BIASED PROBE FOR PLASMA DIAGNOSTICS IN SPHERICAL ELECTROSTATIC INERTIAL PLASMA-CONFINEMENT

The biased probe, as a unique extension of the Langmuir probe, offers several advantages in measuring the charged-particle flux versus position in a beam-dominated plasma such as encountered in the spherical electrostatic inertial confinement (SEIC) device. The probe operates in a non-Maxwellian and locally non-neutral plasma, where the Debye length is large compared to the probe itself. Its conical particle acceptance extension minimizes the measurement error caused by the distortion of the SEIC potential structures. Either the ion or electron flux can be measured using the proper bias on its inner collecting element.