Neutron cross section according to its neutron cross section and how it reacts to an incident neutron. Nuclides that tend to absorb a neutron and either decay or keep the neutron in its nucleus are neutron absorbers and will have a "capture cross section" for that reaction. Isotopes that fission, are fissionable fuels and have a corresponding "fission cross section". The remaining isotopes will simply scatter the neutron, and have a "scatter cross section". Some isotopes, like uranium-238, have nonzero cross sections of all three. Isotopes which have a large scatter cross section and a low mass are good neutron moderators (see chart
Papal Slippers Papal Slippers The papal slippers are a historical accoutrement worn by the Pope. The papal slippers were a form of episcopal sandals worn by bishops. However, unlike the (rarely seen) episcopal sandals, which change with the liturgical colour, the papal slippers were always red. Usually elaborate, papal slippers were made by hand with red satin, red silk, and gold thread; they featured an embroidered cross garnished with rubies and the soles were made of leather. Until the first half of the 20th century, it was customary for pilgrims having an audience with the Pope to kneel and kiss one of