One pulse makes all the difference

Researcher from the Max Planck Institute for Polymer Research in Mainz, Germany, try to measure distances in the range of one millionth of a millimeter. To be able to do this they use double electron-electron resonance (DEER). It measures dipole-dipole interactions of electrons in space. With such DEER-spectra the scientists can elucidate the size and shape of nanoscale objects like synthetic molecules, proteins or fatty acids. To record DEER-spectra without artifacts they improved the method by applying a fourth pulse to overcome the dead-time after pulse excitation.