Electron Density Dependence of Extreme Ultraviolet Line Intensity Ratios in Ar XIV

Abstract

We report the electron density dependence of extreme ultraviolet line intensity ratios in Ar xiv studied using a well-defined electron beam ion trap plasma. The purpose of this study is to examine the potential of the Ar xiv lines in diagnosing the electron density of solar corona active regions with a temperature higher than 3 MK. The experimentally obtained dependence is in good agreement with collisional-radiative model calculations, which ensures the usability of the Ar xiv lines.

Simultaneous observation of noble gases and highly charged ions in an electron beam ion trap for accurate wavelength calibration of optical transitions

“…Here we calculated the limits by employing the typical CoBIT condition. The assumed electron beam size was 0.1 mm 2 [26]. The electron beam energy employed in the calculation was 10 eV lower than the ionization energy to the higher charge state q+1 from the ground in each objective HCI.…”

“…of Ar in the calculation for these ions. The present calculation used a typical CoBIT beam size of S = 0.1 mm 2 [26] and the room temperature of T = 300 K. The collision velocity v was calculated assuming that the kinetic energy of trapped ions predominantly determines the collision energy rather than the temperature of the rare gas. Here, we used half of the confinement potential created by a typical DT voltage of 30 V (i.e.…”

Atomic structure and collision dynamics with highly charged ions

“…[82] Precision spectroscopy of HCIs in EBIT is also applicable to the diagnostic of fusion plasmas and astrophysical plasmas. [83][84][85][86] Since the accurate prediction of the atomic structure in complex systems is still a big challenge for theories, benchmark experiments are essentially required. One such example is tungsten, which will be used in future TOKAMAKs.…”

“…[83] To diagnose the temperature and density of fusion plasmas, [86,88] intensity ratios of EUV lines from highly charged Ar, Fe, and other ions are measured in EBITs. [84,85] It also provides an opportunity to determine the magnetic field in solar flares or the corona as proposed in Ref. [91].…”