OBSERVATION OF COHERENT SMITH-PURCELL RADIATION USING AN INITIALLY CONTINUOUS FLAT BEAM
OBSERVATION OF COHERENT SMITH-PURCELL RADIATION USING AN INITIALLY CONTINUOUS FLAT BEAM
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DOI：
10.1103/physrevstab.12.110701
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发表时间：
2009-11
影响因子：
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通讯作者：
J. Gardelle;L. Courtois;P. Modin;J. Donohue
中科院分区：
文献类型：
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作者：
J. Gardelle;L. Courtois;P. Modin;J. Donohue
几年前，提出了一种从最初连续的电子束产生相干史密斯-珀塞尔（SP）辐射的新理论。它是二维 (2D) 的，并且得到了 2D 粒子代码模拟的支持。我们在这里报告了使用强连续扁平光束进行的实验结果，证实了这一理论。单次脉冲电源提供的最大电压为 100 kV。光束通常宽 10 厘米，厚几毫米，峰值电流为 150 A。层状光栅有 20 个 2 厘米周期，在 4.5 GHz 附近的预测基本光栅模式频率下观察到辐射。在 SP 公式预测的角度处也观察到了二次和三次谐波。使用电流监视器和放置在凹槽末端的拾取环获得了光束聚束的直接证据。总的来说，该实验与理论之间具有良好的一致性。
A few years ago, a new theory for producing coherent Smith-Purcell (SP) radiation from an initially continuous electron beam was proposed. It was two-dimensional (2D), and it has been supported by 2-D particle-in-code simulations. We report here the results of an experiment using an intense continuous flat beam that confirms the theory. A maximum voltage of 100 kV was supplied by a single-shot pulsed-power source. The beam was typically 10 cm wide and a few mm thick, with a peak current of 150 A. The lamellar grating had twenty 2-cm periods, and radiation was observed at the predicted fundamental grating mode frequency near 4.5 GHz. The second and third harmonics were also observed at the angles predicted by the SP formula. Direct evidence for beam bunching was obtained using both a current monitor and a pick-up loop placed at the end of a groove. In general, good agreement between this experiment and theory is found.