ok I just did a quick search on Google that field emission theory was first proposed by Ralph H. Fowler and Lothar Wolfgang Nordheim while thermionic emission can be traced back to Edmond Becquerel, Frederick Guthrie and Thomas Edison. So, we can somehow say there will be no field emission and thermionic emission gas discharge/vacuum tubes without those people?
Field emission is emission of electrons induced by electrostatic fields, and since classical physics, it has been known that some materials, such as amber, attract lightweight particles after rubbing. Electrostatic phenomena arise f…