Hyperfine structure of Mn II by fast ion beam-laser spectroscopy

Abstract

We report the first measurements of the hyperfine splitting of the fine structure levels 3d 5 4s aSS2 and 3 d s 4p z 5Pl° z, 3 in singly ionised manganese in a collinear fast ion beam-laser experiment. The ions are excited by the intracavity frequency doubled output of a ring dye laser. The observed linewidth is sufficiently narrow to identify all hyperfine components of each fine structure level.

Hyperfine structure constants for singly ionized manganese (Mn ii) using Fourier transform spectroscopy

“…We chose as a starting value the A constant for the 3d 5 ( 6 S)4p z 5 P o 3 level obtained by Holt et al (1999). Their value for this level agrees within the joint uncertainty with the less accurate value obtained by Villemoes et al (1991). From this level we obtained the A constant of the 3d 5 ( 6 S)4s a 5 S 2 level, which in turn was used to verify the z 5 P o 2 and z 7 P o 2 constants of Holt et al (1999).…”

“…Blackwell-Whitehead et al (2005b) derived HFS constants for the ground level 3d 5 ( 6 S)4s a 7 S 3 and upper levels in the 3d 5 ( 6 S)4p z 7 P o J term using Fourier transform (FT) spectroscopy. In this paper, we discuss the previously measured spectra that were used in this work, describe our analysis of the spectra and the derivation of our uncertainties, compare our results with previous measurements by (Holt et al 1999), Villemoes et al (1991), andBlackwell-Whitehead et al (2005b), and present new HFS constants for 47 levels in Mn II. …”

“…Holt, Scholl & Rosner (1999) later expanded on this study by independently measuring the HFS constants of 59 levels, including the 3 levels in the z 5 P o J term measured previously by Villemoes et al (1991). Neither of these studies measured the HFS of the ground level in Mn II.…”

“…Previous work on the HFS of Mn II began with Villemoes et al (1991) who used laser spectroscopy to measure HFS constants for the three levels of the 3d 5 ( 6 S)4p z 5 P o J term and 3d 5 ( 6 S)4s a 5 S 2 . Holt, Scholl & Rosner (1999) later expanded on this study by independently measuring the HFS constants of 59 levels, including the 3 levels in the z 5 P o J term measured previously by Villemoes et al (1991).…”

“…The resulting synthetic spectra are a poor fit to the observed stellar spectrum. Hyperfine structure constants are also needed to obtain a more accurate value for the wavelength of a transition, particularly for close-lying levels where it may be difficult to distinguish between HFS and fine-structure components in the observed spectral lines, and second-order hyperfine mixing may be of importance.Previous work on the HFS of Mn II began with Villemoes et al (1991) who used laser spectroscopy to measure HFS constants for the three levels of the 3d 5 ( 6 S)4p z 5 P o J term and 3d 5 ( 6 S)4s a 5 S 2 . Holt, Scholl & Rosner (1999) later expanded on this study by independently measuring the HFS constants of 59 levels, including the 3 levels in the z 5 P o J term measured previously by Villemoes et al (1991).…”