UNIVERSITY OF MARYLAND AT COLLEGE PARK|
The University of Maryland Department of Chemistry and Biochemistry offers a broad program in Nuclear and Environmental chemistry. The groups typically include a total of about three research associates and 12 graduate students, with 4-6 studying fundamental nuclear chemistry and 6-8 studying environmental chemistry. On-campus laboratories include a fully computerized counting room with a host of interconnected PC's, Macintoshes, and DEC devices. Extensive field sampling and sample handling facilities are also available including a class 100 clean room.
Professor William B. Walters research interests are in the study of nuclear decay and structure. Work is currently under way at three national facilities, the recoil Fragment Mass Analyzer (FMA) at the ATLAS heavy-ion accelerator at Argonne, the UNISOR on-line mass separator at the new Radioactive Ion Beam facility at the Holifield Heavy-Ion Accelerator at Oak Ridge, the TRISTAN on-line mass separator at Brookhaven. During the next several years work at the FMA will be focused on the study of new neutron deficient nucleides that decay by beta, alpha, proton, and delayed proton emission, as well as spontaneous fission. In 1995, we expect to initiate experiments with the new radioactive beams in Oak Ridge. New nuclides even further from stability along the N = Z line should be accessible with these beams and the RMS.
Understanding the mechanisms through which heavy nuclei interact is the primary goal of Professor Alice C. Mignerey's research. An experimental program in intermediate energy heavy-ion reactions is now being conducted at the National Superconducting Cyclotron at Michigan State University, with beams of 40-80 MeV/nucleon xenon. The goal of these experiments is to reconstruct the fragmentation or break-up of hot nuclei over a wide range of excitation energies and impact parameters, from grazing collisions to more central collisions. The approval of the construction of the Realitivistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has provided an exciting focus for heavy-ion reaction studies in the coming decade. Dr. Mignerey is currently a member of the PHOBOS collaboration to design and build one of the detectors for future RHIC experiments. Dr. Mignerey is also interested in the development of applications of Accelerator Mass Spectrometry (AMS) to problems of environmental interest. The use of the 36 Cl bomb pulse to monitor recent recharge rates and ground water flows from landfill sites over the past 30 years is also being investigated, as is the potential of using 14C in the dissolved organic carbon (DOC) fraction of ground waters for dating purposes.
Professor George Helz, in addition to his collaboration with Professor Mignerey on the AMS work, has strong interests in the chemical behavior of contaminants in the aquatic environment. The distribution of the long- lived trace radioactivities 210Pb and 10Be has been used to study sedimentation rates in the Chesapeake Bay. In turn, these studies lead to knowledge of the spread of toxic materials. Other studies are aimed at reactions involving organic materials in the esturine environment, and the removal of chlorine produced oxidants from wastewater effluents.
Professor John M. Ondov is using sensitive nuclear analytical techniques to chemically characterize highly size-fractionated samples of atmospheric particulate matter. The resolution of fine structure in the distributions of chemical components in the submicrometer particle size range can lead to improved techniques for resolving the sources of atmospheric pollutants both on the regional and global scale and provide information on atmospheric processes. Samples from the Deep Creek Lake area of Maryland are currently being analyzed in an attempt to discriminate between local and distant sources of aerosols bearing acid substances.
For additional information, please write to Prof. W. B. Walters at:
Department of Chemistry and Biochemistry
University of Maryland
College Park, MD 20742