Hello
I am searching for a simple explanation for Hollow Cathode Effect. I find some references but Im confused.
what happen in a Hollow Cathode which can increases the current in glow discharges?
I think there is a simple interpretation but i can not find it.
Please help me to understand how a Hollow Cathode works.
Thank You
Hollow cathodes are very useful electron generating devices. One of the main advantages of hollow cathodes is that electrons being emitted from the emitter surface may actually accelerate to the opposing emitter surface, being the cathode shape a hollow cylinder, and ionize gas in the way (to put it in simple words). When the energetic electron reaches the opposing surface the electric field slows it down and "shoots" it back up. This way an electron may bounce back and forth between the emitter inner surface, a phenomenon that is also referred to as the "pendulum effect". This effect enables large thermal fluxes into the emitter; therefore keeping it sufficiently hot for thermionic emission. This effect is what makes the hollow cathode a gas-efficient device capable of producing high current densities of over 10 A/cm^2, depending on the emitter type.
Apart from my elementary explanation here you are welcome to check out these two links to some very good sources on hollow cathode operation for space electric propulsion applications (or as any ion beam neutralizing device).
If you have more questions - you are welcome to ask here.
Article An Investigation of Physical Processes in a Hollow Cathode Discharge
Chapter Basic Plasma Physics
In addition, the ionized gas can then run into the cathode, which causes some of the metal atoms to be removed from the surface into the gas phase via sputtering. Those metal atoms can then be excited and emit light, which is why hollow cathode lamps are often used as atomic emission reference sources. They are also used in flame atomic emission sources as the light source. The wavelength of light emitted of course depends on which metal the cathode is made of.
A detailed spectral line intensities with hollow cathode discharges and various processes in hollow cathodes
by Weinstein et al.
You can use a relativly low cost HC source from an obsleete atomic Absorption Spectrometer. It can give different high intesity line emmision wavelenghtes for a given chemical element (eg Ag or Fe). This may help to check if it will work with your experiment.
How to determine the dimensions of the hollow cathode (LaB6) .
hi
how can i design a configuration set-up for hollow cathode sputtering to deposition thin films such DLC ?
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