SEMI-ANNUAL PROGRESS REPORT

Technical Report · Wed Oct 01 00:00:00 EDT 1958

OSTI ID:4258346

4 5 8 6 7 8 8 : 1 3 distribution of elastically scattered 5.6-Mev neutrons from carbon is reported. The experimental procedure to be used for measuring neutron capture cross sections for elements and separate isotopes bombarded by neutrons in the low kev-energy region is presented. Solid Siate Physics. The solid state group has placed in operation a Hitachi Hu-10 electron microscope. Replica techniques usnd in electron microscopy are discussed. The optical properties of solids in the vacuum ultraviolet are discussed. A general mathematical method is being developed by which optical constants (such as the real index of refraction and the absorpiion coefficient) as a function of frequency or photon energy can be derived from reflectivity measured as a function of frequency. Samples of ZnO are being prepared for photodesorption experiments. The sputtering from hypersonic vehicles in the free moleeule flow region is discussed. An estimate of the threshold energy variation with incident angle is derived, based on a single collision model. Microwave propagation through a contaminated plasma is discussed. The solid state group has considered the possibility of using electric-dipohe transitions in solids for maser applications in the millimeter and submillimeter range. Upper Atmosphere Physics. The principles of electrohydrodynamics which describe the motion of a charged body in a plasma are applied to typical satellite motions, and numerical estimates are obtained for various quantities of interest. Among these are the drag, the Mach cone angle, and the increase in ionization across the Mach cone. Plasma Physics. The electrostatic field about an ion moving slowly through a highly ionized gas is being investigated to determin how this field becomes distorted when the ion under consideration moves with velocities small compared to the mean thermal velocity of ions in the gas. The electron density in the wake of a slightly charged body moving through a highly ionized gas is being investigated. The charge accumulation on the surface of a sphere in the extreme upper atmosphere is being investigated. Molecular Physics. Phenomenological formalism is presented for chemical reactions, dissociations, excitations, and the reverse processes in gaseous mixtures. General thermodynamic expressions are derived for the equilibrium of a multicomponent mixture of reacting real gases with radiation, with special emphasis on adiabatic expansion. A graph giving electron concentration for argon-free air in equilibrium is given. A method of solution is presented for generalized isentropic flows and normal shock for hightemperature gases. The thermodynamics of the upper atmosphere and its influence on gas properties behind shocks is presented. A method is being developed for calculating the cross sections for scattering of very slow electrons by nitrogen and oxygen atoms. Molecular Beam Research. Measurements are in progress on the total cross sections for scattering of electrons by atmospheric species. These cross sections are needed for determining the microwave transmissivity, reflectivity and refractivity of the shocked air surrounding hypersonic vehicles that are in the continuum region of the earth's atmosphere. Applied Mathematics. Flow field calculation is presented with real gas effects. Development of numerical techniques is presented. Theoretical work now strongly indicates that a signifi cant reduction of heat transfer to a blunt body in a hypersonic stream can be effected by using a magnetic field built into the body. Physical Mechanics. A study of heat transfer in the free molecule flow region is presented. This study was undertaken for the purpose

• Research Organization: Convair, San Diego, Calif.
• NSA Number: NSA-13-007881
• OSTI ID: 4258346
• Report Number(s): ZPH-020
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS AND MATHEMATICS
ABSORPTION- AIR- ATMOSPHERE- CROSS SECTIONS- ELECTRONS- MACH NUMBER- MEASURED VALUES- MICROWAVES- QUANTITATIVE ANALYSIS- REFLECTION- REFRACTION- SCATTERING- SHOCK WAVES- SPACE VEHICLES- ULTRASONICS
ABSORPTION- ENERGY- FREQUENCY- MACH NUMBER- MATHEMATICS- PHOTONS- REFRACTION
ADIABATIC PROCESSES- EQUATIONS- EXPANSION- GASES- MACH NUMBER- RADIATIONS- THERMODYNAMICS
ADSORPTION- DESORPTION- LIGHT- MACH NUMBER- PREPARATION- - SAMPLING- ZINC OXIDES
AIR- ARGON- DENSITY- DIAGRAMS- ELECTRONS- MACH NUMBER
ANGULAR DISTRIBUTION- CARBON- ELASTIC SCATTERING- FAST NEUTRONS- MACH NUMBER- MEASURED VALUES- NEUTRONS