补充加料过程中逃逸电子的雪崩现象

在靶丸注入和超声分子束注入等补充加料期间，虽然等离子体密度骤然增加，但用五通道碘化汞探测器阵列及碘化钠探测器在此期间均测到很强的X射线辐射，且射线峰爆发时间与靶丸注入及超声分子束注入时间对应得相当好，用二次电子发射形成雪崩型逃逸电子理论解释了实验测量结果。     

CFETR 中性束注入系统概念设计

为了满足中国核聚变工程实验堆(CFETR)对等离子体加热和电流驱动的要求,从总体布局、束传输 系统、束源系统三方面进行了中性束注入系统的概念设计。利用参数计算的方法,根据聚变等离子体的要求明确 了中性束注入系统的性能指标和基本布局;利用束传输空间分布程序评估了束传输性能,确定了各功能部件的空 间布局结构;在此基础上,确定了束源系统的性能指标和引出系统布局方式,结合当前研发进展,明确了束源的 基本技术方案。由此完成了中性束注入系统参数指标、束传输关键尺寸、束源性能指标等设计要求,为后续工程 设计奠定了基础。     

Numerical Modeling of Ion-Optical Systems for Extraction of a Beam of Negative Hydrogen Ions and Its Acceleration and Matching with a Radio-Frequency Quadrupole Accelerator

A source of negative hydrogen ions is constructed at the Institute for High Energy Physics in order to raise the intensity of the U-70 accelerator complex using multiturn charge-exchange injection. The 3D ion-optical IBSimu simulation package was used to model and optimize the system for extraction of an ion beam from plasma, its acceleration to 100 keV, and matching with a radio-frequency quadrupole (RFQ) accelerator. The system of extraction of an ion beam with a current of 50 mA and electron-flow suppression was modeled. The magnetic transport channels with two solenoids and six quadrupole lenses were compared. The end goals of analysis of the matching channel were to obtain the needed Twiss parameters and to minimize the emittance growth at the RFQ input.     

Analysis of electron capture acceleration channel in an Airy beam

Using numerical simulation, we have studied in detail vacuum electron acceleration induced by an Airy beam. The phase of the field varies slowly, and the intensity of the field is independent of the decaying parameter of the beam in the asymmetric field channel [(AFC) Opt. Express 18, 7300 (2010)] formed by the Airy beam. Results show that an electron entering into the AFC may be captured and gain high energy. Meanwhile, the decaying parameter, injection energy, and injection angle of the electron play important roles in the electron energy gain.     

EAST中性束注入角度的NUBEAM模拟研究

采用蒙特卡罗程序NUBEAM对EAST NBI上的中性束注入角度(中性束系统中心线与注入窗口轴线的夹角)进行了分析。讨论了中性束注入角度对电流驱动效率、加热效率和束的穿透功率的影响,对EAST NBI系统选取了一个最优的注入角度。模拟结果表明：对EAST NBI系统,在典型的EAST实验参数和实际工程允许的范围内,19.5°是最优的注入角度。在此注入角度下,可以通过增大等离子体密度的方法来进一步提高加热效率和电流驱动效率,并减少束的穿透功率。     

An IC100 cyclotron based facility for producing nuclear filters and for scientific and applied research

The cyclotron IC-100 station, based on the Laboratory of Nuclear Reactions (JINR, Dubna, Russia), provides the industrial construction of nuclear filters. During modernization, the cyclotron was equipped with a superconducting ECR-ion source and an axial injection system. The specialized beam channel with a two coordinate scanning system and equipment for irradiating polymer films was installed in the implantation part of the station. High intensity heavy ion beams of Ne, Ar, Fe, Kr, Xe, I, and W have been accelerated to 1 MeV/nucleon energy. The investigation into irradiated crystals features and irradiation of different polymer films is provided. Also, a few thousands square meters of track films with holes in the wide range of densities were produced. The cyclotron-based station is capable of solving different kinds of scientific and applied problems as well. The text was submitted by the authors in English.     

An additional carbon ion transport channel for biological research at the nuclotron of the joint institute for nuclear research

This paper describes the construction of the beam ¹²C⁺⁶ transport line for biomedical research at the Joint Institute for Nuclear Research (JINR) Nuclotron accelerator complex. We have studied the scheme and operating modes of magneto-optical elements of the channel. The calculation results are presented for the carbon ion transport channel under study. The control algorithms of the carbon ion beam in the transportation system are discussed. The choice of the magneto-optical system is explained. The beam envelopes in the channel are plotted. The beam scanning control functions are considered.     

Conceptual design of the system of heavy-ion beam injection into the Booster of the NICA accelerator complex

A project of the system of heavy-ion beam injection into the Booster synchrotron of the NICA accelerator complex developed at the Joint Institute for Nuclear Research (Dubna) is considered. The proposed system provides multivariant injection for accumulating beams with required intensity. The main methods of beam injection into the Booster are described. These are the methods of one-turn, multiturn, and multiple injections. The results of beam dynamics simulations are presented.     

Conceptual design of Hefei Advanced Light Source (HALS) injection system

The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.     

Conceptual design of Hefei Advanced Light Source(HALS)injection system

The Hefei Advanced Light Source(HALS)is a super low emittance storage ring and has a very short beam life time.In order to run the ring stablely,top-up injection will be necessary.The injection system will greatly affect the quality of beam.This article first gives a physics design of the injecting system.Then the injecting system is tracked under different errors.The responses of storage beam and injecting beam are given in the article.     

相对论电子束在离子通道中的聚焦与输运

 基于单粒子理论,描述了相对论电子束在离子通道中的聚焦输运过程,讨论了离子-电子密度比、相对论因子、束加速电压和入射电流等系统参数对电子束的聚焦半径、纵向聚焦位置的影响。研究表明,离子通道对电子束具有强烈的聚焦效应,束流在离子通道内的传输是类周期波动传输,随传输距离增加,聚焦点处的半径逐渐增加,束流的波动幅度逐渐减小。选择适当的系统参数,可调节束聚焦点位置和聚焦点半径的大小,实现电子束的长距传输并且减少电子束的耗散。     

SSC注入系统能量接收范围的研究

分析了影响 SSC注入能量的因素和 SSC注入系统适应能量变化的能力 ,计算了在理论等时场下 SSC注入系统对 3种典型离子 O8+,Xe22 +和 Ar15+的能量可接收范围 ,找出了加速较轻的重离子时束流损失较大的部分原因. The SSC injection system and the factors which influence the injecting beam energy were described and the capability of the SSC injection system for accepting the mismatching injecting beam energy was calculated. For most cases, small difference exists between the values of actual injecting beam energy and the theoretical requirements. The capability of accepting three typical particals: O8+ , Xe 22+ and Ar15+ were calculated for the SSC injection stystem with small variation of the in...     

基于射频功率调节的负离子源束流反馈控制研究北大核心CSCD

基于射频负离子源的中性束注入系统是高功率长脉冲(稳态)运行中性束注入系统的最佳选择。负离子源是中性束注入系统的核心部件,需要实现稳定的负离子束引出和加速。在负离子源的运行过程中引出负离子电流会发生变化,尤其在长脉冲、高能量运行条件下会更加明显,因此无法满足稳定运行的要求。为了实现引出束流的稳定引出,开展了束流反馈控制研究,研发了一套基于射频功率调节的束流反馈控制系统,并将束流反馈控制系统应用在射频负离子源测试平台,开展了束流反馈控制测试。测试结果表明束流反馈控制系统能够实现对束流的实时反馈调节以获得束流的稳定引出,验证了基于射频功率调节的束流反馈控制的可行性,为高功率射频负离子源的研制提供支持。     

The Experimental Study of Novel Pseudospark Hollow Cathode Plasma Electron Gun

The high-power microwave devices with plasma-filled have unique properties. One of the major problems associated with plasma-filled microwave sources is that ions from the plasma drift toward the gun regions of the tube. This bombardment is particularly dangerous for the gun, where high-energy ion impacts can damage the cathode surface and degrade its electron emission capabilities. One of the techniques investigated to mitigate this issue is to replace the material cathode with plasma cathode. Now, we study the novel electron gun (E-gun) that can be suitable for high power microwave device applications, adopting two forms of discharge channel, 1: a single hole channel, the structure can produce a solid electron beam; 2: porous holes channel, the structure can generate multiple electronic injection which is similar to the annular electron beam.     

Numerical simulation of ions acceleration and extraction in cyclotron DC-110

In Flerov’s Laboratory of Nuclear Reactions of JINR in the framework of project “Beta” a cyclotron complex for a wide range of applied research in nanotechnology (track membranes, surface modification, etc.) is created. The complex includes a dedicated heavy-ion cyclotron DC-110, which yields intense beams of accelerated ions Ar, Kr and Xe with a fixed energy of 2.5 MeV/A. The cyclotron is equipped with external injection on the base of ECR ion source, a spiral inflector and the system of ions extraction consisting of an electrostatic deflector and a passive magnetic channel. The results of calculations of the beam dynamics in measured magnetic field from the exit of spiral inflector to correcting magnet located outside the accelerator vacuum chamber are presented. It is shown that the design parameters of ion beams at the entrance of correcting magnet will be obtained using false channel, which is a copy of the passive channel, located on the opposite side of the magnetic system. Extraction efficiency of ions will reach 75%.     

Two-dimensional hard x-ray beam compression by combined focusing and waveguide optics

A two-dimensionally confining x-ray channel waveguide structure is combined with a high gain Kirkpatrick-Baez prefocusing mirror system yielding a hard x-ray beam with a cross section of 25 x 47 nm(2) (FWHM). Unlike the previously employed resonant beam coupling scheme, the incoming beam is coupled in from the front side of the waveguide and the waveguided beam is no longer accompanied by spurious reflected or transmitted beams. The field distribution in the waveguide channel has been calculated numerically. The calculated transmission and far-field intensity pattern are in good agreement with the experimental results.     

Using the compute unified device architecture programming environment in simulation of ion-beam injection line with account for space charge effect

A simulation of the beam injection line in a synchrotron is performed within the Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research (VBLHEP JINR), project “The Development and Implementation of Units of a Synchrotron for Hadron Therapy.” The parameters of the injection line are chosen for the transport of beams with intensities of 25–100 mA through the injection channel of the synchrotron with account for the space-charge effect. The simulation was performed using the method of macroparticles (the PIC method). The approach of massively parallel computations on graphics processors using Compute Unified Device Architecture (CUDA) technology was applied for the acceleration of computations. The 66-fold speedup of computations was obtained using the Tesla C1060 computing module instead of a single-core CPU with 2.4 GHz.     

HIRFL-CSR commissioning in 2006 and 2007

HIRFL-CSR, a new heavy ion cooler-storage-ring system at IMP, had been in commissioning since the beginning of 2006. In the two years of 2006 and 2007 the CSR commissioning was finished, including the stripping injection (STI), electron-cooling with hollow electron beam, C-beam stacking with the combination of STI and e-cooling, the wide energy-range synchrotron ramping from 7 MeV/u to 1000 MeV/u by changing the RF harmonic-number at mid-energy, the multiple multi-turn injection (MMI), the beam accumulation with MMI and e-cooling for heavy-ion beams of Ar, Kr and Xe, the fast extraction from CSRm and single-turn injection to CSRe, beam stacking in CSRe and the RIBs mass-spectrometer test with the isochronous mode in CSRe by using the time-of-flight method.     

基于EPICS的CSRe束流诊断控制系统升级

兰州重离子加速器(HIRFL)冷却存储环的实验环（CSRe）提供高品质的束流用于高精度的质量测量、原子物理等实验研究,实现束流参数的准确测量是进行物理实验的前提保障。目前,CSRe加速器控制系统已升级为EPICS架构。介绍了基于EPICS的束流诊断控制系统现状,并利用升级后的控制系统测量了束流相关参数。其中,束流位置系统能够测量注入束流的逐圈位置信息,测量结果发现束流在注入过程中存在一定程度的震荡,影响注入效率。流强测量系统通过高分辨的数据采集卡实现对DCCT信号的精确测量,同时增加了D事例触发功能。升级后的控制系统,可以实现束流参数的测量,并集成于加速器控制系统的EPICS CSS界面。     

HIRFL-CSR commissioning in 2006 and 2007

HIRFL-CSR, a new heavy ion cooler-storage-ring system at IMP, had been in commissioning since the beginning of 2006. In the two years of 2006 and 2007 the CSR commissioning was finished, including the stripping injection (STI), electron-cooling with hollow electron beam, C-beam stacking with the combination of STI and e-cooling, the wide energy-range synchrotron ramping from 7 MeV/u to 1000 MeV/u by changing the RF harmonic-number at mid-energy, the multiple multi-turn injection (MMI), the beam accumulation with MMI and e-cooling for heavy-ion beams of Ar, Kr and Xe, the fast extraction from CSRm and single-turn injection to CSRe, beam stacking in CSRe and the RIBs mass-spectrometer test with the isochronous mode in CSRe by using the time-of-flight method.