共查询到20条相似文献,搜索用时 0 毫秒
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Russian Physics Journal - Coherent optical transition radiation (COTR) from femtosecond electron bunches is simulated using an earlier proposed model. It is shown that partial screening of the COTR... 相似文献
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BFEL装置短电子束团相干同步辐射产生理论计算与实验设计 总被引:1,自引:0,他引:1
分析和数值计算了利用BFEL装置的30MeV射频直线加速器提供的4ps电子束团产生的宽带连续的强相干同步辐射.由讨论可知,该束团可直接用以产生毫米波段相干同步辐射;通过压缩束团宽度至1ps甚至亚ps,可获得宽带连续(覆盖远红外—毫米波段)的强相干辐射.由于这种辐射位于相干辐射的珍稀或空白区,因而具有极高的应用价值.在该波长范围内,相干辐射功率约为非相干辐射的108—109倍.依赖于所选的波长范围和接收角,辐射功率在几百微瓦至毫瓦量级.最后给出辐射产生和束团测量的实验构想. 相似文献
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Gibson Richard A. Bennett Willard H. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(3):174-181
The appearance of large amplitude oscillations and attenuation of beam current have been observed in high perveance electrically self-focused beams. These phenomena are shown to be due to instabilities produced by the interaction of the beam with its self-generated plasma. The critical current which must be exceeded for the instabilities to appear and the frequencies of the oscillations have been related to beam and background parameters and the dimensions of the experimental system. 相似文献
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在电子直线加速器设计中,α-磁铁通常被用来压缩脉冲长度,采用热阴极微波电子枪和α-磁铁相结合的设计,可以获得皮秒或亚皮秒量级脉冲长度的电子束。电子束在α-磁铁中的传输过程较为复杂,相关文献介绍的研究成果均是基于理想模型,且有镜板开孔的α-磁铁的束流传输研究,对α-磁铁的使用具有重要的指导作用。本文首先简单介绍了用于高能电子成像装置的α-磁铁模型的设计,对电子束在理想模型与α-磁铁模型中传输模拟结果进行对比分析,验证了所构建模型可以有效地实现脉冲纵向压缩的结论。此外,对以优化角度进入α-磁铁和在空间电荷效应影响下的单束团及多束团束流动力学模拟结果进行了讨论,提出通过减小入射角度来补偿α-磁铁镜板上的束流进出孔对束流传输影响的方案。通过在α-磁铁与电子枪之间增加四极磁铁组,优化了束流发射度和束团尺寸。 相似文献
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Physics of Atomic Nuclei - Emission of short electron bunches with high charge in RF guns is considered. The emission mechanism in the case of picosecond laser pulses and the presence of a strong... 相似文献
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通过分析束流频谱与高频腔高次模的相互作用,提出了计算单束流和双束流储存环中非均匀束团产生的高频腔高次模功率的方法,推导出了这两种情况下的一般通用公式,并对所得到的解析结果进行了比较和讨论. 相似文献
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电子储存环的电子束流与环中的残余气体碰撞会产生轫致辐射,这也是造成储存环中束流损失的主要原因之一.一直以来,由于各种原因,人们在辐射防护上并没有给予它足够的重视.本文通过一些经验公式对该轫致辐射进行了分析和计算:(1)该轫致辐射会导致较高的剂量率,尤其是在直线节;(2)影响剂量率的几个主要因素;(3)轫致辐射中的高能粒子占有很大的比例. 相似文献
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Ohmi K 《Physical review letters》1995,75(8):1526-1529
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Sh.E. Tsimring 《International Journal of Infrared and Millimeter Waves》2001,22(10):1433-1468
The stability of the electron beams and maximum share of the electrons oscillatory energy, i.e. finally efficiency, power, and pulse duration of the gyrotron to a considerable extent depend on the velocity and the energy spread (VESP) of the HEB. The basic factors determining VESP in the helical beams are discussed. Among these factors static (initial velocities, cathode heterogeneities, space charge fields) and dynamic (negative mass and diochotron instabilities and a global instability connected with the capture of the electrons in the gyrotron adiabatic trap) factors are considered. Qualitative models of the excitation of the space charge oscillation as well the parasite electromagnetic radiation of the HEB are developed. Some experimental data of the investigation of the parasitic electromagnetic radiation spectrum in one gyrotron are discussed. The methods of the experimental investigation of the VESP are described. 相似文献
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Recent experiments on RECE-Christa showed trapping of field-reversing electron rings with large length-to-radius ratios L/R ? 6, compared with L/R ? 1-2 observed so far. These rings translated stably over axial distances of up to 20 ring radii. Their self-field 8Bz (initially up to 2.6 Bz0) decayed smoothly with L/R remaining roughly constant. 相似文献
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A. A. Babaev A. S. Gogolev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2018,12(2):222-226
A theoretical model is developed for the heating and deformation of a thin target at the passage of short electron bunches through it at the energies of modern free electron lasers, and the corresponding simulation is carried out. It is demonstrated that under these conditions, the target can undergo overheating or be irreversibly deformed, which makes it difficult to use such targets for the diagnostics of free electron beams used in modern lasers. 相似文献
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Journal of Experimental and Theoretical Physics - The mechanisms of formation and coherent transport of free and bound electron excited states in organic solar cells are considered. In the model of... 相似文献
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将环形加速器磁聚焦结构设计中, 传统的聚焦和散焦磁铁强度空间中的稳定图方法, 应用到更复杂的含有两个以上磁场梯度变量的超周期结构中, 从而更深入地理解结构共振的形成机制和隐含的物理意义. 利用文中给出的方法, 可以指导环形加速器磁聚焦结构的工作点选择. 对于一个给定的磁聚焦结构, 由于结构共振而导致的束流包络函数变化的不对称性, 则是其动力学孔径不对称的一个重要原因. 作为实例, 给出了在实际机器上的具体应用, 同时给出了动力学孔径的模拟计算结果. 相似文献
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S. V. Kuznetsov 《Physics of Particles and Nuclei Letters》2018,15(7):728-731
The formation and acceleration of electron bunches resulting from the self-injection of electrons into the wake wave from the laser pulse moving through a sharp plasma boundary are investigated in one-dimensional geometry. It is shown that electron trapping in the accelerating wakefield is governed by the electron energy and has a threshold character. The acceleration of the trapped bunch is numerically simulated. 相似文献
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通过解析的方法分析了储存环在部分填充情况下的纵向耦合不稳定性,给出了不稳定性增长率和同步振荡频移的表达式.得到了一个有趣的结果:虚部阻抗对不稳定性的增长率也有贡献.这一点和均匀填充情况是不一样的. 相似文献