Acceleration of heavy ions in inverse free electron laser

Abstract

In conventional linear accelerators, the beam is accelerated with a synchronous harmonic of the radio frequency field where the electric field component is collinear with the beam direction. This approach requires the design of complex accelerating structures, especially for low-energy heavy ions. If the beam motion were sustainably coupled to transverse electromagnetic fields, this could significantly simplify the accelerating structure design, and even allow acceleration with free-space waves. However, despite the long history of the proposed concept for accelerating low-velocity ion beams, it has not found practical application, partially because of the complexity of the technical design. In this paper, we present a practical design approach for this undulator-based accelerator for low-energy heavy-ions, reminiscent of the inverse free electron laser operating principle, but in a different parameter space.

Ultrafast High-Voltage Kicker System for Ion-Clearing Gaps

“…We obtained a spectrum of beam loss over a range of injection parameters-offset and tilting-as shown in Figure 7. 20 From this study, it is clear that the optimal injection parameters range between 5~6 mrad tilting and near 0 mm offset regardless of cavity length. Considering the required pulsed power, it was decided that either 400 mm or 500 mm cavity would be close to the optimal choice, i.e., reasonably low RF power with tolerable beam loss, which was confirmed by the CST simulation.…”

“…In addition to being an enabling technology for EIC, the proposed system or its constituent blocks may find various uses in HV switching applications, including fast beam choppers [17] for injector test facilities, the next-generation free electron laser (FEL) light sources [18], and inverse Compton scattering gamma ray sources using ERLs [19], ion-clearing gaps for ion accelerators, as well as inverse FEL-driven replacement of radio frequency quadrupole (RFQ) accelerating structures [20].…”