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Portable direct reading spectrometer for monitoring oxygen-hydrogen containing contaminants in gas tungsten arc welding process
A simple code for use in analyses of gamma radiation effects in laminated materials is described. Simple and good geometry is assumed so that all multiple collision and scattering events are excluded from consideration. The code is capable of handling laminates up to six layers. However, for laminates of more than six layers, the same code may be used to incorporate two additional layers at a time, making use of punch-tape outputs from previous computation on all preceding layers. Spectrum of attenuated radiation are obtained as both printed output and punch tape output as desired.
The application of nuclear models to the calculation of neutron capture and inelastic scattering gamma yields is discussed. The gamma ray cascade model describes the cascade process in terms of parameters which either: (1) embody statistical assumptions regarding electric and magnetic multipole transition strengths, level densities, and spin and parity distributions or (2) are fixed by experiment such as measured energies, spin and parity values, and transition probabilities for low lying states.
The use of discrete ordinates and Monte Carlo techniques to solve radiation transport problems is discussed. A general discussion of two possible coupling schemes is given for the two methods. The calculation of the reactor radiation scattered from a docked service and command module is used as an example of coupling discrete ordinates (DOT) and Monte Carlo (MORSE) calculations.
A computer technique for treating the motion of charged and neutral particles and called the phase space time evolution method was developed. This technique employs the computer's bookkeeping capacity to keep track of the time development of a phase space distribution of particles. This method was applied to a study of the penetration of electrons. A 1 MeV beam of electrons normally incident on a semi-infinite slab of aluminum was used. Results of the calculation were compared with Monte Carlo calculations and experimental results. Time-dependent PSTE electron penetration results for the same problem are presented.
Most thermionic reactors are designed to allow the fission gases to escape out of the emitter. A scheme to allow the fission gases to escape is proposed. Because of the low activity of the fission products, this method should pose no radiation hazards.
Improvements in the processes and design to reduce the manufacturing costs for low density ablative panels for the space shuttle are discussed. The areas that were studied included methods of loading honeycomb core, alternative reinforcement concepts, and the use of reusable subpanels. A review of previous studies on the fabrication of low-cost ablative panels and on permissible defects that do not affect thermal performance was conducted. Considerable differences in the quoted prices for ablative panels, even though the various contractors had reported similar fabrication times were discovered. How these cost differences arise from different estimating criteria and which estimating assumptions and other costs must be included in order to arrive at a realistic price are discussed.
The work performed in the following areas is summarized: (1) Analysis of Realistic nuclear-propelled vehicle was analyzed using the Marshall Space Flight Center computer code package. This code package includes one and two dimensional discrete ordinate transport, point kernel, and single scatter techniques, as well as cross section preparation and data processing codes, (2) Techniques were developed to improve the automated data transfer in the coupled computation method of the computer code package and improve the utilization of this code package on the Univac-1108 computer system. (3) The MSFC master data libraries were updated.
Detailed descriptions are presented of the input data for each of the MSFC computer codes applied to the analysis of a realistic nuclear propelled vehicle. The analytical techniques employed include cross section data, preparation, one and two dimensional discrete ordinates transport, point kernel, and single scatter methods.
The goal of the ablation technology program is to bring ablation research and development to a high state of readiness for application to space shuttle vehicles. Some recent results and current work in the areas of materials, designs, and refurbishment for ablative TPS are reported. Future research and development needs are also presented.
A passenger compartment surrounded by a fire-retardant shell, to protect the occupants long enough for the fire to burn out or for fire-fighting equipment to reach the aircraft and extinguish it, is proposed as a new concept for saving lives in crash fires. This concept is made possible by the recent development of two new fire-retardant materials: a very lightweight foam plastic, called polyisocyanurate foam, and an intumescent paint. Exposed to heat, the intumescent paint expands to many times its original thickness and insulates the surface underneath it. Demonstration tests are illustrated, described and discussed. However, some problems, such as preventing fuselage rupture and protecting windows, must be solved before such a system can be used.
Study of the vaporization characteristics of samples of ATJ graphite, a material that has been considered for use on a Jovian probe. These samples were subjected to radiative heating loads of approximately 2 kW/sq cm in argon atmospheres of pressures from 0.00046 to 1 atm. Surface temperatures, mass loss rates, and spatially resolved emission spectral data were recorded. These data are analyzed to determine carbon vapor pressure as a function of temperature and are compared with current models for the vapor pressure of carbon. The effects of finite vaporization (i.e., nonequilibrium) rates are considered and compared with experiment. Estimates of the heat of vaporization from an energy balance are also presented.
Analysis of the panel flutter characteristics of a candidate thermal protection system (TPS) for the space shuttle, using piston theory aerodynamics and Lagrange equations. The results show the TPS candidate panel array to be deep in the 'no-flutter' region during launch and, therefore, safe from panel flutter.
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Computer code was developed to determine radioactive emission rates of nuclear fuels. Code is basically written for two different source geometries; however, unfolding routine can be executed for other source geometries.
When sections are being welded, operator varies pulse rate of power supply and simultaneously monitors signal on oscilloscope until rate is found which produces maximum arc gas voltage. Remainder of welding is performed with power supply set at this pulse rate, producing desired maximum weld puddle agitation and fine uniform weld of grain structure.
The author has identified the following significant results. Initial analysis of the bands for images 1039-09322, 1039-09315, and 1040-09371 provide a detailed picture of a zone extending 500 km north-northeast from the northern coast of the Gulf of Bothnia. Highways (on bands 0.5-0.6 and 0.6-0.7), rivers (bands 0.7-0.8, 0.8-1.1) and bare fell tops are visible. Schist belts, as known from ground surveys, can be discerned from areas occupied by their basement rocks or major plutons. A number of sharp lineaments, apparently faults, are visible. Some major fracture zones, up to 50 km wide, that form distinct lineaments in weather satellite pictures and belong to the main objects of this study, are rather indistinct in the images but can be traced.
The author has identified the following significant results. Black and white prints and transparencies of images 1039-09315, 1039-09322, and 1040-09371 with all bands of MSS have been used for the analyses. Bands 4 and 5 reveal the major urban areas, agricultural and timbering areas, highways as well as airfields, and an open pit mine. Even the border between Norway and Finland is clearly visible. Lakes, rivers, and wet swamps were best discerned on IR bands 6 and 7. Block fields formed by frost action are best seen on bands 4 and 5. The ancient shoreline on image 1039-09322 is seen as a narrow block field on bands 4 and 5. The effects of the Quaternary ice sheet on the morphography can be seen quite well in the images. The peat bogs are best seen in band 5, but can also be traced in bands 6 and 7. Eskers, glaciofluvial deposits, and deltas are distinguishable in bands 4 and 5, but can be traced in places also in the IR bands. Fluvial deposits are seen in the image 1039-09322 in the valleys of the Tornio and Kemi Rivers. They are easily discerned in bands 4 and 5, evidently because of the cultivated fields and pasture lands. Bands 4, 5, and 6 of image 1039-09315 reveal parts of eskers and glaciofluvial deltas which are affected by eolian activity. It seems evident that ERTS-1 imagery will be a great help in mapping Quaternary features.