41. This detector shows good efficiency at detecting fast neutrons in a background of thermal neutrons and gamma radiation. 42. The alpha particles emitted by the decay of the americium collide with the light beryllium nuclei, producing fast neutrons . 43. Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. 44. Bombarding 238 U with fast neutrons induces fissions, releasing energy as long as the external neutron source is present. 45. 236 U and most other actinides are fissionable by fast neutrons in a nuclear bomb or a fast neutron reactor. 46. Nuclear explosions form 10 Be by a reaction of fast neutrons with 13 C in the carbon dioxide in air. 47. My main idea was that for the atom bomb the chain reaction would have to be propagated by fast neutrons . 48. A helium-3 and deuterium mix gives off much fewer fast neutrons , but requires about four times the temperature to react. 49. 236 U and most other actinides are fissionable by fast neutrons in a nuclear bomb or a fast neutron reactor. 50. When these fast neutrons collide with hydrogen nuclei present in the soil being studied, they lose much of their energy.
