[Bidagdha_TADIR]

I having a hard time understanding how EDL works. What I understand is this, - the actual lamp is made of quartz bulb containing one or more metal salts and inert gas. The bulb is surrounded by rf coils. Almost every reference is saying that when microwave radiation is applied it will cause ionization of the inert gas. The ionized inert gas will cause excitation of metal atoms. My question is -

1. Will microwave radiation pass through quartz?
2. Is microwave radiation ionizing? I thought it was non-ionizing.

[Borek]

1. Will microwave radiation pass through quartz?

As far as I am aware, yes.

2. Is microwave radiation ionizing? I thought it was non-ionizing.

Define "ionizing".

What happens to any gas (any substance for that matter) when it is heated high enough?

[Bidagdha_TADIR]

What happens to any gas (any substance for that matter) when it is heated high enough?

So, the microwave radiation will generate heat which will cause ionization of the gas -excellent; feeling stupid for not catching that myself.

[Enthalpy]

Yes, microwaves pass perfectly through quartz. The only effect is a step in permittivity.

In the low-pressure gas, they induce a glow discharge. Similar to what electrodes would do, but from distance, through the induced electric field.

It avoids contamination of the gas by the electrodes bombarded with ions, needs no metal-to-glass seals, and more advantages.

"Ionizing" radiation is understood as high-energy particles. It's a matter of wording, but for sure, microwaves don't fit in this category. And in the discharge, electrons and ions ionize more molecules; the microwaves provide the accelerating field only.

[Bidagdha_TADIR]

@Enthalpy, So the acceleration of electron by the microwave causes ionization, a better fit.

[Borek]

@Enthalpy, So the acceleration of electron by the microwave causes ionization, a better fit.

Where do you get the electron from in the neutral gas?

[Bidagdha_TADIR]

I read somewhere that there is always some free electrons available in an environment.