Coherent synchrotron radiation in the far-infrared from a 1 mm electron bunch
Coherent synchrotron radiation in the far-infrared from a 1 mm electron bunch
复制标题
来自 1 毫米电子束的远红外相干同步加速器辐射
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
B. Nelander
中科院分区：
文献类型：
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作者：
Å. Andersson;M. Johnson;B. Nelander
同步辐射的相干产生的电子储存环的预测波长等于或大于电子束团的长度。由于典型的聚束长度约为1 cm，衍射和室屏蔽效应迄今为止阻碍了对来自常规辐射光束线的相干辐射的观察。在低能量，第二代光源MAX-I，磁晶格已被调整到一个小的动量压缩因子，允许均方根束长度短至1毫米。在这里，我们报告的相干远红外发射观察到这样一个束。本文讨论了高斯和非高斯电子聚束相干同步辐射的起源，以及产生这种聚束的过程。发射的特点是使用红外光束线在MAX-I，包括干涉仪，液氦冷却测辐射热计检测器，波导高通滤波器，和导电栅偏振滤波器。相干辐射的强度比普通的非相干同步辐射大2×103到6×103倍，在8到22 cm-1之间可见。
The coherent generation of synchrotron radiation by an electron storage ring is predicted for wavelengths equal to or longer than the electron bunch length. With typical bunch lengths of approximately 1 cm, diffraction and chamber-screening effects have so far blocked observation of coherent radiation from a conventional radiation beamline. In the low-energy, second-generation light source MAX-I, the magnet lattice has been tuned to a small momentum compaction factor, allowing rms bunch lengths as short as 1 mm. Here we report the coherent far-infrared emission observed from such a bunch. The paper discusses the origin of coherent synchrotron radiation for Gaussian and non-Gaussian electron bunches, and the procedure used to generate such bunches. The emission was characterized using the infrared beamline at MAX-I, including an interferometer, a liquid-helium-cooled bolometer detector, waveguide high-pass filters, and a conductive-grid polarization filter. The intensity of the coherent radiation is greater by a factor of 2×103 to 6×103 than normal incoherent synchrotron radiation, and is seen between 8 and 22 cm-1.