Laser Spectroscopic Investigation of the Element Fermium (Z = 100)

Abstract

The level scheme and hyperfine structure of the element fermium (Z = 100) has been investigated with the method of resonance ionization spectroscopy in a buffer gas cell. The experiments were carried out on a 46 pg sample of the isotope 255 Fm with a half-life time of 20.1 h, produced in the high flux nuclear reactor of the ORNL, Oak Ridge, USA. A wave number scan from 27,100 to 28,400 cm j1 was carried through to search for three levels with large Einsteincoefficients, as predicted by ab initio Multi-Configuration-Dirac-Fock (MCDF) calculations, and five new levels were found. In addition, the two known levels at wave numbers (25,099.8 T 0.2) and (25,111.8 T 0.2) cm j1 were studied with a laser band width of 1.5 GHz and hyperfine broadenings were observed.

Prospects for laser spectroscopy, ion chemistry and mobility measurements of superheavy elements in buffer-gas traps

“…11. In a subsequent experiment five more levels were observed in a scan of the wavenumber interval 27,100 ≤ ν ≤ 28,400 cm −1 , see [6]. Based on the accuracy of the ab initio MCDF calculations of ±2400 cm −1 , all five levels are candidates for the three predicted levels with large 5f 12 7s7p admixtures and large Einstein coefficients A ki .…”

“…To avoid power broadening a low pulse energy flux was coupled into the optical cell. The analysis suffered from the many overlapping hyperfine structure components and pumping processes between them, for details see [6].…”

Are MCDF calculations 101% correct in the super-heavy elements range?

“…Correlation energy for the ground state of elements with Z = 102 [67], 103 [68,69], 104 [70], 111 [71], 112 [72], 113 [73], 114 [74,75], 115 [76], 118 [77,78], 122 [79] have been calculated with this approach. The MCDF method was used for evaluating correlation on transition energies and rates for Fm and No, as well as for the element 118 [80,81,41] and 122 [82].…”

Interference Effects in Hyperfine Induced 2s2p3P0,3P2→ 2s21S0Transitions of Be-like Ions

“…Hyperfine spectroscopy is very important tool in study of atomic and nuclear physics, especially which can be used to check fundamental interaction [1,2,3,4,5] such as electromagnetic and electroweak interaction with high accuracy, determine nuclear properties [6,7,8,9,10], develop atomic clock [11,12,13,14,15], and so on. Recently one kind of hyperfine transitions, which is known as hyperfine induced transition or hyperfine quenching, attracts more attention owing to analyzing spectra [16], determining isotopic ratios in stellar and diagnosing low-density plasma [17,18] besides those reasons mentioned above.…”