标题： 平面波荡器中有限发散电子束自发辐射发射的功率密度计算的简单方法 显示英文标题

标题： A simple approach for power density calculation of spontaneous radiation emission from a finite emittance electron beam in planar undulators

摘要： 我们将平面波荡器自发辐射的角功率密度公式扩展到包括电子束的有限发散角和角度错配。然后我们计算并比较了从积分方法估计的功率密度与高斯光束分布以及覆盖粒子束相空间的宏粒子分配的求和方法得到的功率密度。在证明这两种方法收敛于彼此之后，我们应用宏粒子方法研究了国家同步辐射光源II的9-ID光束线前端各种孔径吸收和传输的功率。我们的分析表明，电子束的角度错配可能导致在更紧的孔径处产生不必要的功率沉积，这在使用几何光线追踪方法进行孔径设计/选择过程中原本难以考虑。 显示英文摘要

摘要： We extend the angular power density formulae for spontaneous radiation emission from planar undulators to include finite emittance and angular misalignment of the electron beam. Then we calculate and compare power densities estimated from integral approach with Gaussian beam distribution and summation approach with the macro-particle allocation covering the particle beam phase space. After showing that both approaches converge to each other, we apply the macro-particle approach to study power absorbed and transmitted by various apertures at the front end of the 9-ID beamline at the National Synchrotron Light Source-II. Our analysis indicate that the electron beam misalignment could lead to unwarranted power deposition at tighter apertures that would have been otherwise difficult to account in the aperture design/choice process using the geometric ray-tracing approach.