Observation and Identification of Extreme Ultraviolet Spectra from Ca-like Nd XLI to Na-like Nd L*

Extreme-ultraviolet spectra of M-shell transitions in highly charged Ca-like Nd⁴⁰⁺ to Na-like Nd⁴⁹⁺ has been measured at the electron beam ion trap (EBIT) facility at the National Institute of Standards and Technology ^[1]. To create the corresponding charge states,  the electron beam energy was varied between 3.60 keV and 12.02 keV. The spectra were observed between 2.67 nm and 17.30 nm using a flat-field grazing incidence spectrometer ^[2]. The spectra calibrations were based on well-known lines from neon, xenon, iron, oxygen, and argon produced in the EBIT. Simulated spectra generated with a detailed collisional-radiative (CR) model ^[3] of the non-Maxwellian EBIT plasma were used to classify the observed lines. Forty-seven spectral lines were identified for the first time. The total uncertainties included contributions from estimated systematic uncertainties, statistical uncertainties from fitting, and calibration uncertainties. The measured Nd spectra and the tabulated spectral lines with the associated line identifications will be presented and discussed.

1. J. D. Gillaspy, Phys. Scr. T71, 99 (1997). 2. B. Blagojevic et al., Rev. Sci. Instrum.76, 083102 (2005). 3. Yu. Ralchenko and Y. Maron, J. Quant. Spectr. Rad. Transfer 71, 609 (2001).