Role of beam dynamics studies for accelerator safety

The beam dynamics studies, which are used to work out the configuration of the accelerator, play an important role in safety of the accelerators. These studies mainly involve the calculations of beam envelopes by solving the equations of the motions under the influence of external electric and magnetic fields. One of the objectives of these studies is to optimize the size of the components and minimization of the beam losses in the system. The large beam losses will not only produce radioactivity in the accelerator components but also can melt them due to large beam energy deposition. This can lead to air rush in the system and hence the damage of the whole system. Optimization of the beam dynamics is of great importance particularly in high current accelerators where space charge forces play an important role. In the case of high intensity accelerators several new phenomena like resonances and beam halos formation takes place which leads to large beam losses. For hands on maintenance of the accelerator components for ADS applications it is estimated that the beam loss should be < 1 nA/m which requires a careful beam dynamics studies for the system. It is also useful to understand the beam loss mechanism and their minimization particularly in the case of high current accelerators. (author)