Laser-induced isotopic effects in titanium resonance ionization
Abstract
Titanium isotope ratios have been measured by resonance ionization mass spectrometry (RIMS) with special emphasis on the nature of laser-induced isotopic selectivity. A pronounced wavelength dependence of even mass isotope ratios is caused by large nuclear volume effects near the magic neutron number 28 in ^(50)Ti . Optical isotope shifts, ranging from 0.07 to 0.21 cm^(-l), between ^(50)Ti and ^(46)Ti were measured for several transitions. The ^(50)Ti/^(46)Ti and ^(48)Ti/^(46)Ti ratios, nevertheless, exhibited only mass-dependent fractionation, in which the lighter Ti isotopes were enriched by ~2.5%/amu, when the laser operating parameters were properly controlled. Odd-even mass isotopic selectivity in the resonant ionization process was also examined for several transitions as a function of the laser polarization state and intensity. Under saturating conditions for a ΔJ= +1 transition and a high degree of laser depolarization for a ΔJ = 0 transition, the odd-even isotopic enhancement was reduced below the 2% level. The Ti isotope data agree with our previous results for Os and indicate that, by a careful choice of resonance transitions and laser operating parameters, isotope ratios can be measured accurately and reliably with RIMS.
Additional Information
© 1993 American Chemical Society. Received for review July 6, 1992; accepted February 4, 1993. We thank D. A. Papanastassiou and P. G. Green for assistance in these experiments and M. E. Johnson for manuscript preparation. This work was supported by DOE Grant DE FG03-88ER-13851 (to G.J.W.) and NASA Grant NAGW-1944 (to G.A.B.). The laser system was obtained through support from the David and Lucille Packard and Alfred P. Sloan Foundations (G.A.B.). Division Contribution 5078(749).Attached Files
Published - ac00058a018.pdf
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Additional details
- Eprint ID
- 34201
- Resolver ID
- CaltechAUTHORS:20120919-094950384
- DE FG03-88ER-13851
- Department of Energy (DOE)
- NAGW-1944
- NASA
- David and Lucile Packard Foundation
- Alfred P. Sloan Foundation
- Created
-
2012-09-19Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences
- Other Numbering System Name
- Lunatic Asylum Lab
- Other Numbering System Identifier
- 749