Emission of Electrons from a Metal Needle when Irradiated with an IR Femtosecond Laser at a Wave Length of 1240 nm

The photoemission of electrons from a metal needle under the action of radiation from a femtose-cond IR laser with a wavelength of 1240 nm is studied. Diagnostics of electron bunches using the Faraday cup and the time-of-flight method show the possibility of obtaining electron pulses with a charge of 40 pC at a laser pulse energy of 45 μJ. The dependence of the electron pulse charge, which is proportional to the sixth power of the laser pulse energy, indicates a multiphoton mechanism of electron emission.