Electron Beam (E-beam) Evaporation
2011; Elsevier BV; Linguagem: Inglês
10.1016/b978-1-4377-7867-0.00015-5
Autores Tópico(s)Particle accelerators and beam dynamics
ResumoA filament can be raised in temperature to become white-hot using a low-voltage and high-current power supply. The power to the filament can be either AC or DC. With such high currents being used, a magnetic field is created by the current flowing through the wire, and this will affect the electron emission. The quantity of electrons emitted depends on the current passed through the filament, the temperature achieved, and the work function along with other factors. The anode provides the acceleration to the electron (e)-beam. The acceleration voltage can be as high as 35 kV. Once this beam is produced, it can be focused and manipulated in the same way a cathode ray tube operates using electromagnetic sweep coils. The power supply for e-beam guns must be able to do more than supplying a highly stabilized voltage and current. The nature of the power that is involved means that the supplies have to be well protected from arcing. The emission circuit is reliant on a very high stability source and a current-sensing resistor to ensure a constant electron emission current. The acceleration voltage also uses a constant voltage control circuit, thus keeping everything as stable as possible.
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