Double Cone-in-Shell Design Viable Candidate for Opacity Experiments
By Anirudh Sharma
From the time I picked up Basher Science’s Physics: Why Matter Matters! in third grade, understanding how the most fundamental physical processes create the reality of our universe has wholly fascinated me. The ability to mathematically and scientifically explain why something happens, from a single subatomic interaction to the inescapable pull of a black hole, is what drew me to the field of physics. My exploration took the form of documentaries, MinutePhysics videos on YouTube, books, and, when I entered high school, classes that allowed me to develop my understanding of the field in a more comprehensive way. When I was accepted to a summer research program for high schoolers at the Laboratory for Laser Energetics, I was excited to finally apply my learning experiences toward real-world scientific inquiry and solving novel problems … The Laboratory for Laser Energetics (LLE) at the University of Rochester is dedicated to the study of high-energy-density physics. During the eight weeks I spent there, I worked with a senior scientist at the lab, Dr. Stephen Craxton, and was given a project to pursue. Initially, my project was centered on using 2D hydrodynamics computer simulations to optimize a cone-in-shell target intended for backlighting opacity experiments at the National Ignition Facility. The double cone-in-shell target was first proposed by Dr. Robert Heeter of Lawrence Livermore National Laboratory (LLNL) in order to achieve a short-pulse, point source x-ray signal, which was ideal for backlighting the opacity samples that scientists at LLNL were investigating. Eventually, my work expanded to developing an x-ray diagnostic code that could predict emission histories for the various targets I had simulated. By the end of the program, I had developed an optimized design for a double cone-in-shell x-ray backlighter through analysis of both simulation output data and calculations performed by the program I had written. Through the course of my time at LLE, I found myself not only applying what I had learned in my calculus, physics, and computer science classes, but also discovering new concepts that enabled me to achieve the goal of my project. For example, my advisor assigned me a variety of reading materials at the start of the program, including former high school students’ project reports as well as published papers. I also had to become familiar with the mathematical model - the radiation transfer equation - that would be central to my x-ray diagnostic program. My prior coursework in calculus allowed me to better understand the equations and derivations relevant to my project. I also had to learn Fortran as that was the programming language I developed my code in. I found these learning experiences to be enriching and exciting, as I was implementing my new knowledge to address a real and relevant problem in the field of physics…