[Article] Historical Background to one of the Most Cited and Influential Papers in Physics: Ugo Fano on Configuration Interaction, 1961

Abstract

In the December 15, 1961 issue of Physical Review Ugo Fano, then at the National Bureau of Standards in Washington, D.C., published a paper entitled, “Effects of configuration interaction on intensities and phase shifts." (Fano, 1961) That paper has become one of the most cited papers in American physics. The impetus for the paper was an experimental result, in 1954, by Silverman on an unusual behavior of the continuum of helium in the neighborhood of a discrete peak, under electron impact, reported in a Scientific Report by Silverman and Lassettre in 1957 under an Air Force grant, reported at a conference in 1958, and finally published in the open literature in 1964. The 1957 Report had been brought to Fano's attention by Robert Platzman, a friend and colleague (Fano, 1977, and Fano, personal communication). Fano recognized the shape of the electron impact spectrum as similar to the qualitative characteristics of optical spectra of some of the rare gases (but not including helium) reported in 1935 by Beutler. Fano, in his first post-doctoral paper, published in Il Nuovo Cimento (1935) had outlined a theory to describe these characteristics. Until the measurement of Silverman there had been no measurement, either optical or by electron impact, sufficiently well resolved or defined to serve as a quantitative test of theory. Fano updated his 1935 paper in a paper in 1961, using the Silverman and Lassettre experimental results as a test of his theory. Fano's 1961 paper has become one of the most cited papers in American physics.