Conference on Computational Physics 2024

Igor Bray

Biographical Information:

Igor Bray obtained his PhD in the Department of Mathematical Physics at the University of Adelaide, South Australia, in 1986, entitled “Gravitational Lens effect of Galaxies and Black Holes”. In it he predicted an image of a rotating Black Hole when acting as a gravitational lens. However, as there was no interest in such ideas at the time, he switched to the field of Atomic and Molecular Collision Theory pursued at Flinders University, also in Adelaide. During this time he codeveloped the CCC theory, which is uniquely valid at all projectile energies and for all collision processes, including fully differential (single) ionisation. Currently, he is at Curtin University in Perth, Western Australia, where he is the Head of the Department of Physics and Astronomy. He is a Fellow of the Australian Academy of Science, American Physical Society and the Institute of Physics. In 2022 he was elected to the Western Australian Science Hall of Fame.


Calculation of Atomic and Molecular Collisions

Collisions on the atomic scale are governed by the ubiquitous long-ranged Coulomb interaction. Accordingly, such collisions could not be universally mathematically formulated as in the case of ionising ones the interactions between residual charged particles extended out to infinite distances. Curiously, this problem was solved computationally first, with the correct mathematical formulation following some ten years later! We shall discuss this unusual journey in the development of the Convergent Close-Coupling (CCC) theory for calculating collisions involving (anti)electrons, (anti)protons and photons with atoms and molecules. The computational implementation is based on the hybrid MPI/Openmp parallelism with GPU acceleration.