O’Shea, Patrick G.
Vice President for Research, Professor, Senior Research Officer
ECE, IREAP, Physics, Maryland NanoCenter
A. James Clark School of Engineering
My energy research program funded by the Department of Energy is focused on Inertial Confinement Fusion using heavy ion beams as drivers. The international Heavy-Ion Fusion (HIF) program has the long-term goal of developing fusion energy as a cost-effective and environmentally attractive source of electric power. The technology for HIF involves heating a fusion plasma to ignition temperatures using high energy heavy ions as the driver (e.g. 4 GeV cesium ions). We believe that HIF will ultimately be more cost effective than other fusion approaches.
One of the main engineering challenges for HIF is in developing ion beams of sufficient current and quality to effectively ignite the fusion target. The performance of HIF systems will depend critically on the quality of the driver beams. The need for high quality beams extends to many other applications in high-energy and nuclear physics, materials science nanotechnology and biomedicine (e.g., spallation neutron sources and x-ray free-electron lasers). As we strive to produce evermore intense beams, nonlinear dynamics play an increasingly important role in the evolution of particle distributions and resultant beam quality. At very low intensity, the beam distribution is largely determined by the external accelerating and focusing forces and is independent of the details of the particle distribution. At very high intensity, however, the self-electromagnetic fields of the beam play a dominant role in beam evolution, and these self fields are very much dependent on the particle distribution. My group has developed the University of Maryland Electron Ring (UMER), as a small-scale (4-m diameter) electron model of an intense ions beam system. Even though it operates at only 10 kilovolts, UMER is capable of reaching beam intensities far beyond those of other accelerators. UMER is ideally suited for student projects. UMER’s electron current of 100 milliamps is exceedingly large for such a low energy. When scaled to energies and parameters comparable to higher energy accelerators, the UMER beam possesses orders of magnitude more space charge than other existing machines. The beam in UMER is truly and extreme beam. UMER’s beam intensity, and quality of its beam diagnostics and simulation support place our lab at the forefront of exploring space charge dynamics of intense beams.
I am also very interested in energy policy.