Showing papers on "Projectile published in 1979"

Approach to electron capture into arbitrary principal shells of energetic projectiles

Abstract: An approach for treating electron capture into arbitrary principal shells or into continuum states of energetic projectiles is developed. The approach is based on the momentum-density matrix of the captured electron summed over all substates l, m or integrated over all emission angles, respectively. In conjunction with the kinematics of energetic capture reactions it leads to drastic simplifications in capture theories. Within the eikonal approximation, the present approach yields an exact result for the cross section describing capture of hydrogenic 1s electrons into hydrogenic bound or continuum states of the projectile. The final result is a simple analytical expression factorizing into the Oppenheimer-Brinkman-Kramers cross section times a scaling factor between 0.1 and 0.4. The theoretical scaling factor for the total cross section turns out to be a function of v/v/sub K/ (the ratio of projectile velocity to target K-shell velocity) which is approximately independent of the target and projectile charges. For hydrogen and helium targets surprisingly good agreement is obtained with a large body of experimental data.

Scoring of simulated weapons fire with sweeping fan-shaped beams

Abstract: For scoring of simulated firing of a weapon, having flatwise-angularly sweeping beams of radiation, emitted at the weapon location during a period beginning at or about the instant of simulated firing are used for measuring the position of a target retroreflector in range and in functions of azimuth and elevation. During the same period a calculation is made of the instantaneous positions in range, and in functions of azimuth and elevation, of an imaginary projectile fired from the weapon at the firing instant under conditions then existing, and the relationship is ascertained between the imaginary projectile and each beam in its angular position at interception by the retroreflector. At a scoring instant, when weapon-to-reflector distance equals weapon-to-projectile distance, or when the projectile is at a predetermined elevation relative to the reflector, scoring is based on the relationship of projectile to angular beam position at that instant. Scoring results can be displayed at the weapon location and/or transmitted to the target in beam modulation for evaluation of hit effect at the target.

Strong Compression Effects in Fast Nuclear Collisions

Abstract: The importance of the impact parameter for compression effects and the reaction mechanism in high energy heavy ion collisions (HEHIC) are investigated within three-dimensional nuclear fluid dynamics. For central collisions of a small projectile (Ne) with a heavy target (U) a Mach shock wave is formed resulting in the sidewards emission of matter with azimuthally symmetric fragment distribution. At intermediate impact parameters the Highly-Inelastic Bounce-Off (HIBO) appears, where the large compression potential leads to the sidewards deflection of the projectile, which then explodes. A large collective transverse momentum transfer to the target leads to azimuthally asymmetric (180° correlated) fragment distributions. The deflection angles, energy losses, mean associated multiplicities as well as the maximum compression and thermal excitation of the system are calculated as a function of the impact parameter.

Inner-shell charge transfer in asymmetric ion-atom collisions

Abstract: A method used previously for inner-shell ionization in asymmetric ion-atom collisions is extended to include charge transfer between the target inner shells and projectile K shell. We work in the energy range eta/sup 1/2/ = h v/Z/sub N/e/sup 2/ < or approx. = 1 and use an independent-electron model (Hartree-Fock) for the target. We treat the interaction with the projectile as a time-dependent perturbation due to a bare charge moving on a straight-line path. Our method, as for ionization, is very efficient in that with our target-centered expansion of the system wave function, all requisite matrix elements needed at a particular projectile energy are pretabulated and used at all impact parameters. A critical feature of our results is the recognition of the importance of target continuum states of energy approximately equal to the kinetic energy (in the target frame) of the electron on the projectile, and the development of a method to properly include such resonance states in our pseudostate calculation. We present selected numerical results to illustrate our method and to demonstrate the projectile energy and nuclear charge dependence of the cross sections. A general feature of the results presented is that the computed cross sections are of themore » order of 0.3--0.5 times the Brinkman-Kramers estimate. Simultaneously, we also compute cross sections for electron stripping of the projectile, and find them to be dominated by transitions to the above-described resonant continuum state of the target.« less

Influence of Retardation on the Angular Distribution of Radiative Electron Capture

Abstract: Angular distributions and forward-backward intensities of photons emitted during electron capture have been measured in collisions between fast projectile ions (93-MeV oxygen, 110-123-MeV sulfur) and target atoms. In contrast to previous expectations, the radiation pattern in the laboratory system is not strongly shifted in forward direction but turned out to exhibit forward-backward symmetry independent of the projectile velocity. We attribute these findings to a cancellation between the Doppler-shift and retardation effects.

Kinetic-energy projectile

Abstract: The present invention relates to a new kinetic-energy projectile. The projectile of the invention comprises a piercing head consisting of: a head penetrating means a main penetrating means and a spacing means located between the head penetrating means and the main penetrating means. The projectile of the invention is used to pierce light, heavy and strongly sloping armor.

Doppler-type projectile velocity measurement and communication apparatus, and method

Abstract: Projectile velocity measurement and communication apparatus comprises a microwave probe fixed to a projectile barrel near a muzzle end. An oscillator, having a reference frequency selected for exciting a fundamental electromagnetic mode in the barrel, is connected to the probe through a hybrid mixer configured for extracting, from moving projectile-reflected microwaves, a true Doppler signal having a varying frequency related to projectile barrel velocity. A processor, connected for receiving the Doppler signal, measures, by a clock oscillator, Doppler signal periods (half periods). A data presorter in the processor selects a last "N" number of period measurements before the projectile reaches an interference position relative to the probe, to be fed to a fire control computer interface for determination therein of projectile barrel and muzzle velocities, calibration means being provided to update barrel diameter values used in such determination. An alternative, dual reference frequency variation is described, in which a dual hybrid mixer provides two independent Doppler signals, to eliminate dependency of projectile velocity determinations on barrel diameter. A reference frequency modulator and control means therefor are provided to enable microwave communication of information to the projectile, for example, of projectile target time of flight for fusing purposes. Corresponding methods for projectile velocity measurement and communication are provided.

Double ramp discarding sabot

Abstract: A segmented sabot utilizes a double ramp configuration and a centrally poioned obturating band in alignment with the center of gravity of an in-bore projectile to improve the uniformity of the shear traction forces at the interface between the sabot segments and a subcaliber projectile, to reduce propellant gas blow-by and to enhance projectile in-bore and trajectory stability. The increased uniformity of shear traction forces between sabot and projectile interfaces and propellant gas self-sealing design permits a reduction in sabot weight of sufficient magnitude to increase the velocity of the projectile at the muzzle exit.

A simple estimate of the minimum target obliquity required for the ricochet of a high speed long rod projectile

Abstract: A simple model for the minimum obliquity required to induce ricochet of a high speed long rod projectile from a thick target plate is suggested.

Supersonic, low drag tubular projectile

Abstract: A hollow tubular projectile is disclosed having about 30 percent less masshan conventional ammunition projectiles and considerably less drag, as a result of precise aerodynamic design details.

An arrangement for launching interference material

Abstract: A projectile (1) containing particles of interference material is fired pneumatically from a launching tube (2). Compressed air, which is supplied to the launching tube and acts on the rear face of the projectile during firing, is conducted both to a loading chamber (19) wherein the air pressure is maintained even after the projectile has left the firing tube, and also via the loading chamber to an expansion chamber (20) in which, after a specific time-lag corresponding with a certain launch height on the trajectory of the projectile, an over-pressure builds up which causes the expansion of the chamber to be initiated with simultaneous expulsion of the interference material from the projectile. The compressed air may also be conducted to the chamber (10) in the projectile wherein the interference material is accommodated, tightly packed, in order to enhance the dispersion thereof.

Projectile Penetration in Soil and Rock: Analysis for Non-Normal Impact

Abstract: : An empirical rigid-projectile analysis has been developed for non- normal impact and penetration into soil and rock. The soil penetration analysis uses Young's S-number as the penetrability index. The rock penetration analysis calculates resistance-to-penetration using density, strength, and Rock Quality Designation. Expressions for compressive normal stress are integrated numerically over the projectile surface using the differential area force law in the PENCO2D computer code. The analysis includes free-surface and wake separation-reattachment effects. The PENCO2D code is used to make comparison calculations for Sandia/DNA reverse ballistic tests and several full-scale tests conducted by Sandia Laboratories. A parameter study shows effects of soil penetrability, impact velocity, initial attack and obliquity angles, and projectile geometry on underground trajectories.

Electro-optical projectile analyzer

Abstract: A device for determining the velocity, trajectory and attitude of a projele. Light beams from two perpendicular linear arrays of light emitters are incident upon corresponding linear photodetector arrays. Each light beam in the linear arrays includes an individualized characteristic to permit unique identification of each beam. Trajectory and velocity parameters are determined by identifying which detectors have an interrupted light beam and from the time interval between actuation of the arrays.

Fire control system

Abstract: A fire control system is shown wherein the relative rotational motion between a modulated beam of infrared energy and a spinning projectile is used to determine the displacement of such a projectile during flight from the centerline of such beam so that the trajectory of such projectile may be corrected as required to enable a selected target to be hit.

Method and apparatus for accelerating a solid mass

Abstract: Method and apparatus for accelerating an axi-symetrical mass, such as a projectile, (50) by imploding a plasma discharge against the projectile surface, the plasma inducing an ionized liquid layer, and a magnetic field from the plasma interacting with the ionized liquid layer to accelerate the projectile. In a preferred embodiment the projectile is tapered toward its axis in a direction opposite from the direction of acceleration. To provide a long acceleration path a plurality of cascaded accelerating sections (51-55) are provided along the path and the projectile position, as it advances between the sections, is sensed and discharges are switched on sequentially in the sections.

Warhead for projectiles and rockets

Abstract: Warhead for projectiles and rockets in which the projectile or rocket casing can be relied upon to decompose into splinters of predetermined size, shape, and distribution. To accomplish this result, a thin-walled insert is positioned between the projectile or rocket casing and the explosive charge, such insert being provided with a number of ribs forming a series of saddle-roof shaped structures which exert a cutting charge effect on the casing on the detonation of the explosive charge.

Antitank weapon system and elements therefor

Abstract: An antitank weapon system is shown to include a projectile carrying at least one pulsed laser radar which periodically illuminates swaths of the underlying terrain, means for processing return signals to distinguish between the radar signatures of objects on such terrain and means for firing submunitions to impact on any object whose radar signature corresponds to that of a tank or other desired target.

The influence of non-uniform incident flux upon surface erosion processes

Abstract: The surface topographic development by sputter erosion of a solid resulting from spatially non-uniform projectile bombardment is considered theoretically. It is shown that whilst formal prediction of time-dependent surface geometry is possible, analytic solution of the defining equations is generally unachievable, although an approximate treatment may be made for the case of a Gaussian flux distribution profile and an initially plane surface. It is shown that profile perturbations resulting from erosion rate-projectile incidence angle variations can assume importance when erosion crater depths become of similar order to projectile beam width. This behaviour is also revealed by computer simulation of the erosion process and a sand blasting experimental analogue study.

Armor-piercing projectile

Abstract: An armor-piercing projectile is provided having hardened multi-layers and being relatively simple in design. The projectile includes an axial bore, a continuous strip of metallic glass wound about the core to form for the projectile a laminated body, a generally conical frontal surface, and a transverse rear surface, and a bonding agent for joining the adjacent laminated surfaces.

Munitions round for barrel-type weapons

Abstract: A munitions round for a subcaliber projectile to be fired from a barrel-type weapon has a casing, of a uniform outer cross section substantially over its entire length, receiving the projectile which is at least partially surrounded by the gas-generating propellant charge. A drive body is mounted at the forward end of the projectile and has a rearward pressure-receiving surface which droops inwardly toward the projectile from an outer edge of the body which is engaged by the casing. The body is formed from a plurality of segments which form-fittingly hug the projectile and have confronting angularly spaced separating surfaces bridged by a sealing member. The forward end of the body, formed by the segments, is concave forwardly and has a leading edge which is disposed outwardly and axially ahead of the rearward inner edge of this surface which forms a pocket engaging the air upon propulsion of the projectile from the barrel to effect separation of the segments and dislodgment of the body.

Roll reference sensor

Abstract: A technique for sensing both the earth generated electromagnetic and electrostatic fields is employed on board a remotely guided spin-stabilized projectile or missile in order to accurately determine a vertical reference direction and provide for proper response to received guidance information during the entire flight trajectory.

Overflying munitions device and system

Abstract: In a munitions system, a cylindrical canister is fired over a target. The canister carries a target sensing infrared device and, when a target is detected, a projectile is fired downward from the bottom of the overflying missile. A spinning motion is imparted to the missile to stabilize its flight, and a wobbling motion is imparted to the missile to provide a larger target area. The projectile forms a concave lower end to the missile and is fired by an explosive charge.

Device for launching non-lethal ring airfoil projectiles

Abstract: A sabot launching device attachable to the muzzle of a standard rifle for launching a non-lethal ring airfoil projectile at a desired velocity and for imparting a desired rate of spin to the projectile, the invention comprises a housing having rifle grooves formed proximous to an open distal end thereof for imparting spin to the projectile as said projectile is launched from the open end of the housing. A sabot member engages the projectile within the housing prior to launch and is projected forwardly within the housing while in engagement with the projectile under pressure produced by firing of a gas-producing round in the standard rifle. The forward movement of the sabot member is rapidly slowed by a buffer mechanism disposed within anterior portions of the housing after initial acceleration to cause only the projectiles to exit and thus be launched from the housing, the sabot member thereby remaining within the housing and being reusable. The launching device is particularly useful for momentarily disabling disorderly persons without causing them serious injury, such as is necessary during civil disturbances and similar situations.

Muzzle velocity compensating apparatus and method for a remote set fuze

Abstract: A desired range is selected prior to firing the projectile carrying the remote set fuze and after firing a Doppler radar provides Doppler pulses proportional to the relative velocity of the projectile Constant frequency pulses are counted during a predetermined number of the Doppler pulses to provide an indication of the actual velocity of the projectile and the preselected range-to-function is achieved by means of a time-to-function adjustment to compensate for differences between the actual velocity and a predicted velocity The adjusted time-to-function is transmitted to the remote set fuze in a coded form

Projectile deployed cable weapons system

Abstract: A projectile deployed cable weapons system for defeating helicopter rotor systems is disclosed. The deployed cable is intended to settle on the target helicopter from above, and damage is inflicted on the main rotor blade or tail rotor blade of the helicopter by sudden stoppage or castastrophic failure of the contacted rotor system. A particularly advantageous assemblage for deploying an amount of cable to defeat helicopter rotor systems is also disclosed. The weapons assemblage includes a first cavity for receiving a projectile, a second cavity containing an amount of cable, and a snaring means attached to the first cable and situated with respect to the first cavity so as to intercept the projectile when projected. Most advantageously the assemblage consists of a field container containing both the projectile and cable as a single operating unit to be attached to the muzzle of a mortar cannon of conventional design. In another embodiment a projectile such as a rocket or shell contains the cable and a submunition. After the projectile is aloft the submunition is fired to carry the cable from submunition in strand form.