| Paper | Title | Page |
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| TUPEA077 | Low-Secondary Electron Yield of Ferrromagnetic Materials and Magnetized Surfaces | 1500 |
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We are presenting first results of direct measurements of the secondary electron emission yield (SEY) for several magnetic materials like ferrites at energies of primary electrons from 5 to 1000 eV. In order to minimize the impact of surface charging, the primary electron beam had a short pulse modulation of 400ns with a very low repetition rate. This paper discusses a method of developing a secondary-electron-suppressing highly textured ferrite surface with low SEY by depositing a layer of very fine ferrite particles onto a substrate. The experimental results indicate that the SEY of the particulate ferrite surfaces is much lower than that of flat ferrites. In comparison we have confirmed that ordinary carbon coating with rather large grain size returns SEY value close to unity. However, a surface with very finely powdered carbon has a much smaller secondary emission yield of about 0.5, but the adhesion of these carbon powders to the surface is often not reliable enough for many applications. As a remarkable fact it has been found that gold- and also carbon-coated ferrites have SEY peak values lower than unity up to 1000eV. |