Experimental results from an X-ray imaging crystal spectrometer utilizing multi-wire proportional counter for KSTAR

The inconsistency of the first experimental results from the X-ray imaging crystal spectrometer for the Korea Superconducting Tokamak Advanced Research device utilizing a multi-wire proportional counter (MWPC) is clarified after improving the photon-count rate of the data acquisition system for the MWPC and ground loop isolator for the whole spectrometer system. The improved MWPC is successfully applied to pure Ohmic plasmas as well as plasmas with high confinement modes.

The first experimental results from x-ray imaging crystal spectrometer for KSTAR

The x-ray imaging crystal spectrometer (XICS) for the Korea Superconducting Tokamak Advanced Research has been first applied for the experimental campaign in 2009. The XICS was designed to provide measurements of the profiles of the ion and electron temperatures from the heliumlike argon (Ar XVII) spectra. The basic functions of the XICS are properly working although some satellites lines are not well matched with the expected theoretical values. The initial experimental results from the XICS are briefly described.

Spectral resolution measurement of an x-ray imaging crystal spectrometer for KSTAR

A spectral resolution measurement of the x-ray imaging crystal spectrometer for the Korea Superconducting Tokamak Advanced Research machine utilizing a segmented position-sensitive detector and time-to-digital converter based delay-line readout electronics was performed by using an x-ray tube in a laboratory. The measured spectral resolution is about 12,600, which means the actual energy resolution is 0.32 eV for the x-ray tube's bremsstrahlung peak energy of 4 keV. The results from the spectral resolution measurement are described.

Data acquisition system for an advanced x-ray imaging crystal spectrometer using a segmented position-sensitive detector

A versatile time-to-digital converter based data acquisition system for a segmented position-sensitive detector has been developed. This data acquisition system was successfully demonstrated to a two-segment position-sensitive detector. The data acquisition system will be developed further to support multisegmented position-sensitive detector to improve the photon count rate capability of the advanced x-ray imaging crystal spectrometer system.

Development of advanced x-ray imaging crystal spectrometer utilizing a large area segmented proportional counter for KSTAR

An advanced x-ray imaging crystal spectrometer (XICS) for KSTAR tokamak has been developed by utilizing a segmented two dimensional (2D) position-sensitive multiwire proportional counter. The XICS for the KSTAR tokamak provides time-resolved measurements of the radial ion and electron temperature profiles, toroidal plasma rotation velocity, and ionization equilibrium. The segmented 2D detector with delay-line readout and supporting electronics has been adopted to improve the photon count rate capability. The current fabrication status of the XICS for the KSTAR tokamak and the first performance test results of the prototype segmented 2D detector are presented.