What happens to photons when there is an increase in kilovoltage peak (kVp)?

When there is an increase in kilovoltage peak (kVp), the energy of the photons generated in the X-ray tube increases. This is because kVp determines the maximum energy of the X-rays that are produced. Higher kVp means that the electrons are accelerated more effectively towards the target anode, resulting in the production of X-rays with higher energy.

As the energy of the photons increases, they also exhibit a corresponding increase in frequency, according to the relationship defined by the equation (E = hf), where (E) is energy, (h) is Planck's constant, and (f) is frequency. Since the frequency increases, the wavelength must decrease, as frequency and wavelength are inversely related by the equation (c = \lambda f), where (c) is the speed of light, (\lambda) is wavelength, and (f) is frequency.

Thus, an increase in kVp leads to photons having increased energy, increased frequency, and decreased wavelength, making the first choice correct. It reflects an essential principle in understanding how changes in kilovoltage affect the characteristics of X-ray production.