In this dissertation, I describe the experimental investigation in electron diffraction of molecules in superfluid helium droplets. The project is part of an overall scheme called ‘single molecule serial electron diffraction imaging’ (SS-EDI), with the ultimate goal of building an apparatus to determine atomic structures from oriented macromolecules. In SS-EDI,...
We report electron diffraction of ferrocene doped in superfluid helium droplets. By taking advantage of the velocity slip in our pulsed droplet beam using a pulsed electron gun, and by doping with a high concentration of ferrocene delivered via a pulsed valve, we can obtain high quality diffraction images from...
We compare characteristics of electron impact ionization (EI) and multiphoton ionization (MPI) of doped super fluid helium droplets using the same droplet source. Selected dopant ion fragments from the two ionization schemes demonstrate different dependence on the doping pressure, which could be attributed to the different ionization mechanisms. While EI...
We present two facile time-of-flight (TOF) methods of detecting superfluid helium droplets and droplets with neutral dopants. Without an electron gun and with only a heated filament and pulsed electrodes, the electron impact ionization TOF mass spectrometer can resolve ionized helium clusters such as He₂ ⁺ and He₄ ⁺, which...
We present experimental results of electron diffraction of super fluid helium droplets and droplets doped with phthalocyanine gallium chloride, and discuss the possibility of performing the same experiment with a laser aligned sample. The diffraction profile of pure droplets demonstrates dependence on the nozzle temperature, i. e., on the average...