Tungsten Data for Current and Future Uses in Fusion and Plasma Science

High-Resolution Laboratory Measurements and Identification of Fe IX Lines near 171 Å

A multitude of weaker Fe IX lines have been predicted in the vicinity of the strong 171 Å line that dominates the spectra of many astrophysical and laboratory sources. Some of these weaker lines have only recently been identified in the laboratory, albeit some only tentatively. Here, we present measurements on the Livermore EBIT-I electron beam ion trap that span the region from 170.0 to 173.6 Å, which surrounds the 171 Å line. The measurements stepped through electron beam energy to determine the charge state of iron associated with each observed feature. Moreover, we have minimized the presence of oxygen in the trap, because oxygen lines obscured possible Fe IX lines in past measurements and prevented their identification. Our measurement confirms formerly tentative identifications and adds several new assignments.

Recent Advances in W-Containing Refractory High-Entropy Alloys-An Overview

During the past decade, refractory high-entropy alloys (RHEA) have attracted great attention of scientists, engineers and scholars due to their excellent mechanical and functional properties. The W-containing RHEAs are favored by researchers because of their great application potential in aerospace, marine and nuclear equipment and other high-temperature, corrosive and irradiated fields. In this review, more than 150 W-containing RHEAs are summarized and compared. The preparation techniques, microstructure and mechanical properties of the W-containing RHEAs are systematically outlined. In addition, the functional properties of W-containing RHEAs, such as oxidation, corrosion, irradiation and wear resistance have been elaborated and analyzed. Finally, the key issues faced by the development of W-containing RHEAs in terms of design and fabrication techniques, strengthening and deformation mechanisms, and potential functional applications are proposed and discussed. Future directions for the investigation and application of W-containing RHEAs are also suggested. The present work provides useful guidance for the development, processing and application of W-containing RHEAs and the RHEA components.

Core tungsten radiation diagnostic calibration by small shell pellet injection in the DIII-D tokamak

Injection of small (outer diameter = 0.8 mm) plastic pellets carrying embedded smaller (10 μg) tungsten grains is used to check calibrations of core tungsten line radiation diagnostics in support of the 2016 tungsten ring campaign in the DIII-D tokamak. Observed total brightness (1 eV-10 keV) and soft x-ray (1 keV-10 keV) brightness are found to be reasonably well (<factor 2) predicted using existing calibration factors and rate calculations. Individual core (extreme ultra-violet/soft x-ray) tungsten line brightness appears to be somewhat less reliable (factor 2-4) for the prediction of core tungsten concentration.