Plutonium ionization energy

Radioisotopes have important commercial applications. For example, americium-241 is used in smoke detectors. Its role is to ionize any smoke particles, which then allow a current to flow and set off the alarm. Exposure to radiation is also used to sterilize food and inhibit the sprouting of potatoes. Radioisotopes that give off a lot of energy as heat are also used to provide power in remote locations, where refueling of generators is not possible. Unmanned spacecraft, such as Voyager 2, are powered by radiation from plutonium. 

The ionizing properties of Pu and other radioactive materials is one determinant of the level of hazard associated by different exposure routes. Radioactive elements are those that undergo spontaneous transformation (decay) in which energy is released either in the form of particles, such as alpha or beta particles, or waves, such as gamma or X-ray. Plutonium exists in several isomeric forms, the most important of which are Pu-238 and Pu-239. When these isotopes decay, they emit primarily alpha particles, which are densely ionizing and, therefore, damaging however, the penetration of alpha particles into tissue is slight, so... 

S f distribution ofS-Pu. The plutonium 3d photoabsorption has been analyzed for modifications in the 5/excited states between the a and 5 phases (27, 35). The same sample is maintained at 400 °C during the analysis to give the 5 phase spectrum and at room temperature for the a phase. The variation of the photoabsorption coefficient with photon energy near the My ionization limit is plotted in Fig. 7. A very marked modification in the My photoabsorption according to the temperature is observed. 

Another complication in plutonium solution is the gradual, spontaneous reduction of Pu(VI) to Pu(IV), and Pu(IV) to Pu(III), caused by ionization products of alpha particles emitted in radioactive decay [SI]. The rate of alpha reduction is slow, however. For example, the observed rate of reduction of Pu(VI) in 0.5 M HCl at 25°C is 0.0035 g-equiv/day per mole of plutonium, which corresponds to a half-life of 199 days for reduction of Pu(VI) to Pu(TV). From these rates and the known alpha-decay rate and decay energies of plutoniiun, it is estimated that approximately 80 eV of dissipated alpha energy in this solution brings about the addition of one electron in reducing plutonium ions. After several hundred days the plutonium reaches an average oxidation state intermediate between Pu(III) and Pu(IV). 

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