| Autor: |
Smirnov, A. V. |
| Předmět: |
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| Zdroj: |
Review of Scientific Instruments; Mar2001, Vol. 72 Issue 3, p1649, 8p |
| Abstrakt: |
A special two-period insertion device is considered in terms of useful properties of spontaneous emission. General idea of the geometry can be interpreted as helical transformation applied to an original linear undulator structure to provide superimposed fast and slow transverse oscillations of the electron beam. Periodic sextupolar focusing effect of the device is calculated analytically. Three-dimensional hybrid magnetic design is treated numerically on the base of traditional and specially modified feasible structures. Main properties of the spontaneous emission of single electron were studied using a derived analytical form and numerical computations. The following features of the radiation are outlined: (i) reduction of relative content of higher odd harmonics as the "slow" imposed helical field increases; (ii) radiation enhancement as the number of helical turns increases; (iii) spectral line splitting and intensity adjustment; and (iv) opposite directions of circular polarization for adjacent spectral lines. In particular, unlike most insertion devices this structure does not require any magnetic readjustments or electromagnetic switching to provide opposite polarization. Potential technical advantages in application for single pass superradiant free electron lasers are also discussed. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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