Produção de raios-X 10-100 keV Feixe de elétrons Alvo de Au detector
targets Target with 2-50 mg/cm2 Physical vapour deposition (Te) Sputtering (Ta) frame made on 0.3 mm thick carbon fiber Hole 10 mm in diameter 10 mg/cm2 C film target evaporated/deposited through a 8 mm mask
Elétrons de 98 keV em Ag (Z=47)
Elétrons de 98 keV em Ag e Te (Z=47, 52)
Elétrons de 98 keV em Ag, Pd e Te (Z=47, 48, 52)
Elétrons de E=25,41,60,79 keV em Ag
Elétrons de E=25,41,60,79,98 keV em Ag
Electron interactions Electrons scatter and generate radiation along their path in matter q E E- R R- U qa inelastic scattering q E elastic scattering q E F bremsstrahlung emission q E E+ positron annihilation E- F E- target (atom or electron) Nice diagrams from PENELOPE manual by Salvat, Fernández-Varea, Sempau particle (electron, positron)
Photon interactions q E E- R Inelastic scattering ~ R qa E E q ~ E- U Photoelectric effect qa ~ 0 q E E+ pair formation q- E- target (atom, electron) E = E+ + E- + 2moc2 photon Photoelectric effect × bremsstrahlung Pair formation × positron annihilation Notice the reciprocal character of: