Dember effect
In physics, the Dember effect is when the electron current from a cathode ( I 3 ) {\displaystyle (I_{3})} subjected to both illumination and a simultaneous electron bombardment is greater than the sum of the photoelectric current ( I 1 ) {\displaystyle (I_{1})} and the secondary emission current ( I 2 ) {\displaystyle (I_{2})} . == History == Discovered by Harry Dember (1882–1943) in 1925, this effect is due to the sum of the excitations of an electron by two means: photonic illumination and electron bombardment (i.e.