Stereospecific Control by Molecular Orientation

A new type of electrostatic state-selector that consists of seven sets of adjacent hexapole fields forming a honeycomb field has been newly developed in order to integrate intensities of seven oriented molecular beam lines. We first used Ar gas to check the assembly alignment, and then we used the polar molecule of acetonitrile (CH3CN, mu=3.92 D) seeded in the noble gases to characterize the quantum state-selectivity of the honeycomb field. We obtained the dependence of the focused CH3CN beam intensity on the honeycomb electrode voltages for the first time. We could reproduce the experimental focusing curve by use of a modified trajectory simulation applicable to the honeycomb electric field. The present beam character (i.e. rotational temperature and stream velocity) was confirmed to be maintained as same as the one of the original single beam.