Sep 15 – 21, 2019
Hotel Hermitage, La Biodola Bay, Isola d'Elba, Italy
Europe/Rome timezone

Stable positron acceleration in self-generated hollow channels

Sep 18, 2019, 6:00 PM
20m
SE (Hotel Hermitage)

SE

Hotel Hermitage

Speaker

Thales Silva (GoLP/Instituto Superior Técnico (Lisbon))

Description

Hollow plasma channels are promising candidates for the acceleration of electron and positron beams as the transverse forces are nearly vanishing inside the hollow channel. The acceleration is effective as long as the accelerated bunches are perfectly cylindrically symmetric and injected on the axis of the hollow channel structure. Furthermore, the accelerating fields can also be nearly constant provided that the accelerated bunch current profile is appropriately tailored. These features make it fundamentally possible to preserve beam quality during the acceleration. In realistic situations, however, small asymmetries in the beam profile or small misalignments between the beam and the hollow channel axis will seed the growth of the beam breakup instability, thus stopping the acceleration prematurely and degrading beam quality substantially. These beam breakup instabilities are a severe limitation on the use of hollow channels for particle acceleration.

Here, we investigate a new mechanism for stabilization of positron acceleration in hollow channels. Using theory and particle-in-cell simulations with the code OSIRIS, we show that the ion motion associated with the wakefield force can form a hollow plasma channel self-consistently. A second particle beam then drives a nonlinear plasma wave with focusing and accelerating fields for positrons.

Primary authors

Thales Silva (GoLP/Instituto Superior Técnico (Lisbon)) Jorge Vieira (Instituto Superior Tecnico)

Co-authors

Mark Hogan (SLAC National Accelerator Laboratory) Vitaly Yakimenko (SLAC) Konstantin Lotov (Novosibirsk State University) Rafal Zgadzaj (University of Texas at Austin) Michael Downer (The University of Texas at Austin)

Presentation materials