As the distance doubles, the exposure is cut to 1/4. Inverse square law.
Gamma radiation frequency is coincident with the x-ray spectrum. The main difference between the two is source: x-rays emanate from the electron shell and gamma rays from the nucleus of an atom.
Gamma ray - Wikipedia, the free encyclopedia
Originally Posted by wikipedia
Gamma rays are generally characterized as electromagnetic radiation having the highest frequency and energy, and also the shortest wavelength (below about 10 picometers), within the electromagnetic spectrum. Gamma rays consist of high energy photons with energies above about 100 keV.
Cosmic rays are at the extreme end of the gamma spectrum. Extremely high energies (MeV) and can travel across the universe without interacting with matter.
Gamma is pure photon, the only time heat/energy conversions occur is when a gamma ray impinges on electrons or the nucleus. Since photons are so very small, gamma radiation tends to pass through most matter with little interaction.