In cases, where the basic particle generated in the colored glass tube is positive (red color glass for \(a_{\psi}\gt a_{\psi\,ne}\)), the applied voltage polarities will have to be reversed, such that the particles are always driven towards the emission hole.
If the system can be pulsed, and so squeezed (\(\theta=43.535^{o}\) from the post "Guns With No Recoil" dated 23 Sep 2017), we may have resonance and so reproduce the laser effect.
Goodnight...
