To generate a high power discharge usually a capacitor over a coil is done, but to make it at high power a great capacitor must be used and as long that frequency is inverse proportional to square root of inductance and capacitance, large capacitors should lower the frequency.
It depends on what level of the power you are assumed as high.
There are a lot of vacuum devices with a GW level of pulsed power in S-band:
BWO, TWO, MILO, Vircator and etc.
MW sources based on nonlinear transmission lines are capable to generate hundreds megawatts.
In both cases you have to have GW level of pulsed power voltage source to feed like Marx generator or Tesla coil based source or any other.
If there are no special requirements for the pulse shape, in the S-band, power compressors can be used to obtain a high level of pulse power. These are passive type resonant devices.
It will be used in an ion source with hydrogen ions at 0.2-5 pascals (before ionizing) so it depends of the antenna efficiency when heating the hydrogen, efficiency >50% and continuous working at least during a year.
I do not need so much power so Magnetrons could work that have high efficiency but I think they have short life.
The antenna and plasma will be in the same cavity that have 45mm diameter. The RF generator can be at vacuum sending RF to the antenna through a dielectric.
We can use up to 55kVpp (but would prefer using 1KV)
Yes, you can use magnetron. The commonly available magnetrons operate at ~ 2.45 GHz. We have used such magnetrons to initiate the plasma discharge. They are also helpful for heating purpose and can be operated either in pulsed or continuous form. If you want to modify its circuit for changing its pulse width, I would recommend you to read the following paper.
"Development of Microwave Pre-ionization Source for GLAST Tokamak", Fusion Engineering and Design 126 10-14 (2018).
It seems possible to drive the off-the-shelf $40 microwave oven 2.45 GHz magnetron in a kind of pulsed mode for generating "short" bursts of CW. In some wireless power transmission experiments it was used to create low-cost a few kW sources. It could be done by modifying the standard oven power controller and AC power supply by adding a few extra circuits to enable a sort of pulse modulation. However, this approach requires a lot more mechanical work to channel the magnetron energy into a waveguide or coax to get the power out. To increase output power a bank of magnetrons could be used. Although control and synchronization of several magnetrons would be tricky.
I suppose magnetron can be used by separate using a dielectric betweeN hard vacuum and less vacuum; I have to increase the magnetron life.
It is possible to increase the magnetron life using coils instead of magnets?
it all depends on your " financial impedance.."...if you like to play with some ( old ) microwave oven magnetron yes..one can do this (dont forget about safety) but keep in mind that those magnetrons are rather made for CW operation..thus intermittend CW operation certainly will work had been done in the past..or you can find some old radar magnetron with pulses power supply unit you may be even better off....and of course one can buy such pulse (burst) generators from industry..
There is some other method.
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Pulse magnetrons and CW magnetrons are designed differently, so if you want high power short pulses it is best to use one which has been designed for pulse operation, unless the pulses are within the CW power rating. The cathode is made with different materials that can give very high currents for a short time. A CW magnetron driven at higher current than it was designed for can run out of electrons, and generate a lot of voltage across the cathode coating which then can be blown off.
Magnetrons can't be driven in parallel, as the one that starts (fractionally) first can stop the others from starting. They need individual power supplies. They can be phase locked by an injected signal, so that the outputs can be combined coherently.
Operating one high power magnetron is probably the best option.
One "magnetron man" told me once, that for high power radar pulses you need very advanced cathode composition for increased durability not found in normal magnetrons. This tech is kind of secret of mil companies and agencies. So you need to find a man who worked in mil. business before for acquiring it. Yes, and you can increase the heating power easily by displacing probes in the oven. But for radar, or other apps, you will need a cavity and syncing magnetrons which is neither simple, nor good for durability.
Dear Javier Luis López,
For that, you can use magnetron. Generally, magnetrons operate at your desired frequency of 2.45 GHz.
The velvet cathode is superior in high-power microwaves owing to its shorter turn-on time and better electron beam uniformity.
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