Secondary emission from multialkali photocathodes

Abstract
The secondary emission from high‐sensitivity multialkali photocathodes has been measured. The secondary emission from these photocathodes are found to be very high. A maximum value of 39 for the yield was obtained at a primary energy of 1800 eV. Such high yields have seldom been obtained in materials with positive electron affinity. The approximate escape depth of the secondary electrons was calculated by applying the phenomenological theory of secondary emission. The escape depth was found to be about 400 Å.