Signals from nuclear resonance are usually small because of small population differences between energy levels in a static magnetic field. One of the methods with which one can enhance the population differences of nuclei is the Overhauser effect. It is one of the categories of double resonance which involves simultaneously bringing two distinct transitions into resonance at the same time. The Overhauser effect says that one can produce very large nuclear polarizaiton if one saturates electron spin resonance through which the nuclei relax.
We made up the experimental setup for a double resonance experiment and investigated the Overhauser effect in $Mn^{2+}$ solution. We observed the change of $1^H$ NMR signal.
