Beta Decay Chains in Uranium & Plutonium Fission Products
Since the heavy original nuclei always have a greater proportion of neutrons, the fission product nuclei almost always start out with a neutron/proton ratio significantly greater than what is stable for their mass range. Therefore they undergo multiple beta decays in succession, each converting a neutron to a proton. The first decays tend to have higher decay energy and shorter half-life. These last decays may have low decay energy and/or long half-life.
For example, uranium-235 has 92 protons and 143 neutrons. Fission takes one more neutron, then produces two or three more neutrons; assume that 92 protons and 142 neutrons are available for the two fission product nuclei. Suppose they have mass 99 with 39 protons and 60 neutrons (yttrium-99), and mass 135 with 53 protons and 82 neutrons (iodine-135), then the decay chains can be found in the tables below.
| Nuclide | Half-life |
|---|---|
| 99Y | 1.470(7) s |
| 99Zr | 2.1(1) s |
| 99mNb | 2.6(2) min |
| 99Nb | 15.0(2) s |
| 99m2Mo | 0.76(6) µs |
| 99m1Mo | 15.5(2) µs |
| 99Mo | 2.7489(6) d |
| 99mTc | 6.0058(12) h |
| 99Tc | 2.111(12)E+5 a |
| 99Ru | stable |
| Nuclide | Half-life |
|---|---|
| 135I | 6.57(2) h |
| 135Xe | 9.14(2) h |
| 135Cs | 2.3(3)E+6 a |
| 135Ba | stable |
Read more about this topic: Decay Chain
Other articles related to "fission product, beta decays, decays, decay":
... always have a greater proportion of neutrons, the fission product nuclei almost always start out with a neutron/proton ratio significantly greater than what is stable for their ... Therefore they undergo multiple beta decays in succession, each converting a neutron to a proton ... The first decays tend to have higher decay energy and shorter half-life ...
Famous quotes containing the words fission, products, decay and/or chains:
“The pace of science forces the pace of technique. Theoretical physics forces atomic energy on us; the successful production of the fission bomb forces upon us the manufacture of the hydrogen bomb. We do not choose our problems, we do not choose our products; we are pushed, we are forced—by what? By a system which has no purpose and goal transcending it, and which makes man its appendix.”
—Erich Fromm (1900–1980)
“... white people, like black ones, are victims of a racist society. They are products of their time and place.”
—Shirley Chisholm (b. 1924)
“It had been a moving, tranquil apotheosis, immersed in the transfiguring sunset glow of decline and decay and extinction. An old family, already grown too weary and too noble for life and action, had reached the end of its history, and its last utterances were sounds of music: a few violin notes, full of the sad insight which is ripeness for death.”
—Thomas Mann (1875–1955)
“He that has his chains knocked off, and the prison doors set open to him, is perfectly at liberty, because he may either go or stay, as he best likes; though his preference be determined to stay, by the darkness of the night, or illness of the weather, or want of other lodging. He ceases not to be free, though the desire of some convenience to be had there absolutely determines his preference, and makes him stay in his prison.”
—John Locke (1632–1704)