X1-Experiment : Undulator Radiation


   Smith Purcell




A low energy photon beam in the energy range between 15 eV and about 1 keV could be produced at MAMI with a short period undulator. The feasibility has been demonstrated with a 10 period prototype hybrid undulator (period length 12 mm, gap size 3 mm, magnetic field on axis 1 Tesla). Radiation up to the 7th harmonic has been observed. For a 100 period undulator the spectral brilliance of the first harmonic at 350 eV would amount to about 2*10^15 / (s mm^2 mrad^2 0.1% BW) at a beam current of 0.1 mA.

A novel interferometer , consisting of two undulators and a grating spectrometer, has been developed. It allows the measurement of the complex index of refraction of thin self supporting foils in the VUV
and soft X-ray region [5].
Production Mechanism
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