be computed with simplified algebra and modest numerical resources. This approach was applied to ECRH in magnetic beaches and mirror traps. Applications of this work include plasma processing sources. ECR ion and X-ray sources, and fusion plasma ECRH