noun
thermal neutron
Technical term in nuclear physics for a neutron in thermal equilibrium with its surroundings, typically with kinetic energy around 0.025 eV at room temperature.
熱中性子は原子炉内で核分裂を引き起こすのに使われる。
Thermal neutrons are used to induce nuclear fission in a reactor.
Compound of 熱 (netsu, 'heat, thermal') + 中性子 (chūseishi, 'neutron'), a calque from English 'thermal neutron'.