Six scientists at the U.S. Department of Energy's Brookhaven National Laboratory have been named Fellows of the American Physical Society (APS), a professional organization with more than 47,000 members. Election to APS Fellowship is limited to no more than one half of one percent of its membership in a given year, and election for this honor indicates recognition by scientific peers for outstanding contributions to physics.
The 2009 Fellows from Brookhaven are:
James Alessi
“For his many groundbreaking contributions to the development of intense negatively charged hydrogen (H-) beam sources, both unpolarized and spin-polarized, and the development of a high intensity Electron Beam Ion Source for the production of beams of high charge state heavy ions.”
Alessi develops ion sources to generate beams of particles used in various accelerators at Brookhaven, including the world-class nuclear physics accelerator, the Relativistic Heavy Ion Collider (RHIC). At RHIC, physicists from around the world study extremely hot, dense matter that is thought to have existed a few millionths of a second after the Big Bang. A new Electron Beam Ion Source now being commissioned will generate heavy ion beams for both the NASA Space Radiation Laboratory at Brookhaven, where researchers assess the effects of high-energy charged particles on biological systems, materials, and instruments in an effort to understand the potential risks of exposure to space radiation, and RHIC. Alessi also developed high-intensity ion sources, such as that used for the Brookhaven Linac Isotope Producer, which makes short-lived radioisotopes that are used as diagnostic, research and calibration agents in hospitals and research institutions.
Charles Black
“For pioneering contributions to the integration of nanometer-scale polymer self-assembly in the fabrication of high-performance semiconductor microelectronic devices.”
During his career at IBM, Black pioneered the use of self-assembly in nanotechnology to fabricate high-performance semiconductor devices used in microelectronics. Self-assembly is the spontaneous organization of materials into regular patterns. Under controlled conditions, certain materials will self-organize into patterns on the scale of tens of nanometers with dimensions and uniformity unattainable by conventional means. In his current research at Brookhaven’s Center for Functional Nanomaterials (CFN), Black is designing and applying self-assembly approaches to build nanostructured solar cells from low-cost polymer and nanocrystal materials.
G. Lawrence Carr
“For applications of synchrotron and terahertz radiation to condensed-matter systems.”
At Brookhaven’s National Synchrotron Light Source (NSLS), scientists use light that spans a very wide range of energies along the electromagnetic spectrum, from x-rays to microwaves, to study materials as diverse as computer chips and viruses. The spectral range of light between infrared and microwaves is known as terahertz, which describes the light’s frequency. Carr’s research at the NSLS has demonstrated the importance of terahertz frequencies in studying the electronic behavior of materials such as semiconductors and superconductors.
Milind Diwan
“For his contributions to neutrino and kaon physics.”
Diwan studies neutrinos, unusual particles that can pass through anything in their path. Neutrinos have intrigued scientists around the world, including Brookhaven Lab chemist Raymond Davis, Jr., who won the Nobel Prize in Physics in 2002 for detecting neutrinos originating in the sun. In particular, Diwan is trying to determine if neutrinos play a part in the asymmetry of matter and antimatter in the universe, a puzzle that has confounded physicists for decades.
Diwan also studies heavy subatomic particles called kaons at Brookhaven’s Alternating Gradient Synchrotron. Kaons spontaneously break down, or decay, in various ways, some of them occurring as infrequently as one in ten billion particle interactions. If these rare kaon decays occur significantly more often than predicted by the Standard Model, the modern physics theory of elementary particles, then new physics will have been discovered.
Gregory Hall
“For innovative applications of high resolution molecular spectroscopy to photodissociation dynamics, energy transfer and bimolecular reactions.”
Hall works with lasers to understand how molecules collide, exchange energy, react, and break apart. He and his colleagues have developed and applied experimental techniques using very sensitively controlled laser light to measure the flow of energy inside a molecule as it breaks apart. Using this light, he can also measure velocities of molecules, the orientation of rotating molecules, and molecular collisions that lead to chemical reactions or energy transfer between molecules. This information provides a basis for testing theories used in computer models of combustion, which are used, for instance, by combustion engineers to design fuel-efficient and environmentally friendly combustion devices.
Thomas Ullrich
“For his leading contributions to the study of electrons, and hadrons containing charm and bottom quarks in relativistic heavy ion collisions.”
Measurements from RHIC experiments have revealed compelling evidence for a new state of nuclear matter created at the extremely high densities and temperatures achieved in heavy ion collisions. This type of matter is believed to have existed just microseconds after the Big Bang. By studying electrons and charm and bottom quarks produced at RHIC, Ullrich has found intriguing hints about the properties of the dense matter created in these collisions.