An analysis of spectral-angular characteristics of diffraction radiation, both incoherent and coherent, has been performed. It is shown that radiation processes can be interpreted as Cherenkov radiation, which is produced by a region of dynamic polarization moving along a target edge with superluminal velocity ##IMG## [http://ej.iop.org/images/1063-7869/63/3/303/tex_pu_8784_img1.gif] {$ v _{\rm SL}$} . Such radiation is generated if the condition ##IMG## [http://ej.iop.org/images/1063-7869/63/3/303/tex_pu_8784_img1.gif] {$ v _{\rm SL}$} > ##IMG## [http://ej.iop.org/images/1063-7869/63/3/303/tex_pu_8784_img2.gif] {$ c$} is fulfilled, which is the conventional `threshold' Cherenkov condition.

中文翻译：

---

来自电荷的衍射辐射，作为来自真空中超腔源的辐射

已对衍射辐射的光谱角特性进行了分析，包括非相干和相干。结果表明，辐射过程可以解释为切伦科夫辐射，它是由动态极化区域沿目标边缘以超光速## IMG ## [http://ej.iop.org/images/1063- 7869/63/3/303 / tex_pu_8784_img1.gif] {$ v _ {\ rm SL} $}。如果条件## IMG ## [http://ej.iop.org/images/1063-7869/63/3/303/tex_pu_8784_img1.gif] {$ v _ {\ rm SL} $}，就会产生这种辐射。 > ## IMG ## [http://ej.iop.org/images/1063-7869/63/3/303/tex_pu_8784_img2.gif] {$ c $}被满足，这是常规的“阈值”契伦科夫条件。