Narrow Results

Based on the formula for the average energy required to produce an internal secondary electron (ε) in emitter, the energy band of insulator and the assumption that the maximum exit energy of secondary electron in insulator is reverse to the width of forbidden band, the formula for ε in insulator is deduced. On the basis of the formula for the number of internal secondary electrons produced in the direction of the velocity of primary electrons per unit path length, the energy band of insulator and the characteristic of secondary electron emission, the formula for the probability of secondary electrons passing over the surface barrier of insulator into the vacuum (B) is also deduced. According to some relationship between the parameters of secondary electron yield from insulator, the formula for the mean escape depth (1/α) is successfully deduced. The formulae for ε and 1/α are experimentally proven, respectively, and thereafter the formula for B is indirectly proven to be true by the experimental results. It is concluded that the formulae for ε, B and 1/α are universal to estimate ε, B and 1/α under the condition that primary electrons from 10 keV to 30 keV hit on an insulator, respectively.

Based on primary range $R$, relationships among parameters of secondary electron yield $\delta$ and the processes and characteristics of secondary electron emission (SEE) from negative electron affinity (NEA) semiconductors, the universal formulas for $\delta$ at $0.1\mathrm{\text{keV}}\le E_{\mathrm{\text{p}}}\le 10\mathrm{\text{keV}}$ and at $10\mathrm{\text{keV}}\le E_{\mathrm{\text{p}}}\le 100\mathrm{\text{keV}}$ for NEA semiconductors were deduced, respectively; where $E_{\mathrm{\text{p}}}$ is incident energy of primary electron. According to the characteristics of SEE from NEA semiconductors with $2\mathrm{\text{keV}}\le E_{\mathrm{\text{pmax}}}\le 5\mathrm{\text{keV}}$, $R$, deduced universal formulas for $\delta$ at $0.1\mathrm{\text{keV}}\le E_{\mathrm{\text{p}}}\le 10\mathrm{\text{keV}}$ and at $10\mathrm{\text{keV}}\le E_{\mathrm{\text{p}}}\le 100\mathrm{\text{keV}}$ for NEA semiconductors and experimental data, special formulas for $\delta$ at 0.5$E_{\mathrm{\text{pmax}}}\le E_{\mathrm{\text{p}}}\le 10E_{\mathrm{\text{pmax}}}$ of several NEA semiconductors with $2\mathrm{\text{keV}}\le E_{\mathrm{\text{pmax}}}\le 5\mathrm{\text{keV}}$ were deduced and proved to be true experimentally, respectively; where $E_{\mathrm{\text{pmax}}}$ is the $E_{\mathrm{\text{p}}}$ at which $\delta$ reaches maximum secondary electron yield. It can be concluded that the formula for $B$ of NEA semiconductors with $2\mathrm{\text{keV}}\le E_{\mathrm{\text{pmax}}}\le 5\mathrm{\text{keV}}$ was deduced and could be used to calculate $B$, and that the method of calculating the 1/$\alpha$ of NEA semiconductors with $2\mathrm{\text{keV}}\le E_{\mathrm{\text{pmax}}}\le 5\mathrm{\text{keV}}$ is plausible; where $B$ is the probability that an internal secondary electron escapes into vacuum upon reaching the surface of emitter, and 1/$\alpha$ is mean escape depth of secondary electron.