Steven Pieper

Senior Fellow


Steven C. Pieper received his B.S. degree in physics from the University of Rochester in 1965 and his Ph.D. from the University of Illinois, Urbana-Champaign, in 1970.  After a postdoc at Case Western Reserve, he joined Argonne National Laboratory, where he is currently a senior physicist.  He was chief of the Physics Division theory group from 1987 to 1990.

Since his high-school days, Dr. Pieper has been fascinated by large computers.  His doctoral thesis involved calculations of three-body scattering and led to the first successful calculations of polarization in n-d scattering.  With colleagues, he developed the heavy-ion scattering program Ptolemy, which is still in use.  In 1982 he joined Vijay Pandharipande and Robert Wiringa in doing quantum Monte Carlo calculations of drops of liquid helium as warm-up calculations before doing nuclei.  They made variational Monte Carlo calculations of 16O in the early 1990s, and in 1995 he inherited the Green's function Monte Carlo program that Brian Pudliner had developed with Pandharipande and Joseph Carlson.  Dr. Pieper is still adding new physics capabilities to this program and enabling it to efficiently use forefront computers; with Ewing Lusk and Ralph Butler it has just been adapted to computers with more than 30,000 processors.  It was used to develop the Illinois three-nucleon potentials, which currently reproduce nuclear states up to 12C very well.