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 Mass the ceremony, the pope was vested in the falda (a particular papal vestment which forms a long skirt extending beneath the hem of the alb), amice, alb, cincture, pectoral cross, stole, and a very long cope known as the "mantum" (or "papal mantle"). Finally, the papal tiara was placed on his head. The pope's solemn entry into St. Peter's Basilica was accompanied by the Silveri Symphony, a fanfare played on the trumpets of the Noble Guard. The entrance procession was headed by the cardinals, bishops, prelates, and those who composed the pontifical capella, vested according to their rank and in