STUDY ON THE MAGNETIC COMPRESSION OF INTENSE RELATIVISTIC ELECTRON BEAMS UNDER A CONVERGING MAGNETIC GUIDE FIELD

The magnetic compression of intense relativistic electron beams under a converging magnetic guide field is studied theoretically and experimentally in this paper. A code to evaluate the compressed-beam transport is set up. Calculations of the beam energy fraction transmitted through magnetic mirror are in good agreement with experimental data.     

我国九十年代加速器的发展展望

 在过去的10年里,我国粒子加速器的研究、设计、制造和应用有了巨大的发展和长足的进步.在80年代由于我国三大加速器工程的建成,打破了建国30多年来总在低能加速器上徘徊的局面,从而使我国成为拥有高、中能加速器的国家,标志着我国的科学技术和加工工业已达到或接近国际水平同时,我国的低能加速器在工业、农业、医学和科学技术上的应用日趋广泛,某些低能加速器的制造如医用加速器开始走向系列化、商品化.这表明我国低能加速器的制造技术已日趋成熟.总之,在我国目前除了高能质子加速器外,可以说加速器品种基本齐全,能区连续,有较好的工业基础并有一支高水平的技术队伍.展望未来,我们相信90年代将会有更大的作为.     

高频高效率混合型潘尼管的理论分析

对混合型潘尼管作了等离子体动力学分析和非线性粒子模拟。动力学的分析结果指出，混合型潘尼管是基于潘尼管工作机理的一种混合器件。非线性模拟验证了这一结论，并指出混合型潘尼管具有二个优点:高效率和高频率。     

EXPERIMENTAL STUDY ON THE UNIFORMITY OF LARGE AREA INTENSE RELATIVISTIC ELECTRON BEAMS

The uniformity of intense relativistic electron beams under a converging magnetic guide field is studied experimentally in this paper. In the experiments, fluence calorimeter and X-ray pinhole photograph were used to measure the beam uniformity. The experimental results show that the externally applied magnetic flux density at the cathode and the shape of cathode face have considerable influence on the beam uniformity, The beam uniformity better than 80% is obtained over an area of 200cm² when the externally applied magnetic flux density at the cathode is about 0.6T and the cathode face is concave to a depth of 1.5 mm, relative to the cathode edge.     

THE PROCESS OF SPACE CURRENT NEUTRALIZATION OF INTENSE RELATIVISTIC ELECTRON BEAM UNDER AN EXTERNALLY APPLIED MAGNETIC GUIDE FIELD

The process of space current neutralization of intense relativistic electron beam under an externally applied magnetic guide field is discussed in this paper. Ionization by electron avalanching and by beam electrons impact and recombination is included in the calculation of plasma density buildup, with plasma heating by return current and two- stream instability taken into account. A code to evaluate the process of space current neutralization was set up. The calculations demonstrate that the optimum gas pressure increases as peak beam current increases and it decreases as the risetime of beam pulse increases.