@phdthesis{11684, author = {Hao Wu}, title = {Achieving a large density of hydroxyl radicals for cold collisions}, abstract = {Molecular physics has experienced groundbreaking progress in the fields of precision spec-troscopy, chemical reaction kinetics, quantum state engineering and many-body physics. In order to better observe these phenomena, there is an insatiable pursuit of larger trapped molecular densities and longer lifetime. In this thesis, several key milestones that we have recently achieved towards these goals for hydroxyl radicals (OH) are reported. First, we discovered an enhanced spin-flip behavior of dipolar molecules due to the existence of dual (electric and magnetic) dipole moments and obtained a better understanding of complex spin-dynamics for both Hund’s case (a) and (b) molecules in mixed electric and magnetic fields. Second, we demonstrated that the skimmer cooling technique can be applied to radicals and the production of OH can be enhanced by factor of 30 due to both clogging mitigation and more favorable skimmer-valve distance. Finally, we showed some preliminary results that it is possible to use a newly built Stark decelerator to study electric field controlled sub-kelvin collisions in an intra-beam.}, year = {2019}, journal = {Department of Physics}, volume = {Ph.D.}, pages = {119}, month = {2019-05}, publisher = {University of Colorado Boulder}, address = {Boulder}, }