Radioactive nuclear beam facilities based on projectile fragmentation
Radioactive nuclear beam facilities based on projectile fragmentation
复制标题
基于射弹破碎的放射性核束设施
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
B. Sherrill
中科院分区：
文献类型：
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作者：
D. Morrissey;B. Sherrill
讨论了利用直接飞行分离技术生产放射性离子的问题。用于产生接近射弹速度的放射性束的反应机制大致可分为四类：射弹碎裂、核子转移、裂变和库仑激发。由这些反应产生的放射性核具有较大的前向动量，具有相对尖锐的角分布，峰值接近零度。这种窄分布适合于用磁性装置收集。进一步的光束净化可以通过利用与第二磁选择相结合的异形能量降能器中的原子能量损失过程来实现。次级射束强度可能高达初级射束强度的1%左右，尽管射束发射度取决于产生机制并且可能很差。介绍了其生产反应机理、分离技术的特点，并对国内外的研究进展进行了综述。还讨论了该方法的相对优点和缺点，沿着讨论了可用于克服某些缺点的技术。
The production of radioactive ions by using direct in-flight separation techniques is discussed. The reaction mechanisms used to produce radioactive beams near projectile velocities can be broadly divided into four classes: projectile fragmentation, nucleon transfer, fission, and Coulomb excitation. Radioactive nuclei produced by these reactions have large forward momenta with relatively sharp angular distributions peaked close to zero degrees. Such narrow distributions are suitable for collection with magnetic devices. Further beam purification can be achieved by exploiting atomic energy-loss processes in profiled energy degraders combined with a second magnetic selection. Secondary beam intensities of up to 1%, or so, of the primary beam intensity are possible, although the beam emittance depends on the production mechanism and may be poor. The features of the production reaction mechanisms, separation techniques, and a review of worldwide efforts are presented. Also the relative advantages and disadvantages of the method are discussed along with techniques that can be used to overcome some of the disadvantages.