University of Michigan, Ann Arbor
Thursday, June 20, 2019
Laser-plasma accelerators can generate acceleration gradients 1000 times larger than conventional radio-frequency accelerators, achieving electrons with gigaelectronvolt energies over distances of only a few centimeters. Electron oscillations during plasma acceleration can also produce X-ray sources as bright as those from conventional accelerators, but with ultra-short duration inherited from the laser driver. The small source size and low divergence of these
sources make them powerful tools for high-resolution X-ray probing in medicine, engineering and science.
This seminar will discuss the generation of high-energy electron beams and ultrafast radiation sources using picosecond and femtosecond laser pulses. For pulse durations less than the plasma period, the dominant electron acceleration mechanism is Laser Wakefield Acceleration (LWFA). However, for longer pulse durations electrons gain momentum through Direct Laser Acceleration (DLA). LWFA studies conducted using the HERCULES laser system (University of Michigan) and the Gemini laser (Rutherford Appleton Laboratory, UK) explore the generation of mid-infrared radiation in this regime and the high-resolution imaging capabilities of LWFA X-ray sources. Experiments on the OMEGA EP laser facility (Lab for Laser Energetics) demonstrate acceleration of electrons up to a record 600 MeV via DLA using a high-energy, picosecond pulse at an optimal plasma density.
Amina Hussein defended her PhD in Applied Physics as a member Gérard Mourou Center for Ultrafast Optical Science at the University of Michigan. She received a B.Sc. Hons. in Physics from McGill University in 2013 and a M.S. in Nuclear Engineering from Purdue University in 2015. Amina’s expertise includes the generation and application of novel electron and radiation sources through laser-plasma interaction, laser-wakefield acceleration, and direct laser acceleration. She has also worked in Performance Engineering at the Argonne Leadership Computing Facility. Amina’s research has been supported by the National Science and Engineering Research Council of Canada, SPIE, IEEE and the Michigan Institute for Plasma Science and Engineering. She is the recipient of the 2018 University of Michigan Marian Sarah Parker Prize for academic excellence, leadership qualities and contributions to her community. Amina was awarded the 2019 University of California President’s Postdoctoral Fellowship to develop a platform for timeresolved X-ray measurements of material under extreme conditions.
Christopher P. J. Barty