What is the minimum potential difference between the filamen

What is the minimum potential difference between the filament and the target of an x-ray tube if the tube is to accelerate electrons to produce x rays with a wavelength of 0.120 nm ?

What is the shortest wavelength produced in an x-ray tube operated at 30.4 kV ?

Would the answers to parts (A) and (B) be different if the tube accelerated protons instead of electrons? Why or why not?

Solution

E_photon = h c / lambda

= (1240 eV.nm) / (0.120 nm)

E_photon = 10333 eV

This tube produces electrons of 30.4 keV

lambda = (1240 eV.nm) / 30400

= 0.0407 nm