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Voyager images of the icy satellites of Saturn, Dione and Enceladus, suggest they have been geologically active and are not only composed of ice. Recent observations by HST have shown the presence of ozone at both Dione and Rhea w...
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Voyager images of the icy satellites of Saturn, Dione and Enceladus, suggest they have been geologically active and are not only composed of ice. Recent observations by HST have shown the presence of ozone at both Dione and Rhea which also implies the presence of molecular oxygen at these bodies. The Cassini Plasma Spectrometer (CAPS) will provide the capability to determine the global composition of these bodies by measuring the pickup ions produced by the ionization of their sputter produced atmospheres. We will present a model of these atmospheres and associated pickup ions and demonstrate CAPS ability to distinguish the freshly produced picked up ions from the ambient plasma. Such ions are expected to form a ring distribution that will have a uniquely different energy-angle dependence than the ambient plasma ions. In the case of Dione we expect the potential for a moderate strength interaction for which both Voyager 1 and Pioneer 11 spacecraft measured ion cyclotron waves centered on the Dione L shell and near the equatorial plane. Since Enceladus may be the source of the E-ring, some surprises may be encountered during its close encounter with the Cassini spacecraft. In the case of Dione we will show that a wake pass at 500 km altitude is more than an order of magnitude better than an upstream pass at 500 km altitude. Pickup ion detection for minor ion species such as NH3 is possible for 500 km altitude wake pass but not for a 500 km altitude upstream pass at closest approach. For navigation reasons a 100 km pass is not allowed and therefore it is essential to have a wake pass to maximize the science return for a targeted flyby with Dione. The CAPS observations when combined with magnetometer, plasma wave and energetic particle observations will allow us to estimate the source of ions into Saturn's magnetosphere due to these two bodies and to characterize the nature of the interaction with Saturn's magnetosphere.
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We measured the rate of sulfate anion production for cyclo-octal sulfur grains in frozen water at temperatures, energies, and dose rates appropriate for Europa using energetic electrons.
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This report summarizes the work to develop and deploy near-infrared (NIR) moisture sensing technology for application to the Hanford Site's high-level nuclear waste materials. This work is jointly supported by the U.S. Department ...
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This report summarizes the work to develop and deploy near-infrared (NIR) moisture sensing technology for application to the Hanford Site's high-level nuclear waste materials. This work is jointly supported by the U.S. Department of Energy's (DOE) EM-50 Office of Technology Development Support and the EM-30 Tank Waste Safety and Tank Waste Remediation Systems Programs. A basic NIR system was developed at the Savannah River Laboratory (SRL) with support from DOE's EM-50 Office. The application of this technology to Hanford's high-level wastes (HLW). Including deployment, is supported by DOE's EM-30 Systems Programs. The need to know the moisture content in HLW is driven by concerns for the safety of underground storage tanks that contain or are suspected of containing ferrocyanide and organic types of materials. The NIR technology has application for both ex situ (hot cell core measurements) and in situ waste tank moisture sensing. The cold test/calibration data in this report was generated as part of the total life cycle development path being followed in the development and deployment of the NIR technology at the Hanford Site.
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The effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. were examined. Sputtering is capable of efficiently removing all species from the upper atm...
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The effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. were examined. Sputtering is capable of efficiently removing all species from the upper atmosphere, including the light noble gases; N also is removed by photochemical processes. Due to the diffusive separation by mass above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species, with the lighter mass being preferentially lost. For C and O, this allows us to determine the size of nonatmospheric reservoirs that mix with the atmosphere; these reserviors can be accounted for by exchange with CO2 adsorbed in the regolith and with H2O in the polar ice deposits. Both simple analytical models and time-dependent models of the loss of volatiles from and supply to the Martian atmosphere were constructed. Both Ar and Ne require continued replenishment from outgassing over geologic time.
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We examine the effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. Sputtering is capable of efficiently removing all species from the upper atmosph...
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We examine the effects of loss of Mars atmospheric constituents by solar-wind-induced sputtering and by photochemical escape during the last 3.8 b.y. Sputtering is capable of efficiently removing all species from the upper atmosphere including the light noble gases; N is removed by photochemical processes as well. Due to diffusive separation (by mass) above the homopause, removal from the top of the atmosphere will fractionate the isotopes of each species with the lighter mass being preferentially lost. For C and O, this allows us to determine the size of nonatmospheric reservoirs that mix with the atmosphere; these reservoirs can be CO2 adsorbed in the regolith or H2O in the polar ice caps. We have constructed both simple analytical models and time-dependent models of the loss from and supply of volatiles to the Martian atmosphere.
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The overall objectives of this program were to study and develop an understanding of the characteristics of coupled waveguide gas lasers and to improve their operating characteristics. A flexible test bed laser was designed, fabri...
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The overall objectives of this program were to study and develop an understanding of the characteristics of coupled waveguide gas lasers and to improve their operating characteristics. A flexible test bed laser was designed, fabricated and used to evaluate both ceramic and metal waveguide array structures. The strong tendency to phase lock with adjacent channels out-of-phase was confirmed. Metal waveguide walls were shown to produce power output comparable to ceramic walls. A simple metal slab laser was demonstrated with good discharge and good mode characteristics, and an unstable resonator was used to produce the lowest order cosine-Gaussian mode. A technique of coupling discharge channels with slots in the slab waveguide walls was conceived and shown to lock all-in-phase preferentially over the out-of-phase configuration. A concept for an all-metal, low-cost, microwave-excited waveguide laser using either a simple slab waveguide or the slot coupled array was developed. C02 waveguide lasers; coupled waveguide lasers; dielectric coated waveguides; r-f excited C02 lasers; Parallel-plate waveguide lasers.
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This paper will explore the various instrumentation that has been available in the past and its relevance to the proposed ANSI standard, along with new available instruments that may significantly modify the way compliance measure...
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This paper will explore the various instrumentation that has been available in the past and its relevance to the proposed ANSI standard, along with new available instruments that may significantly modify the way compliance measurements are to be performed. A sample of the changes that may occur includes high frequency (hf) monitoring where previous electric or magnetic field levels must be converted in order to add fractions of each field component to determine if allowable levels of electromagnetic energy are exceeded. The paper will also cover spatial and time-averaged surveys and required instrument characteristics for properly measuring field levels down to the 3 to 10 kHz frequency range. Unwanted characteristics of instruments will be covered, such as magnetic field out-of-band responses, modulation errors, and other measurement phenomena associated with the various methods of detecting non-ionizing radiation. Special attention will be devoted to the calibration of the monitors, the various methods of calibration available, and applicability to a particular frequency range. 4 refs., 2 figs., 1 tab. (ERA citation 14:011686)
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The global air sampling program utilizes commercial aircrafts in scheduled service to measure atmospheric constituents. A fully automated system designed for the 747 aircraft is described. Airline operational constraints and data ...
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The global air sampling program utilizes commercial aircrafts in scheduled service to measure atmospheric constituents. A fully automated system designed for the 747 aircraft is described. Airline operational constraints and data and control subsystems are treated. The overall program management, system monitoring, and data retrieval from four aircraft in global service is described.
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