Use of Superconducting RF Systems in Low-Energy Accelerators

The basic problems of the development and construction of charged-particle accelerators using superconducting rf accelerating structures are discussed. The characteristics of the modular systems currently used in high-energy superconducting accelerators and their application to accelerators for tens or hundreds of MeV are examined. __________ Translated from Atomnaya Energiya, Vol. 99, No. 4, pp. 289–295, October, 2005.     

Wide-Aperture Electron Accelerators

Wide-aperture low-energy electron accelerators, which provide simultaneous irradiation of large surfaces and volumes, are used in radiation technology, ionization setups for gas lasers, and in scientific research. Certain modifications of wide-aperture electron accelerators – ionization setups for CO and CO₂ lasers and ozone generator based on an electron-beam-controlled discharge – are described.     

High Energy Electron Accelerators

The Cambridge Electron Accelerator is now in full-scale operation for research at energies up to 6 Bev, five times higher than earlier electron accelerators. The machine, a synchrotron, uses a ring of 48 alternating gradient magnets in a circle 236 feet in diameter. Electrons are accelerated by RF fields produced in a set of sixteen resonant cavities spaced around the orbit. The frequency used is 476 Mc/s, the 360th harmonic of the orbital frequency. Injection of 30-Mev electrons is accomplished by using a linear accelerator operating at 2855 Mc/s. The main machine accepts and-accelerates to maximum energy beam currents of up to 1.2 x 1012 electrons/sec. The quality of the beam is fully as good as that from a linear accelerator. The CEA laboratory operates five days a week on a three-shift basis and has a staff of 160 people.     

Progress Report on Superconducting Proton Linacs

The work on superconducting proton and heavy ion accelerators will be reviewed. The helix seems to be an adequate structure for low velocity particles. For energies above 15 MeV/N other types of accelerating structures may be used. Superconducting Nb helices were developed at several places. A maximum gradient of 2.8 MV/m witha Q of 2.109 has been obtained recently in Karlsruhe with a ?/2 Nb helix at 90 MHz. First proton acceleration in superconducting helical structures indicates the status of the new technology.     

Race-Track Microtron–Recirculator with Superconducting RF Cavities

The importance of designing and building a modern continuous electron beam accelerator for medium energy and possible directions for the design and implementation of the basic systems of such an accelerator are examined. Substantiation is given for the type of accelerator – a race-track microtorn with energy up to 200 MeV using superconducting accelerating cavities operating at liquid-helium temperature. A novel scheme is proposed for the microtron–recirculator. In this scheme, recirculation with individual deflection and focusing systems is orgnized for the first few orbits; further acceleration occurs in a standard microtron regime.     

230 MeV超导回旋加速器高频腔体的研制

中国原子能科学研究院目前正在研制一台用于质子治疗的230 MeV超导回旋加速器。本文设计用于230 MeV超导回旋加速器的高频腔体,其采用螺旋结构,由4个腔体组成,高频系统采用二次谐波加速,高频腔体工作频率约71.25 MHz。4个半波长的电容加载型谐振腔工作于Push-Pull模式,其中两个腔体在中心平面直连,另外两个腔体在中心区下方使用过桥连接,两组腔体之间存在电容耦合,相差180°。在腔体的设计过程中,采用计算机对4腔体进行联合仿真,经优化后,腔体加速电压分布在中心区部分的为75 kV,大半径部分的提升至110 kV,腔体的无载品质因数仿真结果约8 800。为保证腔体的高频性能,腔体主体材料采用无氧铜材料,其加工难度在于上、下外壳需分别焊接成一个整体,同时要控制其形变量。目前,腔体已完成加工,单个腔体的无载品质因数的测试表明,腔体的无载品质因数均好于7 000,满足要求。     

超导四分之一波长谐振腔高频功率磁耦合器物理设计

为指导超导四分之一波长谐振腔(QWR)高频功率磁耦合器设计，基于三维电磁场程序给出的超导QWR电磁场分布，本工作计算了磁耦合器的位置和伸入深度，给出了一定带宽下的耦合强度，提出了磁耦合器在热力学上的设计要求。      

Electron Loading in L- and S-Band Superconducting Niobium Cavities

Electron loading has been investigated in super-conducting niobium L- and S-band TM010 mode single-cell cavities at high field by observing the x-radiation which electrons accelerated by the RF fields produce on collisison with a cavity wall. This x-radiation has been studied for various cavity lengths, cavity resonant frequencies, and vacuum and surface conditions. Also, electron loading has been found to produce regenerative excitation of higher modes in both L- and S-band cavities.     

Multi-channel FIR Interferometer for Electron Density Measurement on HT-7 Superconducting Tokamak

1. IntroductionHigh-density plasma are of interest in thermonuclear fusion research. Fusion plasma density canbe measured by FIR laser and submillimeter waveinterferometer [l]. Plasma are transparent as longas the plasma frequency wp is smaller than the frequency w of the probe wave. The index of refractionof a medium is easily measurable by using electromagnetic waves for which the medium is transparent [l,21. The values of tile index of refraction, po,correspond to a polarized wave with it…     

Development Progress of CYCIAE-230 Superconducting Cyclotron

正A 230 MeV superconducting key technologies including energy degrader,beam transport line and patient-treatment technology research are developed.The goal is to build a 230 MeV superconducting cyclotron with beam transport line,gantry,nozzle etc.,which is used for proton     

Progress Report of CYCIAE-230 Superconducting Cyclotron

<正>2019 is a key year for the development of the CYCIAE-230 superconducting cyclotron.In this year,the significant progress in the construction and the main process equipment installation has been made,and successful completion of the task of the whole year has been achieved.The construction and commissioning of the cyclotron have made significant progress to fully complete the goals of various tasks,which making a goodfoundation for the commissioning of the 230 MeV superconducting cyclotron in 2020.     

Cryogenic Stand for Testing Cryostats with Superconducting RF Resonators at 1.8 K

A separated K-meson complex is being designed at the Institute of High-Energy Physics. One of the main components is an rf separator consisting of two superconducting niobium resonators. A newly developed cryogenic-vacuum stand for testing resonators is described. The results of cryogenic–vacuum tests of the system for cryogenic support of the resonators at 1.8–4.2 K are presented.     

Progress on Field Mapping System for 230 MeV Superconducting Cyclotron

<正>Isochronism is a key factor to evaluate the performance of a cyclotron,which has to be calculated through field mapping.The field mapping range is from 0to 85cm in radial direction and 0to 360degree in azimuthal direction in the median plane.The maximum field is about4.0T.The required measurement precision is     

Super-Energy Accelerators

The further development of high energy physics through the next decade will require new accelerators capable of energies of an order of magnitude greater than presently available. A brief review is given of the current status of plans for the "super-energy" accelerators. Basic parameters are presented for machines in the 200-1000 BeV energy range and the current study at the Lawrence Radiation Laboratory of a 200 BeV accelerator is described in some detail, as an example of the general class.     

Impact of Accelerators on Technology

Accelerators and accelerator technology has rapidly expanded into Medicine and Industry. The 2500 accelerators in the USA, which represent about 2/3 the worldwide census of accelerators are primarily devoted to practical applications, although the major impact on technology has been produced by a relatively few excellent facilities. Approximately 80% of the current accelerators in the USA are found to be in medical and industrial use representing a capital investment by industry of $200,000,000. Of greater importance is their impact on the treatment of cancer, and the improvement or creation of better products for industrial and consumer use. The development of new accelerators and techniques are required in order to insure continuing benefits to the public.