Photoelectron diffraction mapping: Molecules illuminated from within - art. no. 013002

We demonstrate the use of a multiparticle coincidence technique to image th e diffraction of an electron wave whose source is placed at a specific site in a free molecule. Core-level photoelectrons are used to illuminate the m olecule from within. By measuring the vector momenta of two molecular fragm ents and the photoelectron, a richly structured electron diffraction patter n is obtained in a body-fixed frame of the randomly oriented molecule in th e gas phase. We illustrate this technique for CO, creating a photoelectron from the C(1s) shell and scanning its energy from zero to 30 eV.