41. The 6 Li has a high cross-section for thermal neutron absorption through the 6 Li ( n, ? ) reaction. 42. The 10 B isotope is useful for capturing thermal neutrons ( see neutron cross section # Typical cross sections ). 43. The excitation energy within the compound nucleus is formed from the binding energy of the thermal neutron with the target nucleus. 44. Natural uranium is 99.284 % nuclide existing in nature ( in any appreciable amount ) that is fissile with thermal neutrons . 45. A " thermal neutron " is a free neutron that is kinetic theory " for energies and speeds of molecules ). 46. And better mine detectors _ using radar, microwaves, lasers or thermal neutron analysis _ won't be available for five to 10 years. 47. While a nuclear bomb working on thermal neutrons may be impractical, modern weapons designs may still benefit from some level of moderation. 48. Its precursor 235 U and thermal neutrons ) but also has the highest known thermal neutron capture cross section of any nuclide. 49. Its precursor 235 U and thermal neutrons ) but also has the highest known thermal neutron capture cross section of any nuclide. 50. Beside thermal neutrons , a cold moderator of liquid deuterium ( cold source ) slows neutrons down and shifts their spectrum to lower energies.
