A correction to an equation in the paper by Zhukovsky [(2020). J. Synchrotron Rad.27, 1648–1661] is made and, following from this, values of some Bessel coefficients and some harmonic intensities from an elliptic undulator with the third field harmonic.

中文翻译：

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来自多谐波波荡器的FEL辐射的理论光谱分析。更正

Zhukovsky [（2020）。J.同步加速器辐射 [ 27，1648–1661]作成，并据此得出了具有三次场谐波的椭圆波荡器的某些Bessel系数和某些谐波强度的值。