摘要 |
<p>49,787 An improved long operating lifetime ionization chamber type neutron detector for use within a nuclear reactor. The chamber contains uranium U-235 as the neutron sensitive material and helium or argon fill gas. The atom rate of U-235 to fill gas is from 0.45 to 1.8 for helium, and 2.3 to 9 for argon.</p> |