Ugo Fano

Abstract

Atomic physics has lost in Ugo Fano one of its dominant players during a good part of the 20th century. He has also steadily contributed to this journal during its entire existence as a ‘Correspondent’. One of us (HHS) was occupied for a number of years with experiments on the ‘Fano Effect’ as applied to the intensity ratio anomalies in alkali principal series. This is related to his work on production of polarized electrons by photoionization with polarized light or with polarized atoms. Another (FJdH), together with coworkers at the FOM Institute for Atomic and Molecular Physics, is indebted to Ugo Fano for his stimulation of and his continuous interest in the experiments on total and multiple ionization of noble gas atoms by electron impact. He pointed out to us the relation with photoabsorption by these atoms and the corresponding oscillator strength in the continuum according to the Bethe-Born theory. In addition, the Fano–Lichten theory, describing the promotion of electrons in quasi-molecules formed in keV heavy ion–atom collisions, has been used by us to explain inner-shell ionization and resulting x-rays.It is important to document the work and lives of eminent physicists who have made seminal contributions to atomic, molecular, and optical physics. This was done recently with the special issue of Comments on Atomic and Molecular Physics on the `Casimir Effect'. We are grateful to Mitio Inokuti and A R P Rau, long-time collaborators of Ugo Fano, for the overview of his life's work, his biography and publications.