Atomic and Molecular Phyiscs
Participating Faculty: Stephen Cramer, Richard Freeman, William McCurdy, Ann Orel
The study of atomic and molecular physics includes the examination of basic building blocks of matter, their interaction with each other, and their interaction with light. Fields of research within this study utilize disciplines from Biology to Astrophysics. Examples within the department include
Interaction of Intense Laser Fields with Atoms and Molecules: Development of extremely intense lasers has created a new realm of physics. These powerful tools have an electric field of comparable intensity to forces binding electrons to the nucleus. As a result, professors can study new phenomena ranging from high-order harmonic generation in the interaction of lasers with atoms to the wide range of effects that occur when a laser with power greater than 1020 watts/cm2 transfers its energy into an over dense target. The complexities that occur must be understood if we are ever to achieve the goal of fusion power plants. Work in this area is being carried out on the UC Davis campus, and at Lawrence Berkeley and Lawrence Livermore National Laboratories.
Photoionization: The Advanced Light Source at Lawrence Berkeley National Lab delivers an intense source of light at a well-defined wavelength with extremely high resolution. This enables researchers to study previously unobservable phenomena. For example, researchers are now able to study the changes in spin-state that occur in a organometallic compound when molecules bind to its active site, such as what occurs when oxygen binds to hemoglobin.
Electron-Molecule Scattering: Electron collisions with molecules and molecular ions play a key role in a number of environments, since they produce the radicals and molecular fragments that initiate and drive the relevant chemistries. Such systems can be found in biology, chemistry, and physics; and include plasma-enhanced chemical vapor deposition, planetary atmospheres and interstellar clouds, and environmental chemistries driven by secondary electron cascades in mixed radioactive waste. For example, damage to DNA, once thought to be caused directly by the ionizing radiation, is now believed to be due to secondary electrons. These secondary electrons either attach directly to the DNA and cause the bonds to break, or attach to water molecules, which then fragment. These fragments can then cause damage to the DNA. Faculty and students involved in electron-molecule research utilize equipment and superconductors at the Lawrence Livermore and Lawrence Berkeley National Laboratories.