X-ray spectroscopic diagnostics on JIPPT-IIU and HELIOTRON-E
Abstract
Activities in X-ray spectroscopy at the Institute of Plasma Physics are reported with an emphasis on Ti K-alpha measurements. Two crystal spectrometers of Johann type (wide spectral band spectrometer with small Rowland circle and high resolution spectrometer with large Rowland circle) were constructed for X-ray diagnostics of the JIPPT-IIU tokamak plasma. The detector is a position-sensitive proportional counter (PSPC). A wide spectral band spectrometer was made for measuring a full spectrum of K-alpha transitions. The K-alpha full spectra are obtained in experiments with both lower-hybrid current drive (LHCD) and ion cyclotron radio frequency (ICRF) heating. In LHCD experiments, nonthermal features of Ti K-alpha lines are observed at electron densities below approximately 5 x 10(12) cm(-3). The measured Ti spectra are analyzed under simply assumed radial profiles of nonthermal electrons. In ICRF experiments, time behaviors of Ti, Cr, Fe and Ni K-alpha spectra are measured with time intervals of 10 ms to study the impurity transport. A high-resolution spectrometer was made to measure the ion temperature, electron temperature, toroidal rotation and quantitative contribution of nonthermal electrons. In the ion temperature measurement, narrowing of the Ti He-like resonance line is observed during ohmic heating. The full K-alpha spectra from Ti and Fe ions were also observed in Heliotron-E ICRF and electron cyclotron heating experiments. Most abundant ion species in the central column of the plasma were determined.
- Publication:
-
In its Summary Report on the Japan-US Workshop on the Assessment of Spectroscopic Data for Temperature and Density Measurements p 5 (SEE N88-24512 17-75
- Pub Date:
- March 1988
- Bibcode:
- 1988asdt.work....5M
- Keywords:
-
- Heliotrons;
- Plasma Diagnostics;
- Plasma Spectra;
- Spectrometers;
- Tokamak Devices;
- X Ray Spectroscopy;
- Electron Energy;
- Electron Transitions;
- Ion Temperature;
- Line Spectra;
- Plasma Dynamics;
- Proportional Counters;
- Rotation;
- Toroidal Plasmas;
- Plasma Physics