David Morrissey
University Distinguished Professor (NSCL) Office: N105 NSCL
Phone: 517-355-9672 321 /
Websites: Research Group - Area
Awards & Honors
Genealogy/Graduates
Nuclear Chemistry
(Research Description PDF - 1383 kb)My research lies in the realm of nuclear chemistry and centers on studies of the production and use of the most exotic, short-lived nuclei created in nuclear reactions. We have applied this knowledge to produce beams of very exotic radioactive ions. These nuclei are interesting in their own right, some of which have not been observed before. The experiments are carried out at the National Superconducting Cyclotron Laboratory (NSCL), next door to the Chemistry Building. My graduate students have worked on unraveling the mechanisms of nuclear reactions and on studying the decay properties of exotic nuclei. The NSCL is a unique facility that brings together a strong group of nuclear scientists and provides an exceptional setting for studying the properties of nuclei. The cyclotrons accelerate ions that span the periodic table and have very high kinetic energies. When the fast ions react with a target nucleus, the incident ion is often broken into pieces with a distribution of sizes, many of which are unstable and quite unusual. The probability distributions of the products were early subjects of study by my group and can be predicted with reasonable accuracy. The momenta, or velocities, of the fragments were shown to be distributed around that of the beam and to be predicted by models of the nuclear reaction. These fast moving fragments can be passed through an isotope separator to produce beams of individual radioactive ions. The A1200 fragment separator at the NSCL was the central instrument for research at the NSCL and provided intense beams of unstable ions to study nuclear reactions and decay properties. This separator has been replaced in 2001 by a larger and more efficient device called the A1900 as part of the upgrade of the NSCL facility that brings new possibilities for studying the most exotic, short-lived nuclei. Along with using the new fragment separator, our group has completed the construction and development of an auxiliary device to deliver the exotic reaction products at thermal energies. In this project, we have extended the ion-guide ion-source (IGISOL) technique developed primarily in Europe and Japan and recently by another group at Argonne National Lab to collect individual ions. The new device is tailored to stop and collect the exotic isotopes produced by the A1900 fragment separator at the NSCL using a differentially pumped gas cell in a process related to atmospheric sampling mass spectrometry. The so-called gas-catcher system has begun operation and a number of successful extremely precise mass measurements has been carried out by the group headed by Prof. Bollen (MSU Physics Dept.).
Selected Publications
Discovery of a Nuclear Isomer in 65Fe with Penning Trap Mass Spectrometry, M. Block, et al., Phys. Rev. Lett. 2008, 100 132501.Structure of 23F via Beta Decay of 23O, C. Sumithrarachchi, D.J. Morrissey, et al., Phys. Rev. C 2007, 75, 024305.
Discovery of Exotic Isotopes 40Mg and 42Al Suggests Neutron Drip Line Slant Toward Heavier Nuclei, T. Baumann, et al., Nature 2007, 449, 1022.
Precision Mass Measurements of Rare Isotopes Near N=Z=33 Produced by Fast Beam Fragmentation, P. Schury, et al., Phys. Rev. C 2007, 75, 055801.
Modern Nuclear Chemistry, W. Loveland, D.J. Morrissey and G.T. Seaborg (Wiley Interscience, 2006).
Radioactive Nuclear Beam Facilities Based on Projectile Fragmentation, D. J. Morrissey, and B. M. Sherrill, Proc. Royal Soc. A, 356, 1985 (1998), and Lecture Notes on Physics 2004, 651, 113.
