0000000000427210
AUTHOR
R. Hohmann
Fast, low-level detection of strontium-90 and strontium-89 in environmental samples by collinear resonance ionization spectroscopy
Environmental assessment in the wake of a nuclear accident requires the rapid determination of the radiotoxic isotopes 89Sr and 90Sr. Useful measurements must be able to detect 108 atoms in the presence of about 1018 atoms of the stable, naturally occurring isotopes. This paper describes a new approach to this problem using resonance ionization spectroscopy in collinear geometry, combined with classical mass separation. After collection and chemical separation, the strontium from a sample is surface-ionized and the ions are accelerated to an energy of about 30 keV. Initially, a magnetic mass separator provides an isotopic selectivity of about 106. The ions are then neutralized by charge exc…
Lifetime measurements of highly excited Rydberg states of strontium I
Lifetimes of Rydberg states of the triplet-series 5s ns3S1 withn = 19–23, 35 and 5s nd3D3 withn = 18–20, 23–28 in the spectrum of neutral strontium have been determined. Observation of the exponential decay after excitation by a pulsed laser in a fast atomic beam and subsequent state-selective field ionization was employed. The lifetimes of the states of the3S1-series show the expectedn*3 dependence on the effective principal quantum number, while the3D3-series is disturbed by configuration mixing. Furthermore, state re-populations induced by black-body radiation have been observed.