PAC07 - List of Sessions

TUODC — CONCOM: Controls & Computing (26-Jun-07 17:50—18:35)

Chair: J. A. Holmes, ORNL, Oak Ridge, Tennessee

Paper	Title	Page
TUODC01	Detailed Photoemission Modeling Using the 3D Finite-Element PIC Code MICHELLE	904
	J. J. Petillo K. Jensen, B. Levush NRL, Washington, DC J. N. P. Panagos SAIC, Burlington, Massachusetts
	Funding: We gratefully acknowledge funding by the Joint Technology Office and the Office of Naval Research. Low emittance, high current density sources are required to achieve the small beam size needed for high frequency vacuum electronic devices and for high power free electron lasers (FELs). Emission models are of particular importance in the emittance-dominated regime, where emission non-uniformity and surface structure of the cathode can have an impact on beam characteristics. We have been developing comprehensive time-dependent photoemission models for the simulation codes that account for laser and cathode material and surface characteristics. MICHELLE* is NRL's finite-element self-consistent electrostatic time-domain code: it has the ability to import an RF field, and has unique capabilities for modeling the emission and the self fields, near the cathode. In particular, some instances of surface irregularities and emission non-uniformity (due to work function variation) leading to such effects as beam emittance and high frequency oscillations are possible to model due to the code's conformal meshing capabilities. We will present results of the implementation of the 'next generation' photoemission models in the MICHELLE code for modeling surface roughness and non-uniformity. * John Petillo, et al., "The MICHELLE Three-Dimensional Electron and Collector Modeling Tool: Theory and Design", IEEE Trans. Plasma Sci., vol. 30, no. 3, June 2002, pp. 1238-1264.
	Slides
TUODC02	Development of 3D Beam-Beam Simulation for the Tevatron	905
	E. G. Stern J. F. Amundson, P. Spentzouris, A. Valishev Fermilab, Batavia, Illinois J. Qiang, R. D. Ryne LBNL, Berkeley, California
	We present status of development of a 3D Beam-Beam simulation code. The essential features of the code are 3D particle-in-cell Poisson solver, multi-bunch beam transport and interaction, chromaticity and machine impedance. The simulations match synchro-betatron oscillations measured at the VEPP-2M collider. The impedance model is compared to analytic expressions for instability growth.
	Slides
TUODC03	Parallel Finite Element Particle-In-Cell Code for Simulations of Space-charge Dominated Beam-Cavity Interactions	908
	A. E. Candel A. C. Kabel, K. Ko, L. Lee, Z. Li, C. Limborg-Deprey, C.-K. Ng, E. E. Prudencio, G. L. Schussman, R. Uplenchwar SLAC, Menlo Park, California
	Funding: U. S. DOE contract DE-AC002-76SF00515 Over the past years, SLAC's Advanced Computations Department (ACD) has developed the parallel finite element particle-in-cell code Pic3P (Pic2P) for simulations of beam-cavity interactions dominated by space-charge effects. As opposed to standard space-charge dominated beam transport codes, which are based on the electrostatic approximation, Pic3P (Pic2P) includes space-charge, retardation and boundary effects as it self-consistently solves the complete set of Maxwell-Lorentz equations using higher-order finite element methods on conformal meshes. Use of efficient, large-scale parallel processing allows for the modeling of photoinjectors with unprecedented accuracy, aiding the design and operation of the next-generation of accelerator facilities. Applications to the Linac Coherent Light Source (LCLS) RF gun are presented.
	Slides