Sustainability Aspects of Energy Recovery Linacs (ERL)

Energy Recovery Linacs (ERL) are electron/positron accelerators that

restore most of the energy needed for acceleration by active

deceleration of the beam during later passages through the main accelerating RF 

structure. In addition to the significant reduction in power

consumption, the radiation hazard caused by dumping the particles

after their usage is much reduced due to the low energy of the dumped

beams. The energy recovery process depends on minimizing unwanted losses

especially in the RF accelerating cavities. To this end, superconducting technology

is used, unluckily demanding significant cooling power.

The talk tries to shed light on the actual gain in sustainability

achievable by ERLs and where their implementation is desirable.

The talk also reflects information drawn from the ERL R&D roadmap recently

formulated in Europe with respect to future High Energy Physics

applications.