Effects of an ergodic magnetic limiter on the edge plasma properties of the TEXT tokamak

Spatially resolved VUV emissions from low-Z intrinsic impurities have been used to measure the effects of an ergodic magnetic limiter (EML) on the edge region of the TEXT plasma. Using previously established techniques for determining the electron density ne and the electron temperature T e from line pair ratios within the beryllium-like O V ion, poloidal modulations in n e , and T e are found corresponding to EML induced magnetic islands. In general, increases of 50% in both n e and T e are found near the poloidal locations of X-points and decreases of the same order are found near O-points. Modulations and radial profile broadening of intrinsic carbon and oxygen ions are also found, indicating enhancement of edge impurity transport during EML perturbation.