The plasma facing components in fusion reactors are subject to a number of high flux/high energy events during normal operation of the device. The Divertor Edge and Vapor shielding eXperiment (DEVeX) was developed to produce a pulsed, high density, high temperature plasmas capable of simulating the conditions in events such as type I Edge Localized Modes (ELMs). Several theoretical models predict that evaporated and ejected material from the surface of the PFCs will become ionized during these events forming a vapor cloud, which will absorb some of the incident plasma energy and reduce the erosion and heat loading on the surface of the PFCs. The end goal of DEVeX is to study the dynamics of the vapor cloud that is formed and provide a benchmark for the theoretical models.

Previous work conducted on the ESP-gun experiment showed that in order to produce high density plasmas in a theta-pinch, a fast rise time (< 2 microseconds), high current capacitor bank is required. Subsequently, a capacitor bank is being designed and built that can operate up to 60 kV with 64 kJ of stored energy, which should be more than adequate to produce the desired plasmas.

Several diagnostics, such as a triple langmuir probe (TLP) and an optical spectrometer, are present in the target chamber to measure the density and temperature of the simulated ELM plasma. Additional diagnostics, such as an infrared temperature diagnostic, are planned as the experiment progresses.

DEVeX Shot #43Railgap