Measurements of the Radiation Energy Distribution in the Soft X-Ray Region in the Wendelstein VII-A Stellarator

摘要

The soft X-ray radiation power with 400 eV <= E <= 100 eV originating from resonance lines of C-, O-, Fe-, Cr-, Mo-impurities contributes the major part of the total radiation losses from the plasma centre. A coarse discrimination between the most important impurity species can be obtained by using an array of filters consisting of different material. Different energy windows are defined by the energies of the corresponding L-line absorption edges of the filter materials. The radiation power of each energy band is monitored by a set of surface barrier diodes during the plasma discharges. Information about the energy spectrum is also provided by a two filter method giving an estimation of the mean radiation energy. In addition, X-ray pulse height analysis measurements are presented. The results are correlated with spectroscopic measurements. (ERA citation 11:029003)