LIAR -- A computer program for the modeling and simulation of high performance linacs [report]

R. Assmann, C. Adolphsen, K. Bane, P. Emma, T. Raubenheimer, R. Siemann, K. Thompson, F. Zimmermann
1997 unpublished
The computer program LIAR ("Linear Accelerator Research code") is a numerical modeling and simulation tool for high performance linacs. Amongst others, it addresses the needs of state-of-the-art linear colliders where low emittance, high-intensity beams must be accelerated to energies in the 0.05-l TeV range. LIAR is designed to be used for a variety of different projects. It has been applied to and checked against the existing Stanford Linear Collider (SLC), the linacs of the proposed Next
more » ... e proposed Next Linear Collider (NLC) and the proposed Linac Coherent Light Source (LCLS) at SLAC. LIAR allows the study of single-and multi-particle beam dynamics in linear accelerators. It calculates emittance dilutions due to wakefield deflections, linear and non-linear dispersion and chromatic effects in the presence of multiple accelerator imperfections. Both single-bunch and multi-bunch beams can be simulated. It is possible to simultaneously study the acceleration of positive and negative charges in a linac. Diagnostic and correction devices include beam position monitors, RF pickups, dipole correctors, magnet movers, beam-based feedbacks, multi-device knobs and emittance bumps. Several basic and advanced op-. timization schemes are implemented. Present limitations arise from the incomplete treatment of bending magnets and sextupoles. A major objective of the LIAR project is to provide an open programming platform for the accelerator physics community. We invite interested scientists to join this project. Due to its design, LIAR allows straight-forward access to its internal FORTRAN data structures. The program can easily be extended and its interactive command language ensures maximum ease of use. Presently, versions of LIAR are compiled . for UNIX and MS Windows operating systems. An interface for the graphical visualization of results is provided. Scientific graphs can be saved in the PS and EPS file formats. In addition a Mathematics interface has been developed. LIAR now contains more than 40,000 lines of source code in more than 130 subroutines. This-report describes the theoretical basis of the program, provides a reference for existing features and explains how to add further commands. The LIAR home page and the ONLINE version of this manual can be accessed under: http://www.slac.stanford.edulgrplarb/rwaAiar.htm :
doi:10.2172/505387 fatcat:td64jk7wrzfozjdtwxcyim2iaa