In principle both accelerator types can deliver the required proton beam for ADS applications. However, the nature of each — one compact unit for an isochronous cyclotron, a sequential modular structure for the linac — brings both advantages and disadvantages.

Due to its recirculation nature, a cyclotron is compact and cost effective. However, it lacks every form of redundancy which is crucial for fault tolerance. Hence, a cyclotron will not reach the wanted level of availability, and furthermore an upgrade of its beam energy is not a realistic option.

Linacs on the other hand, can be built as a sequence of many independent accelerating structures (RF cavities), which is a highly modular situation. It is this modularity that makes such a linac particularly well suited to tackle the availability issue. In case of failure of a single accelerating module, independently controlling the RF amplitude and phase of the adjacent modules creates the conceptual possibility of recovering the beam within a short time. Furthermore, increasing the final beam energy is obtained by merely adding accelerating modules.

For these reasons MYRRHA favours the linac option.

Linac versus cyclotron