BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Launch Dynamics of APFSDS (Armor Piercing, Fin-Stabilized, Discarding Sabot) Ammunition

OCT 1984

55 pages

Authors: P. Plostins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The full text of this report is available for sale.

An experimental program to determine the magnitude and nature of the launch perturbations to the projectile angular motion during sabot discard is discussed. The data analysis isolates the sources and quantifies the severity of the launch perturbations. An explanation of how the discard dynamics may be related to the inbore motion of the round is presented. The results show that the discard disturbances cause a net increase of 41% in ...

Nonlinear Waves in a Rod. Results for Incompressible Elastic Materials

OCT 1984

Authors: T. W. Wright; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The full text of this report is not available and therefore is not for sale. This information is provided for reference purposes only.

A nonlinear intrinsic theory is used to describe the motions of a straight round elastic rod including the influence of radial shear and inertia. Consideration of steady wave motions reduces the two coupled partial differential equations to ordinary differential equations for which two integrals of the motion may be found. For incompressible elastic materials with the restriction of small strain gradients, but arbitrary finite strains, a large variety of exact ...

A Virial Equation of State Option for the TIGER Computer Program

OCT 1984

69 pages

Authors: A. K. R. Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

This report describes a truncated virial equation of state option for the TIGER computer program which computes the thermodynamic properties of systems of gases, liquids and solids. The second virial coefficients of the ADDED EQUATION IS BASED ON Lennard-Jones (6-12) intermolecular potential, whereas the third virial coefficient is derived from a simplified rigid sphere approximation. This report provides an outline of the derivation of the pertinent formulas and a listing ...

Volume Averaged Two-Phase (Gas Solid) Interior Ballistics Equations

SEP 1984

Authors: A. K. R. Celmins; J. A. Schmitt; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

This report presents a complete mathematical derivation of governing equations for two-phase (gas-solid) interior ballistic flows. The derivation is based on instantaneous weighted volume averaging of local conservation equations, and it contains a complete discussion of errors that are introduced by the averaging. Initial conditions and boundary conditions that are consistent with the averaging procedure are discussed. The final form of the equations is chosen to facilitate their numerical solution. ...

Detailed Characterization of the Interior Ballistics of Slotted Stick Propellant

SEP 1984

33 pages

Authors: F. W. Robbins; A. W. Horst; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

While classical, lumped-parameter modeling of granular propellant gun firings is often quite successful at reproducing experimental data, a similar treatment of stick propellant firings typically yields somewhat lower pressures and muzzle velocities than actually experienced in the gun. To identify those processes responsible for this behavior, a set of highly-instrumented gun firings has been performed in a 155-mm howitzer, using both stick and granular propellant charges. To simplify the investigation ...

Ambushed by a Lurking Variable,

JUN 1983

Authors: Barry A. Bodt; Jerry Thomas; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

In the formal study of design and analysis of experiments, it is often overlooked that a simple and straight-forward design can become complicated during analysis. Presented here is a specific case in which the design was readily apparent but where difficulties subsequently arose. Analysis, plagued by nonhomogeneity of variance and the suspicion of a lurking variable, is discussed. Answers to questions concerning the performance of a MLRS(Multiple Launcher Rocket System) ...

Modeling of Flow Interaction of a Liquid Jet with a Contaminant Droplet,

FEB 1983

Authors: Lang-Mann Chang; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Two flow models have been developed for investigation of the flow interaction of a liquid jet with a chemical contaminant droplet on a plane wall. This interaction is considered as a two-dimensional viscous flow problem. Computer plots are presented for the flow pattern and the evolution of the droplet upon jet impingement. Displacements and mean velocity of the droplet upstream edge are provided as functions of jet velocity and fluid ...

Calculation of Legendre Functions on the Cut for Integral Order and Complex Degree by Means of Gauss Continued Fractions,

FEB 1983

Authors: Alexander S. Elder; James N. Walbert; Eric C. Benck; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

These functions are required for the calculation of biorthogonal functions for the hollow cone as required for solving problems in elasticity and rheology. The associated legendre functions on the cut for integral order and complex degree are required for several important calculation of biharmonic functions for the hollow cone.

Improved M-11 Copper Crusher Gage,

SEP 1982

Authors: James M. Bender; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Recent testing of the M-11 Copper Crusher gage indicates that it does not meet the NATO standards for precision at the high end of its operating range. The Ballistic Research Laboratory (BRL), of the Armament Research and Development Command (ARRADCOM), at the request of the Materiel Testing Directorate (MTD), of the Test and Evaluation Command (TECOM), performed structural integrity analyses using the finite element method for mechanical behavior of solids. ...

An Assessment of the Current State-of-the-Art of Incapacitation by Air Blast,

AUG 1982

Authors: William Kokinakis; Ronald R. Rudolph; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Target vulnerability methodology requires a criticality measure for all internal components which contribute to a system or to a system's weapon effectiveness, including that of the human target. Such measures have been developed for personnel targets for kinetic energy penetrators; however, there is presently no generally accepted quantitative measure of incapacitation to infantry or crew personnel from the prime blast threat. To address this need, an assessment of the current ...

Computational Parametric Study of the Aerodynamics of Spinning Slender Bodies at Supersonic Speeds,

JUN 1980

Authors: Walter B. Sturek; Donald C. Mylin; Clarence C. Bush; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Recent trends in projectile design have led to shapes with greater length and more slender ogives. Unexpected flight stability problems have been encountered due to decreased aerodynamic stability of these new shapes. Clearly, conventional aerodynamic predictive capabilities were not adequate. In an effort to avoid these problems in the future, the Ballistic Research Laboratory has been developing advanced numerical computational techniques for computing projectile aerodynamic characteristics to improve shell design ...

A Comparison of Navier-Stokes Computations with Experimental Data for a Projectile Shape at Transonic Velocities,

JUN 1980

Authors: Charles J. Nietubicz; Lyle D. Kayser; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A concentrated theoretical and experimental research program has been ongoing at BRL in order to develop the predictive capabilities required for determining projectile aerodynamics. Supersonic computations using combined inviscid flow field and boundary layer techniques have been developed for cone-cylinder and ogive-cylinder configurations. Recent results have been obtained in supersonic flow over a typical boattailed projectile using modern computational techniques for solving the thinlayer Navier-Stokes equations.

Burning Rate Transitions for HMX Burned as a Binderless Propellant,

JUN 1980

Authors: Robert A. Fifer; James E. Cole; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Composite (non-homogeneous) propellants containing crystalline HMX (cyclotetramethylene-tetranitramine) or the similar compound RDX (cyclotrimethylene-trinitramine) imbedded in a polymeric binder are gradually replacing homogeneous nitrocellulose-based propellants in many gun and rocket applications. Propellants containing HMX or RDX are commonly called nitramine propellants. A number of studies have been carried-out to determine the burn rate of pure HMX (1-4), using either large single crystals or pressed powder samples. Single crystal studies have only ...

The Particle Dynamics of Penetration,

JUN 1980

Authors: James Dehn; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Mathematical modeling of the target penetration process is an old field and the great variety of models we now have reflects this fact. At one end of the model spectrum we have simple empirical interpolation formulas which can serve as convenient summaries of what we know already, though they cannot further our understanding. At the other extreme we have very complicated continuum models which include all the science we think ...

Angular Motion of Spinning Almost-Symmetric Missiles.

DEC 1979

Authors: Charles H. Murphy; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Passive MMW Detection in Snow.

MAY 1979

Authors: Paul Dietz; James G. Constantine; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A Model for Bomblet Ejection from Missiles.

AUG 1978

Authors: Raymond Sedney; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Highly Survivable Truss Type Tail Boom,

JUN 1978

Authors: Thomas F. Erline; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Successful completion of Army helicopter missions in future battle scenarios may well depend upon survival of the structure after battle damage. Survivability of a helicopter will depend significantly upon the structure's ability to retain structural integrity. The principle purpose of this study is to develop a structural concept which assures a high degree of confidence in the integrity of a structure that has received combat damage. This study has been ...

Laser-Induced Opto-Acoustic Pulses in a Flame,

JUN 1978

Authors: David R. Crosley; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Another means of detection of the absorption of laser radiation by individual species in a flame environment is the production of opto-acoustic pulses in a flame at 1-atm pressure. The flame is seeded with alkali atoms and a pulsed laser is tuned to the appropriate absorption line. While some of the electronically excited atoms fluoresce, the vast majority lose their energy by collision with other gases present in the flame. ...

An Analysis of Smoke Transmittance Measurements and Techniques.

NOV 1977

Authors: Richard G. Reitz; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The Ballistic Modeling Division has made transmittance measurements at selected regions of the electromagnetic spectrum through various aerosols in field environments. The measurements have been obtained with visual, near infrared, far infrared, and millimetre wave instrumentation. Live firings were conducted at Fort Sill, Oklahoma, using mortar- and artillery-delivered hexachloroethane (HC) and white phosphorous (WP) munitions. At Fort Hood, Texas, 2.75-inch rockets were launched from helicopters to deliver WP wick-produced smoke. ...

Critical Review of One-Dimensional Tube Flow Equations.

OCT 1977

Authors: Aivars K. R. Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Flows through ducts or pipes are often analyzed theoretically and numerically using one-dimensional flow equations. Generally it is assumed that the equations describe relations between average flow properties and that they are adequate if the axial component of the flow dominates. This paper reviews the derivation of the governing equations. It is shown that equations which are traditionally used for tube flows have a very limited scope of applicability. Their ...

BENCHMARK-76: Model Computations for Disturbed Atmospheric Conditions. I. Input Parameters,

OCT 1977

Authors: J. M. Heimerl; F. E. Niles; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The fixed input parameters used in the multispecies code BENCHMARK-76, a version of the AIRCHEM code, are discussed. The coding is given and briefly described. Card input definitions and formats are given. (Author)

Conjecture for Anomalous Spin Decay of the 155mm Binary Shell (XM687).

OCT 1977

Authors: Clarence W. Kitchens Jr.; Raymond Sedney; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

When the XM687 liquid-filled projectile is launched with small yaw a smooth spin record is obtained which can be accurately predicted by theories based on the Wedemeyer spin-up model. A few rounds with large first maximum yaw have a different type of spin record exhibiting a rapid initial spin decay, followed by a corner, or discontinuity in slope.

The Distance between a Point and an Ellipsoid.

OCT 1977

Authors: V. Kucher; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The method of the calculus of variations is used to determine the distance from any point, not in a coordinate plane, to the surface of an ellipsoid. The distance from any point in the coordinate plane to the surface of an ellipsoid is formulated by the method of Lagrange multipliers. A computer program has been developed to compute this distance. (Author)

Coherence Retention during Rotationally Inelastic Collisions of Selectively Excited Diatomic Sulfur,

OCT 1977

Authors: Thomas A. Caughey; David R. Crosley; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

There is ample experimental evidence for the presence of non-equilibrium population distributions, and the occurrence of non-Arrhenius reaction rate behavior, in a wide variety of combustion processes. A full understanding of such systems on a microscopic level requires that such effects be addressed. Recent experiments are now just beginning to provide information on the detailed quantum level dependence of inelastic and reactive collisions for a number of small molecules. However, ...

Quantum Chemistry, Chemisorption, and Erosion. I. Properties of Diatomic Molecules,

OCT 1977

Authors: D. A. Ringers; J. B. Danese Jr; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A method has been developed for performing accurate total energy calculations using the X-alpha theory without the usual arbitrariness in selection of calculational parameters. The use of relatively high alpha-values and atomic sphere radii in the ratio of their atomic (covalent) radii led to results in agreement with experiment for dissociation energies and equilibrium separation distances in NO, CO, and SN. In addition, a method of obtaining dipole moments is ...

An Infrared Data Acquisition and Processing System.

SEP 1977

Authors: morgan T. Reedy; Earl P. Weaver; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

This report presents a description of an Infrared Data Acquisition and Processing System (IRDAPS). The description includes a discussion of the IRDAPS System hardware, system operating software, project oriented special software and its application to high energy laser beam diagnostic measurements. The report also points out that since the IRDAPS contains a flexible FORTRAN language based computing system, it is well suited to the general data acquisition and analysis area. ...

Aerodynamic Interference During Sabot Discard.

SEP 1977

38 pages

Authors: E. M. Schmidt; D. D. Shear; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

An experimental program has been conducted to investigate disturbances to the trajectories of gun-launched, fin-stabilized projectiles during the sabot discard process. Correlated near muzzle and down range measurements of sabot component and projectile motion are acquired using both orthogonal, flash X-rays and a ballistics range. Apparent anomalous yawing motion of projectiles correlates with asymmetries in the sabot discard geometry. The perturbations to the flow around the projectile due to these ...

Storage and Retrieval of Information on Systems of Partial Differential Equations and Their Solutions: Creatabse and the Continuum/Mechanics Center Data Base of Hydrocodes,

SEP 1977

Authors: Morton A. Hirschberg; joseph Lacetera; James A. Schmitt; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A Continuum Mechanics Center has been established for the purposes of evaluating and developing models of interacting continua. Because of the large and growing body of literature concerning such models and related computer codes, the vast number of assumptions made in their use, and the varying types of numerical methods utilized in these codes, a data base analysis system, CREATABASE, was used to store information and characteristics of the different ...

A Physical Model for Computing Fluid Flow Solutions.

SEP 1977

Authors: William P. Wright; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A physical and mathematical scheme is described which can be the basis for the construction of a computer program designed to solve fluid flow problems important to the U.S. Army. Essentially the scheme consists of the determination of contributions of moments of physical quantities over Lagrangian cells of fluid, which move according to the local fluid velocity to neighboring fixed cells. Based on the sums of these contributions of moments, ...

A Note on the Solution for a Circular Gas Jet.

SEP 1977

Authors: William Walters; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The classical solution for a circular gas jet given by Schlichting is obtained in exact form. An exact form of the solution is also presented for a more general form of the governing equations with boundary conditions such that the constants of integration need not be equal to zero. (Author)

A Finite Element Method and Corresponding Pilot Computer Code for Hyperbolic Systems of Equations in Two Spatial Dimensions and Time Applied to Unsteady Gas Flows.

SEP 1977

Authors: James A. Schmitt; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

This report contains a discussion of a numerical method for solving systems of first order time dependent hyperbolic equations in two spatial variables. This scheme which combines the finite element methodology and the properties of a hyperbolic system of differential equations is applied to unsteady gas flow problems. The formulation is based on the elementwise least squares minimization of the differential residual error and on the construction of the finite ...

Effects of High Pressure on Molecular Electronic Spectra: A Comparison of Models,

SEP 1977

Authors: Robert C. Tompkins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The experimental tests by Okamoto and Drickamer of the Drickamer model of high-pressure effects on electronic spectra are reexamined. Correctly interpreted the data contradict the model. However, it is shown that a theory of Lin is compatible with the data and shows promise of practical application. (Author)

Critical Growth Stress for Spallation,

SEP 1977

Authors: Gerald L. Moss; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The slip line field analysis of ductile void development is applied to the problem of fracture with stress waves, i.e., spallation, and an expression is developed for the prediction of the critical growth stress sigma go of voids in an elastic-plastic material. Comparison of experimentally measured values of sigma go with predictions based on the initial state of the material indicates it is important to account for the change in ...

On the Distribution of the Product of Two Gamma Variates.

SEP 1977

Authors: Palmer R. Schlegel; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

In this paper Mellin tranforms are used to determine the distribution of the product of two random variables, each of which is distributed by gamma functions and parameterized by an integer n. Furthermore, a recursive relationship is developed with respect to the parameter n to facilitate the evaluation of the resulting distribution. (Author)

Air Shock Filling of a Model Room.

SEP 1977

Authors: V. Kucher; J. Harrison; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

An Eulerian code was used to numerically investigate the air shock filling by a 5-psi overpressure shock wave of a two-dimensional room (4 in. by 4 in.) having a 1-in. centrally located entrance. Numerical results are presented graphically of pressure and velocity fields, vortex motion, and pressure histories at given locations in the room. Comparisons are made with experimental results which were obtained by shadowgraphs and pressure transducers. (Author)

Shock Propagation in the One-Dimensional Lattice,

AUG 1977

Authors: John D. Powell; Jad H. Batteh; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Shock propagation in a one-dimensional, discrete lattice is studied in some detail both by reviewing existing treatments of the problem and by providing a number of extensions to those treatments. Although some analytic work is presented, most of the study is in the form of a computer simulation. The purpose of the simulation is to solve numerically the classical equations of motion of the atoms of the lattice as they ...

Application of Laser Probing to Ballistic Meteorology,

AUG 1977

Authors: Jad H. Batteh; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Laser probing of the atmosphere is reviewed with particular emphasis on its application to ballistic meteorology. The requirements of the meteorological system are discussed, and the shortcomings of the rawinsonde technique, currently used, are outlined. A brief description of the relevant interactions of laser radiation with the atmosphere is presented. The potential of laser probing techniques for atmospheric measurements, as well as their current limitations, are then discussed in some ...

A Simple Computer-Driven Analog-to-Digital Converter for Use with an 8-Bit Microcomputer.

AUG 1977

Authors: Louis M. Colonna-Romano; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A very simple and inexpensive computer-driven analog-to-digital converter is described for use with an 8-bit microcomputer. Characteristics of the device are discussed along with possible improvements. A computer program written for an 8080A microprocessor to drive the device is given. (Author)

Estimation of Precision of Measurement and Product Variability: A Computer Model.

AUG 1977

Authors: James F. O'Bryon; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

When two or more instruments are used to simultaneously measure the same phenomena, it is possible, with a few assumptions, to obtain the most efficient unbiased estimator for the precision of measurement of each instrument as well as an estimation of the true variability of the event being observed. A computer program written in FORTRAN IV which performs these calculations is presented and discussed. Up to 10 instruments taking simultaneous ...

The Flow of a Liquid-Vapor Mixture through a Duct.

AUG 1977

Authors: William P. Walters; John Boyle; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The critical and subcritical mass flow rate is calculated for a homogeneous, adiabatic, frozen, liquid-vapor mixture flowing through a vent with friction. A critical pressure ratio (defined based on the simplifying assumptions) and other fluid dynamic parameters are calculated. The model is an extension of the compressible, adiabetic, constant duct area gas dynamics equations with wall shear. In spite of the limiting assumptions, the model is in agreement with experimental ...

Relative Transition Probabilities in the A-X System of OD,

AUG 1977

Authors: David R. Crosley; Russell K. Lengel; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

In the fashion of a previous study on the OH molecule, branching ratios for emission from the zeroth, first, and second vibrational levels of the A-doublet-sigma-plus state of OD have been measured using frequency doubled tunable dye laser excitation. The six independent ratios so obtained are used to assess calculations incorporating an electronic transition moment varying linearly with internuclear distance, a form judged superior from the OH work. Calculations of ...

Prediction of Spin-Decay of Liquid-Filled Projectiles.

JUL 1977

34 pages

Authors: Clarence W. Kitchens Jr; Nathan Gerber; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

An accurate method for predicting the spin-decay of liquid-filled projectiles throughout their flight is described. The method is based on Wedemeyer's model for the spin-up of the liquid payload. The in-bore spin-up process is predicted using numerical solutions of the Navier-Stokes equations and Wedemeyer's equation. Spin-decay calculations are compared to spin histories obtained from test firings of 155mm liquid-filled projectiles equipped with yawsondes. The 100%-filled cases show ...

Selected Neutral Species Profiles, 0-100 km.

JUL 1977

Authors: F. E. Niles; J. M. Heimerl; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Daytime and nighttime concentration profiles have been assembled for the following neutral species: CO, CO2, H, H2, H2O, H2O2, HNO2, HNO3, HO, HO2, N, N((2)D), NO, NO2, N2, N2O, O, O((1)D), O2, O2((1)Delta), O2((1)sigma) and O3. Values for each species concentration are given in 5 km intervals for the altitude range 0-100 km.

Nuclear Thermal Effects on the Outer Material of the Blast Hardened S-280 Electrical Shelter Wall.

JUL 1977

Authors: Ennis F. Quigley; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Because of the thermal insulating nature of the Kevlar-49 fiber epoxy resin composite material used in the blast hardened S-280 electrical shelter with the blast hardened wall and roof construction of the shelter, the shelter will survive the recommended nuclear thermal radiation levels. However, since the thermal environment precedes the blast environment and the Kevlar material is an integral part of the walls and roof, the blast hardness of the ...

X ALPHA Calculation of Transition Energies in Multiply Ionized Atoms.

JUL 1977

Authors: D. A. Ringers; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The X alpha method has been applied to the calculation of ionization energies in multiply ionized atoms. It is shown that the accuracy of calculations can be improved if appropriate (different) values of alpha are used for each configuration. Alternatively, one can use the Slater transition state, wherein a total energy difference is related to a difference in single-electron eigenvalues. By a series expansion, the value of alpha for an ...

Comments on the Solution Coupled Stiff Differential Equations.

JUL 1977

Authors: M. D. Kregel; J. M. Heimerl; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The K-method of integrating sets of ordinary differential equations is outlined. This algorithm employs a variable step size, third order predictor-corrector method. It is written to reduce truncation error and to maximize stability consistent with reasonable execution time. The K-method has been used to integrate equations with discontinuous driving functions and this algorithm conserves chemical balance within the machine round-off error. It has been applied to solve kinetics problems in ...

Neutron Damage in Silicon from Neutrons with Energy Near 1-MeV.

JUL 1977

Authors: J. E. Youngblood; C. E. Hollandsworth; W. R. Van Antwerp; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Silicon diodes have been used to evaluate the damage introduced in silicon by monoenergetic neutrons at several neutron energies near 1 MeV. Eight diodes were irradiated at each of the neutron energies; 0.70, 0.96, 1.16, 1.63 and 2.37 MeV. The results are compared with diodes exposed to 14 MeV neutrons and with calculations of displacement (permanent) damage. It is shown that the damage fluctuates severely for neutron energies near 1 ...

Photodissociation of NO(+)(nO) and NO(+)(H2O).

JUL 1977

Authors: J. A. Vanderhoff; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

A drift tube mass spectrometer coupled with ion laser and ion laser pumped tunable dye laser photon sources has been used to measure the thermal energy (300K) photodissociation cross sections for two positive ion clusters, nitric oxide clustered with the nitric oxide ion and water clustered with the nitric oxide ion. Measurements were made spanning a photon wavelength range from 799 to 350 nm. The absolute photodissociation cross sections for ...

Temperature Measurement of Residual Penetration Fragments.

JUL 1977

Authors: W. G. Von Holle; G. Melani; J. Waddell; R. Frey; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

The temperature of residual fragments from the low velocity penetration of 1.27 steel spheres into various targets has been measured by 2-band infrared radiometry. The residual velocities of the fragements were also measured. The temperatures correlate well with the predictions of a simple model based on the conversion of mechanical energy to heat. The residual velocities correlate with theoretical and previous empirical data. (Author)