RIS Group

Group Leader

Research Interests

  • Laser Resonant Ionization Spectroscopy (RIS): Stepwise, resonant laser excitation and ionization uses the unique spectroscopic fingerprint of atoms for element-selective and even isotope-selective ionization with high selectivity and sensitivity. This makes RIS the ideal tool for elemental ultra trace detection, isotope separation, and the production of high purity rare isotope beams.
  • Resonant Ionization Laser Ion Sources (RILIS): At TRIUMF's Isotope Separator On-Line facility rare isotope beams are produced via spallation, fragmentation, or fission when the 500 MeV proton beam from the main cyclotron impinges on the target material. From the multitude of isotopes only a specific one—as requested by the nuclear or particle physics experiment on-line—will be delivered. RILIS allows one to ionize elements selectively, thus providing isobar-free beams with high purity. An added advantage of operating RILIS at on-line rare isotope facilities is that the complex parts of the ion source are serviceable, since they are far removed from the high radiation of the isotope production area. Current excitation schemes under development are: Ca, Sc, At (as of May 2010).
  • Physics of Rare Isotopes: Optical isotope shift and atomic hyperfine-structure measurements along chains of isotopes of a particular element yield changes in the mean squared charge radii— which in turn reflect nuclear structure. Spectroscopy of halo nuclei and highly charged ions (e.g. hydrogen-like uranium) is another way of studying nuclear matter at its extremes. Laser spectroscopy on Astatine is in preparation.
  • Lasers in Environmental, AMO, and Nuclear Physics: The detection of anthropogenic (man-made) isotopes is important in the context of e.g. geology, environmental sciences, and nuclear non-proliferation. The determination of precise isotope ratios has direct applications e.g. in dating and nuclear astrophysics.
  • Laser Development: High repetition rate titanium sapphire lasers for RIS and associated instrumentation are being developed in-house and in collaboration with Mainz University.

Facilities

  • On-line RILIS for experiments at TRIUMF's ISAC1 and ISAC2 facilities
  • Off-line laser ion source test stand
  • Off-line laser development laboratory
  • 10kHz repitition rate TiSa lasers
  • Frequency multipliers for TiSa lasers
  • High finesse laser wavemeters