
We have performed proton beam dynamics simulation for the SARAF, 40 MeV and 4 mA, linac. The calculation is using the GPT code and includes effects of space charge. It demonstrates that for an initial 6D Waterbag distribution beam, a tune can be obtained with longitudinal rms emittance growth of about 10 % and transverse normalized rms emittance growth of 20%, and a transverse beam envelope of 5000 macroparticle well within the linac beam pipe. Beam loss is estimated by fitting a radial Gaussian to the particle distribution along the linac. A 1 nA beam envelope is obtained by extrapolating the tail of the radialGaussian function. The 1nA beam envelope is still well within the beam bore radius. Benchmark simulation with a 6D Gaussian initial distribution, with the same rms quantities, exhibits a more extended tail that may result in a higher beam loss. This point will receive a further study.

