摘要
提出了新的Ｓｍｉｔｈ－Ｐｕｒｃｅｌｌ（ｓｐ）辐射模型，研究了沿金属光栅表面运动的自由电子的轫致辐射中的自发辐射、受激辐射和受激吸收等过程，发现电子的自发辐射也会随着电子束厚度的增加而出现饱和。还讨论了由ＳＰ效应实现短波长自由电子激光器的前景，认为这种前景并不容乐观。最后还对ＳＰ效应中几个急待解决的问题进行了讨论。
Abstract Smith-purcell(SP)radiation is discussed in this paper.In recent experimental andtheory studies[1～6],SP radiation is highlighted on completing short wavelength freeelectron lasers (FELs)in the future. However,we find that,in those papers [5,6], someof the details must be treated carefully.(1)In papers[5,6],electron scattering from metal grating is regarded to get resonantat △k_y=2nπ/α,but it is the resonant condition of electron beam injecting through metallattice. In deed, in SP radiation experiments the coincidence of electron with metal gratingis often avoided.It can be considered that the resonant condition of SP radiation is△k_y=2nπ/λ_g,when n=1 the radiation wavelength≈λ_g,this is in line with the experimentalresults.(2)In papers[5,6], the potential function in metal V(r)=0 is ignored.(3)In papers[5,6],because the SP radiation is treated with semi-quantum theory, nostimulated absorption is considered.In this paper,we will study SP radiation with quantum theory about its spontaneousradiation,stimulated radiation and stimulated absorption. It is found that random radiationwill also saturate with the height of electron beam. Discussions on the characteristics of SPradiation is made later on. However, because of the complication of V_(△k),the exact result ofSP radiation is not available in this paper.
出处
《强激光与粒子束》
EI
CAS
CSCD
1995年第1期41-48,共8页
High Power Laser and Particle Beams
