Interaction cross sections needed for simulation of secondary electron emission spectra from thin metal foils after fast proton impact

Monte Carlo simulations of secondary electron emission from thin metal foils after fast proton impact require reliable interaction cross sections with the target under consideration. Total and energy differential inelastic cross sections have been derived for aluminum, copper, and gold thin-metal foils within the plane-wave first Born approximation (PWFBA) that factorizes the double cross section into the generalized oscillator strength and kinematic factors. The generalized oscillator strength or Bethe surface of the medium is obtained by using a semi-empirical optical oscillator strength distribution published in the literature and an extension algorithm based on the delta-oscillator model. Energy differential, total, and stopping cross sections are then obtained by simple integrations. Comparisons with other calculations and experimental values from the literature show that our model offers a good agreement in the energy range considered. As a final step, the cross sections and a transport model for copper have been implemented into the Monte Carlo track structure code PARTRAC where simulations of secondary electron emission spectra from copper foil  have been performed.  M.S

Electron Emission from Foils and Biological Materials after Proton Impact

Electron emission spectra from thin metal foils with thin layers of water frozen on them (amorphous solid water) after fast proton impact have been measured and have been simulated in liquid water using the event-by-event track structure code PARTRAC. The electron transport model of PARTRAC has been extended to simulate electron transport down to 1 eV by including low-energy phonon, vibrational and electronic excitations as measured by Michaud et al. (Radiat. Res. 159, 3–22, 2003) for amorphous ice. Simulated liquid water yields follow in general the amorphous solid water measurements at higher energies, but overestimate them significantly at energies below 50 eV. Originally published Radiation Physics and Chemistry, Vol. 77, No. 10-12, Oct-Dec 200

Interaction cross sections needed for simulation of secondary electron emission spectra from thin metal foils after fast proton impact

Monte Carlo simulations of secondary electron emission from thin metal foils after fast proton impact require reliable interaction cross sections with the target under consideration. Total and energy differential inelastic cross sections have been derived for aluminum, copper, and gold thin-metal foils within the plane-wave first Born approximation (PWFBA) that factorizes the double cross section into the generalized oscillator strength and kinematic factors. The generalized oscillator strength or Bethe surface of the medium is obtained by using a semi-empirical optical oscillator strength distribution published in the literature and an extension algorithm based on the delta-oscillator model. Energy differential, total, and stopping cross sections are then obtained by simple integrations. Comparisons with other calculations and experimental values from the literature show that our model offers a good agreement in the energy range considered. As a final step, the cross sections and a transport model for copper have been implemented into the Monte Carlo track structure code PARTRAC where simulations of secondary electron emission spectra from copper foil  have been performed. 

Electron Emission from Foils and Biological Materials after Proton Impact

Electron emission spectra from thin metal foils with thin layers of water frozen on them (amorphous solid water) after fast proton impact have been measured and have been simulated in liquid water using the event-by-event track structure code PARTRAC. The electron transport model of PARTRAC has been extended to simulate electron transport down to 1 eV by including low-energy phonon vibrational and electronic excitations as measured by Michaud et al. (Radiat. Res. 159 3–22 2003) for amorphous ice. Simulated liquid water yields follow in general the amorphous solid water measurements at higher energies but overestimate them significantly at energies below 50 eV. Originally published Radiation Physics and Chemistry Vol. 77 No. 10-12 Oct-Dec 200