Composite cesium ionizers with enhanced lifetime characteristics.
Porous cesium ionizer with improved lifetime obtained by adding secondary tantalum to tungsten powder
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Porous cesium ionizer with improved lifetime obtained by adding secondary tantalum to tungsten powder
Cesium ion emission patterns from rear-fed porous refractory metals studied by thermal emission microscope
Cesium vapor ionization on porous tungsten substrate creates gradients in surface atom concentrations diminishing ionization efficiency
Cesium bombardment ion engine performance, giving starting circuit and automatic discharge power control system
Measurement of cesium and mercury ion-atom resonance charge exchange cross section
We present measurements confirming operation of a cesium fountain frequency standard with light shift below 10^-15 (and with evidence suggesting it is several orders of magnitude below this level) but without the use of mechanical shutters. Suppression of the light shift is realized using a master-slave laser configuration by reducing the overall optical power delivered to the physics package as well as spoiling the injection of the slave, causing it to lase far off resonance (1-2 nm) as proposed by the authors several years ago [l]. In the absence of any mitigation, this (AC Stark) shift, due to near-resonant laser light reaching the atoms during their microwave interrogation period, is the largest shift in such frequency standards (2x10^-11 for Our fountain). Mechanical shutters provided adequate light attenuation but have been prone to failure.
A cesium fountain frequency standard has been developed as a ground testbed for the PARCS (Primary Atomic Reference Clock in Space) experiment, an experiment intended to fly on the International Space Station. We report on the performance of the fountain and describe some of the implementations motivated in large part by flight considerations, but of relevance for ground fountains. In particular, we report on a new technique for delivering cooling and trapping laser beams to the atom collection region, in which a given beam is recirculated three times effectively providing much more optical power than traditional configurations. Allan deviations down to 10 have been achieved with this method.
A cesium iodide crystal is fused to the lithium fluoride faceplate of a photon scintillator image tube. The conventional silver chloride solder is then used to attach the faceplate to the metal support.
Energy cost of ion production for atomic helium, argon and cesium calculated by excitation and ionization cross sections
Electric field effect on surface kinetics and thermodynamic stability of cesium on tungsten and molybdenum by field emission microscopy
Prebreakdown gap currents measured between tungsten electrodes with known amounts of cesium and/or oxygen on surfaces
Optimum seed concentrations in cesium and potassium non-equilibrium plasmas
Porous high efficiency predictable-pore-density tungsten ionizers for cesium ion engine
Third Chapman-Enskog approximation to tensor electrical conductivity of partially ionized gas applied to two conductivity mixture rules for atmospheric cesium seeded argon
Flight model cesium ion beam source for electric field strength measuring instrument
Field emission of cesium ions from positive electrode formulated for electric field range that binds ions to electrode surface
Work functions and adsorption of cesium fluoride on fluoride
Probe field emission studies of work function and energy distribution of cesium-oxygen-tungsten system