There is a growing need to consider alternative propellants for operation in Hall thrusters, away from the conventional legacy of using xenon. This particularly case small thrusters; which are exponentially their use, whilst needing be operational on inexpensive propellants. Alternative include condensable (i.e., zinc and iodine), or other gaseous (krypton, argon, nitrogen (N2)) - focus here. A...

High resolution M,,, (3d -+ 4p) x-ray emission spectra from a kwton plasma were measured using a recently developed grazing-incidence reflectiongrating monochromator/spectrometer with very high flux rates at extreme ultraviolet and soft x-ray wavelengths. The nominal resolving power of the instrument, E/AE, is about 300 in this energy range (-80 eV). Three dipole-allowed 3d -+ 4p emission lines...

Radioactive microspheres could offer several advantages over gases in the investigation of pulmonary ventilation. Monodisperse microspheres of human serum albumin have been produced using a spinning-disc generator, and kits were prepared for subsequent labelling with technetium-99m. The average labeling efficiency was 88% and unlabeled Tc-99m was removed before aerosol delivery. A simple system...

Fully quantum state selected and resolved inelastic scattering of NO(X) by krypton has been investigated. Initial Λ-doublet state selection is achieved using an inhomogeneous hexapole electric field. Differential cross sections and even-moment polarization dependent differential cross sections have been obtained at a collision energy of 514 cm(-1) for both spin-orbit and parity conserving and c...

Time-resolved coherent anti-Stokes Raman-scattering (CARS) measurements are carried out for iodine (I2) in solid krypton matrices. The dependence of vibrational dephasing time on temperature and vibrational quantum number v is studied. The v dependence is approximately quadratic, while the temperature dependence of both vibrational dephasing and spectral shift, although weak, fits the exponenti...

We present an experiment where Ramsey-type spectroscopy is applied to autoionizing states of krypton by using the ninth harmonic (88 nm) of a femtosecond Ti:sapphire laser. The ionization process, detected by an electron-energy spectrometer, shows the characteristic quantum interference pattern. The behavior of the fringe contrast compares favorably with a simple essential-state model, whose pa...

We present vapor pressure and high-resolution heat-capacity measurements of multilayer krypton films adsorbed on graphite. We have found a complex phase diagram including reentrant layering transitions for coverages higher than three layers. The third layering transition does not end in a condensation critical point as was previously expected. The second-layer melting transition is preceded by ...

A two-dimensionally imaging spectrometer system was employed to measure spatial variations in the intensities of emission lines in a Cu-Mn-Ni alloy sample when they were excited from a laser-induced plasma with krypton gas. The emission zone of these lines shrank and had greater emission intensities with increasing gas pressure, and the intensities of their background also became more intense. ...

We have developed a synchrotron-based, time-resolved x-ray microprobe to investigate optical strong-field processes at intermediate intensities (10(14) - 10(15) W/cm2). This quantum-state specific probe has enabled the direct observation of orbital alignment in the residual ion produced by strong-field ionization of krypton atoms via resonant, polarized x-ray absorption. We found strong alignme...