James Safranek
SLAC National Accelerator Laboratory
55 Papers
213 Citations
James Safranek is an academic researcher from SLAC National Accelerator Laboratory. The author has contributed to research in topics: Storage ring & Particle accelerator. The author has an hindex of 11, co-authored 55 publications. Previous affiliations of James Safranek include Stanford University.
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Papers
Nonlinear dynamics optimization with particle swarm and genetic algorithms for SPEAR3 emittance upgrade
Xiaobiao Huang,James Safranek +1 more
TL;DR: The result shows that the particle swarm algorithm converges significantly faster to similar or better solutions than the genetic algorithm and it does not require seeding of good solutions in the initial population, which may make it more suitable for many accelerator optimization applications.
An algorithm for online optimization of accelerators
TL;DR: This method combines the conjugate direction set approach of Powell's method with a robust line optimizer which considers the random noise in bracketing the minimum and uses parabolic fit of data points that uniformly sample the bracketed zone.
Measurement of transient atomic displacements in thin films with picosecond and femtometer resolution
Michael Kozina,Te Hu,Joshua S. Wittenberg,Erzsi Szilagyi,Mariano Trigo,Timothy A. Miller,Ctirad Uher,Anoop R. Damodaran,Lane W. Martin,Apurva Mehta,J. Corbett,James Safranek,David A. Reis,Aaron M. Lindenberg +13 more
TL;DR: The combination of high brightness, repetition rate, and stability of the synchrotron, in conjunction with high time resolution, represents a novel means to probe atomic-scale, near-equilibrium dynamics.
29
Realizing the benefits of restored periodicity in the advanced light source
TL;DR: In this paper, the effect of broken and restored periodicity at an actual third generation light source: the Advanced Light Source at Lawrence Berkeley National Laboratory, was studied by fitting measured orbit response matrices.
21
LOCO with constraints and improved fitting technique
Xiaobiao Huang,James Safranek,G. Portmann +2 more
- 18 Jun 2009
TL;DR: In this paper, a constrained LOCO fitting algorithm is proposed to solve a nonlinear least square problem with an iterative approach, where the linear least square technique is applied in each iteration to move the solution toward the minimum.