Rufus H. Ritchie: Some biographical strokes
1992/07/01 Etxenike, Pedro Migel Iturria: Elhuyar aldizkaria
This degree taught by our University, the University of the Basque Country/Euskal Herriko Unibertsitatea, is the most recognized of the University. This grade cannot be requested, it cannot be searched. This degree is offered only to those people who deserve this honor and who are valued by the University. In this case, it is a man who deserves this honor; Professor Rufus Ritchie is the word that is best pronounced (both as a professor and as a human) and excellence is the word that best describes the collaboration between him and our university, the University of the Basque Country.
Rufus Ritchie is a great scientist and human. He is a man of great value in many fields, especially as a scientist, as a teacher and as a person.
Rufus Haynes Ritchie Curriculum Summary
On the other hand, it should be noted that his works have received a large number of appointments. For example, between 1979 and 88 have received an average of 200 appointments/year. In addition, one of his works was considered Citation Classic in 1985. |
Scientific contributions
Professor Rufus Ritchie's scientific career is long and fruitful, and here it can only be exalted. Dr. Ritchie's headquarters has been the Federal Laboratory of Oak Ridge (ORNL) of the USA.
When Dr. Ritchie started working at ORNL, the collaboration between experimental and theoretical researchers was very courageous. This fits well with Dr. Ritchie, who has a great capacity for communication with experimental. Also to understand and interpret experimental results or to suggest experiments that can be carried out to contrast theories or hypotheses.
Dr. Ritchie has been considered one of the founders of current radiation dosimetry and has developed quantitative methods typical of rapid neutron dosimetry, such as proportional quantifier and detector portal methods, among others. The Ichiban program, developed to determine the radial exposure of the inhabitants of Hiroshima and Nagasaki, was based on these works. S.G. This pioneering work, carried out in collaboration with Dr. Hurst, unveiled new key concepts and became the basis of the design and construction of new tools, of great importance in the consolidation of the basis of current health physics.
In the 1950s Dr. Ritchie began to study the influence of borders on the collective movement of electrons in solids. In 1957 he published in the journal Phyisic Review the new concept of surface plasm. He predicted that his influence would be evident in the energy loss experiments of electrons, and drew formulas indicating the likelihood of surface plasmons due to fast charged particles. About three years later, his predictions are confirmed. Currently, the effects of superficial plasmons have been found in different experimental states.
The emergence of the concept of superficial plasmon has led to the publication of numerous works within solid state physics, using the original concept and theoretical framework devised by Dr. Ritchie.
Dr. Ritchie has made a great contribution to the physics of the effects of plasmons associated with radiation emission. He showed that when electrons touch the limits of solids, radioactive transitions occur and explained the characteristics of the emitted photons. He showed that surface plasmons influence photoemission and establish the dynamic currents of classical image potential.
And other important effects. In the effort to understand how collective surface modes can appear in experiments, Dr. Ritchie developed the theory of light emission in solids bombarded by fast charged particles, reporting the creation of both plasmoi/photon coupling and bremsstrahlung. Dr. Ritchie makes the first derivation of autoenergies from delayed fine foils. This work has significant implications for understanding the surface electromagnetic waves of solids, which are currently being investigated intensively, especially in the integrated optics.
The hydrodynamic theory was the first used for the study of the dispersion of surface plasmation, and also carried out a pioneering work through quantum dielectric theory, by researching the overweight plasmas corresponding to the case of surface specular electroreflection.
Fast ions
The work of precursor doctor Ritchie was also developed in the field of interaction between charged particles and valence electrons in solids. He developed the dielectric formulation of the response of a quantum plasma and analyzed the temporal spatial distribution of the excitation generated by the rapid ions that cross the medium. This theory has recently been extended to the study of the processes of penetration of ions channeled into crystals.
R. D. Together with Dr. Birkhoff he designed and built the new high luminosity and transmission electron spectrometer. This apparatus, with energy range of several orders of magnitude, became very appropriate to measure the spectrum of the braking processes of the electrons of the solids. These are the only measures that have been carried out so far and have been of great importance to know the interaction between charged particles and matter.
Dr. Ritchie also pioneered the development of the theory of electronic strokes generated by passing fast ions through solids. Also in the theory of channeling in solids and in the theory of fast ion groups in solids, inventing subtle concepts and developing the Z13 effect theory of braking force. This work has brought great importance to the usual theories of the penetration phenomena of charged particles.
Taking advantage of a new approach to the problem of the application of energy, Dr. Ritchie developed the extended theory of energy applied in metals by inert ions and extended it together with researchers from the University of the Basque Country.
On the other hand, Dr. Ritchie devised the prediction criterion of the maximum achievable resolution using the electronic transmission microscope for energy loss, and A. Together with Professor Howie he developed the statistical theory of the imaginary part of the optical potential complex of solids. Also the theory of energy losses by electron beams.
Professor Ritchie's work has been of great importance in areas such as the study of the effects of brain surfaces by spectroscopy of energy losses of electrons, the generation of superficial excitations of catalysts and other small particles, the mechanism of implantation and transfer of energy in organic crystals affected by the irradiation of electron beams and the development of appropriate expressions of the inelastic free pathway of dispersion. All this together with one of the major contributions of electron microscopy.
Self-energy
Dr. Ritchie, his former colleague J.R. Together with Professor Manson, he has recently developed a new theoretical expression of the dependence on the position of self-energy of a projectile that moves along its target of several bodies. This result is a direct consequence of Rayleigh-Schrödinger's theory of disturbances and has been used to compute quantum imaging force corrections supported by a charged particle that interacts with a dielectric material.
In addition, it was used to conduct an analysis of the retardant corrections of the interatomic force of Van der Walls, and over half a century the correction of a statement was introduced, which was embodied in a work published in the journal Physical Review Letters in 1985. In the same year 1985, the journal Nature filled a complete page with the contents of this article. In the words of John Madox, editor of the journal Nature:
"The greatest interest in this work lies in the subtlety of calculation. As for the interaction between positron atoms, the deviation from I/R6 should also be characteristic in four atomic units, so it could be measured. A deviation from the London result corresponding to the interaction between positrion and other atoms can also be detected. In the meantime, this calculation recalls the need to continually review the most proven algorithms."
Being so clear and subtle the basic expression of theory, its inclusion in textbooks on quantum mechanics would also be modélica. Recently, Dr. Ritchie has been able to successfully generalize this approach to higher orders of the theory of disturbance. This has allowed him to find the non-linear corrections of the image potential supported by a charged particle that interacts with the surface of condensed matter. Also to find non-linear corrections of the binding energy of the surface plasmon, of the exciting states of electrons type Rydberg on surfaces of solids and of any type of dispersion forces.
Last word
Regarding teaching, we have the prestigious doctor Ritchie. Dr. Ritchie, besides being famous in the usual courses, is known his ability to communicate with colleagues and collaborators.
Rufus Ritchie combines the deep study of the history of scientific culture and the discovery of the foundations, with a strong tendency towards new ideas, in a very particular way. The creativity shown by this intelligent man with admirable maturity makes us, besides being an exceptional physicist in the field of condensed matter, a great communicator and teacher.
Pedro Etxenike gave an interesting lecture in the act of his appointment as Doctor Rufus Ritchie Honoris Causa. Next to him, we transcribe part of what was said there. “Rufus Ritchie has co-authored a pioneering research article explaining stele problems using the concept of self-energy. This article written in Basque was well received by the international scientific community. To this 67 year old berraiton who works with the same originality and splendor that we always thank him for his respect for our language. This anecdote, when the Law of Normalization of the Basque Country turns ten years old, leads me to a personal reflection. In the past we have tried to express the need to expand the studies carried out in Basque and, above all, to achieve a desired quality and level for our language. Over the years we have recommended taking care at the university level. Today, on the basis of an attitude of responsibility, I would like to encourage our political and academic authorities to take the necessary measures to increase the use of our language in teaching. Studies conducted in Basque in many areas can be extended in quality and degree. This would be the way to go so that Lizardi's dream about the Basque language, so dear to Koldo Mitxelena, became a reality. But I am a person with a grazing |
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Elhuyarrek garatutako teknologia
