Shockwave Acceleration of Monoenergetic Protons using a Multi-Terawatt CO2 Laser
May 01, 2012
from 02:00 PM to 04:00 PM
|Where||Maxwell Room (57-124 Engr IV)|
|Add event to calendar||
Advisor: Chan Joshi
Compact and affordable ion accelerators based on laser-produced plasmas have potential applications in many fields of science and medicine. However, the requirement of producing focusable, narrow energy spread, energetic beams has proved to be challenging. Here we demonstrate that laser-driven collisionless shocks can accelerate proton beams to ~20 MeV with extremely narrow energy spreads of about 1% and low emittances. This is achieved by the interaction of an intense laser pulse with a gas jet target using the world’s most powerful CO2 laser system developed at the UCLA Neptune Laboratory where record peak powers of up to 15 TW have been achieved. The laser plasma interaction is probed using interferometry to uncover a unique, dynamically formed plasma profile suitable for the launching of collisionless shock waves and the production of a monoenergetic proton beam. 1D and 2D computer simulations are used to model the experiment as well as understand the basics of shockwave physics such as formation, propagation, and proton acceleration. The simulations show the possibility of producing ~200 MeV protons needed for radiotherapy by using current laser technology. These results open a way for developing a compact and versatile, high repetition rate ion source for medical and other applications.
Dan Haberberger was born and raised in St. Louis, Missouri. At the age of 15, he moved to Texas and three years later attended the University of Texas at Austin. Dan graduated in 2005 with a Bachelors of Science degree in Electrical Engineering. He then moved to Los Angeles where he began studying under Professor Chan Joshi in the Plasma Electronics group at UCLA within the Electrical Engineering Department. Throughout the course of his PhD, he helped develop the world’s most powerful CO2 laser at the Neptune Laboratory and performed a proton acceleration experiment using this laser system. In his (limited) free time, he enjoys BBQ’ing, skiing, woodworking, ceramics, and gardening.