Inverse Compton Scattering in the Cosmic Microwave Background Radiation (2006-2008)
The Very Energetic Radiation Imaging Telescope Array System, or VERITAS, is a ground based gamma ray observatory array, located near Tucson, Arizona. My project involved studying inverse Compton scattering of very high-energy electrons when they interact with cosmic microwave background radiation (CMBR) and other uniform and non-uniform photon fields, such as those surrounding stars. My work required a detailed analysis using the 4-vector formalism of special relativity, fully relativistic Compton scattering models for photons and electrons, quantum electrodynamics of the Klein-Nishina scattering cross section, elements of cosmology, and solution of relativistic equations of motion of charged particles in electromagnetic fields. The work also involved creating highly accurate computer simulation capable of precision to 30+ digits. To do so required researching and implementing numerical libraries for double-double and quad-double floating point numbers. Such a high degree of accuracy was necessary to correctly simulate relativistic dynamics with gamma factors exceeding 10E9. Finally, the work required optimization for execution on the UCLA Beowulf cluster designated for astrophysics and particle physics computations, and a final analysis of the results using mathematical modeling software. We successfully derived models for the energies and scattering angles of observable photons that we could then detect with the VERITAS array. In addition to my computation and simulation work, I participated in the construction of the VERITAS observatory in Tuscon, assembling optical and electronics systems for two VERITAS telescopes.
T. Arlen, V. Vassiliev, T. Weisgarber, S. Wakeley, and S. Y. Shafi. Intergalactic magnetic fields and gamma ray observations of extreme TeV blazars, preprint on arXiv, 2012.
T. Arlen, V. Vassiliev, S. Y. Shafi, S. Fegan, Propagation of VHE gamma rays in extragalactic media, American Physical Society, 2009 APS April Meeting, May 2-5, 2009.
Cherenkov Telescope Array (2007-2008)
The Cherenkov Telescope Array (CTA), formerly the Advanced Gamma Ray Imaging System (AGIS), is a next generation gamma-ray telescope observatory. It will improve observation capabilities of intra- and extra- galactic sources by a factor of five to ten. It will significantly improve detection and characterization of extra galactic nucleii and supernova remnants, and in addition open binary star systems, cosmic ray interactions with interstellar gas, and dark accelerators to experimental gamma ray observation. My contribution to the project was a study of mirror surfaces for use in the new system. I characterized the quality and geometry of these surfaces, as well as calibration mechanisms for testing the mirrors, using linear and nonlinear optimization techniques.
Cooperation among Autonomous Robots and Occlusion Video Tracking (2007)
The UCLA Institute for Pure and Applied Mathematics Research in Industrial Projects for Students program is an NSF-sponsored applied mathematics research experience for undergraduates, unique in that it introduces teams of students to real projects from industry in an academic setting. My team studied cooperation and coordination of mobile robots under limited sensing capabilities and video tracking of mobile robots in the presence of visual occlusions.
DIII-D Tokamak Java Simulator (2005)
I was involved in a research internship with the Engineering Physics division of the Fusion Group at General Atomics in San Diego, California. At General Atomics, I was responsible for implementing an overhaul to a Java-based Tokamak simulator. I implemented numerical and computational algorithms to increase the accuracy of simulations and to add functionality so that many different configurations of nuclear reactors could be modeled.