Research projects

Low temperature chemistry with laser cooled ions.

State-to-state reactions represent a frontier in synthesis and are crucial for understanding the mechanism of elementary reactions. Ion traps provide an excellent setup for control of the quantum state of atomic and molecular ions. A number of experiments have been conducted where ion traps were used to control their electronic, vibrational and rotational states (see Tong2012 for one example). The strong confinement of the atomic or molecular ions provides the required localization needed for efficient internal state addressing and final state determination. Ion traps have however been limited to using lasers for driving any required transitions, limiting the rate of processes to the rate of optical transitions. The proposed experiments incorporate a finely tuned electron beam into the vacuum chamber to prepare initial reaction states that may not be easily laser accessible. Other benefits of using ion traps for such experiments include long confinement times within the trap lead to the possibility of long interrogation times. Additionally, well-established non-destructive mass determination techniques exist for species identification of trapped particles.

Atomic properties of highly charged ions

Highly charged ions (HCIs) are atoms in which all or most of the electrons have been stripped off. The remaining few (or one) electrons exist in the presence of the strong electric field generated from the nucleus. For example, in the case of fully stripped Uranium this field is 1016 V cm-1, orders of magnitude stronger than any external field available in a laboratory. These ultra strong fields make HCIs ideal mini laboratories in which to test physical theories in extreme conditions. Specifically, Quantum Electrodynamics (QED) is an extremely powerful and predictive theory describing the interaction of matter and light. However, in the instances where experimental and theoretical results differ there is an opportunity to study non-standard model physics including variations in the fundamental “constants”. Theoretical work suggests that HCIs, with their inherent extreme electric fields, are ideal candidates for probing and investigating these discrepancies. Additionally, while HCIs are rare on Earth, they are commonplace in the universe, in particularly in the high temperature and pressure environments of stars and solar winds. Understanding how to read the photon signature from interactions of HCIs with neutral gases in the universe gives information on the density, temperature and constituents of both. HCIs are also present in the “star-like” environment of fusion plasmas and observed spectra can also be used for diagnostics of these plasmas.