The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Opportunities in High Magnetic Field Science
(See Appendix A for a list of Nobel prizes awarded for research that used or significantly affected the development of high magnetic fields.) There is every reason to believe that it will continue to be so, especially if the field strengths of the magnets available to the scientific community continue to increase. In this connection, it is important to note that charged particles move in circular orbits in a magnetic field, the radius of which shrinks as the magnetic field strength increases. Similarly, the smallest size resolved by magnetic moment or spin probes shrinks with increasing field strength. Thus the need to study and characterize ever smaller objects, both those that exist in nature and those fabricated artificially, will not be satisfied unless magnets are fabricated that deliver fields of ever increasing strength and instrumentation is developed that supports their effective use.
Paralleling the distinction made above, this chapter is divided into three sections. It begins with a discussion of high magnetic field research in condensed-matter and materials physics that emphasizes new phenomena that are likely to be revealed and known phenomena that would be better understood if higher fields were available. The chapter continues with a discussion of the impact of high-field magnets on the disciplines of biology, chemistry, biochemistry, and physiology as a result of their use in instruments that exploit nuclear magnetic resonance (NMR). In particular, the committee highlights the impact high magnetic fields have had, and continue to have, on the study of the solution structures of biological macromolecules by NMR, on solid-state NMR of biological and inorganic materials, and on electron paramagnetic resonance (EPR) of metal centers in proteins and catalysts. The committee discusses the impact high magnetic fields have had on two forms of magnetic resonance spectroscopy that have developed since the Richardson report—namely, magnetic resonance imaging (MRI) and ion cyclotron resonance (ICR) mass spectroscopy. In all these areas, magnets that operate at higher fields than those available today would yield large scientific dividends.
CONDENSED-MATTER AND MATERIALS PHYSICS
High-field research in materials science is intrinsically multidisciplinary, merging ideas from physics, chemistry, biology, and engineering, and integrating both theory and experiment. It is pursued predominantly by condensed-matter physicists, the largest subfield within physics today. Materials science, the dominant activity at the world’s high magnetic field laboratories, utilizes techniques as diverse as thermal and electrical transport, thermodynamic characterization, magnetization, optical spectroscopy, and magnetic resonance. Many classes of materials are
Report of NSF Panel on Large Magnetic Fields, Arlington, Va., National Science Foundation, 1988 (also known as the Richardson report).