摘要 |
A method and an apparatus are disclosed for detecting a first substance within a second substance, preferably for localizing diamonds in kimberlite rocks. The first substance, e.g. the diamonds, have a very long spin-lattice relaxation time (T1) in the order of hours. For rapidly detecting the first substance, the build-up of magnetization of a predetermined kind of nuclei, e.g. <13>C, being abundant in the first substance only is shortened and the nuclear magnetic resonance of that kind of nuclei is measured thereafter. The shortening is executed within a pre-treatment station (12), whereas the measurement takes place within an analyzing station (13). The shortening and the measuring, respectively, are carried out within magnetic fields (B01, B02) of different field strengths (Fig. 2). <IMAGE> |