A recent post here made me think about this so I wanted to ask. Now a x ray tube working principle is basically the opposite of the photoelectric effect, here instead of photons electrons strike a metal target to deposit their energy which is released as heat (IR radiation) and photons. So the out coming photon wavelength (energy) is proportional to the kinetic energy of the electron which in turn is directly proportional to the potential difference that accelerated the electron between cathode and anode. Now what happens when we increase the potential difference between cathode and anode - the electrons have higher kinetic energy which means that the resulting photons will have a shorter wavelength correct? Also I assume that due to the way an x ray tube works a higher voltage across will give electrons higher kinetic energy but it will also increase the electron current so not only the individual photon wavelength will decrease but the total number of photons will increase correct? If so far my assumptions are correct, then a question arises, if we keep on increasing voltage which results in higher energy/shorter wavelength photons why can't we get into the gamma region of photon wavelengths with very high voltages? I obviously realize that some physical constraints limit that possibility like the anode target metal endurance and heat removal etc, but theoretically is that possible?