Soft x-ray spectral analysis of samarium plasmas produced by solid-state laser pulses

Abstract

XUV spectra of 150 ps laser-produced samarium (Sm) plasmas in the 1.8-10 nm wavelength region, where Δn=1, n=4−n=5 and Δn=0, n=4−n=4 transitions dominate the observed emission, were investigated experimentally and theoretically. Ab initio calculations using the flexible atomic code, as well as consideration of isoelectronic trends, are all employed to identify a number of new features in spectra from Sm 16+ to Sm 34+ . The results show that Δn=0, n=4−n=4 emission from highly charged ions merge to form an intense unresolved transition arrays in the 7.5 nm region and Δn=1, n=4−n=5 resonance transitions contribute in the 3-7 nm region of the Sm spectrum. In addition, a number of strong individual lines at shorter wavelengths are seen to arise from Cu-and Zn-like ions and a number of new assignments are made for Zn-like Sm 32+ .

Soft x-ray spectra of cerium laser-produced plasmas

“…This is consistent with the CI calculations for 4d-4f transitions in open 4d ions, as evidenced in table 3 and previous calculations [34]. It is noteworthy that the clear separation of open-4d and open-4f regions of the UTA, evident in figure 1, is not replicated in spectra of heavier rareearth elements, samarium for example [16]. The consistent low level of emission between the two regions of the UTA across the range of power densities observed here leads to the conclusion that plasma absorption does not occur strongly in this region.…”

“…Ionisation stages ranged from Ho 17+ to Ho 36+ , with n = 4-n = 4 and n = 4-n = 5 transitions dominant in the spectra. Lokasani et al [16] performed a study on samarium plasmas, formed with Nd:YAG pulses of 150 ps duration. n = 4-n = 4 and n = 4-n = 5 transitions were again the principal features in the spectrum, with ions observed ranging from Sm 12+ to Sm 31+ .…”

Soft X-Ray Spectroscopy of Rare-Earth Elements in LHD Plasmas

“…Soft X-ray spectra from high Z rare-earth elements have been experimentally studied so far using various light sources such as vacuum sparks [4,10], laser-produced plasmas (LPPs) [11][12][13][14][15][16], magnetically confined fusion (MCF) plasmas [17][18][19][20][21][22][23][24][25], and electron beam ion traps (EBITs) [26][27][28][29]. Systematic observations of the spectra for most lanthanide elements have been performed in earlier studies using high density LPPs under higher opacity conditions [13,14], in which quasicontinuum broadband spectral features with few isolated lines were typically observed as a result of higher opacity.…”

“…Systematic observations of the spectra for most lanthanide elements have been performed in earlier studies using high density LPPs under higher opacity conditions [13,14], in which quasicontinuum broadband spectral features with few isolated lines were typically observed as a result of higher opacity. More recently, soft X-ray spectra of LPPs of several lanthanide elements have been observed using an Nd:YAG laser and an X-ray charge coupled device (CCD) camera, which results in more detailed analyses of the quasicontinuum features and some individual lines [15,16]. Nevertheless, optically thin plasmas would be more suitable for exploring detailed structures of the measured spectra.…”

Identifications of extreme ultraviolet spectra of Br-like to Ni-like neodymium ions using an electron beam ion trap

“…This nature will possibly lead to applications of laser-produced plasmas of lanthanide elements to industrial short-wavelength light sources [1,2]. Recent progress of spectral analyses of soft x-ray emissions from laserproduced lanthanide plasmas have been reported in several papers [3][4][5]. However, experimental data on the spectral line identifications in these isoelectronic sequences are still limited to a few elements or ions with simple electron configurations and hence are insufficient for validating atomic theories of various lanthanide elements.…”