High-resolution measurement of the He-β spectra of heliumlike chromium for possible diagnostic of laser-produced plasmas

Abstract

High-resolution He-β spectra of heliumlike chromium have been recorded in an effort to provide accurate atomic data useful for the development of diagnostics of the electron temperature and density for laser-produced plasmas. The He-β spectra are of particular interest for these very-high-density plasmas (ne≥1024 cm−3) because, unlike the He-α and Ly-α transition, they are optically thin and can be used to determine the parameters of the compressed fuel. In addition, high-Z elements such as chromium will be needed for higher-temperature plasmas to be produced in future laser facilities. The present measurement was performed on the Livermore electron-beam ion trap with a low electron density ne≤5×1012 cm−3 and is used to calibrate in the low-density limit the theoretical calculations employed in modeling the high-ne spectra.