Cbn 09-5

1. OVERVIEW An undesirable situation could develop anytime during ERL operation, even if this could be treated as a rare event. So the protection system must be designed so that despite its occasional triggering, it must yield a controllable beam dump with ~100% probability. In mostly situations the faster dump system isthe lesser the damage could be. One typical example could be represented when the injector stops provision of the electron beam while the ERL filled with the electron bunches. Namely, for exclusion of possible harm to ERL caused by this situation it is necessary to install a controllable beam dump at the entrance of North linac, see Section 4. This dump includes a collimator [1], able to absorb full energy of the beam and fast kicker, which directs the beam to the walls of the collimator, see Fig 1. As we mentioned already, the peculiarity of this system is that it operates occasionally, but needs to be ready any time with minimal probability of failure.