The desorption yields of excited hydrogen atoms from the surfaces of KCl, KBr, NaCl, NaF, and LiF have been measured as a function of incident photon and electron energy and flux, time of irradiation, dosing pressure of H2 and sample temperature. As these surfaces are exposed to H2 gas during electron or photon bombardment, the fluorescence from excited hydrogen atoms ejected from the surface i...

Secondary electron emission (SEE) can potentially lead to beam instabilities, material degradation, beam closure (shorting or pulse shortening), and R.F. breakdown. Under certain conditions, SEE may be desired as a source of electrons for a high power microwave device. Material surface physics, morphology, and possibly the state of the material play a role in the emission process. This DEPSCoR ...

Temperature programmed desorption TPD has been used to investigate the behavior of cyclohexane C6H12 on Zr 0001 and the effects of 500 eV electron bombardment on its desorption characteristics. Following adsorption at 150 K, molecular desorption above 600 K suggests exceptionally strong interaction between C6H12 and Zr 0001 . These high-temperature desorption features shift to higher temperatur...

The electron-stimulated desorption ESD yields and energy distributions for Cs atoms from a cesium layer adsorbed on germanium monolayer-covered tungsten surfaces have been measured as a function of electron energy, cesium coverage , and substrate temperature. Cs is adsorbed at low temperature, 160 K. The measurements have been carried out using a time-of-flight method and surface ionization det...

Graphene already has numerous applications in transmission electron microscopy. Here, we extend its application in electron microscopy by demonstrating its potential to stop electron induced desorption in nonconducting samples, where in essence charge build-up leads to surface atom desorption. Graphene films provide a conduction pathway to prevent charge build-up and do not interfere with the i...

We have investigated the structures of CF3I, and its dissociation products, adsorbed on Ru(001) using lowenergy electron diffraction and electron-stimulated desorption ion angular distribution (ESDIAD). Atomic iodine forms (√3x√3)R30° islands even at very low coverages. At 70% of saturation and above, a (2X2) superstructure forms which we attribute to a p(2X2) unit cell with one CF3 group ...

Unique physical properties such as small effective mass, high electron drift velocities, high electron mobility and small band gap energy make InN a candidate for applications in highspeed microelectronic and optoelectronic devices. The aim of this research is to understand the surface properties, desorption kinetics and thermal stability of InN epilayers that affect the growth processes and de...

A new method, the time of flight-electron-stimulated desorption ion angular distribution method (TOF-ESDIAD), is described. The method permits the mapping of the lateral momentum distribution of adsorbed species on their adsorption sites. Examples of the study of the rotation of chemisorbed PF3 molecules and the frustrated lateral translation of chemisorbed CO molecules, both on single-crystal ...

Two methods can be used to suppress multipacting in a rectangular coupler waveguide. The slotted waveguide method calls for opening slots on the broad walls in the wave propagation direction that perturb the resonance and trap multipacting electrons. The DC magnetic bias method utilizes a solenoid coil wrapped around the waveguide to generate a mild DC magnetic field in the waveguide space that...