We present observations of the radiation produced by electrons making multiple passes through thin targets in a betatron. We show the influence of multiple passes on the distribution of electrons and on the angular distribution of bremsstrahlung. Measurements of electron-beam spots and bremsstrahlung distributions have been performed for 15-33 MeV electrons and target thicknesses of 10-5-3.5×10-3 radiation lengths. Estimates of the number of passes were obtained for thin targets by comparing them with 1.3 mm thick W and 1.5 mm thick Cu targets, through which electrons pass only once. The numbers of 33 MeV electron passes observed were 460 for 3 μm Mylar, 200 for 20 μm Be, 171 for 5 μm Cu and 30 for 15 μm Cu foils. The multiple pass effect can be useful in the future for increasing the efficiency of novel X-ray sources, such as transition and parametric radiators.
|Number of pages||13|
|Journal||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|Publication status||Published - 1 Jan 2001|
ASJC Scopus subject areas
- Nuclear and High Energy Physics