Design study of low-energy beam transport for multi-charge beams at RAON

Abstract

The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance (ECR) ion sources, a lowenergy beam transport (LEBT) system, a CW 81.25 MHz radio frequency quadrupole (RFQ) accelerator, a mediumenergy beam transport system, the SC linac, and a chargestripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90 • dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated beam is selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

Multi-objective optimization with an integrated electromagnetics and beam dynamics workflow

“…The IMPACT code is a parallel particle-in-cell code suite for modeling high intensity, high brightness beams in RF proton linacs, electron linacs, and photoinjectors [6,7,8,9,10,11,12]. It consists of two parallel particle-in-cell tracking codes: IMPACT-Z and IMPACT-T.…”

CW RFQ design and investigation for multi-charge-state acceleration of radioactive beams from BISOL

“…Therefore, the LEBT design must ensure that the multi-charge-state beams have the same energy at the entrance of the RFQ to make multi-charge state acceleration work efficiently. The feasibility of such an LEBT has been proved in theoretical simulations [23,24]. In table 5, the acceleration efficiency of the 132 Sn 20+ beam is relatively low because of insufficient voltage for the 132 Sn 20+ beam, causing a long tail in the longitudinal phase space.…”

Designing and commissioning pre-analysis system for intense D-D/D-T neutron generator

“…Adding a dipole magnet to the transmission line of the beam can help completely separate undesirable ions. For example, the JUNA project uses a solenoid, a dipole magnet, and another solenoid to connect the ion source to the acceleration tube [9], the HBNI-NS project uses two quadrupole magnets, a dipole magnet, and three quadrupole magnets as the transport line for the low-energy beam [10], and the RAON project uses a combination of electric quadrupole lens and a dipole magnet [11]. The magnetic focusing system is more conducive to the transmission of a strong beam than the electrostatic focusing system due to the effect of space charge neutralization [12].…”