There are two main theories which I have been reading into Townsends avalanche effect and Paschen's curve.
I understand that as electrons move from negative to positive electrode they collide with gas particles and ionize so there are more electrons causing avalanche effect.
I also understand Paschens curve shows breakdown voltage Vb = f(pd)
However why specifically does increasing the pressure increase the breakdown voltage?
If you increase the pressure surely there are more electrons so less energy is required for ionization and its easier for avalanche to occur at lower voltages?
Can you put it into simpler terms? e.g. as pressure increases mean free path decreases so electrons are more likely to collide.
Best Answer
increasing the gas pressure increases its density, which decreases the mean free path length of moving ions. This limits the distance an ion can travel before it gets deionized in a collision, and increases the amount of electric field strength required to achieve a breakdown cascade.