Fast-ion-beam laser-induced-fluorescence measurements of oscillator strengths in doubly ionized lanthanides
Accurate oscillator strength data for singly and doubly ionized lanthanides are needed in astrophysics to study the spectra of Chemically Peculiar (CP) stars, which show large overabundances of lanthanides compared to the Standard Abundance Distribution, and for nucleosynthesis studies. We have previously measured oscillator strengths in Sm II, Nd II, and Pr II using fast-ion-beam laser-induced-fluorescence methods. Our new Penning Ion Source provides us doubly-ionized ion beams to study lifetimes and branching fractions of lanthanide ions, which are actually the more abundant charge species in hot CP stars. A new GaAs photomultiplier tube gives us a greater wavelength range (185-930nm) for the detection of spontaneous emission. A new detector-substitution method of detector calibration will make the experimental accuracy significantly below 10%. Recent results will be presented.
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- June 2007