Laser resonance ionization mass spectroscopy of radioactive isotopes

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The program in "Laser resonance ionization mass spectrometry of radioactive isotopes" seeks to investigate trends in the optical isotope shifts in isotopes of At, Ra, Ac, and the actinide elements many of which have not been measured before. Laser resonance ionization has emerged as a highly sensitive and selective method in trace detection, which also allows to probe nuclear structure of ground state and long lived isomeric states of atomic nuclei. In combination with radioactive ion beam facilities that give access to a great number of isotopes of particular elements, this technique can be used to map the evolution of nuclear structure from stability out to the drip lines. The nuclear information is accessed via laser spectroscopy of the atomic electrons that probe the nucleus. This interaction is a sensitive, non-destructive probe that allows to extract subtle nuclear effects in a largely model independent way. The particular nuclear properties measureable are: nuclear spin, magnetic dipole and electric quadrupole moments and changes in the root mean square charge radii among isotopes of a specific element in a nuclear chain. In some cases higher order effects such as magnetic octupole moments can be extracted as well. The results of this work impact areas of nuclear physics from nuclear structure to fundamental symmetry tests within the actinides. The development portion of laser resonance ionization mass spectrometry program advances technology and develops techniques to make isotopes of the actinide elements more accessible both in intensity as well as purity for subsequent high resolution studies by nuclear structure and high resolution laser spectroscopy. The focus for the coming years is to refine an “ion-guide laser ion source” and to capitalize on the time structure of our resonance ionization technique with pulsed laser sources. This will allow for the systematic investigation of isotope chains in astatine, radium and the actinides.The funds requested are to cover the stipend of up to 2 graduate students (1 Ph.D. and 1 M.Sc.) as well as the required buyout of their teaching at their home institutions. In addition travel cost associated with both conference attendance and collaboration meetings are included. Within Canada this is a collaboration between the University of Manitoba and TRIUMF. On an international scale there exists a strong collaboration with the University of Mainz, the University Oldenburg, University of Applied Sciences Emden/Leer, KU Leuven on the University side, and CERN-ISOLDE (Switzerland), GANIL (France) and JYFL (Finnland) which includes frequent exchange of students and collaborative developments.