50 research outputs found
Intensity Dependence of Laser-Induced Emission of Particles from CaF2(111) near the Plasma Threshold
A Study of the Initial Adsorption Processes of Oxygen on the Ti(1010) Surface by TOF-Type Electron Stimulated Desorption
Techniques for the Detection of Photodesorbed Negative Ions
This paper reports the direct observation of H/sup -/ ions released from a Cs-dosed W(100) crystal by photon-stimulated desorption (PSD). This study utilized the 3m toroidal grating monochromator beamline at the University of Wisconsin-Madison Synchrotron Radiation Center. The main technical problem to be overcome in such experiments is the large background from photoemitted electrons which dominate the weak anion signal by many orders of magnitude. The solution ultimately employed utilized both magnetic suppression of photoelectrons and time-of-flight (TOF) mass separation. No internal modifications to the basic cylindrical mirror analyzer (CMA) were required. We are not aware of any previous reports of the detection of negative ions released from surfaces via photon bombardment, with the exception of high flux laser experiments, in which plasma formation is involved in the ionization process. 16 refs., 3 figs