h λ= eV mo:rest mass of 2moeV (1+2moCZ the electron TABLE 1.2 Electron Properties as a Function of Accelerating Voltage Accelerating Non-relativistic Relativistic Mass Velocity voltage(kV) wavelength(nm)） wavelength(nm) (x mo) (×108m/s) 100 0.00386 0.00370 1.196 1.644 120 0.00352 0.00335 1.235 1.759 200 0.00273 0.00251 1.391 2.086 300 0.00223 0.00197 1.587 2.330 400 0.00193 0.00164 1.783 2.484 1000 0.00122 0.00087 2.957 2.823 TABLE 1.1 Fundamental Constants and Definitions Charge (e) (-)1.602×10-19C 1eV 1.602×1019J Rest mass(mo) 9.109×10-31kg Rest energy(moc2) 511 keV Kinetic energy (charge x voltage) 1.602 x 10-19 Nm (for 1 volt potential)=J Planck's constant(h) 6.626×1034Nms 1A 1C/s Speed of light in vacuum(c) 2.998×10m/s 1010 𝜆 = ℎ 2𝑚0𝑒𝑉(1 + 𝑒𝑉 2𝑚0𝐶 2 ) m0 : rest mass of the electron