Optical pumping of ions in buffer gases

Abstract

A method for polarizing thermal ions in buffer gases directly by optical pumping is presented in detail. The production and storage of Sr + (and Ba +) ions in noble gases, their diffusion and relevant collision processes are discussed. An arc discharge hollow cathode for the generation of intense ionic resonance lines is described. The Sr + (5 2St~ z) and electron spin polarizations are treated by rate equations. Fitting the solutions to experimental data obtained from transient signals yields an estimate of a few times 103A 2 for the Sr+ion -electron spin exchange cross section.

Collisional relaxation of ionic2 P 3/2 excited states in rare gases

“…This can be explained by the experimentally observed intensity ratio I(D2)/I(DA)=0.45 to 0.7 (theoretical from the oscillator strengths 1.5) and by the correspondingly smaller absorptions for the/)2 line which are both probably due to an increased self reversal of the arc hollow cathode light source. For the Yb metal having a higher vapour pressure than Ba or Sr the cathode crucible is more massive than that described in [16] and has an additional hole in the bottom containing the liquid Yb metal. Two modes of the arc are observed, one of which emanates from the hole and gives higher D2 to D1 intensity and absorption ratios and also higher intensity to noise ratios whereas the total intensity is smaller than for the arc mode filling the whole crucible.…”

“…The apparatus and the method used to observe the D 2 pumping signals as a function of the buffer gas pressure has been described elsewhere in detail [5,16]. Only the principle of the measurements and some modifications will be treated here.…”

Pulsed UV laser spectroscopy of thermal Eu2+ ions

“…The ion restraining mechanism of gases, in principle known from a production technique for singly charged ions in buffer gases [8,9], has been extended in the present work for the first time to doubly charged ions. The ionization device described here provides free Eu 2+ ions with a density of 107-108/cm 3, a number which is sufficient for spectroscopic purposes.…”

Hyperfine structure measurement of the9Be+ 22 s 1/2 ground state by optical pumping

“…The principles of the experimental set-up have been described previously [ 1,4]. Optical pumping with both D-lines (21=313.2nm and ~.2=313.13nm, o -+ or apolarized) is used to produce a Zeeman and hyperfine polarization in the 2S1/2 ground state of 9Be+ ions.…”

“…Optical pumping of alkali-like ions [1] offers the possibility to measure ionic ground state hyperfine structures (hfs) with an accuracy comparable with those obtained in the case of the neutral alkalis [2]. First examples were the ions 135Ba--and 137Ba+.…”