Robert Damburg, one of the pioneers in development of modern theoretical methods in the field of electron-atom collisions and the Stark effect, died on May 7, 2010 in Riga, Latvia.
Robert was born in Leningrad (St. Petersburg), Russia, on April 4, 1930. Soon after the Robert's birth his family moved to the city of Gorky (Nizhniy Novgorod) where Robert's father worked at the construction of the Gorky auto plant and where Robert grew up. In 1946 the family moved back to Latvia, the homeland of Robert's parents. They settled down in Riga where Robert graduated from high school in 1947 and got his BS degree in physics in 1953 from the Latvian University.
Most of his professional career (1953-1993) Robert spent in the Institute of Physics of the Latvian Academy of Sciences where he also got his Candidate of Science (Ph.D.) degree in 1963, followed by the Doctor of Science degree in 1974 awarded by the Leningrad (St. Petersburg) State University. From 1968 to 1993 he was the head of the theoretical physics group at the Institute. In 1993 the whole group was transferred to the Institute of Atomic Physics and Specroscopy of the Latvian University where Robert got a position of professor of theoretical physics.
In the beginning of the 60s, although thirty years had already passed after creation of quantum mechanics, there were no reliable methods for calculations of electron-atom collision cross sections. Robert Damburg and his colleagues at the Institute of Physics, Raymond Peterkop, Modris Gailitis and Erna Karule, were one of the first to develop close-coupling method and its modification, the pseudostate method, which are very widely used nowadays in calculations of electron-atom and electron-molecule collisions. Robert and his colleagues worked in parallel and independently of the Phil Burke's group at Queen's University, Belfast, and the first resultson close-coupling calculations for electron-hydrogen collisions were published almost simultaneously by both groups.
Perhaps the most famous result obtained by Robert, together with Modris Gailitis, was the prediction of the threshold behavior of cross sections for electron-hydrogen collisions. Because of the degeneracy of excited states with different values of the orbital angular momentum, the hydrogen atom in an excited state behaves as a system with a permanent dipole moment. This makes the excitation cross section finite at the threshold and leads to the famous Gailitis-Damburg oscillations in near-threshold cross sections.
In 1967-68, Robert became a pioneer in Soviet-US scientific cooperation when he became the first scientist from the Soviet Union to be appointed Visiting Fellow at JILA, University of Colorado, where he collaborated with Sidney Geltman on electron impact excitation of hydrogen atoms.
Later in his professional career Robert worked on high-order perturbation theory and its application to the problems of the LoSurdo-Stark effect in the hydrogen atom, the field-ionization of the hydrogen atom, the "exponentially small" splittings of the hydrogen-molecule-ion energy levels, and double-well and triple-well oscillators. His work in this field got a lot of international recognition and led to a long-term collaboration with Harris Silverstone from Johns Hopkins University. In October 1988, at a NATO Advanced Study Institute on Atoms in Strong Fields on the island of Kos, Greece, Robert's comments generated a huge controversy about the interpretation of experiments on the photoionization of hydrogen atoms in an electric field, which he resolved a few years later by a definitive, discrete-resonance-based calculation of the experimental spectrum with Gabriel Alvarez and Silverstone.
After official retirement, in the last years of his life Robert continued to be actively involved with atomic physics and came back to the basic problems of structure of helium atom. Unfortunately this work remained unfinished.
Robert was a very open person, easy to talk with, which was quite untypical for a person standing in a higher hierarchy in the former Soviet Union. He always had time for his graduate students to answer their questions and discuss their progress. He allowed them to work very independently and never claimed coauthorship if he did not make a substantial contribution to the paper. His straightforward approach to people and physics led to several international collaborations, despite the restrictions of his and their various governments.
