The absorption and resonance Raman spectra of yttrium dimers (Y2) in argon matrices are measured for the first time. The absorption spectrum (scattering depletion spectrum SDS) shows a weak, broad transition centered near 485 nm. Resonance Raman spectra obtained by exciting into this absorption band with several visible laser lines (465.5–496.5 nm) give a single, sharp progression with up to ten Stokes transitions. These data give ωe=184.4(4) cm−1, with ωexe=0.30(3) cm−1, leading to a spectroscopic dissociation energy of De=3.5(4) eV. Comparison of our results with several ab initio calculations adds confirmation to the assignment of the ground state of Y2 to be the Σg+1 state.

Worldwide interest in the use of accelerated radioactive ion beams (RIBs) for exploring reactions important in understanding the structure of the nucleus and nuclear astrophysical phenomena has motivated the construction of facilities dedicated to their production and acceleration. Many facilities utilize the Isotope-Separator-On-Line (ISOL) method in which species of interest are generated within a solid or liquid target matrix. Experimentally useful RIBs are often difficult to generate by this technique because of the times required for diffusion from the interior of the target material, and to effusively transport the species of interest to the ion source following diffusion release in relation to its lifetime. Therefore, these delay times must be minimized. We have developed an experimental method that can be used to determine effusive-flow times of arbitrary geometry target/vapor transport systems. The technique utilizes a fast valve to measure effusive-flow times as short as 0.1 ms for any chemically active or inactive species through any target system, independent of size, geometry and materials of construction. In this report, we describe the effusive-flow experimental arrangement and provide time spectra for noble gases through prototype RIB target/vapor-transport systems.