| 摘要 |
An irradiator (4) is provided for irradiating lumps of ore to detect the presence of gold in the lumps by neutron activation analysis. The irradiator (4) consists of a close packed array of three inner cylindrical ducts (14) and three outer cylindrical ducts (12) through which the lumps of ore are passed, with three neutron sources (16) arranged in the spaces between the inner ducts (14) and the outer ducts (12) to irradiate the ducts (12, 14) and to activate any gold by the reaction 197Au (n, n' gamma ) 197Au. Each inner duct (14) is thus adjacent to two neutron sources (16), and is or larger cross-sectional area than the outer ducts (12). |
