There are applications, which require MeV-range multiple-beams consisting of a large number of identical highly packed beamlets. The multiple-beam RFQ (MB-RFQ) arranged as a matrix array of longitudinal rod-electrodes is appropriate candidate. A configuration of MB-RFQ resonator should ensure identical quadrupole fields in every accelerating channel. The MB-RFQ resonators based on TEM transmission lines are studied. The resonators are designed by a periodical multiplication of a 4-rod unit cell in transverse direction. To understand fields of resonator the normal mode technique is applied. Novel configurations of MB-RFQ resonators based on these normal modes are generated. The RF properties of resonators are verified with computer simulations done with MAFIA code. Beam dynamics study for the initial 400-keV MB-RFQ has been performed using PARMTEQ code. The MB-RFQ parameters and the results of beam dynamics simulations are presented. The calculated beam transmission is 33% at injection of 50-keV, 20mA deuteron beam.
We present a novel machine learning-based approach to generate fast-executing virtual radiofrequency quadrupole (RFQ) particle accelerators using surrogate modelling. These could potentially be used as on-line feedback tools during beam commissioning and operation, and to optimize the RFQ beam dynamics design prior to construction. Since surrogate models execute orders of magnitude faster than corresponding physics beam dynamics simulations using standard tools like PARMTEQM and RFQGen, the computational complexity of the multi-objective optimization problem reduces significantly. Ultimately, …
The RFQ design tool DEMIRCI aims to provide fast and accurate simulation of a light ion accelerating cavity and of the ion beam in it. It is a modern tool with a graphical user interface leading to a "point and click" method to help the designer. This article summarises the recent software developments such as the addition of RFQ acceptance match, beam dynamics and 8-term potential coefficient calculations. Its results are compared to other similar software, to discuss the attained compatibility level.
Status Report on the Low-Energy Demonstration Accelerator (LEDA)
75 keV的注入器和6.7 MeV的质子束流，包括连续波，100毫安质子直线加速器的第一部分的加速器生产氚（APT）项目已经建成和运行。LEDA电子束发生器已经过脉冲和连续波输出束流<=100 mA的广泛测试。高达2.2兆瓦的连续波射频功率从350兆赫的射频系统耦合到超导体，包括670千瓦的连续波质子束。由四极磁铁扫描测量确定的93 mA脉冲式双极输出光束的发射度为ex x ey = 0.25 x 0.31（π mm mrad）2 [rms归一化]。一个后续的实验，有意引入和测量光束晕的激光器输出光束，现在正在安装。
The KAHVE Laboratory, at Boğaziçi University, Istanbul, Turkey is home to an educational proton linac project. The proton beam will originate from a 20 keV H+ source and will be delivered to a two module Radio Frequency Quadrupole (RFQ) operating at 800 MHz via a low energy beam transport (LEBT) line. Currently, the design phase being over, commissioning and stability tests are ongoing for the proton beamline which is already produced and installed except the RFQ which is being manufactured. This work summarizes the design, production and test phases of the ion source and LEBT line components.
Compact accelerator-based neutron source facilities are garnering attention and play an important and expanding role in material and engineering sciences, as well as in neutron science education and training. Neutrons are produced by bombarding a low-energy proton beam onto a beryllium or lithium target. In such an accelerator-based neutron source, a radio frequency quadrupole (RFQ) is usually utilized to accelerate a high-intensity proton beam to a few MeV. This study mainly covers the high-frequency structure design optimizations of a 4-vane RFQ with pi-mode stabilizer loops (PISLs) and its …
High-frequency linear accelerators are very suitable for carbon ion therapy, thanks to the reduced operational costs and the high beam quality with respect to synchrotrons, which are presently the only available technology for this application. In the framework of the development of a new linac for carbon ion therapy, this article describes the design of a compact 750 MHz Radio Frequency Quadrupole (RFQ) with trapezoidal vanes. A new semi-analytic approach to design the trapezoidal-vane RFQ is introduced together with the relevant beam dynamics properties. The RFQ is split into two decoupled r…
Modern accelerator front ends almost exclusively include radio-frequency quadrupoles for initial capture and focusing of the low-energy beam. Dynamics in the RFQ define the longitudinal bunch parameters. Simulation of the SNS RFQ with PARMTEQ seeded with a realistic LEBT distribution produces a 2.5 MeV, 40 mA H- beam with root-mean-square emittance of 130 deg-keV. In measurement, a detailed characterization of the longitudinal phase space is made, including a novel study of the dependence of longitudinal emittance on transverse coordinates. This work introduces a new virtual slit technique tha…
A high-intensity continuous wave (CW) radio frequency quadrupole (RFQ) accelerator is designed for boron neutron capture therapy (BNCT). The transmission efficiency of a 20-mA proton beam accelerated from 30 keV to 2.5 MeV can reach 98.7% at an operating frequency of 200 MHz. The beam dynamics has good tolerance to errors. By comparing the high-frequency parameters of quadrilateral and octagonal RFQ cross-sections, the quadrilateral structure of the four-vane cavity is selected owing to its multiple advantages, such as a smaller cross section at the same frequency and easy processing. In addit…
Commissioning of the 1.4 Mev/u High Current Heavy Ion Linac at Gsi
Wideroe型Unilac预剥离器直线加速器的拆卸于1999年初进行。必须获得SIS中最重元素的粒子数增加两个数量级以上。从那时起，新的高电流注入器（HSI）由H型整流器和DTL结构组成，用于双束操作，并成功调试。高电荷注入器（HLI）在此期间提供主直线加速器。同时完成射频发射器和射频结构的调节和运行。HSI调试策略包括在每个运输和加速段之后使用多功能诊断测试台进行束流调查。将讨论LEBT、超透镜、IH槽I和II以及剥离段之后的广泛调试测量结果（例如横向发射度、束流宽度、束流传输）。使用来自MUCIS离子源的40 Ar 1+束来填充直线加速器直到理论空间电荷极限。1999年11月开始进行例行作业。
An adjustable focusing system for a 2 MeV H- ion beam line based on permanent magnet quadrupoles
设计、建造并测试了一个基于四极永磁体（PMQ）的小型可调聚焦系统。使用有限元模拟实现PMQ模型，提供2.35 T的集成场梯度，最大场梯度为57 T/m。构造了一个原型，并测量了磁场，表现出良好的协议与模拟。粒子轨迹模拟提供了四极位置的初始值。相应地，在束线上构造并组装四个PMQ，然后调整它们的位置以在目标上获得（1.2 x 2.2）mm^2的最小束斑尺寸。本文介绍了一种用于外离子束的可调PMQ束线。基于市售NdFeB磁体的新颖紧凑设计为离子束应用提供了高度灵活性。
As an important measure of improving the efficiency and usability of X-ray free electron laser facilities, simultaneous operation of multiple undulator lines realized by a beam distribution system has become a standard configuration in the recent built XFEL facilities. In Shanghai, SXFEL-UF, the first soft X-ray free electron laser user facility in China, has finished construction and started commissioning recently. Electron beam from linac is alternately distributed between the two parallel undulator beam lines by a beam distribution system with a 6° deflection line. The beam distribution sys…
