| alpha particle |
a positively charged particle given off as radiation from some fission or decay processes, consisting of two protons and two neutrons. |
| atomic |
of, relating to, or resulting from bombs whose explosive power comes from a series of reactions beginning with the fission of the nuclei of certain atoms. [1/3 definitions] |
| atomic energy |
the energy that is released by an atom in nuclear reactions such as fission or fusion. [1/2 definitions] |
| beta particle |
a high-speed positron or electron ejected from a nucleus in radioactive decay or fission. |
| chain reaction |
in physics, a self-sustaining reaction in which the particles produced by nuclear fission cause the fission of other nuclei. [1/3 definitions] |
| control rod |
a rod or bar in a nuclear reactor that contains a neutron-absorbing material, and that is lowered into or raised from the core to control the fission chain reaction. |
| fissile |
of matter, able to undergo nuclear fission. [1/2 definitions] |
| fissionable |
combined form of fission. |
| moderator |
a substance, such as graphite or heavy water, used in nuclear reactors to slow down neutrons, thus increasing the probability of fission. [1/2 definitions] |
| nuclear energy |
energy released from atomic nuclei, as in nuclear fission or fusion. |
| nuclear reactor |
any of several devices that initiate and control a nuclear fission chain reaction to produce energy and material used for experimental and medical purposes. |
| pile1 |
the part of a nuclear reactor in which fission takes place. [1/7 definitions] |
| plutonium |
a radioactive chemical element of the actinide series that has ninety-four protons in each nucleus and that is capable of explosive nuclear fission in a chain reaction, used as fuel in some types of nuclear reactors. (symbol: Pu) |
| prokaryote |
an organism that lacks a nucleus membrane and that reproduces by fission. (Cf. eukaryote.) |
| schizo- |
split; fission. |
| scission |
the act or result of cutting, dividing, or splitting; fission. |
| strontium |
a highly reactive chemical element of the alkaline-earth group that has thirty-eight protons in each nucleus, that occurs naturally only in compounds, and that has highly toxic radioactive isotopes that are by-products of some types of nuclear fission reactions. (symbol: Sr) |
| subcritical |
of a nuclear reactor or device, unable to sustain a fission chain reaction. [1/2 definitions] |
| vegetative |
having to do with asexual reproduction, as by fission. [1/3 definitions] |