CALCULATING AN ION BEAM EVOLUTION IN A LINEAR ACCELERATOR SECTION WITH SPATIALLY UNIFORM QUADRUPOLE FOCUSING BASED ON A "MULTILEVEL" REPRESENTATION OF BEAM PARTICLES

E. S. Galpern, V. N. Lyakhovitsky
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki 1988. Вып.3. С. 21-26.

      We describe a program modeling the behavior of a proton beam in a linear accelerator section with spatially uniform quadrupole focusing. Some calcula- tional results are given. No symmetries are assumed in electromagnetic field configurations and in a motion of macroparticle groups representing a beam. The beam eigenfield calculation uses Lienar-Wichert potentials combined with a "multilevel" formation of macroparticles representing a beam. Macroparticles at the levels 2 and 3 are formed by averaging level 1 groups of macroparticles simulating the beam behavior which permits to reduce substantially the sorting field of macroparticles from the level 1 and also to decrease the computation time. Calculating a beam moving longitudinally in a section with spatially uniform quadrupole focusing is illustrated by "model examples".