Measurement of molybdenum ion density for L-mode and H-mode plasma discharges in the EAST tokamak*

Abstract

We report the measurement of total molybdenum ion density for L-mode and H-mode plasmas on EAST using spectral lines observation and calculation based on an impurity transport code. A flat-filed extreme ultraviolet spectrometer with some spatial resolution is used to obtain the radial profiles of molybdenum spectral line emissions. The absolute calibration for the extreme ultraviolet spectrometer is finished by comparing the calculated bremsstrahlung intensity with the readings of CCD detector. Molybdenum ion transport study is performed using the radial ion density profiles and one-dimensional impurity transport code STRAHL. The total molybdenum density profiles are determined from the transport analysis. The molybdenum density during L-mode and H-mode phases are obtained, which are about 3 and 4 orders of magnitude smaller than the electron density, respectively. An inward pinch is found during the H-mode phase that leads to the peaked profile of molybdenum density.

Edge-Mode Lasing in 1D Topological Active Arrays

“…These include unidirectional light transport, backscattered-free light propagation as well as immunity to structural imperfections [6]. In photonics, the availability of gain and loss (non-Hermiticity) and the possibility of utilizing optical nonlinearities [18][19][20][21][22][23][24][25][26] -a set of attributes not present in solid-state materials -can provide an even richer ground for topological physics. In this respect, one may ask a number of fundamental questions.…”

Vacuum-Ultraviolet spectrometer system for impurity emission measurement on a Compact Torus Injection System of EAST

“…Spectroscopy provides an effective method for impurity measurement. The impurity ion density can be calculated by combining the impurity spectral lines emissions, electron density, electron temperature, and atomic data [10][11][12][13]. The total impurity density can be obtained by simulating the impurity transport code with experimental results [13].…”

“…The impurity ion density can be calculated by combining the impurity spectral lines emissions, electron density, electron temperature, and atomic data [10][11][12][13]. The total impurity density can be obtained by simulating the impurity transport code with experimental results [13]. Then, the impurity radiation intensity can be calculated, and its impact on the main plasma is evaluated based on the results of the main plasma internal energy calculation.…”