Density and Temperature Measurements in the ELM Simulating Plasma (ESP) Gun

Edge Localized Modes (ELMs) represent a significant disruption to current and future fusion reactors. Of concern in a device such as the International Thermonuclear Experimental Reactor (ITER) is that ELMs could be the limiting factor for successful operation. ITER ELMs are predicted to impart between 1 10 MJ/m² onto the surface of the diverter and first wall of the reactor. This could lead to significant erosion of the diverters and possible melting. The ELM simulating plasma gun (ESP-gun) currently being operated at UIUC is intended to produce plasmas similar to those found in ELM events from TOKAMAKS. The PFN is connected to the conical theta pinch to produce high temperature, high density plasmas similar to ELM events. These plasmas are intended to reproduce the plasma conditions and potential material damage in an ELM event from a large scale fusion experiment such as NSTX or ITER. A Triple Langmuir Probe (TLP) has been used to diagnosis and measure the quality of the plasmas produced by the ESP-gun. To date, electron densities of 1(10)¹⁷/m³ and greater with electron temperatures greater than 100 eV in the target area have been measured. Additionally a fast, IR measurement is used during the simulated ELM event to determine target heating and estimate the energy flux on the target due to the plasma load