Why Field emission method is considered dangerous?
Dear Student Field emission :
When the surface of a material is subjected to a strong electrostatic electric field,there is an emission of electrons.This phenomenon is called field emission.So you can say it is emission of electrons induced by an electrostatic field.
Field emission from the cathode electrode puts a serious constraint on the field strength of the electrode and respectively on the operating voltage of the DC electron gun. The emission electrons pose many dangers to the gun’s function and its structure.
For instance, the field emitted electrons can cause charging, which can lead to the breakdown of the ceramic insulator and seriously damage the support of the cathode. Also the emission electrons can cause melting of the materials they clash with and this can lead to arcing or structural breakdowns inside the gun.
Moreover, electrons from field emission induce certain gases when they strike materials. These gases can chemically damage the high quantum efficiency photocathodes and produce residual gas, causing ion back bombardment and harming the photocathode
Regards
Field emission :
When the surface of a material is subjected to a strong electrostatic electric field,there is an emission of electrons.This phenomenon is called field emission.So you can say it is emission of electrons induced by an electrostatic field.
Field emission from the cathode electrode puts a serious constraint on the field strength of the electrode and respectively on the operating voltage of the DC electron gun. The emission electrons pose many dangers to the gun’s function and its structure.
For instance, the field emitted electrons can cause charging, which can lead to the breakdown of the ceramic insulator and seriously damage the support of the cathode. Also the emission electrons can cause melting of the materials they clash with and this can lead to arcing or structural breakdowns inside the gun.
Moreover, electrons from field emission induce certain gases when they strike materials. These gases can chemically damage the high quantum efficiency photocathodes and produce residual gas, causing ion back bombardment and harming the photocathode
