Theory of Coherent Radiation from Periodic Structures

在现代科学中，强x光子源如GeV同步辐射装置的作用是相当重要的。毫无疑问，一个更紧凑、可调谐、单色和强的x光子源将在科学、技术和医学的各个领域带来进一步的发展。在此基础上，我们必须探索除通道辐射、参数x辐射等已知相干辐射之外的相干辐射源的新机制，努力寻找相干辐射的新机制，并对这一领域的实验结果进行解释。以下是我们对这个问题的主要研究结果。预测了MeV平面通道电子的一种新型强x光子发射。它被发射到接近于电子束的布拉格角的方向。预测的x光子的谱密度比参数x辐射的谱密度大数百倍以上。给出了最近观测到的层状硅单晶单色x辐射的理论。我们的数值计算结果与实验数据吻合。理论是基于量子力学方法的衍射跃迁辐射。对通道电子的非相干轫致进行了计算机模拟。我们的结果与1.3GeV通道电子对1.04GeV光子角依赖性的实验结果很好地吻合。

In the modern science the role of strong x-photon sources such as the GeV synchrotron radiation facilities is quite important. There is no doubt that a more compact, tunable, monochromatic as well as strong x-photon source will bring a further developments in a varaety of fields of science, technology, and medicine. In this connection, we have to investigate a new mechanism for such sources beyond the known coherent radiations such as channeling radiation, parametric x radiation, etc, We are trying to find a new mechanism of coherent radiation as well as explaining experimental results in this field. Followings are our main results related on this problem.1. A new type of strong X-photon emission is predicted for MeV planar channeled electrons. It is emitted into the direction close to the Bragg angle with respect to the electron beam. The spectral density of the predicted X-photons is more than hundreds times larger than that of parametric x radiation.2. Theory of monochromatic x radiation from stratified Si single crystal observed recently has been given. Our numerical results agree with the experimental data. Theory is based on the quantum-mechanical approach to the diffracted transition radiation.3. Computer simulation on the incoherent bremsstrahlung from channeled electrons has been per-formed. Our result agrees well with the experimental result of the angular dependence of 1.04GeV photons from 1.3GeV channeled electrons electrons in Si crystals that has not been explained theoretically so far.