Longitudinal Beam Dynamics for the Heavy-Ion Synchrotron Booster Ring at HIAF

D Y Yin,F C Cai,J Liu,L J Mao,H Du,W P Chai,J C Yang,G D Shen

doi:10.1155/2021/6665132

D Y Yin, F C Cai + Show 6 more

Open Access

https://doi.org/10.1155/2021/6665132

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Abstract

To accelerate high-intensity heavy-ion beams to high energy in the booster ring (BRing) at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) project, we take the typical reference particle 238U35+, which can be accelerated from an injection energy of 17 MeV/u to the maximal extraction energy of 830 MeV/u, as an example to study the basic processes of longitudinal beam dynamics, including beam capture, acceleration, and bunch merging. The voltage amplitude, the synchronous phase, and the frequency program of the RF system during the operational cycle were given, and the beam properties such as bunch length, momentum spread, longitudinal beam emittance, and beam loss were derived, firstly. Then, the beam properties under different voltage amplitude and synchronous phase errors were also studied, and the results were compared with the cases without any errors. Next, the beam properties with the injection energy fluctuation were also studied. The tolerances of the RF errors and injection energy fluctuation were dictated based on the CISP simulations. Finally, the effect of space charge at the low injection energy with different beam intensities on longitudinal emittance and beam loss was evaluated.

Highlights

In China, the Heavy Ion Research Facility at Lanzhou (HIRFL) [1, 2] is one major national research facility focusing on nuclear physics, atomic physics, heavy ion applications, and interdisciplinary research
We take 238U35+, which can be accelerated up to roughly 830 MeV/u corresponding to the maximum magnetic rigidity of 34 Tm, as an example to study the longitudinal beam dynamics by theoretical calculation and numerical simulation. e numerical model is given by a scalable multi-macroparticle simulation platform CISP [20], and 10000 macroparticles are applied during the simulation process
Ions’ distribution evolution in the phase space is simulated, and the beam properties are derived; the space charge effect on longitudinal emittance growth is discussed; in Section 3, the basic RF program for beam acceleration is calculated, and the beam properties are derived by simulations; and in Section 4, the bunch merging processes are studied, and the basic RF program is given

Summary

Introduction

In China, the Heavy Ion Research Facility at Lanzhou (HIRFL) [1, 2] is one major national research facility focusing on nuclear physics, atomic physics, heavy ion applications, and interdisciplinary research. To realize these purposes, it is necessary to control the emittance growth and beam loss to an allowable level of each process including capture, acceleration, and an additional bunch merging. Ions’ distribution evolution in the phase space is simulated, and the beam properties are derived; the space charge effect on longitudinal emittance growth is discussed; in Section 3, the basic RF program for beam acceleration is calculated, and the beam properties are derived by simulations; and, the bunch merging processes are studied, and the basic RF program is given. In our case, an additional multibunch merging process converting four bunches into one is needed

Beam Capture at Injection Energy

Beam Acceleration

Findings

Multiple Bunch Merging at the Extraction Energy Platform