Studies of Ultimate Intensity Limits for High Power Proton Linacs

Although modern high power proton machines can now routinely deliver MW level operating powers, the next generation accelerators will be required to reach powers orders of magnitude higher. Significant developments will be needed both in technology and in understanding the limits of high intensity operation. The present study investigates the beam dynamics in three experimental linac designs when the beam intensity is increased above current levels such that for CW regimes, beam powers of up to 400 MW can be attained. In the first, a 1 A proton beam is accelerated to 400 MeV using normal conducting structures. In the second, a comparison is made when two front ends accelerate 0.5 A beams to ~20 MeV where they are funnelled to 1 A and accelerated to 400 MeV. Similarly, in the third, two 0.25 A beams are funnelled to 0.5 A and then accelerated in superconducting structures to 800 MeV. In addition, alternative unconventional methods of generating high current beams are also discussed. The further studies that are needed to be undertaken in the future are outlined, but it is considered that the three linac configurations found are sufficiently promising for detailed technical designs to follow.