UC San Diego
Optimization of Rastered Beam for Increased Isotope Production at LANSCE
- Author(s): Ha, Nicholas
- Advisor(s): Krstic, Miroslav
- et al.
The Isotope Production Facility (IPF) receives pulsed H+ beam from the accelerator at the Los Alamos Neutron Science Center (LANSCE) to produce isotopes for various research and medical uses. Work over 2 summers has been conducted to improve diagnostics, reliability, and control for equipment on the IPF beamline, as well as to optimize beam delivered to IPF to increase isotope yield. This second goal is the subject of this document. Specifically, it is desired to maximize beam delivery onto a target without risking damage to the target window or spill too much beam outside a specified aperture. A specified beam profile and repeating beam raster pattern of concentric circles is currently being used to achieve this. The goal addressed here is to determine an improved beam profile and raster pattern. While a specific answer is needed for certain operation conditions, a general method is even better. A constrained optimization problem is formulated, and several approaches for solving it are discussed. It is found that with appropriate design of cost function, a Gradient Descent algorithm is effective at making improvements to a good initial guess. A bounded Extremum Seeking algorithm also shows some effectiveness, while some unbounded versions did not show effectiveness for this problem. The problem formulation, models, methods, results, are presented. They show significant potential to advance IPF’s goals of higher isotope production yield.