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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,171 records · Page 65
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Recovery of Rare Earth Elements from Coal and Coal Byproducts via a Closed Loop Leaching Process: Final Report

Objectives: Through this grant, Battelle proposes to address Area of Interest (AOI) 1 to develop a bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal ash. U.S. coal and coal byproducts provide the opportunity for a domestic source of REEs. The DOE’s National Energy Technology Laboratory (NETL) has characterized various coal and coal byproducts samples and has found varying concentrations of REE ranging up to 1,000 parts per million by weight. The primary project objective is to validate the economic viability of recovering REEs from the coal byproduct coal ash using Battelle’s patented closed-loop Acid Digestion Process (ADP). This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a Techno-Economic Analysis (TEA) for the proposed process. The regional availability of REE-laden coal ash, the regional market for rare earth concentrates, and the system capital and operating costs for rare earth recovery using the ADP technology will be accounted for in the TEA. Limited laboratory testing will be conducted to generate the parameters needed for the design of a bench scale system for REE recovery. The ultimate project outcome will be the design for an optimized, closed loop process to economically recovery REEs such that the process may be demonstrated at the bench scale in a Phase 2 project. Project Description: The project will encompass evaluation of the ADP technology for the economic recovery of REEs from coal and coal ash. The ADP was originally designed and demonstrated for the U.S. Army to facilitate demilitarization of cast-cured munitions via acid digestion in a closed-loop process. Proof of concept testing has been conducted on a sample of Ohio-based Middle Kittanning coal and has demonstrated the feasibility of recovering REEs using the ADP technology. In AOI 1, Ohio coal sources with the potential to provide a consistent source of rare earth element concentrations above 300 parts per million will be identified. Coal sample inventories from West Virginia and Pennsylvania will also be assessed for purposes of comparison. Three methods of preparing the coal ash will be evaluated for their potential to enhance the technical feasibility and economics of REE recovery. Three sources of coal ash are targeted for evaluation of the economics of REE recovery in this project: (1) coal ash from power generation stations, to include fly ash and/or bottom ash, (2) ash generated in a lower temperature ashing process, and (3) ash residual from Battelle’s coal liquefaction process. Making use of residual ash from coal liquefaction processes directly leverages work currently being conducted by Battelle for DOE NETL in response to DE-FOA-0000981 entitled “Greenhouse Gas Emissions Reductions Research and Development Leading to Cost-Competitive Coal-to-Liquids Based Jet Fuel Production.” Using the sample characterization results and regional information regarding REE concentration, availability and cost, a TEA will be developed. The previously generated laboratory testing results for leaching and REE recovery via the ADP will be used to perform the TEA, along with common engineering assumptions for scale up of equipment and labor costs. Finally, upon validation of the economic feasibility of the process by the TEA, limited laboratory testing will be performed to support the design of a bench scale system. In a future project phase, it is envisioned that the bench scale system will be constructed and operated to prove the process on a continuous basis.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2020

Using Strain in the Vadose Zone During Sinusoidal-Rate Well Tests to Characterize an Aquifer

Well tests with sinusoidal variation in pumping rate are appealing because of the ability to filter competing signals and they also can be set up with no net removal of water, which is an advantage at contaminated sites. Current methods of interpreting sinusoidal-rate well tests analyze the phase lag and amplitude of pressure signals in the aquifer. This approach is restricted by the availability of monitoring wells. An alternative approach could be to measure the stain in the vadose zone instead of pressure in the aquifer. The goal of this research is to evaluate the feasibility of using signals from in-situ sensors in the vadose zone to characterize sinusoidal-rate well tests. Well tests with a variety of periods and amplitudes were performed using a well completed in an unconfined saprolite aquifer with a water table at 9m depth at our test site near Clemson, South Carolina. Vertical strain was measured every meter between 1 to 7 m using a distributed optical fiber sensing technique called coherence length gated microwave photonics interferometry (CMPI). A novel packaging system was designed to couple the optical fiber to the saprolite. The results show that strain measured in the vadose zone during sinusoidal-rate pumping varies periodically with amplitudes from 0.1 to 3 microstrain, depending on the amplitude of the sinusoidal pumping rate. Hydraulic heads at similar radial distances were also periodic with changing amplitudes ranging up to ±0.2 meters. The strain in the vadose zone responds to pressure in the underlying aquifer—the strain is tensile when the pressure is falling, and compressive when the pressure is rising. The phase lag between the pumping rate and the strain was 3 min with a pumping period of 15 minutes, and this gives a hydraulic diffusivity of 0.06 m2/s. This is the same diffusivity obtained by analyzing a constant rate pumping test, and it is slightly larger than the diffusivity (0.044 m2/s) obtained by analyzing the phase lag of the pressure in a nearby monitoring well. Strain measurements in the vadose zone could be made with much less cost and effort than installing a deep monitoring well. These results suggest that strain measurements in the vadose zone could be used to supplement monitoring wells, thereby increasing the resolution, and reducing costs of analyzing well tests.

well test, sinusoidal, periodic pumping, strain↗
NASA NTRS2022

Mars 2020 Perseverance Rover Surface Operations Commissioning Phase Overview

This paper presents work done by the Mars 2020 Project to plan, test, and execute the Mars 2020 Perseverance Rover surface operations commissioning phase. Immediately after the successful landing of Mars 2020 Perseverance rover at Jezero Crater on February 18, 2021, the rover autonomously initiated mission critical commanding necessary to transition the vehicle from a Cruise/EDL to Surface operations configuration. This began the surface operations commissioning phase, referred to as Surface Operations Transition (SOX). The objective of SOX phase is to establish vehicle health and safety and to verify that the operational characteristics of the vehicle, now operating in the Martian environment, are as-expected and safe to proceed into nominal operations. The SOX commissioning phase is organized into six logical sub-phases occurring in the following chronological order; (1) SOX1a, (2) FSW Transition, (3) SOX1b, (4) SOX2a, (5) Heli, (6) SOX2b. In total, the SOX commissioning phase was expected to take up-to 111 sols (Martian days). The Perseverance rover is an extremely complex, highly-integrated, robotic system-of-systems that requires numerous activities to incrementally and methodically verify their safe operations. This paper will discuss the development process used to plan, test, and execute the SOX commissioning phase for Mars 2020 Perseverance rover surface operations. We will discuss key challenges associated with SOX development as well as actual operations execution experience.

Koch, Justin↗
DOE OSTI2020

Oak Ridge National Laboratory Current Magnitude and Frequency Response of SIPROTEC Relays

This project examined the current magnitude and frequency response of 7SJ61 and 7SJ62 SIPROTEC relays. The measured sample frequencies for the 7SJ61 and 7SJS62 relays were 800 and 960 Hz, respectively. The relays were tested at frequencies of up to 1 and 20.16 kHz. Two experiments were run in a lab environment. The first experiment was run at frequencies of up to 1 kHz every 10 Hz. The second one was run at frequencies of up to 20.16 kHz every 200 and 240 Hz (common factors of sample rate frequency) for the 7SJ61 and 7SJ62 SIPROTEC relays, respectively. Both experiments were set at a current magnitude of 0.1 and 0.5 Arms. A testbed with a Relay Test Equipment (RTE) was set to run the experiment at frequencies of up to 1 kHz, while a testbed with a RTE and High Frequency Power Source/ Amplifier (HFPS/A) was set to run at frequencies of up to 20.16 kHz. Currents of 0.1 and 0.5 Arms at different frequencies were connected at Phase A of the relays, and a current of 1 Arms (60 Hz) was connected at Phase B of relays. The 1 Arms current allowed the relays to trip and saved their record events by setting both relays at a definite-time overcurrent protection function. The record events were collected after the 7SJ61 and 7SJ62 relays tripped, and the current magnitude and frequency were plotted. The record events from the relays were collected using the DIGSI® 4 software. The SYNCHROWAVE® Event and MATLAB® software were then used to plot the current magnitude and frequency, respectively, from the relay record events. The current magnitude and frequency were plotted at time and frequency domain, respectively.The 7SJ61 and 7SJ62 relays measured source frequencies of up to 400 and 480 Hz, respectively. The percentage error of frequency for the relays increased after 400 and 480 Hz, respectively. The 7SJ62 relay with 0.1 and 0.5 Arms measured the alias frequency up to 1440 Hz. The 7SJ61 relay with 0.1 and 0.5 Arms measured the alias frequency up to 1000 and 1200 Hz, respectively. At frequencies higher than the alias frequency, the relays measured a DC amplitude current instead of an AC amplitude current. In the DC amplitude current zone, non-desired frequencies were measured by both relays. The current magnitude intensity (dB) for the 7SJ61 and 7SJ62 relays from 1 to 20.16 kHz were plotted. The current magnitude intensity for the 7SJ61 relay decreased up to 2600 and 1200 Hz for 0.5 and 0.1 Arms tests, respectively. However, the current magnitude intensity for the 7SJ62 relay decreased up to 4800 and 2640 Hz for 0.5 and 0.1 Arms tests, respectively. The current magnitude and frequency response study for the 7SJ61 and 7SJ62 relays was performed satisfactorily, observing the source, alias, and non-desired measured frequency zones for both relays.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Development of Conceptual Lead Cartridge Design to Perform Irradiation Experiments in VTR

This paper seeks to introduce the latest design of the Extended Length Test Assembly–Cartridge Lead (ELTA-CL) with associated thermal-hydraulic (TH) assessment and related experiment activities to support the critical component development performed by the ELTA-CL team (Los Alamos National Laboratory, Westinghouse Electric Company, and the University of New Mexico). The goal of the ELTA-CL program is to develop and validate an experimental capability to perform irradiation experiments in the Versatile Test Reactor (VTR) addressing Lead Fast Reactor (LFR) technology gaps, in support of the commercial development of advanced lead-cooled fast reactor concepts. Through a design maturation process and parametric study, a conceptual design is proposed to meet the requirements for material and corrosion testing. Thermal-hydraulic characteristics for the conceptual design at desired operating conditions are assessed with systems-level (one-dimensional) and computational fluid dynamics (three-dimensional) simulations. Along with the conceptual design work, experimental activities for the development of critical components such as the pump and flowmeter are undertaken. From both the modeling study and the experimental results, the design requirements of the Phase 1 ELTA-CL (e.g., 500°C and 2 m/s) are achievable with the current conceptual design. Additional design improvements and safety assessments at both steady-state and transient conditions for the final ELTA-CL design will be pursued.

42 ENGINEERING↗
DOE OSTI2022

Distilling physical origins of hardness in multi-principal element alloys directly from ensemble neural network models

Abstract Despite a plethora of data being generated on the mechanical behavior of multi-principal element alloys, a systematic assessment remains inaccessible via Edisonian approaches. We approach this challenge by considering the specific case of alloy hardness, and present a machine-learning framework that captures the essential physical features contributing to hardness and allows high-throughput exploration of multi-dimensional compositional space. The model, tested on diverse datasets, was used to explore and successfully predict hardness in Al x Ti y (CrFeNi) 1- x - y , Hf x Co y (CrFeNi) 1- x - y and Al x (TiZrHf) 1- x systems supported by data from density-functional theory predicted phase stability and ordering behavior. The experimental validation of hardness was done on TiZrHfAl x . The selected systems pose diverse challenges due to the presence of ordering and clustering pairs, as well as vacancy-stabilized novel structures. We also present a detailed model analysis that integrates local partial-dependencies with a compositional-stimulus and model-response study to derive material-specific insights from the decision-making process.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Update to the Phase II Corrective Action Investigation Plan for Corrective Action Units 101 and 102, Central and Western Pahute Mesa, Nevada National Security Site, Nye County, Nevada

This report is an update to the Phase II Corrective Action Investigation Plan for Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada (NNSA/NSO, 2009) activities resulting from data collection and analysis conducted between 2009 and 2019. This report contains two sections: (1) a summary of how the new data have informed the updated approach to complete the characterization activities under the corrective action investigation (CAI), and (2) a table documenting the specific activities identified in the CAIP with a status and expected outcome of each activity (see Table A-1 in Appendix A). As stated in Sections 1.5 and 1.5.1 of the CAIP, the CAIP was conceptualized to be iterative, with continuous review and assessment of the data, data analysis, and modeling to provide a guide for decisions regarding additional work. This report provides the revised plan, based on an assessment of the data, to complete the characterization activities identified in the CAIP.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

V31 Test Report

The V31 containment vessel was procured by the US Army Recovered Chemical Material Directorate (RCMD) as a third - generation EDS containment vessel. It is the fifth EDS vessel to be fabricated under Code Case 2564 of the 2019 ASME Boiler and Pressure Vessel Code, which provides rules for the design of impulsively loaded vessels. The explosive rating for the vessel, based on the code case, is twenty-four (24) pounds TNT - equivalent for up to 1092 detonations. This report documents the results of explosive tests that were performed on the vessel at Sandia National Laboratories in Albuquerque, New Mexico to qualify the vessel for field operations use. There were three design basis configurations for qualification testing. Qualification test (1) consisted of a simulated M55 rocket motor and warhead assembly of 24lbs of Composition C-4 (30 lb TNT equivalent). This test was considered the maximum load case, based on modeling and simulation methods performed by Sandia prior to the vessel design phase. Qualification test (2) consisted of a regular, right circular cylinder, unitary charge, located central to the vessel interior of 19.2 lb of Composition C-4 (24 lb TNT equivalent). Qualification test (3) consisted of a 12-pack of regular, right circular cylinders of 2 lb each, distributed evenly inside the vessel (totaling 19.2 lb of C-4, or 24 lb TNT equivalent). All vessel acceptance criteria were met.

42 ENGINEERING↗
DOE OSTI2023

V31 Test Report

The V31 containment vessel was procured by the US Army Recovered Chemical Materiel Directorate (RCMD) as a third-generation EDS containment vessel. It is the fifth EDS vessel to be fabricated under Code Case 2564 of the 2019 ASME Boiler and Pressure Vessel Code, which provides rules for the design of impulsively loaded vessels. The explosive rating for the vessel, based on the code case, is twenty-four (24) pounds TNT-equivalent for up to 1092 detonations. This report documents the results of explosive tests that were performed on the vessel at Sandia National Laboratories in Albuquerque, New Mexico to qualify the vessel for field operations use. There were three design basis configurations for qualification testing. Qualification test (1) consisted of a simulated M55 rocket motor and warhead assembly of 24lbs of Composition C-4 (30 lb TNT equivalent). This test was considered the maximum load case, based on modeling and simulation methods performed by Sandia prior to the vessel design phase. Qualification test (2) consisted of a regular, right circular cylinder, unitary charge, located central to the vessel interior of 19.2 lb of Composition C-4 (24 lb TNT equivalent). Qualification test (3) consisted of a 12-pack of regular, right circular cylinders of 2 lb each, distributed evenly inside the vessel (totaling 19.2 lb of C-4, or 24 lb TNT equivalent). All vessel acceptance criteria were met .

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Field-Scale Testing of a High-Efficiency Membrane Reactor (MR)—Adsorptive Reactor (AR) Process for H2 Generation and Pre-Combustion CO2 Capture

The study objective was to field-validate the technical feasibility of a membrane- and adsorption-enhanced water gas shift reaction process employing a carbon molecular sieve membrane (CMSM)-based membrane reactor (MR) followed by an adsorptive reactor (AR) for pre-combustion CO2 capture. The project was carried out in two different phases. In Phase I, the field-scale experimental MR-AR system was designed and constructed, the membranes, and adsorbents were prepared, and the unit was tested with simulated syngas to validate functionality. In Phase II, the unit was installed at the test site, field-tested using real syngas, and a technoeconomic analysis (TEA) of the technology was completed. All project milestones were met. Specifically, (i) high-performance CMSMs were prepared meeting the target H2 permeance (>1 m3/(m2.hbar) and H2/CO selectivity of >80 at temperatures of up to 300 °C and pressures of up to 25 bar with a <10% performance decline over the testing period; (ii) pelletized adsorbents were prepared for use in relevant conditions (250 °C < T < 450 °C, pressures up to 25 bar) with a working capacity of >2.5 wt.% and an attrition rate of <0.2; (iii) TEA showed that the MR-AR technology met the CO2 capture goals of 95% CO2 purity at a cost of electricity (COE) 30% less than baseline approaches.

42 ENGINEERING↗
NASA NTRS1973

Surface electrical properties experiment study phase, volume 1

The evolution of a conceptual design of the flight hardware for the surface electrical properties experiment (SEP), the definition of requests for proposals, the analysis of proposals submitted by prospective flight hardware subcontractors, and recommendations for the flight configuration to be implemented are discussed. Initial efforts were made to assess the electromagnetic environment of the SEP experiment. An EMI receiver and tri-loop antenna were constructed and tests of opportunity were performed with a lunar roving vehicle (LRV). Initial analyses were made of data from these tests with support from this contract, analyses which were continued in depth under the hardware contract.

Meyer, J. W.↗
NASA NTRS1975

Summary of nozzle-exhaust plume flowfield analyses related to space shuttle applications

Exhaust plume shape simulation is studied, with the major effort directed toward computer program development and analytical support of various plume related problems associated with the space shuttle. Program development centered on (1) two-phase nozzle-exhaust plume flows, (2) plume impingement, and (3) support of exhaust plume simulation studies. Several studies were also conducted to provide full-scale data for defining exhaust plume simulation criteria. Model nozzles used in launch vehicle test were analyzed and compared to experimental calibration data.

Penny, M. M.↗
NASA NTRS1996

Effects of Sustained Low-Level Elevations of Carbon Dioxide on Cerebral Blood Flow and Autoregulation of the Intracerebral Arteries in Humans

Cerebral blood flow velocity (CBFv) was measured by insonating the middle cerebral arteries of 4 subjects using a 2 Mhz transcranial Doppler. Ambient CO2 was elevated to 0.7% for 23 days in the first study and to 1.2% for 23 days in the same subjects in the second study. By non-parametric testing CBFv was elevated significantly by +35% above pre-exposure levels during the first 1-3 days at both exposure levels after which CBFv progressively readjusted to pre-exposure levels. Despite similar CBFv responses, headache was only reported during the initial phase of exposure to 1.2% CO2. Vascular reactivity to CO2 assessed by rebreathing showed a similar pattern with the CBFv increases early in the exposures being greater than those elicited later. An increase in metabolic rate of the visual cortex was evoked by having the subjects open and close their eyes during a visual stimulus. Evoked CBFv responses measured in the posterior cerebral artery were also elevated in the first 1-3 days of both studies returning to pre-exposure levels as hypercapnia continued. Cerebral vascular autoregulation assessed by raising head pressure during 10 deg head-down tilt both during the low-level exposures and during rebreathing was unaltered. There were no changes in the retinal microcirculation during serial fundoscopy studies. The time-dependent changes in CO2 vascular reactivity might be due either to retention of bicarbonate in brain extracellular fluid or to progressive increases in ventilation, or both. Cerebral vascular autoregulation appears preserved during chronic exposure to these levels of ambient CO2.

Sliwka, U.↗
NASA NTRS1999

Rocket-Based Combined-Cycle Propulsion Technology for Access-to-Space Applications

NASA's Office of Aero-Space Technology (OAST) established three major goals, referred to as, "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala. focuses on future space transportation technologies under the "Access to Space" pillar. One of the main activities over the past three years has been on advancing the hydrogen fueled rocket-based combined cycle (RBCC) technologies. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion. Aerojet and Boeing-Rocketdyne designed, built and ground tested their RBCC engine concepts. In addition, ASTROX, Georgia Institute of Technology, McKinney Associates, Pennsylvania State University (PSU), and University of Alabama in Huntsville conducted supporting activities. The RBCC activity included ground testing of components (e.g., injectors, thrusters, ejectors and inlets) and integrated flowpaths. Inlet testing was performed at the Lewis Research Center's 1 x 1 wind tunnel. All direct connect and free-jet engine testing were conducted at the GASL facilities on Long Island, New York. Testing spanned the Mach range from sea level static to Mach 8. Testing of the rocket-only mode, simulating the final phase of the ascent mission profile, was also performed. The originally planned work on these contracts was completed in 1999. Follow-on activities have been initiated for both hydrogen and hydrocarbon fueled RBCC concepts. Studies to better understand system level issues with the integration of RBCC propulsion with earth-to-orbit vehicles have also been conducted. This paper describes the status, progress and future plans of the RBCC activities funded by NASA/MSFC with a major focus on the benefits of utilizing air-breathing combined-cycle propulsion in access-to-space applications.

Hueter, Uwe↗
NASA NTRS2002

Center for Space Telemetering and Telecommunications Systems, New Mexico State University

This viewgraph presentation gives an overview of the Center for Space Telemetering and Telecommunications Systems activities at New Mexico State University. Presentations cover the following topics: (1) small satellite communications, including nanosatellite radio and virtual satellite development; (2) modulation and detection studies, including details on smooth phase interpolated keying (SPIK) spectra and highlights of an adaptive turbo multiuser detector; (3) decoupled approaches to nonlinear ISI compensation; (4) space internet testing; (4) optical communication; (5) Linux-based receiver for lightweight optical communications without a laser in space, including software design, performance analysis, and the receiver algorithm; (6) carrier tracking hardware; and (7) subband transforms for adaptive direct sequence spread spectrum receivers.

Horan, Stephen↗
NASA NTRS1997

Angiogenesis and osteogenesis in an orthopedically expanded suture

The purpose of this study was to examine the angiogenic and the subsequent osteogenic responses during a 96-hour time-course after sutural expansion. Fifty rats were divided into: (1) a control group that received only angiogenic induction through injection of 5 ng/gm recombinant human endothelial cell growth factor (rhECGF); (2) an experimental group that received orthopedic expansion and rhECGF; (3) a sham group that received expansion and sodium chloride (NaCl) injection; and (4) a baseline group that received no expansion or injection. All rats were injected with 3H-thymidine (1.0 microCi/gm) 1 hour before death to label the DNA of S-phase cells. Demineralized sections (4 microm thick) were stained with hematoxylin and eosin. Angiogenesis and cell migration were analyzed with a previously established cell kinetics model. Analysis of variance was used to test the hypothesis that enhancement of angiogenesis stimulates reestablishment of osteogenic capability. Blood vessel number, area, and endothelial cell-labeled index significantly increased in experimental groups, but no difference was found between control and baseline groups. Labeled-pericyte index and activated pericyte numbers in the experimental group were also higher than in the sham groups. These results show that supplemental rhECGF enhances angiogenesis in expanded sutures but not in nonexpanded sutures. Data also suggest that pericytes are the source of osteoblasts in an orthopedically expanded suture.

NASA Discipline Musculoskeletal↗
DOE OSTI2017

A Test of the Interstellar Boundary EXplorer Ribbon Formation in the Outer Heliosheath

NASA’s Interstellar Boundary EXplorer ( IBEX ) mission is imaging energetic neutral atoms (ENAs) propagating to Earth from the outer heliosphere and local interstellar medium (LISM). A dominant feature in all ENA maps is a ribbon of enhanced fluxes that was not predicted before IBEX . While more than a dozen models of the ribbon formation have been proposed, consensus has gathered around the so-called secondary ENA model. Two classes of secondary ENA models have been proposed; the first class assumes weak scattering of the energetic pickup protons in the LISM, and the second class assumes strong but spatially localized scattering. Here we present a numerical test of the “weak scattering” version of the secondary ENA model using our gyro-averaged kinetic model for the evolution of the phase-space distribution of protons in the outer heliosheath. As input for our test, we use distributions of the primary ENAs from our MHD-plasma/kinetic-neutral model of the heliosphere-LISM interaction. The magnetic field spectrum for the large-scale interstellar turbulence and an upper limit for the amplitude of small-scale local turbulence (SSLT) generated by protons are taken from observations by Voyager 1 in the LISM. The hybrid simulations of energetic protons are also used to set the bounding wavenumbers for the spectrum of SSLT. Our test supports the “weak scattering” version. This makes an additional solid step on the way to understanding the origin and formation of the IBEX ribbon and thus to improving our understanding of the interaction between the heliosphere and the LISM.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1974

Rubidium 87 gas cell studies, phase 2

The design, development, and characteristics of a rubidium 87 maser are discussed. The design of a receiver capable of locking a crystal oscillator to the maser signal is reported. The subjects considered are: (1) maser construction, (2) maser control electronics, (3) the characteristics of the receiver, and (4) results of experimental maser tests.

Vanier, J.↗