Tracz, P.S. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-194-6 10.18429/JACoW-LINAC2018-TUPO085 English 528-530 TUPO085 linac simulation quadrupole gun emittance Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-LINAC2018-TUPO085 http://jacow.org/linac2018/papers/tupo085.pdf The Gamma Beam System at the ELI-NP (Extreme Light Infrastructure - Nuclear Physics) currently being constructed in Magurele/Bucharest, Romania will be a high-brilliance advanced source of gamma rays based on laser Compton back-scattering. For a successful operation of the GBS a high brightness low emittance electron beam is of crucial importance. The warm RF linac is designed in two stages - one with the beam up to 300 MeV, and another one about 720 MeV. The S-band photo-injector is combined with a C-band linac. The beam is transported by transfer lines to the interaction points. In this paper we report the results of computer simulations of the electron beam transport in the low energy linac and transfer line up to the low energy interaction point (IP1). The simulation model makes it possible to predict the beam parameters to be recuperated in case of failure of any magnetic or accelerating elements as well as it enables to determine the optimal parameters of replaced components. It will be used for the development of the Gamma Beam System in the future.