Determination of the Sickafus index by positron-stimulated secondary electron emission

Thickness dependence of positron induced secondary electron emission in forward geometry from thin carbon foils

“…4. Unlike the results of Overton when they used 2 keV positron beam to bombard copper [3], the high energy tail of SE in our result is quite short and the main peak is within 10 eV. Fig.…”

“…It has received a great deal of attention in the past because it gives an insight into the Physics of electron-solid interactions [3] and has many applications such as electrical discharges, surface analysis and space environment [4]. In our previous work [5], we also gave a novel design of a cylindrically symmetric VEPALS system based on secondary electron (SE) emission from carbon foil.…”

“…Matthew et al measure different samples to find m within 0.5-1.5 [14] and their Monte Carlo simulation of the SE background in the range from 200 to 2000 eV also showed that the background could be characterized by the Sickafus form, with m close to unity [15]. Overton et al used a 2 keV incident positron beam to bombard copper and found m % 2 [3].…”

Measurement of the Energy Spectrum of Secondary Electrons Ejected from Solids by Positron Impact

“…It has been experimentally demonstrated that the low-energy secondary electron cascade spectra for both incident electrons and positrons are similar [9,10], but no measurements have been made to date in the Sickafus region. In a preliminary measurement the authors obtained a value of m close to 2 for a 2 keV positron beam incident at glancing angle ͑#5 ± ͒ on copper [11], in disagreement with previous experimental and theoretical results for electrons. The work presented in this Letter was motivated by the evident need for further measurements of m for different primary positron energies, target species, and incident angles.…”