Simulation of the LBNL scaled final focus experiment

In the Scaled Final Focus Experiment at LBNL, the beam dynamics of the HIBA LL-II final focus system are studied by scaling its beam parameters down to values suitable for laboratory experiments. The final focus system is base d on vacuum ballistic focusing, in which the beam first expands and is subs equently focused onto a small spot. Particle-in-cell simulations using the WARP code were done to understand the behavior of the beam as measured in t he experiment. In order to closely resemble the anal focus system under con sideration, the experimental conditions were replicated accurately in the s imulation. Special attention was given to the non-ideal effects present in the experiment, such as fringe fields, image charges, and chromatic aberrat ions. It was shown that simulations can be used to determine which of these effects are likely to significantly affect the beam, and which are not. (C ) 2001 Published by Elsevier Science B.V.