Vacuum simulation of the LINAC4 H- source

The 160 MeV H- Linac4 will replace the 50 MeV proton Linac2. Linac4 H- source is the new ion source. In order to study its dynamic behaviour from the vacuum point of view, the electrical network – vacuum analogy have been used. This technique allows the evaluation of the hydrogen partial pressure profile as a function of time and position, giving important information about plasma chamber and LEBT pressures. Aiming at benchmarking the following simulations, several experimental calibration campaigns are foreseen in the near future: the H- source of Linac4 requires a pulsed injection of hydrogen to reach the typically 0.1 mbar pressure mandatory for plasma formation. First preliminary results show good agreement between the experimental and the simulated profiles.