| 摘要 |
<p>The invention relates to an apparatus and method for detecting the presence of an element of interest within an object (12). The object (12) is positioned where a beam of gamma rays (15) of the required energy are directed to be scattered by the element (16) of interest. The gamma rays (15) are provided by excited atoms of the element (16) of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target (14). The excited atoms deexcite, releasing gamma rays (15) which are scattered by the element (16) of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object (12). A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.</p> |
