MYRRHA accelerator: Linear accelerator (linac)

In a linear accelerator (linac), charged particles are accelerated in a long array of cells (cavities). Each cavity is essentially a tube over which a radio frequency voltage is applied so that the particle feels the accelerating field when passing through a gap. A linac is not quite straightforward because each cell must be adjusted to account for the increasing particle speed and the relative phase of the electromagnetic wave and the particle speed in the accelerator must be matched. Present linacs are optimized by shaping each waveguide cavity so that the phase velocity of the electromagnetic wave matches the particle speed at the locations where acceleration occurs.

The linac option for the MYRRHA accelerator would consist of three seperate sections :

• An ion source coupled to a radio frequency quadrupole (RFQ) to shape the beam an do initial acceleration to 5 MeV
• The intermediate stage using superconducting spoke cavities and accelerating the beam to 100 MeV
• The high energy section where elliptical cavities are applied. The beam is brought to 600 MeV. However the linac can be upgraded to higher energies by adding more cavities