The introduction of OIH labelled with "'123 I "', with its short physical half-life ( 13 hours ) and its gamma emission of 159 KeV has greatly improved the diagnostic potential of renal studies by combining the production of high-quality functional images with the ability to derive a renogram.
32.
Thorium-cycle fuels produce hard gamma emissions, which damage electronics, limiting their use in military bomb triggers . cannot be chemically separated from from used nuclear fuel; however, chemical separation of thorium from uranium removes the decay product and the radiation from the rest of the decay chain, which gradually build up as reaccumulates.
33.
Technetium-99m can be readily detected in the body by medical equipment because it emits 140.5 keV gamma rays ( these are about the same wavelength as emitted by conventional X-ray diagnostic equipment ), and its half-life for gamma emission is six hours ( meaning 94 % of it decays to 99 Tc in 24 hours ).
34.
It is well suited to the role, because it emits readily detectable gamma rays with a photon energy of 140 keV ( these 8.8 pm photons are about the same wavelength as emitted by conventional X-ray diagnostic equipment ) and its half-life for gamma emission is 6.0058 hours ( meaning 93.7 % of it decays to 99 Tc in 24 hours ).
35.
For example, in uranium-235 this delayed energy is divided into about 6.5 MeV in betas, 8.8 MeV in antineutrinos ( released at the same time as the betas ), and finally, an additional 6.3 MeV in delayed gamma emission from the excited beta-decay products ( for a mean total of ~ 10 gamma ray emissions per fission, in all ).
36.
Tc-99m decays mainly by gamma emission, slightly less than 88 % of the time . ( 99m Tc ?! 99 Tc + ? ) About 98.6 % of these gamma decays result in 140.5 keV gamma rays and the remaining 1.4 % are to gammas of a slightly higher energy at 142.6 keV . These are the radiations that are picked up by a gamma camera when 99m Tc is used as a radioactive tracer for medical imaging.
