HYBRID Thursday, July 28, 2022 3:45 – 4:45 pm (MT) Rosen Auditorium 53-0001-B105 Speaker: Dr. Marylesa Howard Scientist Nevada National Security Site “Diagnostics in the Fast Lane: History of Photonic Doppler Velocimetry” Abstract: The U.S. Stockpile Stewardship Program combines experiment data with physics and computer modeling in the assessment and certification of the nuclear weapons stockpile, in the absence of nuclear testing. Subcritical experiments (SCE) use chemical high explosives to generate pressures, applied to nuclear materials, but in such configurations and quantities that no self-sustaining nuclear fission chain occurs. A common way to assess the dynamic behavior of an SCE is to field diagnostics, such as high-speed imaging or radiography, to capture an instantaneous view of what is happening, but these diagnostics lack a temporally-dense dataset. Over the recent decades, advancements in technology have led to the development of optical laser diagnostics that temporally assess behavior at a single point in space. Photonic Doppler velocimetry (PDV) is used to estimate the velocity of a moving surface via Doppler-shifted laser light and commercial off the shelf components to drive down cost and increase accessibility. In this presentation, we will cover the history and development of velocimetry diagnostics, including generational improvements for PDV, applications, and the complimentary diagnostic: broadband laser ranging. Bio: Dr. Marylesa Howard received her PhD in mathematics from The University of Montana and joined the Nevada National Security Site (NNSS) as a scientist in 2013. She was recently recognized as the only Nevada recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE) for her demonstrated research and leadership. She is an influential leader among scientists in Nevada, at the U.S. National Laboratories, and at universities across the country. She leads a team of scientists in data analysis for physics applications and spends time working in underground facilities. Dr. Howard is a champion for women in science, helping to direct graduate research and guide the careers of women around the country. She also works with universities to bring real-world scientific problems to students nationwide.