VUV spectroscopy of armor erosion from plasma gun disruption simulation experiments
- Sandia National Lab., Albuquerque, NM (United States); and others
Extensive simulations of Tokamak disruptions have provided a picture of material erosion that is limited by the transfer of energy from the incident plasma to the armor solid surface through a dense vapor shield. The authors have designed and utilized two transmission grating vacuum ultraviolet (VUV) spectrographs to study the plasma-material interface in plasma gun simulation experiments. Target materials included POCO graphite, ATJ graphite, boron nitride, and plasma-sprayed tungsten. Detailed spectra were recorded with a spatial resolution of {approximately}0.7 mm resolution on VIKA at Efremov and on 2MK-200 at Troitsk. Time-resolved data with 40-200 ns resolution was then recorded along with the same spatial resolution on 2MK-200. The data from both plasma gun facilities demonstrated that the hottest plasma region was sitting several millimeters above the armor tile surface. This apparently constituted the absorption region, which confirmed past computer simulations. Spectra indicated both the species and ionization level that were being ablated from the target, demonstrating impurity content, and showing plasma ablation velocity. Graphite samples clearly showed C V lines as well as impurity lines from O V and O VI. The BN tiles produced textbook examples of B IV and B V, and extensive N IV, V, and VI lines. These are being compared to radiation-hydrodynamic calculations.
- OSTI ID:
- 197062
- Report Number(s):
- CONF-940664--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Results from the US/USSR exchange for heat load material studies of simulated tokamak disruptions
Results from the US/USSR exchange for heat load material studies of simulated tokamak disruptions