Design study of a single bunch selection method for neutron TOF experiment at RAON heavy ion accelerator

Abstract

To enable neutron time-of-flight (TOF) experiments at the RAON heavy-ion accelerator facility, we propose a single bunch beam selection method by combining a fast chopper and double gap buncher in the low-energy beam transport (LEBT) section. The fast chopper operates with switching times of tens of ns to convert a CW beam into a pulsed beam. Then, the double gap buncher performs bunching to shorten the beam pulse duration to less than one radio frequency quadrupole (RFQ) cycle. Ideally, a single isolated bunch can be achieved after the RFQ. In this study, we discuss the system design of the proposed single bunch selection scheme and present detailed beam dynamics simulations.