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Sample records for a1900 projectile fragment

  1. Angular Momentum Population in Projectile Fragmentation

    NASA Astrophysics Data System (ADS)

    Podolyák, Zs.; Gladnishki, K. A.; Gerl, J.; Hellström, M.; Kopatch, Y.; Mandal, S.; Górska, M.; Regan, P. H.; Wollersheim, H. J.; Schmidt, K.-H.; Gsi-Isomer Collaboration

    2004-02-01

    Isomeric states in neutron-deficient nuclei around A ≈190 have been identified following the projectile fragmentation of a relativistic energy 238U beam. The deduced isomeric ratios are compared with a model based on the abrasion-ablation description. The experimental isomeric ratios are lower by a factor of ≈2 than the calculated ones assuming the `sharp cutoff' approximation. The observation of the previously reported isomeric Iπ=43/2- state in 215Ra represents the current record for the highest discrete spin state observed following a projectile fragmentation reaction.

  2. Fragmentation of hypervelocity aluminum projectiles on fabrics

    NASA Astrophysics Data System (ADS)

    Rudolph, Martin; Schäfer, Frank; Destefanis, Roberto; Faraud, Moreno; Lambert, Michel

    2012-07-01

    This paper presents work performed for a study investigating the ability of different flexible materials to induce fragmentation of a hypervelocity projectile. Samples were chosen to represent a wide range of industrially available types of flexible materials like ceramic, aramid and carbon fabrics as well as a thin metallic mesh. Impact conditions and areal density were kept constant for all targets. Betacloth and multi-layer insulation (B-MLI) are mounted onto the targets to account for thermal system engineering requirements. All tests were performed using the Space light-gas gun facility (SLGG) of the Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI. Projectiles were aluminum spheres with 5 mm diameter impacting at approximately 6.3 km/s. Fragmentation was evaluated using a witness plate behind the target. An aramid and a ceramic fabric lead the ranking of fabrics with the best projectile fragmentation and debris cloud dispersion performance. A comparison with an equal-density rigid aluminum plate is presented. The work presented can be applied to optimize the micrometeoroid and space debris (MM/SD) shielding structure of inflatable modules.

  3. Improvements to a model of projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Mallik, S.; Chaudhuri, G.; Das Gupta, S.

    2011-11-01

    In a recent paper [Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.83.044612 83, 044612 (2011)] we proposed a model for calculating cross sections of various reaction products which arise from disintegration of projectile-like fragments resulting from heavy-ion collisions at intermediate or higher energy. The model has three parts: (1) abrasion, (2) disintegration of the hot abraded projectile-like fragment (PLF) into nucleons and primary composites using a model of equilibrium statistical mechanics, and (3) possible evaporation of hot primary composites. It was assumed that the PLF resulting from abrasion has one temperature T. Data suggested that, while just one value of T seemed adequate for most cross-section calculations, a single value failed when dealing with very peripheral collisions. We have now introduced a variable T=T(b) where b is the impact parameter of the collision. We argue that there are data which not only show that T must be a function of b but, in addition, also point to an approximate value of T for a given b. We propose a very simple formula: T(b)=D0+D1[As(b)/A0] where As(b) is the mass of the abraded PLF and A0 is the mass of the projectile; D0 and D1 are constants. Using this model we compute cross sections for several collisions and compare with data.

  4. Projectile fragmentation wall for CHICSi detector

    NASA Astrophysics Data System (ADS)

    Budzanowski, A.; Czech, B.; Siwek, A.; Skwirczyńska, I.; Staszel, P.; CHIC Collaboration

    2002-04-01

    The Forward Wall Detector (FWD) is designed to identify projectile-like fragments from heavy-ion reactions at the CELSIUS storage ring in Uppsala, Sweden. FWD covers the polar angle from 3.9° to 11.7° with geometrical efficiency of 81%. The single-detection module can be either of phoswich type (10 mm fast plastic+80 mm CsI(Tl)) or Δ E- E telescope (750 μm Si+80 mm CsI(Tl)). It is expected to have charge identification up to Z=18 and mass resolution for H and He isotopes.

  5. Experimental and numerical study on fragmentation of steel projectiles

    NASA Astrophysics Data System (ADS)

    Råkvaag, K. G.; Børvik, T.; Hopperstad, O. S.; Westermann, I.

    2012-08-01

    A previous experimental study on penetration and perforation of circular Weldox 460E target plates with varying thicknesses struck by blunt-nose projectiles revealed that fragmentation of the projectile occurred if the target thickness or impact velocity exceeded a certain value. Thus, numerical simulations that do not account for fragmentation during impact can underestimate the perforation resistance of protective structures. Previous numerical studies have focused primarily on the target plate behaviour. This study considers the behaviour of the projectile and its possible fragmentation during impact. Hardened steel projectiles were launched at varying velocities in a series of Taylor tests. The impact events were captured using a high-speed camera. Fractography of the fragmented projectiles showed that there are several fracture mechanisms present during the fragmentation process. Tensile tests of the projectile material revealed that the hardened material has considerable variations in yield stress and fracture stress and strain. In the finite element model, the stress-strain behaviour from tensile tests was used to model the projectile material with solid elements and the modified Johnson-Cook constitutive relation. Numerical simulations incorporating the variations in material properties are capable of reproducing the experimental fracture patterns, albeit the predicted fragmentation velocities are too low.

  6. Momentum distributions of isotopes produced by fragmentation of relativistic C-12 and O-16 projectiles

    NASA Technical Reports Server (NTRS)

    Greiner, D. E.; Lindstrom, P. J.; Heckman, H. H.; Cork, B.; Bieser, F. S.

    1975-01-01

    The fragment momentum distributions in the projectile rest frame are, typically, Gaussian shaped, narrow, consistent with isotropy, depend on fragment and projectile, and have no significant correlation with target mass or beam energy. The nuclear temperature is inferred from the momentum distributions of the fragments and is approximately equal to the projectile nuclear binding energy, indicative of small energy transfer between target and fragment.

  7. Momentum distributions of isotopes produced by fragmentation of relativistic C-12 and O-16 projectiles

    NASA Technical Reports Server (NTRS)

    Greiner, D. E.; Lindstrom, P. J.; Heckman, H. H.; Cork, B.; Bieser, F. S.

    1975-01-01

    The fragment momentum distributions in the projectile rest frame are, typically, Gaussian shaped, narrow, consistent with isotropy, depend on fragment and projectile, and have no significant correlation with target mass or beam energy. The nuclear temperature is inferred from the momentum distributions of the fragments and is approximately equal to the projectile nuclear binding energy, indicative of small energy transfer between target and fragment.

  8. Improved empirical parameterization for projectile fragmentation cross sections

    NASA Astrophysics Data System (ADS)

    Mei, B.

    2017-03-01

    A new empirical parametrization is developed for calculating the fragment cross sections in projectile fragmentation reactions at high energies (>100 MeV/nucleon). The new parametrization, FRACS, consists of two main parts, i.e., the mass yield and the isobaric distribution, on the basis of previous parametrizations. The formalism for the mass yield is improved to describe the target and the projectile energy dependences observed in measured fragmentation cross sections. The parametrization of the isobaric distribution is also modified to reproduce recent experimental data. Furthermore, an additional term is proposed and first implemented in the FRACS parametrization to account for the evident odd-even staggering effect observed in many experimental cross sections. Comparisons with extensive cross sections measured in various fragmentation reactions reveal that FRACS is in much better agreement with experimental data and can reproduce measured cross sections in most cases within a factor of 1.84, which is a much smaller rms deviation as compared to that of the recent parametrization EPAX3.

  9. The collision of a hypervelocity massive projectile with free-standing graphene: Investigation of secondary ion emission and projectile fragmentation.

    PubMed

    Geng, Sheng; Verkhoturov, Stanislav V; Eller, Michael J; Della-Negra, Serge; Schweikert, Emile A

    2017-02-07

    We present here the study of the individual hypervelocity massive projectiles (440-540 keV, 33-36 km/s Au400(4+) cluster) impact on 1-layer free-standing graphene. The secondary ions were detected and recorded separately from each individual impact in the transmission direction using a time-of-flight mass spectrometer. We observed C1-10(±) ions emitted from graphene, the projectiles which penetrated the graphene, and the Au1-3(±) fragment ions in mass spectra. During the projectile-graphene interaction, the projectile loses ∼15% of its initial kinetic energy (∼0.18 keV/atom, 72 keV/projectile). The Au projectiles are neutralized when approaching the graphene and then partially ionized again via electron tunneling from the hot rims of the holes on graphene, obtaining positive and negative charges. The projectile reaches an internal energy of ∼450-500 eV (∼4400-4900 K) after the impact and then undergoes a ∼90-100 step fragmentation with the ejection of Au1 atoms in the experimental time range of ∼0.1 μs.

  10. Perforation of fragment simulating projectiles into goat skin and muscle.

    PubMed

    Breeze, Johno; James, G R; Hepper, A E

    2013-06-01

    Ballistic gelatin is the most common tissue simulant used to reproduce the penetration of projectiles into muscle but published data to support its use are primarily based on bullets, despite explosive fragments being the most common cause of injury to soldiers on current operational deployments. Published ballistic tests using animal and artificial skin and muscle tissue surrogates also lack standardisation in methodology such that limited comparisons with that of human tissues can currently be made. Three masses of cylindrical NATO standardised fragment simulating projectiles (FSPs) were fired at 20% ballistic gelatin and the hind thighs of a killed goat. Threshold (V(th)) and V(50) velocities required for skin perforation and depth of penetration (DoP) into muscle were compared with gelatin. The intercept and gradient of the linear regression lines for DoP versus velocity were compared between gelatin and goat with significance defined as p<0.05. V(50) goat skin perforation velocities for the 0.16, 0.49 and 1.10 g FSPs were 121.1, 103.7 and 97.8 m/s, respectively. There was a significant difference in the V(50) required to perforate the gelatin surface compared with goat skin for the 0.16 and 0.49 g FSPs but not the 1.10 g. There was no statistical difference in the gradients for DoP versus velocity between animal and gelatin for either the 0.16 or 1.10 g FSPs. This study has produced data for skin perforation velocities and generated algorithms describing velocity versus predicted DoP into muscle for three standardised projectiles, which will be used to improve the fidelity of future injury models. 20% gelatin was demonstrated to accurately reproduce the retardation of the 1.10 g FSPs into goat muscle but the addition of a skin simulant will be required to accurately predict DoP for FSPs less than 1.10 g.

  11. Transition from fractal cracking to fragmentation due to projectile penetration

    NASA Astrophysics Data System (ADS)

    Kun, F.; Halász, Z.

    2014-12-01

    We present a theoretical study of the fracture of two-dimensional disc-shaped samples due to the penetration of a projectile focusing on the dynamics of fracturing and on the geometrical structure of the generated crack pattern. The penetration of a cone is simulated into a plate of circular shape using a discrete element model of heterogeneous brittle materials varying the speed of penetration in a broad range. As the cone penetrates a destroyed zone is created from which cracks run to the external boundary of the plate. Computer simulations revealed that in the low speed limit of loading two cracks are generated with nearly straight shape. Increasing the penetration speed the crack pattern remains regular, however, both the number of cracks and their fractal dimension increases. High speed penetration gives rise to a crack network such that the sample gets fragmented into a large number of pieces. We give a quantitative analysis of the evolution of the system from simple cracking through fractal cracks to fragmentation with a connected crack network. Simulations showed that in the low speed limit of loading the growing cracks proceed in discrete jumps separated by periods when the crack tips are pinned. The statistics of the size of jumps and of the waitng times shows scale free behaviour, i.e. power law distributions are obtained with universal exponents. Dependence on the loading speed was pointed out only for the cutoffs of the distributions. In the high speed limit of loading the sample falls apart forming a large number of fragments. The size of fragments proved to be power law distributed where dependence on the loading speed is observed only for the cutoffs. The value of the exponent has good agreement with experiments.

  12. Production of exotic nuclei in projectile fragmentation at relativistic and Fermi energies

    NASA Astrophysics Data System (ADS)

    Ogul, R.; Ergun, A.; Buyukcizmeci, N.

    2017-02-01

    Isotopic distributions of projectile fragmentation in peripheral heavy ion collisions of 86Kr on 112Sn are calculated within the statistical multifragmentation model. Obtained data are compared to the experimental cross section measurements. We show the enhancement in the production of neutron-rich isotopes close to the projectile, observed in the experiments. Our results show the universality of the limitation of the excitation energy induced in the projectile residues.

  13. Prediction of initiation of low and high explosive fillers due to fragment or projectile impact

    NASA Technical Reports Server (NTRS)

    Zabel, P. H.; Parr, V. B.

    1980-01-01

    A methodology is presented which provides predictions for the probability of initiation of explosion in high explosive filled warheads and in propellant filled rocket motor cases given the impact of compact fragments or of small projectiles. Equations of velocities at which 50 percent of the explosive filled cases will initiate either high or low order are developed for compact fragments, and for projectiles. These data are used to establish the standard deviation of the data from the 50 percent initiation line. Standard deviation is used to provide predictions of the probability of initiation given the impact velocity and other pertinent parameters using equations and logic which are established in a computer model. This computer model uses fragment material properties and encounter parameters to predict fragment impact initiation, and projectile and casing material properties and encounter parameters to predict projectile impact initiation.

  14. Prediction of initiation of low and high explosive fillers due to fragment or projectile impact

    NASA Technical Reports Server (NTRS)

    Zabel, P. H.; Parr, V. B.

    1980-01-01

    A methodology is presented which provides predictions for the probability of initiation of explosion in high explosive filled warheads and in propellant filled rocket motor cases given the impact of compact fragments or of small projectiles. Equations of velocities at which 50 percent of the explosive filled cases will initiate either high or low order are developed for compact fragments, and for projectiles. These data are used to establish the standard deviation of the data from the 50 percent initiation line. Standard deviation is used to provide predictions of the probability of initiation given the impact velocity and other pertinent parameters using equations and logic which are established in a computer model. This computer model uses fragment material properties and encounter parameters to predict fragment impact initiation, and projectile and casing material properties and encounter parameters to predict projectile impact initiation.

  15. Manipulating atomic fragmentation processes by controlling the projectile coherence.

    PubMed

    Egodapitiya, K N; Sharma, S; Hasan, A; Laforge, A C; Madison, D H; Moshammer, R; Schulz, M

    2011-04-15

    We have measured the scattering angle dependence of cross sections for ionization in p+H2 collisions for a fixed projectile energy loss. Depending on the projectile coherence, interference due to indistinguishable diffraction of the projectile from the two atomic centers was either present or absent in the data. This shows that, due to the fundamentals of quantum mechanics, the preparation of the beam must be included in theoretical calculations. The results have far-reaching implications on formal atomic scattering theory because this critical aspect has been overlooked for several decades.

  16. Application of isochronous mass spectrometry for the study of angular momentum population in projectile fragmentation reactions

    NASA Astrophysics Data System (ADS)

    Tu, X. L.; Kelić-Heil, A.; Litvinov, Yu. A.; Podolyák, Zs.; Zhang, Y. H.; Huang, W. J.; Xu, H. S.; Blaum, K.; Bosch, F.; Chen, R. J.; Chen, X. C.; Fu, C. Y.; Gao, B. S.; Ge, Z.; Hu, Z. G.; Liu, D. W.; Litvinov, S. A.; Ma, X. W.; Mao, R. S.; Mei, B.; Shuai, P.; Sun, B. H.; Sun, Y.; Sun, Z. Y.; Walker, P. M.; Wang, M.; Winckler, N.; Xia, J. W.; Xiao, G. Q.; Xing, Y. M.; Xu, X.; Yamaguchi, T.; Yan, X. L.; Yang, J. C.; Yuan, Y. J.; Zeng, Q.; Zhang, W.; Zhao, H. W.; Zhao, T. C.; Zhou, X. H.

    2017-01-01

    Isochronous mass spectrometry was applied to measure isomeric yield ratios of fragmentation reaction products. This approach is complementary to conventional γ -ray spectroscopy in particular for measuring yield ratios for long-lived isomeric states. Isomeric yield ratios for the high-spin I =19 /2 ℏ states in the mirror nuclei 53Fe and 53Co are measured to study angular momentum population following the projectile fragmentation of 78Kr at energies of ˜480 A MeV on a beryllium target. The 19/2 state isomeric ratios of 53Fe produced from different projectiles in the literature have also been extracted as a function of mass number difference between projectile and fragment (mass loss). The results are compared to abrabla07 model calculations. The isomeric ratios of 53Fe produced using different projectiles suggest that the theory underestimates not only the previously reported dependence on the spin but also the dependence on the mass loss.

  17. Numerical Simulations of Fragmentation Onset Velocity of Projectile Impact on Thin Bumper

    NASA Astrophysics Data System (ADS)

    Wei, Zhang; Caixia, Jiang; Wenlai, Ma; Baojun, Pang

    2007-12-01

    The conventional spacecraft meteoroids and orbital debris shielding system is the Whipple shield. In general there is a threshold velocity that is just sufficient to shatter the projectile for each system consisting of a projectile and bumper. This velocity is known as the fragmentation onset velocity. To determine the fragmentation onset velocity experimentally, a number of experiments have been conducted with different projectile/bumper configuration. The numerical simulations of fragmentation onset velocity of different material projectile hypervelocity impacts on bumpers with different combination of impact velocities and bumper-thicker-to-projectile-diameter ratios (t/D) have been performed using the SPH technique of AUTODYN. The spherical projectile materials are aluminum, steel and copper. All bumper material is aluminum alloy 6061-T6. The simulation velocities were in the range of 1 km/s˜7 km/s. The ratios of t/D were varied from 0.01 to 0.8. The material model contains Mie-Gruneisen (shock) equation of state, Steinberg-Guinan strength model, principal tensile stress failure model and Grady fragmentation failure model. The simulation results are given and compared with the experimental results. The simulation results are consistent very well with the experimental results. The effects of t/D and material shock impedance etc. on fragmentation onset velocity have been given in Figures and equations.

  18. Scaling phenomena of isobaric yields in projectile fragmentation, spallation, and fission reactions

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Wang; Huang, Ling; Song, Yi-Dan

    2017-02-01

    Background: The isobaric ratio difference scaling phenomenon, which has been found for the fragments produced in projectile fragmentation reactions, is related to the nuclear density change in reaction systems. Purpose: To verify whether the isobaric ratio difference scaling exists in the fragments produced in the spallation and fission reactions. Methods: The isobaric ratio difference scaling, denoted by SΔ lnR21 , is in theory deduced within the framework of the canonical ensemble theory at the grand-canonical limitation. The fragments measured in a series of projectile fragmentation, spallation, and fission reactions have been analyzed. Results: A good SΔ lnR21 scaling phenomenon is shown for the fragments produced both in the projectile fragmentation reactions and in the spallation reactions, whereas the SΔ lnR21 scaling phenomenon for the fragments in the fission reaction is less obvious. Conclusions: The SΔ lnR21 scaling is used to probe the properties of the equilibrium system at the time of fragment formation. The good scaling of SΔ lnR21 suggests that the equilibrium state can be achieved in the projectile fragmentation and spallation reactions. Whereas in the fission reaction, the result of SΔ lnR21 indicates that the equilibrium of the system is hard to achieve.

  19. Characteristics study of projectile's lightest fragment for 84Kr36-emulsion interaction at around 1 A GeV

    NASA Astrophysics Data System (ADS)

    Marimuthu, N.; Singh, V.; Inbanathan, S. S. R.

    2017-04-01

    In this article, we present the results of our investigations on the projectile's lightest fragment (proton) multiplicity and probability distributions with 84Kr36 emulsion collision at around 1 A GeV. The multiplicity and normalized multiplicity of projectile's lightest fragment (proton) are correlated with the compound particles, shower particles, black particles, grey particles; alpha (helium nucleus) fragments and heavily ionizing charged particles. It is found that projectile's lightest fragment (proton) is strongly correlated with compound particles and shower particles rather than other particles and the average multiplicity of projectile's lightest fragment (proton) increases with increasing compound, shower and heavily ionizing charge particles. Normalized projectile's lightest fragment (proton) is strongly correlated with compound particles, shower particles and heavily ionizing charge particles. The multiplicity distribution of the projectile's lightest fragment (proton) emitted in the 84Kr36 + emulsion interaction at around 1 A GeV with different target has been well explained by KNO scaling. The mean multiplicity of projectile's lightest fragments (proton) depends on the mass number of the projectile and does not significantly dependent of the projectile energy. The mean multiplicity of projectile's lightest fragment (proton) increases with increasing the target mass number.

  20. Characteristics study of projectile's lightest fragment for 84Kr36-emulsion interaction at around 1 A GeV

    NASA Astrophysics Data System (ADS)

    Marimuthu, N.; Singh, V.; Inbanathan, S. S. R.

    2016-12-01

    In this article, we present the results of our investigations on the projectile's lightest fragment (proton) multiplicity and probability distributions with 84Kr36 emulsion collision at around 1 A GeV. The multiplicity and normalized multiplicity of projectile's lightest fragment (proton) are correlated with the compound particles, shower particles, black particles, grey particles; alpha (helium nucleus) fragments and heavily ionizing charged particles. It is found that projectile's lightest fragment (proton) is strongly correlated with compound particles and shower particles rather than other particles and the average multiplicity of projectile's lightest fragment (proton) increases with increasing compound, shower and heavily ionizing charge particles. Normalized projectile's lightest fragment (proton) is strongly correlated with compound particles, shower particles and heavily ionizing charge particles. The multiplicity distribution of the projectile's lightest fragment (proton) emitted in the 84Kr36 + emulsion interaction at around 1 A GeV with different target has been well explained by KNO scaling. The mean multiplicity of projectile's lightest fragments (proton) depends on the mass number of the projectile and does not significantly dependent of the projectile energy. The mean multiplicity of projectile's lightest fragment (proton) increases with increasing the target mass number.

  1. Numerical Simulations of Fragmentation Onset Velocity of Projectile Impact on Thin Bumper

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Jiang, Caixia; Ma, Wenlai; Pang, Baojun

    2007-06-01

    The conventional spacecraft meteoroids and orbital debris shielding system is the Whipple shield. In general there is a threshold velocity that is just sufficient to shatter the projectile for each system consisting of a projectile and bumper. This velocity is known as the fragmentation onset velocity. To determine the fragmentation onset velocity experimentally, a number of experiments have been conducted with different projectile/bumper configuration. The numerical simulation of fragmentation onset velocity of different material projectile hypervelocity impacts on bumpers with different combination of impact velocities and bumper-thicker-to-projectile-diameter ratios (t/D) has been performed using the SPH technique of AUTODYN. The spherical projectile materials are aluminum, steel and copper. All bumper materials are aluminum alloy 6061-T6. The simulation velocities were in the range of 1km/s-7km/s. The ratios of t/D were varied from 0.01 to 0.80. The material models were consisted of Mie-Gruneisen (shock) equation of state, Steinberg-Guinan strength model and Grady fragmentation failure model. The simulation results are given and compared with the experimental results. The simulation results are consistent very well with the experimental results.

  2. Model for projectile fragmentation: Case study for Ni on Ta and Be, and Xe on Al

    SciTech Connect

    Mallik, S.; Chaudhuri, G.; Das Gupta, S.

    2011-04-15

    For projectile fragmentation, we work out details of a model whose origin can be traced back to the Bevalac era. The model positions itself between the phenomenological empirical parametrization of fragmentation cross sections (EPAX) and microscopic transport models like the heavy ion phase-space exploration (HIPSE) model and antisymmetrized molecular dynamics (AMD) model. We apply the model to some recent data of projectile fragmentation of Ni on Ta and Be at beam energy 140 MeV/nucleon and some older data of Xe on Al at beam energy 790 MeV/nucleon. Reasonable values of cross sections for various composites populated in the reactions are obtained.

  3. Changes in target fragmentation mechanisms with increasing projectile energy in intermediate energy nuclear collisions

    SciTech Connect

    Loveland, W. ); Aleklett, K.; Sihver, L. ); Xu, Z.; Casey, C. ); Morrissey, D.J. ); Liljenzin, J.O. ); de Saint-Simon, M. ); Seaborg, G.T. )

    1990-03-01

    We have measured the target fragment production cross sections and angular distributions for the interaction of 16 MeV/nucleon {sup 32}S, 32 MeV/nucleon {sup 40}Ar, and 44 MeV/nucleon {sup 40}Ar with {sup 197}Au. We have deduced the fragment isobaric yield distributions and moving frame angular distributions from these data. The fission cross sections decrease with increasing projectile energy and the heavy residue cross sections (which are much larger than previous counter measurements) increase. There is an unusual change in the fragment isobaric yield distributions in the reactions induced by 32 MeV/nucleon {sup 40}Ar and 44 MeV/nucleon {sup 40}Ar. We have used the symmetry properties of the moving frame distributions to show the relative time scale of the reaction mechanisms involved. The fission fragments associated with the peripheral collision peak in the folding angle distribution originate in a normal, slow fission process in which statistical equilibrium has been established. At the two lowest projectile energies, the fission fragments associated with the central collision peak in the folding angle distribution originate in part in fast, nonequilibrium processes. At the highest projectile energies, there are no fission fragments associated with high-momentum-transfer events. The intermediate mass fragments originate primarily in events in which statistical equilibrium has not been established.

  4. On projectile fragmentation at high-velocity perforation of a thin bumper

    NASA Astrophysics Data System (ADS)

    Myagkov, N. N.; Stepanov, V. V.

    2014-09-01

    By means of 3D numerical simulations, we study the statistical properties of the fragments cloud formed during high-velocity impact of a spherical projectile on a mesh bumper. We present a quantitative description of the projectile fragmentation, and study the nature of the transition from the damage to the fragmentation of the projectile when the impact velocity varies. A distinctive feature of the present work is that the calculations are carried out by smoothed particle hydrodynamics (SPH) method applied to the equations of mechanics of deformable solids (MDS). We describe the materials behavior by the Mie-Grüneisen equation of state and the Johnson-Cook model for the yield strength. The maximum principal stress spall model is used as the fracture model. It is shown that the simulation results of fragmentation based on the MDS equations by the SPH method are qualitatively consistent with the results obtained earlier on the basis of the molecular dynamics and discrete element models. It is found that the power-law distribution exponent does not depend on energy imparted to the projectile during the high-velocity impact. At the same time, our calculations show that the critical impact velocity, the power-law exponent and other critical exponents depend on the fracture criterion.

  5. A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions

    SciTech Connect

    Engelage, J.; Crawford, H.J.; Greiner, L.; Kuo, C.

    1996-06-01

    The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed.

  6. Neutron multiplicity distributions for neutron-rich projectile fragments at the NSCL

    NASA Astrophysics Data System (ADS)

    Mazza, Maria; Christ, Peter; Stephenson, Sharon; MoNA Collaboration

    2016-09-01

    Projectile fragmentation is one of the mechanisms used at nuclear science facilities around the world for the production of rare isotope beams. The study of the projectile fragmentation mechanism informs beam simulation codes, but relatively few studies of the fragmentation process have been done, especially at intermediate energies. The MoNA Collaboration used an 86 MeV/u 32Mg beam on a natural beryllium target at the National Superconducting Cyclotron Laboratory to produce neutron multiplicities distributions in coincidence with charged fragments for isotopes ranging from 29Na to 20F. Particle identification for the isotopes from fluorine, neon, and sodium will be presented, as well as preliminary neutron multiplicities distributions. Supported by NSF Grants 1203357, 1613429 and HHMI Grant 52007540.

  7. Odd-even staggering in yields of neutron-deficient nuclei produced by projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Mei, B.; Xu, H. S.; Zhang, Y. H.; Wang, M.; Tu, X. L.; Schmidt, K.-H.; Litvinov, Yu. A.; Sun, Z. Y.; Zhou, X. H.; Yuan, Y. J.; Blaum, K.; Ricciardi, M. V.; Kelić-Heil, A.; Mao, R. S.; Hu, Z. G.; Shuai, P.; Zang, Y. D.; Ma, X. W.; Zhang, X. Y.; Xia, J. W.; Xiao, G. Q.; Guo, Z. Y.; Yang, J. C.; Zhang, X. H.; Xu, X.; Yan, X. L.; Zhang, W.; Zhan, W. L.

    2016-10-01

    Background: Fragment yields exhibit a strong odd-even staggering (OES). This OES has been experimentally observed in different fragmentation reactions with different projectile-target combinations. However, the experimental data are still scarce for fragments close to drip lines and the origin of this OES is not well understood. Purpose: More experimental data are needed to explore the origin of this OES in fragment yields and to validate fragmentation reaction models, especially for nuclei close to the drip lines. To study the pronounced OES near the proton drip line, we measured the yields of Tz=-1 and Tz=-3 /2 nuclei over a wide range of mass number. Methods: The combination of a fragment separator and a storage ring at the Heavy Ion Research Facility in Lanzhou has been used to measure the yields of Tz=-1 and Tz=-3 /2 fragments, produced by 58Ni projectiles impinging on a beryllium target at an energy of about 463 MeV/nucleon. Results: A very strong OES is observed in the measured yields of both Tz=-1 and Tz=-3 /2 fragments. Our experimental data demonstrate that the shell structure has a significant impact on the magnitude of this OES. A comparison of different fragmentation reaction data indicates that this OES is almost independent of the projectile-target combinations and the fragmentation energy between 140 and 650 MeV/nucleon. Conclusions: Our study reveals that the OES of fragment yields originates mainly from the OES of particle-emission threshold energies, which is very close to the OES of fragment yields when the Coulomb barrier is considered in particle-emission threshold energies.

  8. Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates

    NASA Astrophysics Data System (ADS)

    Paris, V.; Weiss, A.; Vizel, A.; Ran, E.; Aizik, F.

    2012-08-01

    In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH) armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile's core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.

  9. Search for projectile fragments with fractional charge in relativistic heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Hoffmann, A.; Brechtmann, C.; Heinrich, W.; Benton, E. V.

    1988-01-01

    We measured the charge of about 35000 projectile fragments with Z > or = 5e produced by 14.5 GeV/nucleon and 200 GeV/nucleon 16O beams in a Pb target using CR39 plastic nuclear track detectors. A minimum track length of 3 mm in the detector without nuclear interaction was required. No evidence for fragments carrying a fractional charge was found.

  10. Search for projectile fragments with fractional charge in relativistic heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Hoffmann, A.; Brechtmann, C.; Heinrich, W.; Benton, E. V.

    1988-01-01

    We measured the charge of about 35000 projectile fragments with Z > or = 5e produced by 14.5 GeV/nucleon and 200 GeV/nucleon 16O beams in a Pb target using CR39 plastic nuclear track detectors. A minimum track length of 3 mm in the detector without nuclear interaction was required. No evidence for fragments carrying a fractional charge was found.

  11. Projectiles

    DTIC Science & Technology

    1979-04-01

    to +43.30 C (-70* and linseed oil . to +1100 F). B-2 1 April 1979 TOP 4-2-501 Type Criteria for Selection High Temperature Wax-Base Use as an inert...and linseed oil . to +160’ F). Polyurethane Filler - A mix- Use as an inert filler with un- ture of a prepolymer and limited application. From an resin...in diam- carriages. Yrnvides in economical eter, clear, with slight coat and quick L’ading operation for of oil . projectiles when centers of gravity

  12. Limiting Fragmentation Behavior of Projectile Helium (Z = 2) Fragments in Nucleus--Nucleus Interactions at 14.6 A GeV

    NASA Astrophysics Data System (ADS)

    Kumar, Ashwini; Singh, Gurmukh; Singh, Bhartendu K.

    2012-12-01

    An analysis of projectile helium (Z = 2) fragments based on 855 minimum-bias inelastic events induced by 14.6 A GeV 28Si beam in a nuclear emulsion is presented in order to test the hypothesis of limiting fragmentation. The projected angular distributions of projectile helium fragments have been fitted with Gaussian curves in individual helium reaction channels and also in different emulsion target events. Furthermore, average emission angle of projectile helium fragments has been studied in individual helium reaction channels with different emulsion target groups. On the basis of pseudo-rapidity distribution, an energy independent limiting fragmentation behavior of projectile helium fragments is also investigated in the fragmentation region.

  13. Refrigeration and freezing of porcine tissue does not affect the retardation of fragment simulating projectiles.

    PubMed

    Breeze, J; Carr, D J; Mabbott, A; Beckett, S; Clasper, J C

    2015-05-01

    Explosively propelled fragments are the most common cause of injury to UK service personnel in modern conflicts. Numerical injury models to simulate such injuries utilise algorithms based upon gelatin and animal tissue testing but data is limited on many fragment simulating projectiles and these simulants cannot represent human anatomy. Testing with post mortem specimens may overcome this limitation but no information exists about how post mortem tissue changes and storage conditions in humans or animals may affect projectile penetration. Two chisel nosed cylinders (0.49 g and 1.10 g) and a 0.51 g (5 mm) sphere were fired into three groups of porcine tissue (fresh, refrigerated and frozen then refrigerated) and compared to 20% gelatin. Depth of projectile penetration was ascertained with the assistance of computed tomography and kinetic energy absorption by tissues measured using Doppler radar and high speed photography. No difference in depth of penetration was found between porcine tissue stored in the different manners compared with 20% gelatin by impact velocities less than 100 m/s. Insufficient numbers of projectiles were retained in tissue at higher velocities for statistical analysis to be undertaken. Energy absorbed per millimetre of tissue ranged between 0.42 and 0.98 J/mm for different porcine tissue despite differing storage. This pilot study would suggest that the effect of refrigerating or freezing porcine tissue followed by thawing has no effect on its ability to retard these projectiles. Further research is required to ascertain if these results occur at greater velocities and for other types of projectile.

  14. Unexpected multiple intra-abdominal injuries after projectile fragmentation: report of three cases.

    PubMed

    Unlü, Aytekin; Petrone, Patrizio; Karşıdağ, Tamer; Asensio, Juan A

    2012-11-01

    Explosives create and energize particles that act as projectiles prone to further fragmentation or create other secondary missiles in the body. These fragments may result in secondary injuries. This has been repeatedly described in the orthopedic and neurosurgical literature. We report the same process for abdominal injuries after fascial penetration in the military setting. This is an observational case series study. Local wound exploration as a standard approach was performed in conscious patients who sustained abdominal wall injuries. Patients with negative physical examination were excluded from the study. An intraperitoneal injury was assumed in those with a full-thickness fascial defect, and laparotomy was performed. Twenty patients met the study eligibility criteria. Of those 20 patients, 12 had negative wound exploration and were excluded from the study, while abdominal organ injuries were found in eight (40%) patients. During laparotomy, projectile-induced injuries in a sprayed distribution were found in three (38%) of these patients. These injuries were far from the predictable trajectory and in the absence of bone fragmentation. The overall mean number of peritoneal defects was 1.7, and a mean 6.8 intra-abdominal injuries for each peritoneal defect were found when through-and-through injuries were excluded.Despite a single peritoneal defect, there may be multiple intraperitoneal injuries due to further fragmentation of the projectile. Under mass casualties, wound exploration with a full-thickness fascial defect could serve as an indicator of possible intra-abdominal injuries, and consequently indicate exploratory laparotomy.

  15. Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes

    NASA Astrophysics Data System (ADS)

    Thies, R.; Heinz, A.; Adachi, T.; Aksyutina, Y.; Alcantara-Núñes, J.; Altstadt, S.; Alvarez-Pol, H.; Ashwood, N.; Aumann, T.; Avdeichikov, V.; Barr, M.; Beceiro-Novo, S.; Bemmerer, D.; Benlliure, J.; Bertulani, C. A.; Boretzky, K.; Borge, M. J. G.; Burgunder, G.; Camaño, M.; Caesar, C.; Casarejos, E.; Catford, W.; Cederkäll, J.; Chakraborty, S.; Chartier, M.; Chulkov, L. V.; Cortina-Gil, D.; Crespo, R.; Datta, U.; Díaz Fernández, P.; Dillmann, I.; Elekes, Z.; Enders, J.; Ershova, O.; Estradé, A.; Farinon, F.; Fraile, L. M.; Freer, M.; Freudenberger, M.; Fynbo, H. O. U.; Galaviz, D.; Geissel, H.; Gernhäuser, R.; Göbel, K.; Golubev, P.; Gonzalez Diaz, D.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Henriques, A.; Holl, M.; Ickert, G.; Ignatov, A.; Jakobsson, B.; Johansson, H. T.; Jonson, B.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knöbel, R.; Kröll, T.; Krücken, R.; Kurcewicz, J.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lepyoshkina, O.; Lindberg, S.; Machado, J.; Marganiec, J.; Maroussov, V.; Mostazo, M.; Movsesyan, A.; Najafi, A.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Perea, A.; Petri, M.; Pietri, S.; Plag, R.; Prochazka, A.; Rahaman, A.; Rastrepina, G.; Reifarth, R.; Ribeiro, G.; Ricciardi, M. V.; Rigollet, C.; Riisager, K.; Röder, M.; Rossi, D.; Sanchez del Rio, J.; Savran, D.; Scheit, H.; Simon, H.; Sorlin, O.; Stoica, V.; Streicher, B.; Taylor, J. T.; Tengblad, O.; Terashima, S.; Togano, Y.; Uberseder, E.; Van de Walle, J.; Velho, P.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Weigand, M.; Wheldon, C.; Wilson, G.; Wimmer, C.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M. V.; Zilges, A.; Zuber, K.; R3B Collaboration

    2016-05-01

    Background: Models describing nuclear fragmentation and fragmentation fission deliver important input for planning nuclear physics experiments and future radioactive ion beam facilities. These models are usually benchmarked against data from stable beam experiments. In the future, two-step fragmentation reactions with exotic nuclei as stepping stones are a promising tool for reaching the most neutron-rich nuclei, creating a need for models to describe also these reactions. Purpose: We want to extend the presently available data on fragmentation reactions towards the light exotic region on the nuclear chart. Furthermore, we want to improve the understanding of projectile fragmentation especially for unstable isotopes. Method: We have measured projectile fragments from 10,12 -18C and B-1510 isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent data set. We compare our data to model calculations. Results: One-proton removal cross sections with different final neutron numbers (1 p x n ) for relativistic 10,12 -18C and B-1510 isotopes impinging on a carbon target. Comparing model calculations to the data, we find that the epax code is not able to describe the data satisfactorily. Using abrabla07 on the other hand, we find that the average excitation energy per abraded nucleon needs to be decreased from 27 MeV to 8.1 MeV. With that decrease abrabla07 describes the data surprisingly well. Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data has allowed a systematic investigation of the role of the excitation energy induced in projectile fragmentation. Most striking is the apparent mass dependence of the average excitation energy per abraded nucleon. Nevertheless, this parameter, which has been related to final-state interactions, requires further study.

  16. HIFI: a computer code for projectile fragmentation accompanied by incomplete fusion

    SciTech Connect

    Wu, J.R.

    1980-07-01

    A brief summary of a model proposed to describe projectile fragmentation accompanied by incomplete fusion and the instructions for the use of the computer code HIFI are given. The code HIFI calculates single inclusive spectra, coincident spectra and excitation functions resulting from particle-induced reactions. It is a multipurpose program which can calculate any type of coincident spectra as long as the reaction is assumed to take place in two steps.

  17. Behavior of expelled glass fragments during projectile penetration and perforation of glass.

    PubMed

    Haag, Lucien C

    2012-03-01

    Bullets striking common forms of flat glass with an orthogonal intercept angle result in a cloud of ejected glass fragments that are in concert with the exiting bullet's flight path. This is not the case with strikes at angles other than orthogonal. In these situations, the expelled glass fragments follow a very different course from that of the exiting projectile. This is both counterintuitive and a potential source of serious error in the evaluation and reconstruction of a shooting victim's position and orientation at the moment the victim was struck by a bullet that has passed through a nearby source of glass such as a vehicle side window or a window in a building. The flight path of the ejected glass fragments is, however, predictable and is dictated by the orientation of the plane of the glass opposite the projectile's impact site.In all cases, these expelled glass particles have considerable velocity and can produce pseudostippling of the skin in individuals located downrange of bullet-struck glass and near the projectile's exit site. The distribution and location of such pseudostippling and its relationship to the associated bullet hole in glass have important reconstructive value. A proper and reliable reconstruction of the victim's position in such cases will require the integration of scene information with the autopsy findings.

  18. Projectile fragmentation of {sup 40,48}Ca and isotopic scaling in a transport approach

    SciTech Connect

    Mikhailova, T. I. Erdemchimeg, B.; Artukh, A. G.; Toro, M. Di; Wolter, H. H.

    2016-07-15

    We investigate theoretically projectile fragmentation in reactions of {sup 40,48}Ca on {sup 9}Be and {sup 181}Ta targets using a Boltzmann-type transport approach, which is supplemented by a statistical decay code to describe the de-excitation of the hot primary fragments. We determine the thermodynamical properties of the primary fragments and calculate the isotope distributions of the cold final fragments. These describe the data reasonably well. For the pairs of projectiles with different isotopic content we analyze the isotopic scaling (or isoscaling) of the final fragment distributions, which has been used to extract the symmetry energy of the primary source. The calculation exhibits isoscaling behavior for the total yields as do the experiments. We also perform an impact-parameter-dependent isoscaling analysis in view of the fact that the primary systems at different impact parameters have very different properties. Then the isoscaling behavior is less stringent, which we can attribute to specific structure effects of the {sup 40,48}Ca pair. The symmetry energy determined in this way depends on these structure effects.

  19. In medium fragment break-up of projectile in 58Ar+36Ni central collisions

    NASA Astrophysics Data System (ADS)

    Francalanza, L.

    2017-06-01

    Latest results concerning the study of central collisions in 36Ar+58Ni reactions, carried out by using the INDRA 4π detector at the GANIL are presented. Reaction mechanisms involved in very central collisions for such asymmetric system and their evolution as function of incident energy are studied, from 32 to 95 AMeV, suggesting an in-medium “break-up” process of the projectile where the presence of nuclear transparency plays an important role. Such a process, leading to forward emission of fragments and lights particles in the laboratory frame, is found to be more and more relevant at high energies, when the contribution from quasi-fusion processes vanishes. Evidences of emissions from an excited quasi-target (QT*), moving along the beam direction with velocity rising with incident energy under the dragging effect of the in-medium “crumbling” of the projectile are highlighted.

  20. Theoretical Study of Projectile Fragmentations in Relativistic Heavy-Ion Reactions

    NASA Astrophysics Data System (ADS)

    Ogul, R.; Imal, H.; Ergun, A.; Buyukcizmeci, N.; Botvina, A. S.; Trautmann, W.

    2015-05-01

    We have investigated and interpreted the production cross sections and isotopic distributions of projectile-like residues in the reactions 124Sn + 124Sn and 112Sn + 112Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. For the interpretation of the data, calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters. The possible modification of symmetry energy parameter, in the multifragmentation region at the low density and hot freeze-out environment, is studied. It is reconfirmed that a significant reduction of the symmetry energy term is found necessary to reproduce experimental results at these conditions. We have also found a decreasing trend of the symmetry energy for large neutron-rich fragments of low excitation energy which is interpreted as a nuclear-structure effect.

  1. Degree of impactor fragmentation under collision with a regolith surface—Laboratory impact experiments of rock projectiles

    NASA Astrophysics Data System (ADS)

    Nagaoka, Hiroki; Takasawa, Susumu; Nakamura, Akiko M.; Sangen, Kazuyoshi

    2014-01-01

    Some meteorites consist of a mix of components of various parent bodies that were presumably brought together by past collisions. Impact experiments have been performed to investigate the degree of target fragmentation during such collisions. However, much less attention has been paid to the fate of the impactors. Here, we report the results of our study of the empirical relationship between the degree of projectile fragmentation and the impact conditions. Millimeter-sized pyrophyllite and basalt projectiles were impacted onto regolith-like sand targets and an aluminum target at velocities of up to 960 m s-1. Experiments using millimeter-sized pyrophyllite blocks as targets were also conducted to fill the gap between this study and the previous studies of centimeter-sized rock targets. The catastrophic disruption threshold for a projectile is defined as the energy density at which the mass of the largest fragment is the half of the original mass. The thresholds with the sand target were 4.5 ± 1.1 × 104 and 9.0 ± 1.9 × 104 J kg-1, for pyrophyllite and basalt projectiles, respectively. These values are two orders of magnitude larger than the threshold for impacts between pyrophyllite projectiles onto aluminum targets, but are qualitatively consistent with the fact that the compressive and tensile strengths of basalt are larger than those of pyrophyllite. The threshold for pyrophyllite projectiles and the aluminum target agrees with the threshold for aluminum projectiles and pyrophyllite targets within the margin of error. Consistent with a previous result, the threshold depended on the size of the rocks with a power of approximately -0.4 (Housen and Holsapple 1999). Destruction of rock projectiles occurred when the peak pressure was about ten times the tensile strength of the rocks.

  2. Yields of projectile fragments in sulphur-emulsion interactions at 3.7 A GeV

    NASA Astrophysics Data System (ADS)

    Kamel, S.; Osman, W.; Fayed, M.

    2017-05-01

    This work presents the basic characteristics of singly, doubly and heavily charged projectile fragments (PFs) emitted in inelastic interactions of 32S ions with photo-emulsion nuclei at Dubna energy (3.7 A GeV). Our experimental data are compared with the corresponding data for other projectiles at the same incident energy. The study of mean multiplicities of different charged PFs against the projectile mass shows a power-law relationship. The multiplicity distributions of singly and doubly charged PFs have been fitted well with a Gaussian distribution function. The yields of PFs broken up from the interactions of 32S projectile nuclei with different target nuclei are studied. The beam energy dependence in terms of the various order moments is studied as well.

  3. Projectile-breakup-induced fission-fragment angular distributions in the 6Li+232Th reaction

    NASA Astrophysics Data System (ADS)

    Pal, A.; Santra, S.; Chattopadhyay, D.; Kundu, A.; Ramachandran, K.; Tripathi, R.; Roy, B. J.; Nag, T. N.; Sawant, Y.; Sarkar, D.; Nayak, B. K.; Saxena, A.; Kailas, S.

    2017-08-01

    Background: Experimental anisotropy in fission-fragment (FF) angular distribution in reactions involving weakly bound stable projectiles with actinide targets are enhanced compared to statistical saddle-point model (SSPM) predictions. Contributions from breakup- or transfer-induced fission to total fission are cited as possible reasons for such enhancement. Purpose: To identify the breakup- or transfer-induced fission channels in 6Li+232Th reaction and to investigate their effects on FF angular anisotropy. Methods: The FF angular distributions have been measured exclusively at three beam energies (28, 32, and 36 MeV) around the Coulomb barrier in coincidence with projectile breakup fragments like α , d , and p using Si strip detectors. The angular anisotropy obtained for different exclusive breakup- or transfer-induced fission channels are compared with that for total fission. SSPM and pre-equilibrium fission models have been employed to obtain theoretical FF angular anisotropy. Results: Angular anisotropy of the fission fragments produced by different transfer- or breakup-induced fission reactions have been obtained separately in the rest frame of respective recoiling nuclei. Some of these anisotropies were found to be stronger than those of the inclusive fission. Overall angular distributions of transfer or breakup fission, integrated over all possible recoil angles with weight factor proportional to differential cross section of the complementary breakup fragment emitted in coincidence in all possible directions, were obtained. It was observed that the overall FF angular anisotropy for each of these fission channels is less than or equal to the anisotropy of total fission at all the measured energies. Assuming isotropic out-of-plane correlations between the fission fragments and light-charged particles, the overall breakup- or transfer-induced fission fragment angular distributions do not explain the observed enhancement in FF anisotropy of total fission. Pre

  4. Feasibility of Isotope Harvesting at a Projectile Fragmentation Facility: 67Cu

    NASA Astrophysics Data System (ADS)

    Mastren, Tara; Pen, Aranh; Peaslee, Graham F.; Wozniak, Nick; Loveless, Shaun; Essenmacher, Scott; Sobotka, Lee G.; Morrissey, David J.; Lapi, Suzanne E.

    2014-10-01

    The work presented here describes a proof-of-principle experiment for the chemical extraction of 67Cu from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A 67Cu beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 +/- 3% and the radiochemical yield was >=95%. These results show that extraction of radioisotopes from an aqueous projectile-fragment beam dump is a feasible method for obtaining radiochemically pure isotopes.

  5. High precision Penning trap mass spectrometry of rare isotopes produced by projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Barquest, B. R.; Block, M.; Bollen, G.; Campbell, C. M.; Ferrer, R.; Lincoln, D. L.; Morrissey, D. J.; Pang, G. K.; Redshaw, M.; Ringle, R.; Schwarz, S.; Savory, J.

    2011-09-01

    The Low Energy Beam and Ion Trap (LEBIT) is the only present facility to combine high precision Penning trap mass spectrometry with fast beam projectile fragmentation. Located at the National Superconducting Cyclotron Laboratory (NSCL), LEBIT is able to measure radionuclides produced in a chemically independent process with minimal decay losses. Recent exotic mass measurements include 66As, 63-66Fe, and 32Si. 66As is a new candidate to test the Conserved Vector Current (CVC) hypothesis. The masses of the neutron-rich iron isotopes provide additional information about the mass surface and the subshell closure at N = 40. 32Si is a member of the A = 32, T = 2 quintet; its measurement permits the most stringent test of the validity of the isobaric multiplet mass equation (IMME). An overview of some recent measurements will be presented as well as advanced techniques for ion manipulation.

  6. Nuclear Alignment in Projectile Fragmentation as a Tool for Moment Measurements

    SciTech Connect

    Georgiev, G.; Matea, I.; Oliveira Santos, F. de; Lewitowicz, M.; Daugas, J.M.; Belier, G.; Goutte, H.; Meot, V.; Roig, O.; Astabatyan, R.; Lukyanov, S.; Penionzhkevich, Yu.E.; Balabanski, D.L.; Borremans, D.; Himpe, P.; Neyens, G.; Sawicka, M.

    2004-02-27

    The application of the Time Dependent Perturbed Angular Distribution (TDPAD) method to study isomeric states produced and oriented in projectile-fragmentation reactions provides the opportunity to perform nuclear-moment measurements in a wide range of neutron-rich nuclei, unaccessible by other means. An absolute necessity for the application of the TDPAD technique is a spin-aligned ensemble of nuclei. The preliminary results from a recent application of this method on 61mFe and 54mFe at GANIL, Caen, France showed that a significant increase of the amount of the observed alignment, compared to our previous measurement on 67mNi and 69mCu, can be obtained. Some experimental details, concerning the conservation of the reaction obtained alignment, are discussed.

  7. Feasibility of isotope harvesting at a projectile fragmentation facility: ⁶⁷Cu.

    PubMed

    Mastren, Tara; Pen, Aranh; Peaslee, Graham F; Wozniak, Nick; Loveless, Shaun; Essenmacher, Scott; Sobotka, Lee G; Morrissey, David J; Lapi, Suzanne E

    2014-10-21

    The work presented here describes a proof-of-principle experiment for the chemical extraction of (67)Cu from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A (67)Cu beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 ± 3% and the radiochemical yield was ≥95%. These results show that extraction of radioisotopes from an aqueous projectile-fragment beam dump is a feasible method for obtaining radiochemically pure isotopes.

  8. Feasibility of Isotope Harvesting at a Projectile Fragmentation Facility: 67Cu

    PubMed Central

    Mastren, Tara; Pen, Aranh; Peaslee, Graham F.; Wozniak, Nick; Loveless, Shaun; Essenmacher, Scott; Sobotka, Lee G.; Morrissey, David J.; Lapi, Suzanne E.

    2014-01-01

    The work presented here describes a proof-of-principle experiment for the chemical extraction of 67Cu from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A 67Cu beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 ± 3% and the radiochemical yield was ≥95%. These results show that extraction of radioisotopes from an aqueous projectile-fragment beam dump is a feasible method for obtaining radiochemically pure isotopes. PMID:25330839

  9. Projectile and Target Fragmentation in the Interaction of 12C and 27Al

    SciTech Connect

    Foertsch, S.V.; Steyn, G.F.; Lawrie, J.J.; Smit, F.D.; Cerutti, F.; Colleoni, P.; Gadioli, E.; Mairani, A.; Connell, S.H.; Fearick, R.W.; Thovhogi, T.; Machner, H.; Goldenbaum, F.; Pysz, K.

    2005-05-24

    The emission of intermediate mass fragments (IMFs) produced in the inclusive 12C+27Al and 27Al+12C reactions at incident energies corresponding to a c.m. excitation energy of 107.5 MeV were studied at lab. angles of 12 deg. to 25 deg. Double differential cross sections of the IMF spectra are compared to model calculations, which include direct breakup of both the projectile and target, nucleon coalescence, as well as partial and complete fusion. This study indicates the importance of the complementary nature of a reaction together with its inverse process in fully understanding the driving reaction mechanisms in the interaction of two light-mass nuclei.

  10. Half-life measurements of isomeric states populated in projectile fragmentation

    SciTech Connect

    Bowry, M.; Podolay, Zs.

    2012-10-20

    The half-lives of excited isomeric states observed in {sup 195}Au, {sup 201}Tl and {sup 215}Rn are reported for the first time. Delayed {gamma}-rays were correlated with nuclei produced in the projectile fragmentation of relativistic {sup 238}U ions, unambiguously identified in terms of their atomic number (Z) and mass-to-charge ratio (A/Q) after traversing an in-flight separator. The observation of a long-lived isomeric state in {sup 195}Au with t{sub 1/2} = 16{sub -4}{sup +8}{mu}s is presented. Two shorter-lived isomeric states were detected in {sup 201}Tl and {sup 215}Rn with t{sub 1/2} = 95{sub -21}{sup +39} and 57{sub -12}{sup +21} ns respectively. In total 24 isomeric states were identified in different nuclei from Pt to Rn (A {approx} 200) during the current study, the majority of which were previously reported. The wealth of spectroscopic data provides the opportunity to determine the isomeric ratios over a wide range of Z, A and angular momentum (I h) of the reaction products. In particular, high-spin states with I Greater-Than-Or-Equivalent-To 18 h provide a robust test of theoretical models of fragmentation.

  11. Half-life measurements of isomeric states populated in projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Bowry, M.; Podolyák, Zs.; Kurcewicz, J.; Pietri, S.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Allegro, P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Gerl, J.; Gorska, M.; Gottardo, A.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Litvinov, Y. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Kurz, N.; Denis Bacelar, A. M.; Bruce, A. M.; Farrelly, G. F.; Alkhomashi, N.; Al-Dahan, N.; Scheidenberger, C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Takeda, H.; Tanihata, I.; Terashima, S.; Valiente Dobon, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.

    2012-10-01

    The half-lives of excited isomeric states observed in 195Au, 201Tl and 215Rn are reported for the first time. Delayed γ-rays were correlated with nuclei produced in the projectile fragmentation of relativistic 238U ions, unambiguously identified in terms of their atomic number (Z) and mass-to-charge ratio (A/Q) after traversing an in-flight separator. The observation of a long-lived isomeric state in 195Au with t1/2 = 16-4+8 μs is presented. Two shorter-lived isomeric states were detected in 201Tl and 215Rn with t1/2 = 95-21+39 and 57-12+21 ns respectively. In total 24 isomeric states were identified in different nuclei from Pt to Rn (A ˜ 200) during the current study, the majority of which were previously reported. The wealth of spectroscopic data provides the opportunity to determine the isomeric ratios over a wide range of Z, A and angular momentum (I ħ) of the reaction products. In particular, high-spin states with I ≳ 18 ħ provide a robust test of theoretical models of fragmentation.

  12. The FRS Ion Catcher - A facility for high-precision experiments with stopped projectile and fission fragments

    NASA Astrophysics Data System (ADS)

    Plaß, W. R.; Dickel, T.; Purushothaman, S.; Dendooven, P.; Geissel, H.; Ebert, J.; Haettner, E.; Jesch, C.; Ranjan, M.; Reiter, M. P.; Weick, H.; Amjad, F.; Ayet, S.; Diwisch, M.; Estrade, A.; Farinon, F.; Greiner, F.; Kalantar-Nayestanaki, N.; Knöbel, R.; Kurcewicz, J.; Lang, J.; Moore, I.; Mukha, I.; Nociforo, C.; Petrick, M.; Pfützner, M.; Pietri, S.; Prochazka, A.; Rink, A.-K.; Rinta-Antila, S.; Schäfer, D.; Scheidenberger, C.; Takechi, M.; Tanaka, Y. K.; Winfield, J. S.; Yavor, M. I.

    2013-12-01

    At the FRS Ion Catcher at GSI, projectile and fission fragments are produced at relativistic energies, separated in-flight, range-focused, slowed down and thermalized in a cryogenic stopping cell. A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) is used to perform direct mass measurements and to provide an isobarically clean beam for further experiments, such as mass-selected decay spectroscopy. A versatile RF quadrupole transport and diagnostics unit guides the ions from the stopping cell to the MR-TOF-MS, provides differential pumping, ion identification and includes reference ion sources. The FRS Ion Catcher serves as a test facility for the Low-Energy Branch of the Super-FRS at the Facility for Antiproton and Ion Research (FAIR), where the cryogenic stopping cell and the MR-TOF-MS will be key devices for the research with stopped projectile and fission fragments that will be performed with the experiments MATS and LaSpec. Off-line tests of the stopping cell yield a combined ion survival and extraction efficiency for 219Rn ions of about 30% and an extraction time of about 25 ms. The stopping cell and the MR-TOF-MS were commissioned on-line as part of the FRS Ion Catcher. For the first time, a stopping cell for exotic nuclei was operated on-line at cryogenic temperatures. Using a gas density almost two times higher than ever reached before for a stopping cell with RF ion repelling structures, various 238U projectile fragments were thermalized and extracted with very high efficiency. Direct mass measurements of projectile fragments were performed with the MR-TOF-MS, among them the nuclide 213Rn with a half-life of 19.5 ms only.

  13. Observation of anomalous reaction mean free paths of nuclear-projectile fragments in research emulsion from 2 A GeV heavy-ion collisions

    SciTech Connect

    Karant, Y.J.

    1981-07-01

    From an analysis of 1460 projectile fragment collisions in nuclear research emulsion exposed to 2.1 A GeV /sup 16/O and 1.9 A GeV /sup 56/Fe at the Bevalac, evidence is presented for the existence of an anomalously short interaction mean free path of projectile fragments for the first several cm after emission. The result is significant to beyond the 3 standard deviation confidence level.

  14. Effect of projectile breakup on fission-fragment mass distributions in the Li,76 + 238U reactions

    NASA Astrophysics Data System (ADS)

    Santra, S.; Pal, A.; Rath, P. K.; Nayak, B. K.; Singh, N. L.; Chattopadhyay, D.; Behera, B. R.; Singh, Varinderjit; Jhingan, A.; Sugathan, P.; Golda, K. S.; Sodaye, S.; Appannababu, S.; Prasad, E.; Kailas, S.

    2014-12-01

    Background: Detailed studies on the effect of the breakup of weakly bound projectile on fission are scarce. Distinguishing the events of compound nuclear (CN) fission from the breakup or transfer induced fission to understand the properties of measured fission fragments is difficult but desirable. Purpose: To investigate the effect of projectile breakup and its breakup threshold energy on fission-fragment (FF) mass distributions and folding angle distributions for Li,76 + 238U reactions and find out the differences in the properties of the fission events produced by complete fusion (CF) from the total fusion (TF). Methods: The FF mass and folding angle distributions have been measured at energies around the Coulomb barrier using gas detectors by time-of-flight technique. The results are compared with the ones involving tightly bound projectiles as well as predictions from systematics to bring out the effect of the breakup. Results: A sharp increase in the peak to valley (P:V) ratio of FF mass distribution with the decrease in bombarding energy for Li,76 + 238U reactions is observed when all events are assumed to be CN fission. As the beam energy falls through the fusion barrier, the full width half maximum (FWHM) of the FF folding angle distribution is found to increase at sub-barrier energies, unlike the reactions involving tightly bound projectiles where a linear decrease in FWHM is expected. By selecting pure CN events from the scatter plot of the velocity components of the composite nuclei, the energy dependence of the deduced FWHM is found to be consistent with the ones involving tightly bound projectiles. Similarly, the P:V ratio obtained for the selected CN events is consistent with the theoretical calculations as well as the experimental data for the proton induced reaction forming similar CN. Conclusions: The presence of projectile breakup induced fission and a relatively low breakup threshold for 6Li compared to 7Li explains the observed differences in

  15. Production of rare isotope beams with the NSCL fragment separator

    NASA Astrophysics Data System (ADS)

    Stolz, A.; Baumann, T.; Ginter, T. N.; Morrissey, D. J.; Portillo, M.; Sherrill, B. M.; Steiner, M.; Stetson, J. W.

    2005-12-01

    Rare isotope beams at the National Superconducting Cyclotron Laboratory are produced by projectile fragmentation of medium energy primary beams on beryllium targets. The fragments of interest are selected by the A1900 high-acceptance fragment separator. The A1900 consists of superconducting magnets: four 45° dipoles and eight quadrupole triplets with a maximum magnetic rigidity of 6 Tm. A momentum acceptance of Δp/p = 5% with a solid angle acceptance of ΔΩ = 8 msr makes the A1900 one of the highest-acceptance separators in the world. Detector systems installed within the device allow tracking and unambiguous identification of individual isotopes. During the first three years of operation of the A1900, more than 200 different rare isotope beams approaching both the neutron and proton driplines have been delivered to experiments.

  16. Rate capability of a cryogenic stopping cell for uranium projectile fragments produced at 1000 MeV/u

    NASA Astrophysics Data System (ADS)

    Reiter, M. P.; Rink, A.-K.; Dickel, T.; Haettner, E.; Heiße, F.; Plaß, W. R.; Purushothaman, S.; Amjad, F.; Ayet San Andrés, S.; Bergmann, J.; Blum, D.; Dendooven, P.; Diwisch, M.; Ebert, J.; Geissel, H.; Greiner, F.; Hornung, C.; Jesch, C.; Kalantar-Nayestanaki, N.; Knöbel, R.; Lang, J.; Lippert, W.; Miskun, I.; Moore, I. D.; Nociforo, C.; Petrick, M.; Pietri, S.; Pfützner, M.; Pohjalainen, I.; Prochazka, A.; Scheidenberger, C.; Takechi, M.; Tanaka, Y. K.; Weick, H.; Winfield, J. S.; Xu, X.

    2016-06-01

    At the Low-Energy Branch (LEB) of the Super-FRS at FAIR, projectile and fission fragments will be produced at relativistic energies, separated in-flight, energy-bunched, slowed down and thermalized in a cryogenic stopping cell (CSC) filled with ultra-pure He gas. The fragments are extracted from the stopping cell using a combination of DC and RF electric fields and gas flow. A prototype CSC for the LEB has been developed and successfully commissioned at the FRS Ion Catcher at GSI. Ionization of He buffer gas atoms during the stopping of energetic ions creates a region of high space charge in the stopping cell. The space charge decreases the extraction efficiency of stopping cells since the high amount of charge distorts the applied DC electric drag fields. Thus the understanding of space charge effects is of great importance to make full use of the high yields at future RIB facilities such as the Super-FRS at FAIR. For this purpose a detailed study of space charge effects in the CSC was performed using experiments and simulations. The dependence of the extraction efficiency, the extraction time and the temporal ion extraction profile on the intensity of the impinging beam and the electric field strength was studied for two different 238 U projectile fragments produced at 1000 MeV/u and separated with the FRS. Good agreement between experiments and simulations was found.

  17. Computed tomography can improve the selection of fragment simulating projectiles from which to test future body armor materials.

    PubMed

    Breeze, John; Leason, Joanna; Gibb, Iain; Hunt, Nicholas C; Hepper, Alan; Clasper, Jon

    2013-06-01

    Ballistic protective materials used in body armor are tested with fragment simulating projectiles (FSPs). The type of FSP used has historically been made by choosing fragments representative of those produced by controlled explosions, which may not be representative of those fragments actually injuring soldiers. 75 cylindrical FSPs of three different sizes were fired into six euthanized pigs, imaged using computed tomography (CT) and the wound tracks dissected. Skin entry wound locations, as determined by surface-shaded CT, were compared to clinical photographs. FSP dimensions and depth of penetration derived from CT were compared to surgical dissection using a Mann-Whitney U test. Skin entry wound locations derived from CT were identical to that seen clinically. FSP dimensions were consistently 15% to 19% larger than the true measurements, reflecting the magnifying effect associated with metallic artifact. No statistical difference (p = 0.26) was found between depth of penetration measured radiologically compared to dissection when a projectile did not hit bone but there was a statistical difference when bone was hit (p < 0.05). CT has the potential to accurately ascertain values required to improve the selection of representative FSPs from which future ballistic protective materials are tested. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

  18. [Human bone fragment acting as a secondary projectile set off by an explosion].

    PubMed

    Rezende-Neto, João Baptista de; Carneiro, Júnia Lira; Sampaio, Felipe Dias; Rodrigues, João Batista; Drumond, Domingos André F

    2012-01-01

    We report a case of a secondary projectile emanated from a fractured human bone from a victim of a bomb explosion. We also refer to the potential of transmition of blood-borne or body fluid pathogens by this mechanism of injury.

  19. ANOMALOUS REACTION MEAN FREE PATHS OF NUCLEAR PROJECTILE FRAGMENTS FROM HEAVY ION COLLISIONS AT 2 AGeV

    SciTech Connect

    Friedlander, E.M.; Gimpel, R.W.; Heckman, H.H.; Karant, Y.J.; Judek, B.; Ganssauge, E.

    1982-08-01

    We present in detail the description and the analysis of two independent experiments using Bevalac beams of {sup 16}O and {sup 56}Fe. From their results it is concluded that the reaction mean free paths of relativistic projectile fragments, 3 {<=} Z {<=} 26, are shorter for a few centimeters after emission than at large distances where they are compatible with values predicted from experiments on beam nuclei. The probability that this effect is due to a statistical fluctuation is <10{sup -3}. The effect is enhanced in later generations of fragments, the correlation between successive generations suggesting a kind of "memory" for the anomaly. Various systematic and spurious effects as well as conventional explanations are discussed mainly on the basis of direct experimental observations internal to our data, and found not to explain our results. The data can be interpreted by the relatively rare occurrence of anomalous fragments that interact with an unexpectedly large cross section. The statistical methods used in the analysis of the observations are fully described.

  20. Determination of Impact Parameters in Aligned Breakup of Projectile-like Fragments in $^{197}$Au + $^{197}$Au Collisions at 23$A$MeV

    SciTech Connect

    Cap, T.; Siwek-Wilczyńska, K.; Wilczynski, J.; Auditore, L.; Cardella, G.; De Filippo, E.; Geraci, E.; Grassi, L.; Grzeszczuk, A.; La Guidara, E.; Han, J.; Kozik, T.; Lanzalone, G.; Lombardo, I.; Najman, R.; Nicolis, N. G.; Pagano, A.; Papa, M.; Piasecki, E.; Pirrone, S.; Planeta, R.; Politi, G.; Rizzo, F.; Russotto, P.; Skwira-Chalot, I.; Trifiro, A.; Trimarchi, M.; Verde, G.; Zipper, W.

    2016-03-01

    Symmetric and asymmetric aligned breakup of projectile-like fragments in $^{197}$Au + $^{197}$Au collisions at 23$A$,MeV was studied. Independently of the asymmetry, the reaction yields have been found peaked at a common, very narrow range of impact parameters.

  1. Determination of Impact Parameters in Aligned Breakup of Projectile-like Fragments in $$^{197}$$Au + $$^{197}$$Au Collisions at 23$A$MeV

    DOE PAGES

    Cap, T.; Siwek-Wilczyńska, K.; Wilczynski, J.; ...

    2016-03-01

    Symmetric and asymmetric aligned breakup of projectile-like fragments inmore » $$^{197}$$Au + $$^{197}$$Au collisions at 23$A$,MeV was studied. Independently of the asymmetry, the reaction yields have been found peaked at a common, very narrow range of impact parameters.« less

  2. Systematic study of projectile fragments in nucleus-nucleus collisions at 4.1-4.5 A GeV/c and multi-source thermal model

    NASA Astrophysics Data System (ADS)

    Rahim, M. A.; Fakhraddin, S.; Asharabi, H.

    2012-08-01

    The multiplicity distributions of projectile fragments (PFs) produced in interactions of (4He, 12C, 16O, 22Ne and 28Si with emulsion (Em) at 4.1-4.5 A GeV/ c beam energies, and their dependence on target groups (H, CNO and AgBr) are presented and have been reproduced by using a multi-source thermal model. The dependence of the mean multiplicities on masses of projectile and target nuclei is investigated. The experimental results are compared with the corresponding ones from the theoretically calculated ones. The experimental results agree with theoretical calculations using the multi-source thermal model.

  3. Parasitic production of slow RI-beam from a projectile fragment separator by ion guide Laser Ion Source (PALIS)

    NASA Astrophysics Data System (ADS)

    Sonoda, Tetsu

    2009-10-01

    The projectile fragment separator BigRIPS of RIBF at RIKEN provides a wide variety of short-lived radioactive isotope (RI) ions without restrictions on their lifetime or chemical properties. A universal slow RI-beam facility (SLOWRI) to decelerate the beams from BigRIPS using an RF-carpet ion guide has been proposed as a principal facility of RIBF. However, beam time at such a modern accelerator facility is always limited and operational costs are high. We therefore propose an additional scheme as a complementary option to SLOWRI to drastically enhance the usability of such an expensive facility. In BigRIPS, a single primary beam produces thousands of isotopes but only one isotope is used for an experiment while the other >99.99% of isotopes are simply dumped in the slits or elsewhere in the fragment separator. We plan to locate a compact gas cell with 1 bar Ar at the slits. The thermalized ions in the cell will be quickly neutralized and transported to the exit by gas flow and resonantly re-ionized by lasers. Such low energy RI-beams will always be provided without any restriction to the main experiment. It will allow us to run parasitic experiments for precision atomic or decay spectroscopy, mass measurements. Furthermore, the resonance ionization in the cell itself can be used for high-sensitive laser spectroscopy, which will expand our knowledge of the ground state property of unstable nuclei.

  4. Secondary Damage to Aircraft by Ricocheted Small Arms Projectiles and Fragments

    DTIC Science & Technology

    1976-11-01

    fiber-reinforced plastic ( GFRP ), or 0.25-inch-thick plate of 2024-T4 (see Table 1 and Figure 4). This study of ricochet and post-peprtration...titanium alloys) promote greater fragmentation of impinging steel armor-piercing cores than do softer materials (aluminum alloys, GFRP ). Since at a given

  5. Fragment Hazard Investigation Program: Natural Communication Detonation of 155-mm Projectiles

    DTIC Science & Technology

    1981-07-01

    an accurate representa- S - tion of the percentage of hazardous fragments as a function of range. A good fit to thesO data Is provided by K k i;• vPH ...projected on a sphere equal to the radius of the recovery media, is divided into the total surface area of the polar zone. This ratio yields a zone factor

  6. Energy distributions of H{sup +} fragments ejected by fast proton and electron projectiles in collision with H{sub 2}O molecules

    SciTech Connect

    Barros, A. L. F. de; Lecointre, J.; Luna, H.; Montenegro, E. C.; Shah, M. B.

    2009-07-15

    Experimental measurements of the kinetic energy distribution spectra of H{sup +} fragment ions released during radiolysis of water molecules in collision with 20, 50, and 100 keV proton projectiles and 35, 200, 400, and 1000 eV electron projectiles are reported using a pulsed beam and drift tube time-of-flight based velocity measuring technique. The spectra show that H{sup +} fragments carrying a substantial amount of energy are released, some having energies well in excess of 20 eV. The majority of the ions lie within the 0-5 eV energy range with the proton spectra showing an almost constant profile between 1.5 and 5 eV and, below this, increasing gradually with decreasing ejection energy up to the near zero energy value while the electron spectra, in contrast, show a broad maximum between 1 and 3 eV and a pronounced dip around 0.25 eV. Beyond 5 eV, both projectile spectra show a decreasing profile with the electron spectra decreasing far more rapidly than the proton spectra. Our measured spectra thus indicate that major differences are present in the collision dynamics between the proton and the electron projectiles interacting with gas phase water molecules.

  7. Extraction of Thermalized Projectile Fragments from a Large Volume Gas Cell

    SciTech Connect

    Cooper, K.; Sumithrarachchi, C. S.; Morrissey, D. J.; Levand, A.; Rodriguez, J. A.; Savard, G.; Schwarz, S.; Zabransky, B.

    2014-11-01

    Experiments to determine the stopping and extraction efficiency of energetic (90 MeV/u) 76Ga fragments in a 1.2 m long gas cell filled with helium at 123 mbar are reported. The thermalized ions were transported by DC and RF fields as well as gas flow, then jetted through a supersonic nozzle into a RF quadrupole ion-guide and accelerated into an electrostatic beam line. The ions were collected in either a Faraday cup or a silicon beta-detector immediately after acceleration or after magnetic analysis. The range distributions of the ions and extraction efficiency of the system were measured for different implantation rates and compared with the theoretically calculated values. The singly charged 76Ga ions were observed as [76Ga(H2O)n]+ molecular ions with n=0, 1, and 2. The stopping efficiency and the extraction efficiency were obtained from the measured distributions and compared to previous results from other devices.

  8. Production of new neutron-rich isotopes of heavy elements in fragmentation reactions of {sup 238}U projectiles at 1A GeV

    SciTech Connect

    Alvarez-Pol, H.; Benlliure, J.; Casarejos, E.; Cortina-Gil, D.; Fernandez-Dominguez, B.; Pereira, J.; Audouin, L.; Enqvist, T.; Schmidt, K.-H.; Yordanov, O.; Junghans, A. R.; Jurado, B.; Rejmund, F.

    2010-10-15

    The production of heavy neutron-rich nuclei has been investigated using cold-fragmentation reactions of {sup 238}U projectiles at relativistic energies. The experiment performed at the high-resolving-power magnetic spectrometer Fragment Separator at GSI made it possible to identify 40 new heavy neutron-rich nuclei: {sup 205}Pt, {sup 207-210}Au, {sup 211-216}Hg, {sup 214-217}Tl, {sup 215-220}Pb, {sup 219-224}Bi, {sup 223-227}Po, {sup 225-229}At, {sup 230,231}Rn, and {sup 233}Fr. The production cross sections of these nuclei were also determined and used to benchmark reaction codes that predict the production of nuclei far from stability.

  9. Direct mass measurements of neutron-rich 86Kr projectile fragments and the persistence of neutron magic number N=32 in Sc isotopes

    NASA Astrophysics Data System (ADS)

    Xu, Xing; Wang, Meng; Zhang, Yu-Hu; Xu, Hu-Shan; Shuai, Peng; Tu, Xiao-Lin; Yuri, A. Litvinov; Zhou, Xiao-Hong; Sun, Bao-Hua; Yuan, You-Jin; Xia, Jia-Wen; Yang, Jian-Cheng; Klaus, Blaum; Chen, Rui-Jiu; Chen, Xiang-Cheng; Fu, Chao-Yi; Ge, Zhuang; Hu, Zheng-Guo; Huang, Wen-Jia; Liu, Da-Wei; Lam, Yi-Hua; Ma, Xin-Wen; Mao, Rui-Shi; Uesaka, T.; Xiao, Guo-Qing; Xing, Yuan-Ming; Yamaguchi, T.; Yamaguchi, Y.; Zeng, Qi; Yan, Xin-Liang; Zhao, Hong-Wei; Zhao, Tie-Cheng; Zhang, Wei; Zhan, Wen-Long

    2015-10-01

    In this paper, we present direct mass measurements of neutron-rich 86Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of 52-54Sc nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, 53Sc and 54Sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes. Supported by 973 Program of China (2013CB834401), the NSFC (U1232208, U1432125, 11205205, 11035007) and the Helmholtz-CAS Joint Research Group (HCJRG-108)

  10. Fission studies of secondary beams from relativistic uranium projectiles: The proton even-odd effect in fission fragment charge yields

    SciTech Connect

    Junghans, A. R.; Benlliure, J.; Schmidt, K.-H.; Voss, B.; Boeckstiegel, C.; Clerc, H.-G.; Grewe, A.; Heinz, A.; Jong, M. de; Mueller, J.; Steinhaeuser, S.; Pfuetzner, M.

    1999-09-02

    Nuclear-charge yields of fragments produced by fission of neutron-deficient isotopes of uranium, protactinium, actinium, and radium have been measured. These radioactive isotopes were produced as secondary beams, and electromagnetic fission was induced in a lead target with an average excitation energy around 11 MeV. The local even-odd effect in symmetric and in asymmetric fission of thorium isotopes is found to be independent of Z{sup 2}/A. The charge yields of the fission fragments of the odd-Z fissioning protactinium and actinium show a pronounced even-odd effect. In asymmetric fission the unpaired proton predominantly sticks to the heavy fragment. A statistical model based on the single-particle level density at the Fermi energy is able to reproduce the overall trend of the local even-odd effects both in even-Z and odd-Z fissioning systems.

  11. Projectile stopping system

    DOEpatents

    Karr, Thomas J.; Pittenger, Lee C.

    1996-01-01

    A projectile interceptor launches a projectile catcher into the path of a projectile. In one embodiment, signals indicative of the path of a projectile are received by the projectile interceptor. A flinger mechanism has a projectile catcher releasably attached thereto, such that the projectile catcher can be released and launched from the flinger mechanism. A controller connected to the flinger mechanism uses the signals indicative of the path of the projectile to determine the launch parameters of the projectile catcher. The controller directs the flinger mechanism to release the projectile catcher such that the projectile catcher is launched into the path of the projectile and intercepts the projectile.

  12. Projectile stopping system

    DOEpatents

    Karr, T.J.; Pittenger, L.C.

    1996-11-26

    A projectile interceptor launches a projectile catcher into the path of a projectile. In one embodiment, signals indicative of the path of a projectile are received by the projectile interceptor. A flinger mechanism has a projectile catcher releasably attached thereto, such that the projectile catcher can be released and launched from the flinger mechanism. A controller connected to the flinger mechanism uses the signals indicative of the path of the projectile to determine the launch parameters of the projectile catcher. The controller directs the flinger mechanism to release the projectile catcher such that the projectile catcher is launched into the path of the projectile and intercepts the projectile. 13 figs.

  13. Benchmarking of calculated projectile fragmentation cross-sections using the 3-D, MC codes PHITS, FLUKA, HETC-HEDS, MCNPX_HI, and NUCFRG2

    NASA Astrophysics Data System (ADS)

    Sihver, L.; Mancusi, D.; Niita, K.; Sato, T.; Townsend, L.; Farmer, C.; Pinsky, L.; Ferrari, A.; Cerutti, F.; Gomes, I.

    several particle and heavy-ion MC transport codes exist, e.g. Particle and Heavy-Ion Transport code System (PHITS), High Energy Transport Code-Human Exploration and Development of Space (HETC-HEDS), SHIELD-HIT, GEANT4, FLUKA, MARS, and MCNPX. In this paper, we present an extensive benchmarking of the calculated projectile fragmentation cross-sections from the reactions of 300-1000MeV/u28Si, 40Ar, and 56Fe on polyethylene, carbon, aluminum, and copper targets (relevant to space radioprotection) using PHITS, FLUKA, HETC-HEDS, and MCNPX, against measurements. The influence of the different models used in the different transport codes on the calculated results is also discussed. Some measured cross-sections are also compared to the calculated cross-sections using NUCFRG2, which are incorporated in the 1-dimensional, deterministic radiation transport code HZETRN.

  14. Dynamic effects of interaction of composite projectiles with targets

    SciTech Connect

    Zakharov, V. M.

    2016-01-15

    The process of high-speed impact of projectiles against targets of finite thickness is experimentally investigated. Medium-hard steel plates are used as targets. The objective of this research is to carry out a comparative analysis of dynamic effects of interaction of various types of projectiles with targets, such as characteristics of destruction of the target, the state of the projectile behind the target, and particularities of the after-penetration stream of fragments after the target has been pierced. The projectiles are made of composites on the basis of tungsten carbide obtained by caking and the SHS-technology. To compare effectiveness of composite projectiles steel projectiles are used. Their effectiveness was estimated in terms of the ballistic limit. High density projectiles obtained by means of the SHS-technology are shown to produce results comparable in terms of the ballistic limit with high-strength projectiles that contain tungsten received by caking.

  15. Dynamic effects of interaction of composite projectiles with targets

    NASA Astrophysics Data System (ADS)

    Zakharov, V. M.

    2016-01-01

    The process of high-speed impact of projectiles against targets of finite thickness is experimentally investigated. Medium-hard steel plates are used as targets. The objective of this research is to carry out a comparative analysis of dynamic effects of interaction of various types of projectiles with targets, such as characteristics of destruction of the target, the state of the projectile behind the target, and particularities of the after-penetration stream of fragments after the target has been pierced. The projectiles are made of composites on the basis of tungsten carbide obtained by caking and the SHS-technology. To compare effectiveness of composite projectiles steel projectiles are used. Their effectiveness was estimated in terms of the ballistic limit. High density projectiles obtained by means of the SHS-technology are shown to produce results comparable in terms of the ballistic limit with high-strength projectiles that contain tungsten received by caking.

  16. Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon

    SciTech Connect

    Abramov, B. M.; Alexeev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Gudima, K. K.; Dukhovskoy, I. A.; Krutenkova, A. P. Kulikov, V. V.; Martemianov, M. A.; Matsyuk, M. A.; Mashnik, S. G.; Turdakina, E. N.; Khanov, A. I.

    2016-09-15

    The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T{sub 0} = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.

  17. Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon

    NASA Astrophysics Data System (ADS)

    Abramov, B. M.; Alexeev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Gudima, K. K.; Dukhovskoy, I. A.; Krutenkova, A. P.; Kulikov, V. V.; Martemianov, M. A.; Matsyuk, M. A.; Mashnik, S. G.; Turdakina, E. N.; Khanov, A. I.

    2016-09-01

    The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T 0 = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion-ion interactions: BC, INCL++, LAQGSM03.03, and QMD.

  18. 30-MM Tubular Projectile

    DTIC Science & Technology

    1984-10-01

    Suiza tubular projectile 20 9. Inspection of Hispano Suiza sabot 21 10. Inspection of GAU-8 sabot 22 11. Firing data - 30-rn tubular projectile (Hispano... Suiza 23 copper banded) 12. Firing data - 30-m tubular projectile (GAU-8 plastic 24 banded) 13. Firing data - 30-m tubular projectile (GAU-8 copper 25...42 13. In-flight Hispano Suiza tubular projectiles 43 14. In-flight C4U-8 (plastic) tubular projectile 44 15. In-flight GCU-8 (copper) tubular

  19. Projectile Motion Details.

    ERIC Educational Resources Information Center

    Schnick, Jeffrey W.

    1994-01-01

    Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)

  20. Projectile Motion Details.

    ERIC Educational Resources Information Center

    Schnick, Jeffrey W.

    1994-01-01

    Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)

  1. Superconducting Magnetic Projectile Launcher

    NASA Technical Reports Server (NTRS)

    Jan, Darrell L.; Lawson, Daniel D.

    1991-01-01

    Proposed projectile launcher exploits Meissner effect to transfer much of kinetic energy of relatively massive superconducting plunger to smaller projectile, accelerating projectile to high speed. Because it operates with magnetic fields, launcher not limited by gas-expansion thermodynamics. Plunger energized mechanically and/or chemically, avoiding need for large electrical power supplies and energy-storage systems. Potential applications include launching of projectiles for military purposes and for scientific and industrial tests of hypervelocity impacts.

  2. High Performance Hollow Projectiles

    DTIC Science & Technology

    Development of hollow projectiles was first advocated to achieve ’silent’ (low pressure signal) projectiles having higher performance. Although the...present effort concentrates on small arms (specifically 7.62 mm), the confirmed fundamental theory applies to all sizes of hollow projectiles. The...report can thus serve as a basis for (1) evaluating specific hollow projectile developments and (2) formulating programs to develop a wide spectrum of

  3. Forensic and clinical issues in the use of frangible projectile.

    PubMed

    Komenda, Jan; Hejna, Petr; Rydlo, Martin; Novák, Miroslav; Krajsa, Jan; Racek, František; Rejtar, Pavel; Jedlička, Luděk

    2013-08-01

    Frangible projectiles for firearms, which break apart on impact, are mainly used by law enforcement agencies for training purposes, but can also be used for police interventions. Apart from the usual absence of lead in the projectiles, the main advantage of using frangible projectiles is the reduced risk of ricochet after impact with a hard target. This article describes the design and function of frangible projectiles, and describes gunshot wounds caused by ultra-frangible projectiles which fragment after penetration of soft tissues. Shooting experiments performed by the authors confirmed that differences in the geometry and technology of frangible projectiles can significantly modify their wounding effects. Some frangible projectiles have minimal wounding effects because they remain compact after penetration of soft tissues, comparable to standard fully jacketed projectiles. However, a number of ultra-frangible projectiles disintegrate into very small fragments after impact with a soft tissue substitute. In shooting experiments, we found that the terminal behavior of selected ultra-frangible projectiles was similar in a block of ballistic gel and the soft tissues of the hind leg of a pig, except that the degree of disintegration was less in the gel. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  4. Centrifugal projectile launchers

    NASA Astrophysics Data System (ADS)

    Felber, F. S.

    1982-01-01

    The concept of a centrifugal projectile launcher as an alternative to both chemical and electromagnetic launchers for anti-tank and air defence systems is discussed. It is shown that centrifugal projectile launchers can provide reliable, efficient, compact systems that will accelerate projectiles to 2-3 km/s with energies up to one megajoule. State-of-the-art composite rotors can be modified to launch projectiles of tens of grams to the order of 1 km/s. A demonstration rotor with reasonable energy density can be designed to accelerate 60 gram projectiles to 3 km/s repetitively.

  5. The EMET railgun projectile

    SciTech Connect

    Burton, R.L.; Witherspoon, F.D.; Goldstein, S.A. )

    1991-01-01

    This paper reports on the EMET projectile which uses joule heating to accelerate the projectile in a railgun with a predominantly electrothermal driving force. The structure is designed to conduct armature current within a thin annular band around the shank of the large L/D dumbbell-shaped projectile. Current is initiated by a fuse located around the shank, and an impedance of 8 m{Omega} is achieved, compared to the 1-2 m{Omega} observed for EM guns. A supersonic nozzle in the projectile tail section expands and cools the armature plasma to raise its resistivity, prevent secondary arcs and provide additional accelerating thrust. Experimental data is presented for 9.5 mm diameter, 5 gm projectiles, accelerated to nearly 600 m/sec at 55 kA in a 0.9 m railgun. The armature remains confined in the projectile structure, and 75% of the acceleration is provided electrothermally.

  6. Development of a fast cyclotron gas stopper for intense rare isotope beams from projectile fragmentation: Study of ion extraction with a radiofrequency carpet

    SciTech Connect

    Bollen, Georg; Morrissey, David

    2011-01-16

    Research and development has been performed in support of the design of a future rare isotope beam facility in the US. An important aspect of plans for earlier RIA (Rare Isotope Accelerator) and a requirement of FRIB (Facility of Rare Isotope Beams) to be built at Michigan State University are the availability of so-called “stopped beams” for research that contributes to answering questions like how elements in the universe are created and to provide better insight into the nature of Fundamental Interactions. In order to create “stopped beams” techniques are required that transform fast rare isotopes beams as they are available directly after addresses questions like the origin of that will allow and High priority is given to the evaluation of intensity limitations and the efficiency of stopping of fast fragment beams in gas cells and to the exploration of options to increase the efficiency and the reduction of space charge effects. Systematic studies performed at MSU as part of the RIA R&D with a linear gas cell under conditions close to those expected at RIA and related simulations confirm that the efficiency of stopping and extracting ions decreases with increasing beam intensity. Similar results have also been observed at RIKEN in Japan. These results indicate the concepts presently under study will not be able to cover the full range of intensities of fast beams expected at RIA without major losses. The development of a more robust concept is therefore critical to the RIA concept. Recent new beam simulation studies performed at the NSCL show that the stopping of heavy ions in a weakly focusing gas-filled magnetic field can overcome the intensity limitation of present systems while simultaneously providing a much faster ion extraction. We propose to design and build such a cyclotron gas stopper and to test it at the NSCL under conditions as close as possible to those found at RIA.

  7. Projectile Motion Revisited.

    ERIC Educational Resources Information Center

    Lucie, Pierre

    1979-01-01

    Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)

  8. Hybrid armature projectile

    DOEpatents

    Hawke, Ronald S.; Asay, James R.; Hall, Clint A.; Konrad, Carl H.; Sauve, Gerald L.; Shahinpoor, Mohsen; Susoeff, Allan R.

    1993-01-01

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasama blowby.

  9. Projectile Motion Revisited.

    ERIC Educational Resources Information Center

    Lucie, Pierre

    1979-01-01

    Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)

  10. Hybrid armature projectile

    DOEpatents

    Hawke, R.S.; Asay, J.R.; Hall, C.A.; Konrad, C.H.; Sauve, G.L.; Shahinpoor, M.; Susoeff, A.R.

    1993-03-02

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasma blowby.

  11. Teaching Projectile Motion

    ERIC Educational Resources Information Center

    Summers, M. K.

    1977-01-01

    Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)

  12. Teaching Projectile Motion

    ERIC Educational Resources Information Center

    Summers, M. K.

    1977-01-01

    Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)

  13. Projectile Point Classification.

    ERIC Educational Resources Information Center

    Plants, Robert W.

    1984-01-01

    Describes a unit on local history developed through the classification of projectile points which may be gathered on a field trip or viewed at a local museum. Suggestions for starting the unit and illustrating the nomenclature of projectile points are provided. (JM)

  14. Survivability of copper projectiles during hypervelocity impacts in porous ice: A laboratory investigation of the survivability of projectiles impacting comets or other bodies

    NASA Astrophysics Data System (ADS)

    McDermott, K. H.; Price, M. C.; Cole, M.; Burchell, M. J.

    2016-04-01

    During hypervelocity impact (>a few km s-1) the resulting cratering and/or disruption of the target body often outweighs interest on the outcome of the projectile material, with the majority of projectiles assumed to be vaporised. However, on Earth, fragments, often metallic, have been recovered from impact sites, meaning that metallic projectile fragments may survive a hypervelocity impact and still exist within the wall, floor and/or ejecta of the impact crater post-impact. The discovery of the remnant impactor composition within the craters of asteroids, planets and comets could provide further information regarding the impact history of a body. Accordingly, we study in the laboratory the survivability of 1 and 2 mm diameter copper projectiles fired onto ice at speeds between 1.00 and 7.05 km s-1. The projectile was recovered intact at speeds up to 1.50 km s-1, with no ductile deformation, but some surface pitting was observed. At 2.39 km s-1, the projectile showed increasing ductile deformation and broke into two parts. Above velocities of 2.60 km s-1 increasing numbers of projectile fragments were identified post impact, with the mean size of the fragments decreasing with increasing impact velocity. The decrease in size also corresponds with an increase in the number of projectile fragments recovered, as with increasing shock pressure the projectile material is more intensely disrupted, producing smaller and more numerous fragments. The damage to the projectile is divided into four classes with increasing speed and shock pressure: (1) minimal damage, (2) ductile deformation, start of break up, (3) increasing fragmentation, and (4) complete fragmentation. The implications of such behaviour is considered for specific examples of impacts of metallic impactors onto Solar System bodies, including LCROSS impacting the Moon, iron meteorites onto Mars and NASA's ;Deep Impact; mission where a spacecraft impacted a comet.

  15. A Projectile Motion Bullseye.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1985-01-01

    Explains a projectile motion experiment involving a bow and arrow. Procedures to measure "muzzle" velocity, bow elastic potential energy, range, flight time, wind resistance, and masses are considered. (DH)

  16. Measuring projectile speed

    NASA Technical Reports Server (NTRS)

    Jordan, J. E.; Kassel, P. C., Jr.

    1979-01-01

    Apparatus uses optoelectric detector to measure station-to-station time-of-flight of small spherical aluminum projectile down steel barrel. Instrument has been used to study impact resistance of composite materials used in aircraft structural research program.

  17. A Projectile Motion Bullseye.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1985-01-01

    Explains a projectile motion experiment involving a bow and arrow. Procedures to measure "muzzle" velocity, bow elastic potential energy, range, flight time, wind resistance, and masses are considered. (DH)

  18. Projectile Motion with Mathematica.

    ERIC Educational Resources Information Center

    de Alwis, Tilak

    2000-01-01

    Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)

  19. Projectile Motion with Mathematica.

    ERIC Educational Resources Information Center

    de Alwis, Tilak

    2000-01-01

    Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)

  20. Small caliber guided projectile

    DOEpatents

    Jones, James F.; Kast, Brian A.; Kniskern, Marc W.; Rose, Scott E.; Rohrer, Brandon R.; Woods, James W.; Greene, Ronald W.

    2010-08-24

    A non-spinning projectile that is self-guided to a laser designated target and is configured to be fired from a small caliber smooth bore gun barrel has an optical sensor mounted in the nose of the projectile, a counterbalancing mass portion near the fore end of the projectile and a hollow tapered body mounted aft of the counterbalancing mass. Stabilizing strakes are mounted to and extend outward from the tapered body with control fins located at the aft end of the strakes. Guidance and control electronics and electromagnetic actuators for operating the control fins are located within the tapered body section. Output from the optical sensor is processed by the guidance and control electronics to produce command signals for the electromagnetic actuators. A guidance control algorithm incorporating non-proportional, "bang-bang" control is used to steer the projectile to the target.

  1. High Explosive Deonation Threshold Sensitivity Due to Multiple Fragment Impacts

    SciTech Connect

    Georgevich, V; Pincosy, P; Chase, J

    2004-01-07

    Fragments, bullets or projectiles can initiate a detonation in a high explosive (HE). For this to happen certain critical conditions need to be exceeded. For a given explosive, these critical conditions are the projectile velocity, the projectile size and shape, and the projectile material properties. A lot of work has been done in the area of metal shaped charge jets and individual fragments impacting the HE. One major gap in understanding initiation phenomena is the effect of multiple fragment impact. This study shows that multiple fragments can lower the fragment size and the kinetic energy thresholds.

  2. Phenomenological model for light-projectile breakup

    NASA Astrophysics Data System (ADS)

    Kalbach, C.

    2017-01-01

    Background: Projectile breakup can make a large contribution to reactions induced by projectiles with mass numbers 2, 3, and 4, yet there is no global model for it and no clear agreement on the details of the reaction mechanism. Purpose: This project aims to develop a phenomenological model for light-projectile breakup that can guide the development of detailed theories and provide a useful tool for applied calculations. Method: An extensive database of double-differential cross sections for the breakup of deuterons, 3He ions, and α particles was assembled from the literature and analyzed in a consistent way. Results: Global systematics for the centroid energies, peak widths, and angular distributions of the breakup peaks have been extracted from the data. The dominant mechanism appears to be absorptive breakup, where the unobserved projectile fragment fuses with the target nucleus during the initial interaction. The global target-mass-number and incident-energy dependencies of the absorptive breakup cross section have also been determined, along with channel-specific normalization constants. Conclusions: Results from the model generally agree with the original data after subtraction of a reasonable underlying continuum. Absorptive breakup can account for as much as 50%-60% of the total reaction cross section.

  3. More on Projectile Motion.

    ERIC Educational Resources Information Center

    Molina, M. I.

    2000-01-01

    Mathematically explains why the range of a projectile is most insensitive to aiming errors when the initial angle is close to 45 degrees, whereas other observables such as maximum height or flight time are most insensitive for near-vertical launching conditions. (WRM)

  4. More on Projectile Motion.

    ERIC Educational Resources Information Center

    Molina, M. I.

    2000-01-01

    Mathematically explains why the range of a projectile is most insensitive to aiming errors when the initial angle is close to 45 degrees, whereas other observables such as maximum height or flight time are most insensitive for near-vertical launching conditions. (WRM)

  5. Projectiles and Aerodynamic Forces.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1984-01-01

    Discusses the air resistance on projectiles, examining (in separate sections) air resistance less than gravity and air resistance greater than gravity. Also considers an approximation in which a trajectory is divided into two parts, the first part neglecting gravity and the second part neglecting the air resistance. (JN)

  6. Projectiles and Aerodynamic Forces.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1984-01-01

    Discusses the air resistance on projectiles, examining (in separate sections) air resistance less than gravity and air resistance greater than gravity. Also considers an approximation in which a trajectory is divided into two parts, the first part neglecting gravity and the second part neglecting the air resistance. (JN)

  7. Subcaliber discarding sabot airgun projectiles.

    PubMed

    Frank, Matthias; Schönekeß, Holger; Herbst, Jörg; Staats, Hans-Georg; Ekkernkamp, Axel; Nguyen, Thanh Tien; Bockholdt, Britta

    2014-03-01

    Medical literature abounds with reports on injuries and fatalities caused by airgun projectiles. While round balls or diabolo pellets have been the standard projectiles for airguns for decades, today, there are a large number of different airgun projectiles available. A very uncommon--and until now unique--discarding sabot airgun projectile (Sussex Sabo Bullet) was introduced into the market in the 1980s. The projectile, available in 0.177 (4.5 mm) and 0.22 (5.5 mm) caliber, consists of a plastic sabot cup surrounding a subcaliber copper-coated lead projectile in typical bullet shape. Following the typical principle of a discarding sabot projectile, the lightweight sabot is supposed to quickly loose velocity and to fall to the ground downrange while the bullet continues on target. These sabot-loaded projectiles are of special forensic interest due to their non-traceability and ballistic parameters. Therefore, it is the aim of this work to investigate the ballistic performance of these sabot airgun projectiles by high-speed video analyses and by measurement of the kinetic parameters of the projectile parts by a transient recording system as well as observing their physical features after being fired. While the sabot principle worked properly in high-energy airguns (E > 17 J), separation of the core projectile from the sabot cup was also observed when discharged in low-energy airguns (E < 7.5 J). While the velocity of the discarded Sussex Sabo core projectile was very close to the velocity of a diabolo-type reference projectile (RWS Meisterkugel), energy density was up to 60 % higher. To conclude, this work is the first study to demonstrate the regular function of this uncommon type of airgun projectile.

  8. Semiconductor projectile impact detector

    NASA Technical Reports Server (NTRS)

    Shriver, E. L. (Inventor)

    1977-01-01

    A semiconductor projectile impact detector is described for use in determining micrometeorite presence, as well as its flux and energy comprising a photovoltaic cell which generates a voltage according to the light and heat emitted by the micrometeorites upon impact. A counter and peak amplitude measuring device were used to indicate the number of particules which strike the surface of the cell as well as the kinetic energy of each of the particles.

  9. Projectile Base Flow Analysis

    DTIC Science & Technology

    2007-11-02

    S) AND ADDRESS(ES) DCW Industries, Inc. 5354 Palm Drive La Canada, CA 91011 8. PERFORMING ORGANIZATION...REPORT NUMBER DCW -38-R-05 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research Office...Turbulence Modeling for CFD, Second Edition, DCW Industries, Inc., La Cañada, CA. Wilcox, D. C. (2001), “Projectile Base Flow Analysis,” DCW

  10. Skirted projectiles for railguns

    DOEpatents

    Hawke, R.S.; Susoeff, A.R.

    1994-01-04

    A single skirt projectile (20) having an insulating skirt (22) at its rear, or a dual trailing skirt projectile (30, 40, 50, 60) having an insulating skirt (32, 42, 52, 62) succeeded by an arc extinguishing skirt (34, 44, 54, 64), is accelerated by a railgun accelerator 10 having a pair of parallel conducting rails (1a, 1b) which are separated by insulating wall spacers (11). The insulating skirt (22, 32, 42, 52, 62) includes a plasma channel (38). The arc extinguishing skirt (34, 44, 54, 64) interrupts the conduction that occurs in the insulating skirt channel (38) by blocking the plasma arc (3) from conducting current from rail to rail (1a, 1b) at the rear of the projectile (30, 40, 50, 60). The arc extinguishing skirt may be comprised of two plates (36a, 36b) which form a horseshoe wherein the plates are parallel to the rails (1a, b); a chisel-shape design; cross-shaped, or it may be a cylindrical (64). The length of the insulating skirt channel is selected such that there is sufficient plasma in the channel to enable adequate current conduction between the rails (1a, 1b).

  11. Skirted projectiles for railguns

    DOEpatents

    Hawke, Ronald S.; Susoeff, Allan R.

    1994-01-01

    A single skirt projectile (20) having an insulating skirt (22) at its rear, or a dual trailing skirt projectile (30, 40, 50, 60) having an insulating skirt (32, 42, 52, 62) succeeded by an arc extinguishing skirt (34, 44, 54, 64), is accelerated by a railgun accelerator 10 having a pair of parallel conducting rails (1a, 1b) which are separated by insulating wall spacers (11). The insulating skirt (22, 32, 42, 52, 62) includes a plasma channel (38). The arc extinguishing skirt (34, 44, 54, 64) interrupts the conduction that occurs in the insulating skirt channel (38) by blocking the plasma arc (3) from conducting current from rail to rail (1a, 1b) at the rear of the projectile (30, 40, 50, 60). The arc extinguishing skirt may be comprised of two plates (36a, 36b) which form a horseshoe wherein the plates are parallel to the rails (1a, b); a chisel-shape design; cross-shaped, or it may be a cylindrical (64). The length of the insulating skirt channel is selected such that there is sufficient plasma in the channel to enable adequate current conduction between the rails (1a, 1b).

  12. Water radiolysis by low-energy carbon projectiles from first-principles molecular dynamics.

    PubMed

    Kohanoff, Jorge; Artacho, Emilio

    2017-01-01

    Water radiolysis by low-energy carbon projectiles is studied by first-principles molecular dynamics. Carbon projectiles of kinetic energies between 175 eV and 2.8 keV are shot across liquid water. Apart from translational, rotational and vibrational excitation, they produce water dissociation. The most abundant products are H and OH fragments. We find that the maximum spatial production of radiolysis products, not only occurs at low velocities, but also well below the maximum of energy deposition, reaching one H every 5 Å at the lowest speed studied (1 Bohr/fs), dissociative collisions being more significant at low velocity while the amount of energy required to dissociate water is constant and much smaller than the projectile's energy. A substantial fraction of the energy transferred to fragments, especially for high velocity projectiles, is in the form of kinetic energy, such fragments becoming secondary projectiles themselves. High velocity projectiles give rise to well-defined binary collisions, which should be amenable to binary approximations. This is not the case for lower velocities, where multiple collision events are observed. H secondary projectiles tend to move as radicals at high velocity, as cations when slower. We observe the generation of new species such as hydrogen peroxide and formic acid. The former occurs when an O radical created in the collision process attacks a water molecule at the O site. The latter when the C projectile is completely stopped and reacts with two water molecules.

  13. Survivability of Meteorite Projectiles - Results from Impact Experiments

    NASA Technical Reports Server (NTRS)

    Bland, P. A.; Cintala, M. J.; Hoerz, F.; Cressey, G.

    2001-01-01

    An experimental impact study investigating the fragmentation of various projectiles, including meteorite, at speeds up to 1.8 km/s. The results have implications for the survivability of meteorites impacting planetary and asteroidal surfaces. Additional information is contained in the original extended abstract.

  14. Wound ballistics of injuries caused by handguns with different types of projectiles.

    PubMed

    von See, Constantin; Stuehmer, Alexander; Gellrich, Nils-Claudius; Blum, Katrin S; Bormann, Kai-Hendrik; Rücker, Martin

    2009-07-01

    There are considerable differences in the shape and composition of military and civilian projectiles. Five different projectiles with the same kinetic energy were fired into the heads of freshly sacrificed pigs (n=30) through the submental region in the occipital direction. Computed tomography (CT) and 3D face scans of the animal skulls were obtained before and after firing. The image data sets were fused and provided the basis for a quantitative analysis of destruction patterns. As a result of the destruction of the parietal bone at the potential exit site, there were significant volume difference between the Action 4 (6.45 +/- 3.42 ml) and the Hydra-Shok projectile (12.71 +/- 2.86 ml). The partial metal-jacketed projectile showed a minor increase in volume (4.89 +/- 1.47 ml) and a partial loss of soft projectile components. Radiology showed differences between the various projectiles in fragmentation and bone and soft-tissue destruction. Although the projectiles had the same kinetic energy, there were considerable differences in injury patterns between full metal-jacketed projectiles, which are the only projectiles permitted for military use under the Geneva Conventions, and the other investigated projectiles. These injuries present a major medical challenge to both first responders and surgeons.

  15. Interactions of relativistic neon to nickel projectiles in hydrogen, elemental production cross sections

    NASA Astrophysics Data System (ADS)

    Knott, C. N.; Albergo, S.; Caccia, Z.; Chen, C.-X.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Jones, F. C.; Lindstrom, P. J.; Mitchell, J. W.; Potenza, R.; Romanski, J.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

    1996-01-01

    This paper reports the elemental production cross sections for 17 projectile-energy combinations with energies between 338 and 894 MeV/nucleon interacting in a liquid hydrogen target. These results were obtained from two runs at the LBL Bevalac using projectiles ranging from 22Ne to 58Ni. Cross sections were measured for all fragment elements with charges greater than or equal to half the charge of the projectile. The results show that, over the energy and ion range investigated, the general decrease in cross section with decreasing fragment charge is strongly modified by the isospin of the projectile ion. Significant additional modifications of the cross sections due to the internal structure of the nucleus have also been seen. These include both pairing and shell effects. Differences in the cross sections due to the differing energies of the projectile are also considerable.

  16. A hypervelocity projectile launcher for well perforation

    SciTech Connect

    Albright, J.N.; Fugelso, L.E.; Lagner, G.C.; Burns, K.L.

    1989-01-01

    Current oil well perforation techniques use low- to medium-velocity gun launchers for completing wells in soft rock. Shaped-charge jets are normally used in harder, more competent rock. A device to create a much higher velocity projectile was designed. This launcher will provide an alternative technique to be used when the conventional devices do not yield the maximum well performance. It is an adaptation of the axial cavity in a high explosive (HE) annulus design, with the axial cavity being filled with a low density foam material. Two configurations were tested; both had an HE annulus filled with organic foam, one had a projectile. Comparison of the two shots was made. A time sequence of Image Intensifier Camera photographs and sequential, orthogonal flash x-ray radiographs provided information on the propagation of the foam fragments, the first shock wave disturbance, the projectile motion and deformation, and the direct shock wave transmission from the main HE charge. DYNA2D calculations were made to assist in the experimental interpretation. 25 refs., 9 figs.

  17. Fragment Penetration Tests of Armor

    DTIC Science & Technology

    1983-03-15

    Identify by block numbhr) Provides techniques for evaluating armor resistance to attack by HE projectile fragments. Includes static detonations of shell...DISTRIBUTION D. REFERENCES * . . . ........ . ........... D-1 1. SCOPE. This TOP describes the available techniques for testing armor for resistance to attack by...Projectiles Against Armor Plates ("Yankee Stadium" Test-). 4.1.1 hCjective. The objective is to determine the resistance to penetration of various armor

  18. Ballistic projectile trajectory determining system

    DOEpatents

    Karr, T.J.

    1997-05-20

    A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile. 8 figs.

  19. Ballistic projectile trajectory determining system

    DOEpatents

    Karr, Thomas J.

    1997-01-01

    A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

  20. Intact capture of hypervelocity projectiles

    NASA Technical Reports Server (NTRS)

    Tsou, P.

    1990-01-01

    The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.

  1. Intact capture of hypervelocity projectiles

    NASA Technical Reports Server (NTRS)

    Tsou, P.

    1990-01-01

    The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.

  2. Intact capture of hypervelocity projectiles.

    PubMed

    Tsou, P

    1990-01-01

    The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.

  3. Water radiolysis by low-energy carbon projectiles from first-principles molecular dynamics

    PubMed Central

    Kohanoff, Jorge

    2017-01-01

    Water radiolysis by low-energy carbon projectiles is studied by first-principles molecular dynamics. Carbon projectiles of kinetic energies between 175 eV and 2.8 keV are shot across liquid water. Apart from translational, rotational and vibrational excitation, they produce water dissociation. The most abundant products are H and OH fragments. We find that the maximum spatial production of radiolysis products, not only occurs at low velocities, but also well below the maximum of energy deposition, reaching one H every 5 Å at the lowest speed studied (1 Bohr/fs), dissociative collisions being more significant at low velocity while the amount of energy required to dissociate water is constant and much smaller than the projectile’s energy. A substantial fraction of the energy transferred to fragments, especially for high velocity projectiles, is in the form of kinetic energy, such fragments becoming secondary projectiles themselves. High velocity projectiles give rise to well-defined binary collisions, which should be amenable to binary approximations. This is not the case for lower velocities, where multiple collision events are observed. H secondary projectiles tend to move as radicals at high velocity, as cations when slower. We observe the generation of new species such as hydrogen peroxide and formic acid. The former occurs when an O radical created in the collision process attacks a water molecule at the O site. The latter when the C projectile is completely stopped and reacts with two water molecules. PMID:28267804

  4. Water Entry of Projectiles

    NASA Astrophysics Data System (ADS)

    Truscott, Tadd T.; Epps, Brenden P.; Belden, Jesse

    2014-01-01

    The free-surface impact of solid objects has been investigated for well over a century. This canonical problem is influenced by many physical parameters, including projectile geometry, material properties, fluid properties, and impact parameters. Through advances in high-speed imaging and visualization techniques, discoveries about the underlying physics have improved our understanding of these phenomena. Improvements to analytical and numerical models have led to critical insights into cavity formation, the depth and time of pinch-off, forces, and trajectories for myriad different impact parameters. This topic spans a wide range of regimes, from low-speed entry phenomena dominated by surface tension to high-speed ballistics, for which cavitation is important. This review surveys experimental, theoretical, and numerical studies over this broad range, utilizing canonical images where possible to enhance intuition and insight into the rich phenomena.

  5. Protection from high-velocity projectiles

    NASA Astrophysics Data System (ADS)

    Gerasimov, A.; Pashkov, S.

    2012-08-01

    Creation of reliable system of target protection demands research of various ways of counteraction high-speed elongated projectiles. This paper considers the interaction of projectiles with plates and rods thrown towards by explosion. At contact projectiles and rods form a crosswise configuration. Deformation and destruction of projectiles reduce their penetrability and capacity to strike armor-target.

  6. Recovery of Uranium Fragments

    NASA Astrophysics Data System (ADS)

    James, H. R.; McElrue, D. H.; Winter, R. E.

    2002-07-01

    We describe a theory for calculating the penetration of fragments into foam. Comparisons with regular projectiles show that the drag term is similar in value to the analogous term in aerodynamics. This, plus the simple model used to describe porosity, enables the theory to be used in predicting the levels of stress present when uranium fragments are arrested in foam catchers. Consequently the theory can be used to assist in the design of catchers which will not distort uranium fragments travelling at 1-3 km/s. The theory is tested against experiments using some current designs.

  7. Projectile remnants in central peaks of lunar impact craters

    NASA Astrophysics Data System (ADS)

    Yue, Z.; Johnson, B. C.; Minton, D. A.; Melosh, H. J.; di, K.; Hu, W.; Liu, Y.

    2013-06-01

    The projectiles responsible for the formation of large impact craters are often assumed to melt or vaporize during the impact, so that only geochemical traces or small fragments remain in the final crater. In high-speed oblique impacts, some projectile material may survive, but this material is scattered far down-range from the impact site. Unusual minerals, such as magnesium-rich spinel and olivine, observed in the central peaks of many lunar craters are therefore attributed to the excavation of layers below the lunar surface. Yet these minerals are abundant in many asteroids, meteorites and chondrules. Here we use a numerical model to simulate the formation of impact craters and to trace the fate of the projectile material. We find that for vertical impact velocities below about 12kms-1, the projectile may both survive the impact and be swept back into the central peak of the final crater as it collapses, although it would be fragmented and strongly deformed. We conclude that some unusual minerals observed in the central peaks of many lunar impact craters could be exogenic in origin and may not be indigenous to the Moon.

  8. Air-Powered Projectile Launcher

    NASA Technical Reports Server (NTRS)

    Andrews, T.; Bjorklund, R. A.; Elliott, D. G.; Jones, L. K.

    1987-01-01

    Air-powered launcher fires plastic projectiles without using explosive propellants. Does not generate high temperatures. Launcher developed for combat training for U.S. Army. With reservoir pressurized, air launcher ready to fire. When pilot valve opened, sleeve (main valve) moves to rear. Projectile rapidly propelled through barrel, pushed by air from reservoir. Potential applications in seismic measurements, avalanche control, and testing impact resistance of windshields on vehicles.

  9. Air-Powered Projectile Launcher

    NASA Technical Reports Server (NTRS)

    Andrews, T.; Bjorklund, R. A.; Elliott, D. G.; Jones, L. K.

    1987-01-01

    Air-powered launcher fires plastic projectiles without using explosive propellants. Does not generate high temperatures. Launcher developed for combat training for U.S. Army. With reservoir pressurized, air launcher ready to fire. When pilot valve opened, sleeve (main valve) moves to rear. Projectile rapidly propelled through barrel, pushed by air from reservoir. Potential applications in seismic measurements, avalanche control, and testing impact resistance of windshields on vehicles.

  10. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  11. Prevention of breakdown behind railgun projectiles

    DOEpatents

    Hawke, R.S.

    1992-10-13

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  12. Prevention of breakdown behind railgun projectiles

    DOEpatents

    Hawke, R.S.

    1992-09-01

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  13. Prevention of breakdown behind railgun projectiles

    SciTech Connect

    Hawke, R.S.

    1989-04-20

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF{sub 6}. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has traveled. The projectile may have a cavity at its rear to control the release of ablation products. 9 figs.

  14. Prevention of breakdown behind railgun projectiles

    DOEpatents

    Hawke, Ronald S.

    1992-01-01

    An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 444) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14 ) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).

  15. Prevention of breakdown behind railgun projectiles

    DOEpatents

    Hawke, Ronald S.

    1992-01-01

    An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 414) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).

  16. Geochemical processes between steel projectiles and silica-rich targets in hypervelocity impact experiments

    NASA Astrophysics Data System (ADS)

    Ebert, Matthias; Hecht, Lutz; Deutsch, Alexander; Kenkmann, Thomas; Wirth, Richard; Berndt, Jasper

    2014-05-01

    The possibility of fractionation processes between projectile and target matter is critical with regard to the classification of the impactor type from geochemical analysis of impactites from natural craters. Here we present results of five hypervelocity MEMIN impact experiments (Poelchau et al., 2013) using the Cr-V-Co-Mo-W-rich steel D290-1 as projectile and two different silica-rich lithologies (Seeberger sandstone and Taunus quartzite) as target materials. Our study is focused on geochemical target-projectile interaction occurring in highly shocked and projectile-rich ejecta fragments. In all of the investigated impact experiments, whether sandstone or quartzite targets, the ejecta fragments show (i) shock-metamorphic features e.g., planar-deformation features (PDF) and the formation of silica glasses, (ii) partially melting of projectile and target, and (iii) significant mechanical and chemical mixing of the target rock with projectile material. The silica-rich target melts are strongly enriched in the "projectile tracer elements" Cr, V, and Fe, but have just minor enrichments of Co, W, and Mo. Inter-element ratios of these tracer elements within the contaminated target melts differ strongly from the original ratios in the steel. The fractionation results from differences in the reactivity of the respective elements with oxygen during interaction of the metal melt with silicate melt. Our results indicate that the principles of projectile-target interaction and associated fractionation do not depend on impact energies (at least for the selected experimental conditions) and water-saturation of the target. Partitioning of projectile tracer elements into the silicate target melt is much more enhanced in experiments with a non-porous quartzite target compared with the porous sandstone target. This is mainly the result of higher impact pressures, consequently higher temperatures and longer reaction times at high temperatures in the experiments with quartzite as

  17. Fluidic control systems for projectiles

    NASA Astrophysics Data System (ADS)

    Garlow, D.; Muggeridge, D.

    1983-06-01

    Current indirect fire weapons, such as artillery and large caliber mortars, are characterized by the low cost and high fire rate of their purely ballistic projectiles. A major prospective development in antiarmor technology will involve the incorporation of terminal guidance technology into these indirect fire projectiles in order to increase their effectiveness. Attention is presently given to the development of a cost-competitive, guided projectile that can survive the shock of gun launching, employing fluidic reaction jet controls in lieu of aerodynamic surfaces. The fluidic reaction jet control system presently described employs warm gas as its working fluid and has survived 15,000-g launch shocks, delivering 15 lbs of thrust control in a two-axis system with a 50-Hz dynamic response.

  18. Target-projectile interaction during impact melting at Kamil Crater, Egypt

    NASA Astrophysics Data System (ADS)

    Fazio, Agnese; D'Orazio, Massimo; Cordier, Carole; Folco, Luigi

    2016-05-01

    In small meteorite impacts, the projectile may survive through fragmentation; in addition, it may melt, and chemically and physically interact with both shocked and melted target rocks. However, the mixing/mingling between projectile and target melts is a process still not completely understood. Kamil Crater (45 m in diameter; Egypt), generated by the hypervelocity impact of the Gebel Kamil Ni-rich ataxite on sandstone target, allows to study the target-projectile interaction in a simple and fresh geological setting. We conducted a petrographic and geochemical study of macroscopic impact melt lapilli and bombs ejected from the crater, which were collected during our geophysical campaign in February 2010. Two types of glasses constitute the impact melt lapilli and bombs: a white glass and a dark glass. The white glass is mostly made of SiO2 and it is devoid of inclusions. Its negligible Ni and Co contents suggest derivation from the target rocks without interaction with the projectile (<0.1 wt% of projectile contamination). The dark glass is a silicate melt with variable contents of Al2O3 (0.84-18.7 wt%), FeOT (1.83-61.5 wt%), and NiO (<0.01-10.2 wt%). The dark glass typically includes fragments (from few μm to several mm in size) of shocked sandstone, diaplectic glass, lechatelierite, and Ni-Fe metal blebs. The metal blebs are enriched in Ni compared to the Gebel Kamil meteorite. The dark glass is thus a mixture of target and projectile melts (11-12 wt% of projectile contamination). Based on recently proposed models for target-projectile interaction and for impact glass formation, we suggest a scenario for the glass formation at Kamil. During the transition from the contact and compression stage and the excavation stage, projectile and target liquids formed at their interface and chemically interact in a restricted zone. Projectile contamination affected only a shallow portion of the target rocks. The SiO2 melt that eventually solidified as white glass behaved as

  19. Sabot-Projectiles for Cannon

    DTIC Science & Technology

    1943-11-01

    model designed for the 20,-^nm Hispano- Suiza cannon. Let Ms be the mass of the sabot in pounds; M . "the mass of the subcali- ber projectile in...its projectile. This model xs designed for the 20-mm Hispano- Suiza cannon, but as with all deep-cup sabots tested, does not prove successful in...the 20-mm Hispano- Suiza , for example, the f. maximum pressure is I48OOO lb/in? and for the 37-mm A.T. gun it is • ^0000 lb/in?). V i Attention

  20. Projectile-generating explosive access tool

    SciTech Connect

    Jakaboski, Juan-Carlos; Hughs, Chance G; Todd, Steven N

    2013-06-11

    A method for generating a projectile using an explosive device that can generate a projectile from the opposite side of a wall from the side where the explosive device is detonated. The projectile can be generated without breaching the wall of the structure or container. The device can optionally open an aperture in a solid wall of a structure or a container and form a high-kinetic-energy projectile from the portion of the wall removed to create the aperture.

  1. A semiempirical nuclear fragmentation model

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Townsend, Lawrence W.; Badavi, F. F.

    1987-01-01

    An abrasion/ablation model of heavy ion fragmentation is derived which includes a second order correction for the surface energy term and provides a reasonable representation of the present elemental fragmentation cross sections. The full development of the model must await the resolution of disagreement among different experiments and an expansion of the experimental data base to a broader set of projectile-target combinations.

  2. Having Fun with a 3-D Projectile

    ERIC Educational Resources Information Center

    Lammi, Matthew; Greenhalgh, Scott

    2011-01-01

    The use of projectiles is a concept familiar to most students, whether it is a classic slingshot, bow and arrow, or even a spit wad through a straw. Perhaps the last thing a teacher wants is more projectiles in the classroom. However, the concept of projectiles is relevant to most students and may provide a means of bringing more authenticity into…

  3. Having Fun with a 3-D Projectile

    ERIC Educational Resources Information Center

    Lammi, Matthew; Greenhalgh, Scott

    2011-01-01

    The use of projectiles is a concept familiar to most students, whether it is a classic slingshot, bow and arrow, or even a spit wad through a straw. Perhaps the last thing a teacher wants is more projectiles in the classroom. However, the concept of projectiles is relevant to most students and may provide a means of bringing more authenticity into…

  4. Current CFD efforts in projectile aerodynamics

    NASA Technical Reports Server (NTRS)

    Nietubicz, Charles J.

    1987-01-01

    Information is given in viewgraph form on current computational fluid dynamics (CFD) efforts in projectile aerodynamics. Topics covered include spinning projectiles, fin stabilized projectiles, model geometry, the variation of base drag with base bleed, the variation of normal force with Mach number, and chordwise pressure distribution.

  5. Electrical analog to projectile motion

    NASA Astrophysics Data System (ADS)

    Vondracek, Mark

    1998-04-01

    This article describes an electrical analog to traditional projectile problems given in high school and introductory college classes. It also discusses the importance of stressing the understanding of physical laws and principles to students, and that the physics behind a problem is more important than being able to memorize and use various equations.

  6. Projectile Motion Gets the Hose

    ERIC Educational Resources Information Center

    Goff, John Eric; Liyanage, Chinthaka

    2011-01-01

    Students take a weekly quiz in our introductory physics course. During the week in which material focused on projectile motion, we not-so-subtly suggested what problem the students would see on the quiz. The quiz problem was an almost exact replica of a homework problem we worked through in the class preceding the quiz. The goal of the problem is…

  7. Projectile Motion Gets the Hose

    ERIC Educational Resources Information Center

    Goff, John Eric; Liyanage, Chinthaka

    2011-01-01

    Students take a weekly quiz in our introductory physics course. During the week in which material focused on projectile motion, we not-so-subtly suggested what problem the students would see on the quiz. The quiz problem was an almost exact replica of a homework problem we worked through in the class preceding the quiz. The goal of the problem is…

  8. The Projectile Inside the Loop

    ERIC Educational Resources Information Center

    Varieschi, Gabriele U.

    2006-01-01

    The loop-the-loop demonstration can be easily adapted to study the kinematics of projectile motion, when the moving body falls inside the apparatus. Video capturing software can be used to reveal peculiar geometrical effects of this simple but educational experiment.

  9. The Projectile Inside the Loop

    ERIC Educational Resources Information Center

    Varieschi, Gabriele U.

    2006-01-01

    The loop-the-loop demonstration can be easily adapted to study the kinematics of projectile motion, when the moving body falls inside the apparatus. Video capturing software can be used to reveal peculiar geometrical effects of this simple but educational experiment.

  10. Novice Rules for Projectile Motion.

    ERIC Educational Resources Information Center

    Maloney, David P.

    1988-01-01

    Investigates several aspects of undergraduate students' rules for projectile motion including general patterns; rules for questions about time, distance, solids and liquids; and changes in rules when asked to ignore air resistance. Reports approach differences by sex and high school physics experience, and that novice rules are situation…

  11. Novice Rules for Projectile Motion.

    ERIC Educational Resources Information Center

    Maloney, David P.

    1988-01-01

    Investigates several aspects of undergraduate students' rules for projectile motion including general patterns; rules for questions about time, distance, solids and liquids; and changes in rules when asked to ignore air resistance. Reports approach differences by sex and high school physics experience, and that novice rules are situation…

  12. Developmental changes in children's understanding of horizontal projectile motion.

    PubMed

    Mou, Yi; Zhu, Liqi; Chen, Zhe

    2015-08-01

    This study investigated 5- to 13-year-old children's performance in solving horizontal projectile motion problems, in which they predicted the trajectory of a carried object released from a carrier in three different contexts. The results revealed that 5- and 8-year-olds' trajectory predictions were easily distracted by salient contextual features (e.g. the relative spatial locations between objects), whereas a proportion of 11- and 13-year-olds' performance suggested the engagement of the impetus concept in trajectory prediction. The impetus concept is a typical misconception of inertial motion that assumes that motion is caused by force. Children's performance across ages suggested that their naïve knowledge of projectile motion was neither well-developed and coherent nor completely fragmented. Instead, this study presented the dynamic process in which children with age gradually overcame the influences of contextual features and consistently used the impetus concept across motion problems.

  13. The preservation of fossil biomarkers during meteorite impact events: Experimental evidence from biomarker-rich projectiles and target rocks

    NASA Astrophysics Data System (ADS)

    Parnell, John; Bowden, Stephen; Lindgren, Paula; Burchell, Mark; Milner, Daniel; Price, Mark; Baldwin, Emily C.; Crawford, Ian A.

    2010-08-01

    A Devonian siltstone from Orkney, Scotland, shows survival of biomarkers in high-velocity impact experiments. The biomarkers were detected in ejecta fragments from experiments involving normal incidence of steel projectiles at 5-6kms-1, and in projectile fragments from impact experiments into sand and water at 2-5kms-1. The associated peak shock pressures were calculated to be in the range of 110-147GPa for impacts of the steel projectiles into the siltstone target, and hydrocode simulations are used to show the variation of peak pressure with depth in the target and throughout the finite volume projectiles. Thermally sensitive biomarker ratios, including ratios of hopanoids and steranes, and the methylphenanthrene ratio, showed an increase in thermal maturity in the ejecta, and especially the projectile, fragments. Measurement of absolute concentrations of selected biomarkers indicates that changes in biomarker ratios reflect synthesis of new material rather than selective destruction. Their presence in ejecta and projectile fragments suggests that fossil biomarkers may survive hypervelocity impacts, and that experiments using biomarker-rich rock have high potential for testing survival of organic matter in a range of impact scenarios.

  14. Microspoiler Actuation for Guided Projectiles

    DTIC Science & Technology

    2016-01-06

    objectives, including mechanical design and fabrication, trade study analysis, and limited flight experiments were defined as a collaborative effort...between the Georgia Institute of Technology (Georgia Tech) and the Army Research Laboratory (ARL) for DARPA.  Objective 1: Perform Trade Studies to...Optimize Microspoiler Configuration Extensive trade studies will be performed for an example medium-caliber projectile (in the 30mm and/or 57mm class

  15. Collision forces for compliant projectiles

    NASA Technical Reports Server (NTRS)

    Grady, Joseph E.

    1990-01-01

    Force histories resulting from the impact of compliant projectiles were determined experimentally. A long instrumented rod was used as the target, and the impact force was calculated directly from the measured strain response. Results from a series of tests on several different sized impactors were used to define four dimensionless parameters that determine, for a specified impactor velocity and size, the amplitude, duration, shape, and impulse of the impact force history.

  16. Deceleration of Projectiles in Snow,

    DTIC Science & Technology

    1982-08-01

    contents of this report are not to be used for advertising or promotional purposes. Citation of brand names does not constitute an official endorsement or...projectile are directly wired els were used in these tests. The snow targets were to recording equipment, and the target is not accel- prepared by sifting...the snow target are identified in The target box was placed in a rigid stand located the figure. The travel times between these impacts on a tangent to

  17. Ablative shielding for hypervelocity projectiles

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A. (Inventor)

    1993-01-01

    A hypervelocity projectile shield which includes a hollow semi-flexible housing fabricated from a plastic like, or otherwise transparent membrane which is filled with a fluid (gas or liquid) is presented. The housing has a inlet valve, similar to that on a tire or basketball, to introduce an ablating fluid into the housing. The housing is attached by a Velcro mount or double-sided adhesive tape to the outside surface of a structure to be protected. The housings are arrayed in a side-by-side relationship for complete coverage of the surface to be protected. In use, when a hypervelocity projectile penetrates the outer wall of a housing it is broken up and then the projectile is ablated as it travels through the fluid, much like a meteorite 'burns up' as it enters the earth's atmosphere, and the housing is deflated. The deflated housing can be easily spotted for replacement, even from a distance. Replacement is then accomplished by simply pulling a deflated housing off the structure and installing a new housing.

  18. Wind-influenced projectile motion

    NASA Astrophysics Data System (ADS)

    Bernardo, Reginald Christian; Perico Esguerra, Jose; Day Vallejos, Jazmine; Jerard Canda, Jeff

    2015-03-01

    We solved the wind-influenced projectile motion problem with the same initial and final heights and obtained exact analytical expressions for the shape of the trajectory, range, maximum height, time of flight, time of ascent, and time of descent with the help of the Lambert W function. It turns out that the range and maximum horizontal displacement are not always equal. When launched at a critical angle, the projectile will return to its starting position. It turns out that a launch angle of 90° maximizes the time of flight, time of ascent, time of descent, and maximum height and that the launch angle corresponding to maximum range can be obtained by solving a transcendental equation. Finally, we expressed in a parametric equation the locus of points corresponding to maximum heights for projectiles launched from the ground with the same initial speed in all directions. We used the results to estimate how much a moderate wind can modify a golf ball’s range and suggested other possible applications.

  19. Sequential injection gas guns for accelerating projectiles

    SciTech Connect

    Lacy, Jeffrey M; Chu, Henry S; Novascone, Stephen R

    2011-11-15

    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  20. Sonic Simulation of Near Projectile Hits

    NASA Technical Reports Server (NTRS)

    Statman, J. I.; Rodemich, E. R.

    1988-01-01

    Measured frequencies identify projectiles and indicate miss distances. Developmental battlefield-simulation system for training soldiers uses sounds emitted by incoming projectiles to identify projectiles and indicate miss distances. Depending on projectile type and closeness of each hit, system generates "kill" or "near-kill" indication. Artillery shell simulated by lightweight plastic projectile launched by compressed air. Flow of air through groove in nose of projectile generates acoustic tone. Each participant carries audio receiver measure and process tone signal. System performs fast Fourier transforms of received tone to obtain dominant frequency during each succeeding interval of approximately 40 ms (an interval determined from practical signal-processing requirements). With modifications, system concept applicable to collision-warning or collision-avoidance systems.

  1. Projectile-generating explosive access tool

    DOEpatents

    Jakaboski, Juan-Carlos; Todd, Steven N.

    2011-10-18

    An explosive device that can generate a projectile from the opposite side of a wall from the side where the explosive device is detonated. The projectile can be generated without breaching the wall of the structure or container. The device can optionally open an aperture in a solid wall of a structure or a container and form a high-kinetic-energy projectile from the portion of the wall removed to create the aperture.

  2. A computational study of projectile melt in impact with typical Whipple shields

    SciTech Connect

    Alme, M.L.; Rhoades, C.E. Jr.

    1994-06-03

    This paper presents scaling results based on simulations with the CALE hydrodynamics code of aluminum projectile impacts on typical aluminum Whipple shields at speeds of 6 to 14 km/s. The objective was to determine the extent of projectile and target material melting. The approach was to perform a matrix of computer simulations varying the impact speed from 6 to 14 km/s and varying the areal density of the shield from 5 percent to 80 percent of the centerline areal density of the projectile. The projectile radius was fixed at 9.5 mm (mass = 1.27 grams). The melt state of the projectile material and the shield material was assessed after release of the initial shock. The post-release specific energy in the projectile and in the shield was compared with the enthalpy of incipient melt and the enthalpy of complete melt provided in the Hultgren Tables. Material with specific energy greater than the enthalpy of complete melt was assumed to be fully melted; material with specific energy greater than the enthalpy of incipient melt but less than that of complete melt was assumed to be partially solid and partially melted mixed phase material with no strength; and material with specific energy less than the enthalpy of incipient melt was assumed to be in a solid state with strength. It is likely that this solid material is in a highly fragmented state as a result of the initial shock.

  3. Projectile development for railguns using hypervelocity preacceleration

    SciTech Connect

    Susoeff, A.R.; Hawke, R.S. ); Sauve, G.L. ); Konrad, C.H. ); Hickman, R.J. )

    1991-02-01

    The STARFIRE Project is a joint Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL) effort to achieve hypervelocity projectile launches up to 15 km/s. The apparatus used to achieve this goal is a three stage acceleration system made up of a two-stage light-gas gun (2SLGG) is used as a preaccelerator capable of injecting 2 gram projectiles at velocities of 6 km/s or more. Projectiles used in this environment are subject to many conditions. Some of these which effect projectile design include: acceleration loading, structural response, barrel condition and alignment. Development of a projectile to satisfy the programmatic requirements is underway. This report covers the evolution of design and fabrication for railgun projectiles from previous experience at LLNL to the replenished plasma armature and projectile now used on STARFIRE. Projectile design, development and fabrication methods which use off-the-shelf materials and standard techniques to meet the operational criteria of the experimental program are discussed in this paper. Initial work involving the design and fabrication of skirted projectiles, which are expected to further reduce interaction phenomena between the plasma armature and railgun barrel, is also described.

  4. Projectile development for railguns using hypervelocity preacceleration

    SciTech Connect

    Susoeff, A.R.; Hawke, R.S. ); Ang, J.A.; Asay, J.R.; Hall, C.A.; Konrad, C.H. ); Sauve, G.L. . Rocky Flats Plant); Hickman, R.J. )

    1992-03-20

    The STARFIRE Project is a joint Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL) effort to achieve hypervelocity projectile launches up to 15 km/s. The apparatus used to achieve this goal is a three stage acceleration system made up of a two-stage light-gas gun (2SLGG) coupled to a railgun. The 2SLGG is used as a preaccelerator capable of injecting 2 gram projectiles at velocities of 6 km/s or more. Projectiles used in this environment are subject to many conditions. Some of these which effect projectile design include: acceleration loading, structural response, barrel condition and alignment. Development of a projectile to satisfy the programmatic requirements is underway. This report covers the evolution of design and fabrication for railgun projectiles from previous experiment at LLNL to the replenished plasma armature and projectile now used on STARFIRE. Projectile design, development and fabrication methods which use off-the-shelf materials and standard techniques to meet the operational criteria of the experimental program are discussed in this paper. Initial work involving the design and fabrication of skirted projectiles, which are expected to further reduce interaction phenomena between the plasma armature and railgun barrel, is also described.

  5. Stopping power: Effect of the projectile deceleration

    SciTech Connect

    Kompaneets, Roman Ivlev, Alexei V.; Morfill, Gregor E.

    2014-11-15

    The stopping force is the force exerted on the projectile by its wake. Since the wake does not instantly adjust to the projectile velocity, the stopping force should be affected by the projectile deceleration caused by the stopping force itself. We address this effect by deriving the corresponding correction to the stopping force in the cold plasma approximation. By using the derived expression, we estimate that if the projectile is an ion passing through an electron-proton plasma, the correction is small when the stopping force is due to the plasma electrons, but can be significant when the stopping force is due to the protons.

  6. REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION

    SciTech Connect

    Mark Machina

    2002-01-09

    The Projectile Based Excavation (ProjEX) program has as its goal, the reduction of energy required for production mining and secondary breakage through the use of a projectile based excavation system. It depends on the development of a low cost family of projectiles that will penetrate and break up different types of ore/rock and a low cost electric launch system. The electric launch system will eliminate the need for high cost propellant considered for similar concepts in the past. This document reports on the progress made in the program during the past quarter. It reports on projectile development experiments and the development of the electric launch system design.

  7. REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION

    SciTech Connect

    Mark Machina

    2002-10-12

    The Projectile Based Excavation (ProjEX) program has as its goal, the reduction of energy required for production mining and secondary breakage through the use of a projectile based excavation system. It depends on the development of a low cost family of projectiles that will penetrate and break up different types of ore/rock and a low cost electric launch system. The electric launch system will eliminate the need for high cost propellant investigated for similar concepts in the past. This document reports on the progress made in the program during the past quarter. It reports on projectile development and the development of the electric launch system design.

  8. Chunk projectile launch using the Sandia Hypervelocity Launcher Facility

    SciTech Connect

    Chhabildas, L.C.; Trucano, T.G.; Reinhart, W.D.; Hall, C.A.

    1994-07-01

    An experimental technique is described to launch an intact ``chunk,`` i.e. a 0.3 cm thick by 0.6 cm diameter cylindrical titanium alloy (Ti-6Al-4V) flyer, to 10.2 km/s. The ability to launch fragments having such an aspect ratio is important for hypervelocity impact phenomenology studies. The experimental techniques used to accomplish this launch were similar but not identical to techniques developed for the Sandia HyperVelocity Launcher (HVL). A confined barrel impact is crucial in preventing the two-dimensional effects from dominating the loading response of the projectile chunk. The length to diameter ratio of the metallic chunk that is launched to 10.2 km/s is 0.5 and is an order of magnitude larger than those accomplished using the conventional hypervelocity launcher. The multi-dimensional, finite-difference (finite-volume), hydrodynamic code CTH was used to evaluate and assess the acceleration characteristics i.e., the in-bore ballistics of the chunky projectile launch. A critical analysis of the CTH calculational results led to the final design and the experimental conditions that were used in this study. However, the predicted velocity of the projectile chunk based on CTH calculations was {approximately} 6% lower than the measured velocity of {approximately}10.2 km/S.

  9. Complex Impact Craters Morphologies Created by Granular Projectiles

    NASA Astrophysics Data System (ADS)

    Bartali, R.; Rodriguez-Liñan, G.; Nahmad-Molinari, Y.; Ruiz-Suarez, C.; Sarocchi, D.

    2012-12-01

    Most, high and low energy, experiments, devoted to reproduce impact crater morphologies as those observed on planets and satellites, are done smashing solid projectiles on solid or granular targets. Our experiments, instead, are aimed to understand the behavior of granular projectiles impacting on granular targets. This approach is a by-product of the improvements in astronomical instrumentation and data processing capabilities, made during the past few years, which allowed the recognition of the granular structure of several asteroids. Planetary surfaces are also covered by regolith, produced by the fragmentation of impacting bodies, giving them, also, a granular structure. Comparing our experimental results with impact craters on the moon, mars and satellites, we can show that the different morphologies of complex impact craters are reproduced more faithfully by using granular materials for both the projectile and the target. C) Experimental central dome crater D) Un-named central dome crater on Mars E) Experimental central peak crater F) Tycho crater, Moon, central peak G) Experimental ray crater H) Kepler crater, Moon, ray crater

  10. Projectile and Fragment Penetration in Snow and Frozen Soil,

    DTIC Science & Technology

    1976-01-01

    penetration data for the 5.56-mm steel FSP’s fired into Hanover silt are given in Figure 3. These data show that penetration into the frozen silt was...coefficient of deformation, CD 2 • @ Cold Room @Firing Room SInstrumentation Room @D Loading Room Figure 1. CRREL terminal ballistics facility ( TBF ). in cm 4 10...1 1 , 0 0 Unfrozen 0 S-30C 8 - -10% 3 & -25"C PNAIO 00 BALL AMMO = 6- 0 . a AK 0A C 0 ," o• •&& && . 4 - AA& STEEL 2 7 S!2 -AO• CUBE w 0 200 400 600

  11. High-Velocity Impact Fragmentation of Projectiles Experimental Results

    DTIC Science & Technology

    2016-10-01

    3 3. Material Legend for Test Matrices ... matrices can be found in Tables 1 and 2 and separated by single material shots, arrayed shots, and arranged in chronological order. The material...Titanium 17.12 965 8182 4 Table 3. Material Legend for Test Matrices Key Material CF carbon fiber SiC silicon carbide SiOC silicon oxycarbide E

  12. Projectile Motion Gets the Hose

    NASA Astrophysics Data System (ADS)

    Goff, John Eric; Liyanage, Chinthaka

    2011-10-01

    Students take a weekly quiz in our introductory physics course. During the week in which material focused on projectile motion, we not-so-subtly suggested what problem the students would see on the quiz. The quiz problem was an almost exact replica of a homework problem we worked through in the class preceding the quiz. The goal of the problem is to find the launch speed if the final horizontal and vertical positions and launch angle are given. Figure 1 shows a schematic of the trajectory.

  13. Asymmetry effects in fragment production

    NASA Astrophysics Data System (ADS)

    Kaur, Manpreet; Kaur, Varinderjit

    2016-05-01

    The production of different fragments has been studied by taking into account the mass asymmetry of the reaction and employing the momentum dependent interactions. Two different set of asymmetric reactions have been analyzed while keeping Atotal fixed using soft momentum dependent equation of state. Our results indicate that the impact of momentum dependent interactions is different in lighter projectile systems as compared to heavier ones. The comparative analysis of IQMD simulations with the experimental data in case of heavier projectile and lighter target system for the reaction of 197Au+27Al (η = 0.7) at E = 600 MeV/nucleon shows that with the inclusion of MDI we are able, upto some extent, to reproduce the experimental universality of rise and fall of intermediate mass fragments (IMFs).

  14. Asymmetry effects in fragment production

    SciTech Connect

    Kaur, Manpreet; Kaur, Varinderjit

    2016-05-06

    The production of different fragments has been studied by taking into account the mass asymmetry of the reaction and employing the momentum dependent interactions. Two different set of asymmetric reactions have been analyzed while keeping At{sub otal} fixed using soft momentum dependent equation of state. Our results indicate that the impact of momentum dependent interactions is different in lighter projectile systems as compared to heavier ones. The comparative analysis of IQMD simulations with the experimental data in case of heavier projectile and lighter target system for the reaction of {sup 197}Au+{sup 27}Al (η = 0.7) at E = 600 MeV/nucleon shows that with the inclusion of MDI we are able, upto some extent, to reproduce the experimental universality of rise and fall of intermediate mass fragments (IMFs).

  15. The development of a flight termination parachute system for a 1900 lb payload

    SciTech Connect

    Waye, D.E.

    1997-04-01

    A 30-ft-diameter ringslot/solid parachute was designed, developed, and tested at Sandia National Laboratories as the major component of a flight termination system required for a 1900-lb gliding delivery platform. Four full-scale sled tests were performed to validate the design models of the parachute, determine reefing line length, demonstrate structural adequacy of the parachute materials, and demonstrate that performance met the design requirements.

  16. Graphical Method for Determining Projectile Trajectory

    ERIC Educational Resources Information Center

    Moore, J. C.; Baker, J. C.; Franzel, L.; McMahon, D.; Songer, D.

    2010-01-01

    We present a nontrigonometric graphical method for predicting the trajectory of a projectile when the angle and initial velocity are known. Students enrolled in a general education conceptual physics course typically have weak backgrounds in trigonometry, making inaccessible the standard analytical calculation of projectile range. Furthermore,…

  17. Aerodynamic flail for a spinning projectile

    DOEpatents

    Cole, James K.

    1990-01-01

    A flail is provided which reduces the spin of a projectile in a recovery system which includes a parachute, a cable connected to the parachute, a swivel, and means for connecting the swivel to the projectile. The flail includes a plurality of flexible filaments and a rotor for attaching the filaments to the front end of the projectile. The rotor is located radially with respect to the spinning axis of the projectile. In one embodiment, the projectile includes a first nose cone section housing a deployable spin damping assembly; a second nose cone section, housing a deployable parachute assembly; a shell section, supporting the first and second nose cone sections during flight of the projectile; a mechanism for releasing the first nose cone section from the second cone section; and a mechanism for releasing the second nose cone section from the shell section. In operation of this embodiment, the deployable spin damping assembly deploys during flight of the projectile when the mechanism for releasing the first nose cone section from the second nose cone section are actuated. Then, upon actuation of the mechanism for releasing the second nose cone section from the shell section, two things happen: the spin damping assembly separates from the projectile; and the deployable parachute assembly is deployed.

  18. Aerodynamic flail for a spinning projectile

    DOEpatents

    Cole, James K.

    1990-05-01

    A flail is provided which reduces the spin of a projectile in a recovery system which includes a parachute, a cable connected to the parachute, a swivel, and means for connecting the swivel to the projectile. The flail includes a plurality of flexible filaments and a rotor for attaching the filaments to the front end of the projectile. The rotor is located radially with respect to the spinning axis of the projectile. In one embodiment, the projectile includes a first nose cone section housing a deployable spin damping assembly; a second nose cone section, housing a deployable parachute assembly; a shell section, supporting the first and second nose cone sections during flight of the projectile; a mechanism for releasing the first nose cone section from the second cone section; and a mechanism for releasing the second nose cone section from the shell section. In operation of this embodiment, the deployable spin damping assembly deploys during flight of the projectile when the mechanism for releasing the first nose cone section from the second nose cone section are actuated. Then, upon actuation of the mechanism for releasing the second nose cone section from the shell section, two things happen: the spin damping assembly separates from the projectile; and the deployable parachute assembly is deployed.

  19. Predicting the Accuracy of Unguided Artillery Projectiles

    DTIC Science & Technology

    2016-09-01

    aerodynamic coefficients, physical properties, and error budgets. 14. SUBJECT TERMS accuracy, error, artillery, unguided, modified point mass, indirect...unguided projectile given the required aerodynamic coefficients, physical properties, and error budgets. vi THIS PAGE INTENTIONALLY LEFT BLANK vii TABLE...15 Figure 9. Initial Overturning Moment and Direction of Torque in a Spinning Projectile

  20. Graphical Method for Determining Projectile Trajectory

    ERIC Educational Resources Information Center

    Moore, J. C.; Baker, J. C.; Franzel, L.; McMahon, D.; Songer, D.

    2010-01-01

    We present a nontrigonometric graphical method for predicting the trajectory of a projectile when the angle and initial velocity are known. Students enrolled in a general education conceptual physics course typically have weak backgrounds in trigonometry, making inaccessible the standard analytical calculation of projectile range. Furthermore,…

  1. Projectile Combustion Effects on Ram Accelerator Performance

    NASA Astrophysics Data System (ADS)

    Chitale, Saarth Anjali

    University of Washington Abstract Projectile Combustion Effects on Ram Accelerator Performance Saarth Anjali Chitale Chair of the Supervisory Committee: Prof. Carl Knowlen William E. Boeing Department of Aeronautics and Astronautics The ram accelerator facility at the University of Washington is used to propel projectiles at supersonic velocities. This concept is similar to an air-breathing ramjet engine in that sub-caliber projectiles, shaped like the ramjet engine center-body, are shot through smooth-bore steel-walled tubes having an internal diameter of 38 mm. The ram accelerator propulsive cycles operate between Mach 2 to 10 and have the potential to accelerate projectile to velocities greater than 8 km/s. The theoretical thrust versus Mach number characteristics can be obtained using knowledge of gas dynamics and thermodynamics that goes into the design of the ram accelerator. The corresponding velocity versus distance profiles obtained from the test runs at the University of Washington, however, are often not consistent with the theoretical predictions after the projectiles reach in-tube Mach numbers greater than 4. The experimental velocities are typically greater than the expected theoretical predictions; which has led to the proposition that the combustion process may be moving up onto the projectile. An alternative explanation for higher than predicted thrust, which is explored here, is that the performance differences can be attributed to the ablation of the projectile body which results in molten metal being added to the flow of the gaseous combustible mixture around the projectile. This molten metal is assumed to mix uniformly and react with the gaseous propellant; thereby enhancing the propellant energy release and altering the predicted thrust-Mach characteristics. This theory predicts at what Mach number the projectile will first experience enhanced thrust and the corresponding velocity-distance profile. Preliminary results are in good agreement

  2. Three-phase hypervelocity projectile launcher

    DOEpatents

    Fugelso, L. Erik; Langner, Gerald C.; Burns, Kerry L.; Albright, James N.

    1994-01-01

    A hypervelocity projectile launcher for use in perforating borehole casings provides improved penetration into the surrounding rock structure. The launcher includes a first cylinder of explosive material that defines an axial air-filled cavity, a second cylinder of explosive material defining an axial frustum-shaped cavity abutting and axially aligned with the first cylinder. A pliant washer is located between and axially aligned with the first and second cylinders. The frustum shaped cavity is lined with a metal liner effective to form a projectile when the first and second cylinders are detonated. The washer forms a unique intermediate projectile in advance of the liner projectile and enables the liner projectile to further penetrate into and fracture the adjacent rock structure.

  3. REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION

    SciTech Connect

    Unknown

    2001-10-12

    The hypothesis to be tested is that the addition of steel or other synthetic fiber and/or high strength, low cost aggregate to strong grouts or concrete will result in a projectile of sufficient strength to produce cracking and spall enough to make its use cost effective for mining. Based on experiments conducted to date, no conclusions can yet be reached. Results of the experiments conducted suggest that reinforcement of a concrete projectile can yield performance that portends cost effective projectile based excavation. It is recognized that the projectile is but one component of the matrix. The electric launch system to be developed in the next phase of the program is the other factor that weighs heavily in the cost effectiveness equation. At this point, however, emerging low cost options for the projectile are very promising.

  4. Passive electro-optical projectiles tracker

    NASA Astrophysics Data System (ADS)

    Agurok, Ilya; Falicoff, Waqidi; Alvarez, Roberto; Shatford, Will

    2012-06-01

    Surveillance, detection, and tracking of multiple high-speed projectiles, particularly bullets, RPGs, and artillery shells, can help military forces immediately locate sources of enemy fire and trigger countermeasures. The traditional techniques for detection and tracing of fast moving objects typically employ various types of radar, which has inherently low resolution for such small objects. Fast moving projectiles are aerodynamically heated up to several hundred degree Kelvin temperatures depending on the speed of a projectile. Thereby, such projectiles radiate in the Mid- Infrared (MWIR) region, where electro-optical resolution is far superior, even to microwave radars. A new passive electro-optical tracker (or PET) uses a two-band IR intensity ratio to obtain a time-varying speed estimate from their time-varying temperatures. Based on an array of time-varying speed data and an array of azimuth/ elevation angles, PET can determines the 3D projectile trajectory and back track it to the source of fire. Various methods are given to determine the vector and range of a projectile, both for clear and for non-homogeneous atmospheric conditions. One approach uses the relative intensity of the image of the projectile on the pixels of a CCD camera to determine the azimuthal angle of trajectory with respect to the ground, and its range. Then by using directions to the tracked projectile (azimuth and elevation angles of the trajectory) and the array of instant projectile speeds, PET determines the distance to the projectile at any point on its tracked trajectory or its predicted trajectory backwards or forwards in time. A second approach uses a least-squares optimization technique over multiple frames based on a triangular representation of the smeared image to yield a real-time trajectory estimate. PET's estimated range accuracy is 0.2 m and the azimuth of the trajectory can be estimated within 0.2°.

  5. Geochemical identification of projectiles in impact rocks

    NASA Astrophysics Data System (ADS)

    Tagle, Roald; Hecht, Lutz

    2006-11-01

    The three major geochemical methods for impactor identification are evaluated with respect to their potential and limitations with regards to the precise detection and identification of meteoritic material in impactites. The identification of a projectile component in impactites can be achieved by determining certain isotopic and elemental ratios in contaminated impactites. The isotopic methods are based on Os and Cr isotopic ratios. Osmium isotopes are highly sensitive for the detection of minute amounts of extraterrestrial components of even <<0.05 wt% in impactites. However, this only holds true for target lithologies with almost no chemical signature of mantle material or young mantle-derived mafic rocks. Furthermore, this method is not currently suitable for the precise identification of the projectile type. The Cr-isotopic method requires the relatively highest projectile contamination (several wt%) in order to detect an extraterrestrial component, but may allow the identification of three different groups of extraterrestrial materials, ordinary chondrites, an enstatite chondrites, and differentiated achondrites. A significant advantage of this method is its independence of the target lithology and post-impact alteration. The use of elemental ratios, including platinum group elements (PGE: Os, Ir, Ru, Pt, Rh, Pd), in combination with Ni and Cr represents a very powerful method for the detection and identification of projectiles in terrestrial and lunar impactites. For most projectile types, this method is almost independent of the target composition, especially if PGE ratios are considered. This holds true even in cases of terrestrial target lithologies with a high component of upper mantle material. The identification of the projectile is achieved by comparison of the "projectile elemental ratio" derived from the slope of the mixing line (target-projectile) with the elemental ratio in the different types of possible projectiles (e.g., chondrites). However

  6. Inclusive breakup of three-fragment weakly bound nuclei

    NASA Astrophysics Data System (ADS)

    Carlson, B. V.; Frederico, T.; Hussein, M. S.

    2017-04-01

    The inclusive breakup of three-fragment projectiles is discussed within a four-body spectator model. Both the elastic breakup and the non-elastic breakup are obtained in a unified framework. Originally developed in the 80's for two-fragment projectiles such as the deuteron, in this paper the theory is successfully generalized to three-fragment projectiles. The expression obtained for the inclusive cross section allows the extraction of the incomplete fusion cross section, and accordingly generalizes the surrogate method to cases such as (t, p) and (t, n) reactions. It is found that two-fragment correlations inside the projectile affect in a conspicuous way the elastic breakup cross section. The inclusive non-elastic breakup cross section is calculated and is found to contain the contribution of a three-body absorption term that is also strongly influenced by the two-fragment correlations. This latter cross section contains the so-called incomplete fusion where more than one compound nuclei are formed. Our theory describes both stable weakly bound three-fragment projectiles and unstable ones such as the Borromean nuclei.

  7. Projectile channeling in chain bundle dusty plasma liquids: Wave excitation and projectile-wave interaction

    SciTech Connect

    Chang, Mei-Chu; Tseng, Yu-Ping; I, Lin

    2011-03-15

    The microscopic channeling dynamics of projectiles in subexcitable chain bundle dusty plasma liquids consisting of long chains of negatively charged dusts suspended in low pressure glow discharges is investigated experimentally using fast video-microscopy. The long distance channeling of the projectile in the channel formed by the surrounding dust chain bundles and the excitation of a narrow wake associated with the elliptical motions of the background dusts are demonstrated. In the high projectile speed regime, the drag force due to wake wave excitation increases with the decreasing projectile speed. The excited wave then leads the slowed down projectile after the projectile speed is decreased below the resonant speed of wave excitation. The wave-projectile interaction causes the increasing projectile drag below the resonant speed and the subsequent oscillation around a descending average level, until the projectile settles down to the equilibrium point. Long distance projectile surfing through the resonant crest trapping by the externally excited large amplitude solitary wave is also demonstrated.

  8. Projectile channeling in chain bundle dusty plasma liquids: Wave excitation and projectile-wave interaction

    NASA Astrophysics Data System (ADS)

    Chang, Mei-Chu; Tseng, Yu-Ping; I, Lin

    2011-03-01

    The microscopic channeling dynamics of projectiles in subexcitable chain bundle dusty plasma liquids consisting of long chains of negatively charged dusts suspended in low pressure glow discharges is investigated experimentally using fast video-microscopy. The long distance channeling of the projectile in the channel formed by the surrounding dust chain bundles and the excitation of a narrow wake associated with the elliptical motions of the background dusts are demonstrated. In the high projectile speed regime, the drag force due to wake wave excitation increases with the decreasing projectile speed. The excited wave then leads the slowed down projectile after the projectile speed is decreased below the resonant speed of wave excitation. The wave-projectile interaction causes the increasing projectile drag below the resonant speed and the subsequent oscillation around a descending average level, until the projectile settles down to the equilibrium point. Long distance projectile surfing through the resonant crest trapping by the externally excited large amplitude solitary wave is also demonstrated.

  9. The Zero-Degree Detector System for Fragmentation Studies

    NASA Technical Reports Server (NTRS)

    Adams, J. H., Jr.; Christl, M. J.; Howell, L. W.; Kuznetsov, E.

    2006-01-01

    The measurement of nuclear fragmentation cross sections requires the detection and identification of individual projectile fragments. If light and heavy fragments are recorded in 'ne same detector, it may be impossible distinguish the signal from the light fragment. To overcome this problem, we have developed the Zero-Degree Detector System. The ZDDS enables the measurement of cross sections for light fragment production by using pixelated detectors to separately measure the signals of each fragment. The system has been used to measure the fragmentation of beams as heavy as Fe at the NASA Space Radiation Laboratory at Brookhaven National Laboratory and the Heavy Ion Medical Accelerator in Chiba, Japan.

  10. Magnetic detector for projectiles in tubes

    NASA Technical Reports Server (NTRS)

    Bogdanoff, D. W.; Knowlen, C.; Murakami, D.; Stonich, I.

    1990-01-01

    A new wall-mounted, magnetic detector is presented for measuring projectile passage times in tubes. The detector has the advantages of simplicity over laser and microwave techniques and has other advantages over the electrical contact wire technique. Representative data are presented. The detector is shown to be very insensitive to strong pressure waves and combustion, but able to detect the passage of the projectile (carrying one or two magnets) clearly. Two modes of operation of the detector are described and the use of these detectors to measure projectile velocities, accelerations, and spin rates is discussed.

  11. Magnetic detector for projectiles in tubes

    NASA Technical Reports Server (NTRS)

    Bogdanoff, D. W.; Knowlen, C.; Murakami, D.; Stonich, I.

    1990-01-01

    A new wall-mounted, magnetic detector is presented for measuring projectile passage times in tubes. The detector has the advantages of simplicity over laser and microwave techniques and has other advantages over the electrical contact wire technique. Representative data are presented. The detector is shown to be very insensitive to strong pressure waves and combustion, but able to detect the passage of the projectile (carrying one or two magnets) clearly. Two modes of operation of the detector are described and the use of these detectors to measure projectile velocities, accelerations, and spin rates is discussed.

  12. CO2 Cluster Ion Beam, an Alternative Projectile for Secondary Ion Mass Spectrometry.

    PubMed

    Tian, Hua; Maciążek, Dawid; Postawa, Zbigniew; Garrison, Barbara J; Winograd, Nicholas

    2016-09-01

    The emergence of argon-based gas cluster ion beams for SIMS experiments opens new possibilities for molecular depth profiling and 3D chemical imaging. These beams generally leave less surface chemical damage and yield mass spectra with reduced fragmentation compared with smaller cluster projectiles. For nanoscale bioimaging applications, however, limited sensitivity due to low ionization probability and technical challenges of beam focusing remain problematic. The use of gas cluster ion beams based upon systems other than argon offer an opportunity to resolve these difficulties. Here we report on the prospects of employing CO2 as a simple alternative to argon. Ionization efficiency, chemical damage, sputter rate, and beam focus are investigated on model compounds using a series of CO2 and Ar cluster projectiles (cluster size 1000-5000) with the same mass. The results show that the two projectiles are very similar in each of these aspects. Computer simulations comparing the impact of Ar2000 and (CO2)2000 on an organic target also confirm that the CO2 molecules in the cluster projectile remain intact, acting as a single particle of m/z 44. The imaging resolution employing CO2 cluster projectiles is improved by more than a factor of two. The advantage of CO2 versus Ar is also related to the increased stability which, in addition, facilitates the operation of the gas cluster ion beams (GCIB) system at lower backing pressure. Graphical Abstract ᅟ.

  13. CO2 Cluster Ion Beam, an Alternative Projectile for Secondary Ion Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Tian, Hua; Maciążek, Dawid; Postawa, Zbigniew; Garrison, Barbara J.; Winograd, Nicholas

    2016-09-01

    The emergence of argon-based gas cluster ion beams for SIMS experiments opens new possibilities for molecular depth profiling and 3D chemical imaging. These beams generally leave less surface chemical damage and yield mass spectra with reduced fragmentation compared with smaller cluster projectiles. For nanoscale bioimaging applications, however, limited sensitivity due to low ionization probability and technical challenges of beam focusing remain problematic. The use of gas cluster ion beams based upon systems other than argon offer an opportunity to resolve these difficulties. Here we report on the prospects of employing CO2 as a simple alternative to argon. Ionization efficiency, chemical damage, sputter rate, and beam focus are investigated on model compounds using a series of CO2 and Ar cluster projectiles (cluster size 1000-5000) with the same mass. The results show that the two projectiles are very similar in each of these aspects. Computer simulations comparing the impact of Ar2000 and (CO2)2000 on an organic target also confirm that the CO2 molecules in the cluster projectile remain intact, acting as a single particle of m/z 44. The imaging resolution employing CO2 cluster projectiles is improved by more than a factor of two. The advantage of CO2 versus Ar is also related to the increased stability which, in addition, facilitates the operation of the gas cluster ion beams (GCIB) system at lower backing pressure.

  14. Penetration of fast projectiles into resistant media: From macroscopic to subatomic projectiles

    NASA Astrophysics Data System (ADS)

    Gaite, José

    2017-09-01

    The penetration of a fast projectile into a resistant medium is a complex process that is suitable for simple modeling, in which basic physical principles can be profitably employed. This study connects two different domains: the fast motion of macroscopic bodies in resistant media and the interaction of charged subatomic particles with matter at high energies, which furnish the two limit cases of the problem of penetrating projectiles of different sizes. These limit cases actually have overlapping applications; for example, in space physics and technology. The intermediate or mesoscopic domain finds application in atom cluster implantation technology. Here it is shown that the penetration of fast nano-projectiles is ruled by a slightly modified Newton's inertial quadratic force, namely, F ∼v 2 - β, where β vanishes as the inverse of projectile diameter. Factors essential to penetration depth are ratio of projectile to medium density and projectile shape.

  15. Fragment Capture Simulation for MANPADS Test Arena Optimization

    DTIC Science & Technology

    2014-03-27

    values cited by Cooper (1996) in Table 27.1. Aerodynamic drag likely has a strong effect on fragment velocities in physical tests. However, using...SUBJECT TERMS MANPADS, survivability, projectile fragments, blast simulation U U U UU 74 Raymond R. Hill (ENS) (937) 255-3636 ext. 7469

  16. Basic Simple Modeling of Balloting Motion of Railgun Projectiles.

    DTIC Science & Technology

    1991-07-01

    force of the armature, and the clearance between the projectile and the barrel is presented. The computation of the axial projectile motion with a...system 3 2 Barrel and projectile package configuration showing propulsion and 6 interacting forces 3 Rail current versus time 9 4 Cocking angle versus...the projectile. It affects the lateral impact of the projectile on the barrel , muzzle jump, intermediate and terminal ballistics and, consequently

  17. REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION

    SciTech Connect

    Mark Machina

    2003-06-06

    The Projectile Based Excavation (ProjEX) program has as its goal, the reduction of energy required for production mining and secondary breakage through the use of a projectile based excavation system. It depends on the development of a low cost family of projectiles that will penetrate and break up different types of ore/rock and a low cost electric launch system. The electric launch system will eliminate the need for high cost propellant considered for similar concepts in the past. This document reports on the program findings through the first two phases. It presents projectile design and experiment data and the preliminary design for electric launch system. Advanced Power Technologies, Inc., now BAE SYSTEMS Advanced Technologies, Inc., was forced to withdraw from the program with the loss of one of our principal mining partners, however, the experiments conducted suggest that the approach is feasible and can be made cost effective.

  18. Hypervelocity High Speed Projectile Imagery and Video

    NASA Technical Reports Server (NTRS)

    Henderson, Donald J.

    2009-01-01

    This DVD contains video showing the results of hypervelocity impact. One is showing a projectile impact on a Kevlar wrapped Aluminum bottle containing 3000 psi gaseous oxygen. One video show animations of a two stage light gas gun.

  19. A Study of the Trajectories of Projectiles.

    ERIC Educational Resources Information Center

    Grant, A. Ruari

    1990-01-01

    Described is a procedure for studying the trajectories of projectiles using ball bearings and aluminum foil. Trajectories were measured with and without the effects of air resistance. Multiflash photography was used to determine the flight paths of all objects. (KR)

  20. A Study of the Trajectories of Projectiles.

    ERIC Educational Resources Information Center

    Grant, A. Ruari

    1990-01-01

    Described is a procedure for studying the trajectories of projectiles using ball bearings and aluminum foil. Trajectories were measured with and without the effects of air resistance. Multiflash photography was used to determine the flight paths of all objects. (KR)

  1. Hypervelocity High Speed Projectile Imagery and Video

    NASA Technical Reports Server (NTRS)

    Henderson, Donald J.

    2009-01-01

    This DVD contains video showing the results of hypervelocity impact. One is showing a projectile impact on a Kevlar wrapped Aluminum bottle containing 3000 psi gaseous oxygen. One video show animations of a two stage light gas gun.

  2. Graphical Method for Determining Projectile Trajectory

    NASA Astrophysics Data System (ADS)

    Moore, J. C.; Baker, J. C.; Franzel, L.; McMahon, D.; Songer, D.

    2010-12-01

    We present a nontrigonometric graphical method for predicting the trajectory of a projectile when the angle and initial velocity are known. Students enrolled in a general education conceptual physics course typically have weak backgrounds in trigonometry, making inaccessible the standard analytical calculation of projectile range. Furthermore, research shows that standard instructional techniques fail to confront student misconceptions about motion in a gravitational field.1-4 We have designed a guided inquiry-based lesson that specifically addresses these misconceptions with minimal mathematics.

  3. A Multipurpose Projectile for Penetrating Urban Targets

    DTIC Science & Technology

    2007-04-01

    experiments were fabricated from Vascomax 300 maraging steel (Allvac, 2006). A photograph of this projectile is shown in Figure 1. Six...The CRH=2 projectiles used in the second set of experiments were also fabricated from Vascomax 300 maraging steel . A photograph of the CRH=2...experiments included steel -reinforcing material (rebar). The rebar, however, was not represented in the Zapotec computational model of the target, nor

  4. Elastic scattering with weakly bound projectiles

    SciTech Connect

    Figueira, J. M.; Abriola, D.; Arazi, A.; Capurro, O. A.; Marti, G. V.; Martinez Heinmann, D.; Pacheco, A. J.; Testoni, J. E.; Barbara, E. de; Fernandez Niello, J. O.; Padron, I.; Gomes, P. R. S.; Lubian, J.

    2007-02-12

    Possible effects of the break-up channel on the elastic scattering threshold anomaly has been investigated. We used the weakly bound 6,7Li nuclei, which is known to undergo break-up, as projectiles in order to study the elastic scattering on a 27Al target. In this contribution we present preliminary results of these experiments, which were analyzed in terms of the Optical Model and compared with other elastic scattering data using weakly bound nuclei as projectile.

  5. The child as a projectile.

    PubMed

    Tibbs, R E; Haines, D E; Parent, A D

    1998-12-01

    Unintentional injury is the leading cause of death in children under the age of fourteen. The majority of these injuries/deaths occur when the child becomes airborne during an accident. The most common mechanisms by which children become airborne are motor vehicle collisions, bicycling accidents, and falls. A head injury is seen in a significant number of children in this setting. This includes injury to the scalp, skull, coverings of the brain, or the brain itself. These injuries are the most common cause of death in children resulting from unintentional injury. Other typical injuries include external bruises and abrasions, extremity fractures, and bruising or bleeding of internal organs. We propose to name this constellation of injuries the projectile child syndrome. This refers to those injuries occurring in infants and children as a result of becoming airborne during the events of an accident. The pattern of injuries seen as related to the anatomy of the child is stressed. A review of the impact to society and guidelines for prevention are presented.

  6. Heavy Ion Fragmentation Experiments at the Bevatron

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.

    1975-01-01

    Fragmentation processes of heavy nuclei in matter using the heavy-ion capability of the Bevatron were studied. The purpose was to obtain the single particle inclusive spectra of secondary nuclei produced at 0 deg by the fragmentation of heavy ion beam projectiles. The process being examined is B+T yields F + anything, where B is the beam nucleus, T is the target nucleus, and F is the detected fragment. The fragments F are isotopically identified by experimental procedures involving magnetic analysis, energy loss and time-of-flight measurements. Attempts were also made to: (1) measure the total and partial production cross section for all isotopes, (2) test the applicability of high-energy multi-particle interaction theory to nuclear fragmentation, (3) apply the cross-section data and fragmentation probabilities to cosmic ray transport theory, and (4) search for systematic behavior of fragment production as a means to improve existing semi-empirical theories of cross sections.

  7. CHRONICALLY EMBEDDED LEAD PROJECTILES IN WILDLIFE: A CASE SERIES INVESTIGATING THE POTENTIAL FOR LEAD TOXICOSIS.

    PubMed

    LaDouceur, Elise E B; Kagan, Rebecca; Scanlan, Michael; Viner, Tabitha

    2015-06-01

    Research has demonstrated that intramuscularly embedded lead in humans and rats may cause direct plumbism, albeit rarely, and has identified risk factors to this end. To the authors' knowledge, this has not been investigated in wildlife, despite a high incidence of embedded lead in these animals secondary to cynegetic activities. Fourteen wildlife cases submitted to the National Fish and Wildlife Forensics Laboratory for cause-of-death determination had chronically embedded lead projectiles that were unrelated to the cause of death. Tissue lead levels were measured in all cases and revealed clinically significant hepatic lead levels in two cases. The results corroborate comparative literature and suggest that embedded lead fragments carry a low risk for direct plumbism, even in the face of risk factors such as fractures, inflammation, and projectile fragmentation. Wildlife morbidity and mortality from embedded lead is more commonly realized secondary to incidental ingestion and ballistic trauma rather than by direct toxicity.

  8. Ballistic Performance of Alimina/S-2 Glass-Reinforced Polymer-Matrix Composite Hybrid Lightweight Armor Against Armor Piercing (AP) and Non-AP Projectiles

    DTIC Science & Technology

    2007-01-01

    Armor Piercing Projectile, Fragment Simulating Projectile, Ceramic/Composite Hybrid Armor, AUTODYN NOMENCLATURE A - Material Specific Constant...Phenomena All the calculations carried out in the present work are done using AUTODYN , a general purpose non-linear dynamics modeling and simulation...software [8]. AUTODYN falls into a group of computer programs known as “hydrocodes”, which are particularly suited for modeling explosion, blast, impact

  9. Target and Projectile: Material Effects on Crater Excavation and Growth

    NASA Technical Reports Server (NTRS)

    Anderson, J. L. B.; Burleson, T.; Cintala, Mark J.

    2010-01-01

    Scaling relationships allow the initial conditions of an impact to be related to the excavation flow and final crater size and have proven useful in understanding the various processes that lead to the formation of a planetary-scale crater. In addition, they can be examined and tested through laboratory experiments in which the initial conditions of the impact are known and ejecta kinematics and final crater morphometry are measured directly. Current scaling relationships are based on a point-source assumption and treat the target material as a continuous medium; however, in planetary-scale impacts, this may not always be the case. Fragments buried in a megaregolith, for instance, could easily approach or exceed the dimensions of the impactor; rubble-pile asteroids could present similar, if not greater, structural complexity. Experiments allow exploration into the effects of target material properties and projectile deformation style on crater excavation and dimensions. This contribution examines two of these properties: (1) the deformation style of the projectile, ductile (aluminum) or brittle (soda-lime glass) and (2) the grain size of the target material, 0.5-1 mm vs. 1-3 mm sand.

  10. Molecular dynamics simulations of sputtering of Langmuir-Blodgett multilayers by keV C60 projectiles

    PubMed Central

    Paruch, R.; Rzeznik, L.; Czerwinski, B.; Garrison, B. J.; Winograd, N.; Postawa, Z.

    2009-01-01

    Coarse-grained molecular dynamics computer simulations are applied to investigate fundamental processes induced by an impact of keV C60 projectile at an organic overlayer composed of long, well-organized linear molecules. The energy transfer pathways, sputtering yields, and the damage induced in the irradiated system, represented by a Langmuir-Blodgett (LB) multilayers composed from molecules of bariated arachidic acid, are investigated as a function of the kinetic energy and impact angle of the projectile and the thickness of the organic system. In particular, the unique challenges of depth profiling through a LB film vs. a more isotropic solid are discussed. The results indicate that the trajectories of projectile fragments and, consequently, the primary energy can be channeled by the geometrical structure of the overlayer. Although, a similar process is known from sputtering of single crystals by atomic projectiles, it has not been anticipated to occur during C60 bombardment due to the large size of the projectile. An open and ordered molecular structure of LB films is responsible for such behavior. Both the extent of damage and the efficiency of sputtering depend on the kinetic energy, the impact angle, and the layer thickness. The results indicate that the best depth profiling conditions can be achieved with low-energy cluster projectiles irradiating the organic overlayer at large off-normal angles. PMID:20174461

  11. Penetration experiments in aluminum 1100 targets using soda-lime glass projectiles

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Cintala, Mark J.; Bernhard, Ronald P.; Cardenas, Frank; Davidson, William E.; Haynes, Gerald; See, Thomas H.; Winkler, Jerry L.

    1995-01-01

    The cratering and penetration behavior of annealed aluminum 1100 targets, with thickness varied from several centimeters to ultra-thin foils less than 1 micrometer thick, were experimentally investigated using 3.2 mm diameter spherical soda-lime glass projectiles at velocities from 1 to 7 km/s. The objective was to establish quantitative, dimensional relationships between initial impact conditions (impact velocity, projectile diameter, and target thickness) and the diameter of the resulting crater or penetration hole. Such dimensional relationships and calibration experiments are needed to extract the diameters and fluxes of hypervelocity particles from space-exposed surfaces and to predict the performance of certain collisional shields. The cratering behavior of aluminum 1100 is fairly well predicted. However, crater depth is modestly deeper for our silicate impactors than the canonical value based on aluminum projectiles and aluminum 6061-T6 targets. The ballistic-limit thickness was also different. These differences attest to the great sensitivity of detailed crater geometry and penetration behavior on the physical properties of both the target and impactor. Each penetration experiment was equipped with a witness plate to monitor the nature of the debris plume emanating from the rear of the target. This plume consists of both projectile fragments and target debris. Both penetration hole and witness-plate spray patterns systematically evolve in response to projectile diameter/target thickness. The relative dimensions of the projectile and target totally dominate the experimental products documented in this report; impact velocity is an important contributor as well to the evolution of penetration holes, but is of subordinate significance for the witness-plate spray patterns.

  12. Computational studies of projectile melt in impact with typical whipple shields

    SciTech Connect

    Rhoades, C.E. Jr.; Alme, M.L.

    1994-12-01

    Protecting space-based structures against the impact of orbital debris is an important problem of current interest. This paper presents scaling results based on simulations with the CALE computer program of aluminum projectile impacting typical aluminum Whipple shields at speeds of 6 to 14 km/s. The objective was to determine the extent of projectile and shield material melting. The approach was to perform a matrix of computer simulations varying the impact speed from 6 to 14 km/s and varying the areal density of the shield from 5 percent to 80 percent of the centerline areal density of the projectile. The projectile radius was fixed at 9.5 mm (mass = 1.27 grams). The melt state of the projectile material and the shield material was assessed after release of the initial shock. The post-release specific energy in the projectile and in the shield was compared with the enthalpy of incipient melt and the enthalpy of complete melt provided in the Hultgren Tables. Material with specific energy greater than the enthalpy of complete melt was assumed to be fully melted. Material with specific energy greater than the enthalpy of incipient melt but less than that of complete melt was assumed to be partially solid and partially melted mixed phase material with no strength. Material with specific energy less than the enthalpy of incipient melt was assumed to be in a solid state with strength. It is likely that this solid material is in a highly fragmented state as a result of the initial shock.

  13. Evaluating simulant materials for understanding cranial backspatter from a ballistic projectile.

    PubMed

    Das, Raj; Collins, Alistair; Verma, Anurag; Fernandez, Justin; Taylor, Michael

    2015-05-01

    In cranial wounds resulting from a gunshot, the study of backspatter patterns can provide information about the actual incidents by linking material to surrounding objects. This study investigates the physics of backspatter from a high-speed projectile impact and evaluates a range of simulant materials using impact tests. Next, we evaluate a mesh-free method called smoothed particle hydrodynamics (SPH) to model the splashing mechanism during backspatter. The study has shown that a projectile impact causes fragmentation at the impact site, while transferring momentum to fragmented particles. The particles travel along the path of least resistance, leading to partial material movement in the reverse direction of the projectile motion causing backspatter. Medium-density fiberboard is a better simulant for a human skull than polycarbonate, and lorica leather is a better simulant for a human skin than natural rubber. SPH is an effective numerical method for modeling the high-speed impact fracture and fragmentations. © 2015 American Academy of Forensic Sciences.

  14. 3D finite element simulations of high velocity projectile impact

    NASA Astrophysics Data System (ADS)

    Ožbolt, Joško; İrhan, Barış; Ruta, Daniela

    2015-09-01

    An explicit three-dimensional (3D) finite element (FE) code is developed for the simulation of high velocity impact and fragmentation events. The rate sensitive microplane material model, which accounts for large deformations and rate effects, is used as a constitutive law. In the code large deformation frictional contact is treated by forward incremental Lagrange multiplier method. To handle highly distorted and damaged elements the approach based on the element deletion is employed. The code is then used in 3D FE simulations of high velocity projectile impact. The results of the numerical simulations are evaluated and compared with experimental results. It is shown that it realistically predicts failure mode and exit velocities for different geometries of plain concrete slab. Moreover, the importance of some relevant parameters, such as contact friction, rate sensitivity, bulk viscosity and deletion criteria are addressed.

  15. Analytical performance study of explosively formed projectiles

    NASA Astrophysics Data System (ADS)

    Hussain, G.; Hameed, A.; Hetherington, J. G.; Malik, A. Q.; Sanaullah, K.

    2013-01-01

    Hydrocode simulations are carried out using Ansys Autodyn (version 11.0) to study the effects of the liner material (mild steel, copper, armco iron, tantalum, and aluminum) on the shape, velocity, traveled distance, pressure, internal energy, temperature, divergence or stability, density, compression, and length-to-diameter ratio of explosively formed projectiles. These parameters are determined at the instants of the maximum as well as stable velocity during the flight towards the target. The results of these parameters present the potential capability of each liner material used to fabricate explosively formed projectiles. An experimental analysis is performed to study the velocity status and the length-to-diameter ratio of explosively formed projectiles.

  16. Flight trajectory simulation of fluid payload projectiles

    SciTech Connect

    Vaughn, H.R.; Wolfe, W.P.; Oberkampf, W.L.

    1985-01-01

    A flight trajectory simulation method has been developed for calculating the six degree of freedom motion of fluid filled projectiles. Numerically calculated internal fluid moments and experimentally known aerodynamic forces and moments are coupled to the projectile motion. Comparisons of predicted results with flight test data of an M483 155mm artillery projectile with a highly viscous payload confirm the accuracy of the simulation. This simulation clearly shows that the flight instability is due to the growth of the nutation component of angular motion caused by the viscous effects of the fluid payload. This simulation procedure, when used in conjunction with the previously developed method for calculating internal fluid moments, allows the designer to examine the effects of various liquid payloads and container geometries on the dynamic behavior of flight vehicles.

  17. The representational dynamics of remembered projectile locations.

    PubMed

    De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Oliveira, Armando Mónica

    2013-12-01

    When people are instructed to locate the vanishing location of a moving target, systematic errors forward in the direction of motion (M-displacement) and downward in the direction of gravity (O-displacement) are found. These phenomena came to be linked with the notion that physical invariants are embedded in the dynamic representations generated by the perceptual system. We explore the nature of these invariants that determine the representational mechanics of projectiles. By manipulating the retention intervals between the target's disappearance and the participant's responses, while measuring both M- and O-displacements, we were able to uncover a representational analogue of the trajectory of a projectile. The outcomes of three experiments revealed that the shape of this trajectory is discontinuous. Although the horizontal component of such trajectory can be accounted for by perceptual and oculomotor factors, its vertical component cannot. Taken together, the outcomes support an internalization of gravity in the visual representation of projectiles.

  18. Ocular Injuries Due to Projectile Impacts

    PubMed Central

    (Michael) Scott, William R.; Lloyd, William C.; Benedict, James V.; Meredith, Roy

    2000-01-01

    An animal model has been developed using enucleated porcine eyes to evaluate ocular trauma. The eyes were pressurized to approximately 18mmHg and mounted in a container with a 10% gelatin mixture. The corneas of sixteen pressurized eyes were impacted by a blunt metal projectile (mass of 2.6gm, 3.5gm or 45.5gm) at velocities of 4.0 to 38.1 m/s. The impacted eyes were evaluated by an ophthalmologist. A numerical classification scheme was used to categorize the severity of the ocular injury. A chi-squared test indicates that the injury level is associated with the kinetic energy (KE) and not the momentum of the projectile. The enucleated eyes began to experience lens dislocations when the KE of the projectile was approximately 0.75Nm, and retinal injuries when the KE was approximately 1.20Nm. PMID:11558084

  19. Ocular injuries due to projectile impacts.

    PubMed

    Scott, W R; Lloyd, W C; Benedict, J V; Meredith, R

    2000-01-01

    An animal model has been developed using enucleated porcine eyes to evaluate ocular trauma. The eyes were pressurized to approximately 18 mmHg and mounted in a container with a 10% gelatin mixture. The corneas of sixteen pressurized eyes were impacted by a blunt metal projectile (mass of 2.6 gm, 3.5 gm or 45.5 gm) at velocities of 4.0 to 38.1 m/s. The impacted eyes were evaluated by an ophthalmologist. A numerical classification scheme was used to categorize the severity of the ocular injury. A chi-squared test indicates that the injury level is associated with the kinetic energy (KE) and not the momentum of the projectile. The enucleated eyes began to experience lens dislocations when the KE of the projectile was approximately 0.75 Nm, and retinal injuries when the KE was approximately 1.20 Nm.

  20. Additional Crime Scenes for Projectile Motion Unit

    NASA Astrophysics Data System (ADS)

    Fullerton, Dan; Bonner, David

    2011-12-01

    Building students' ability to transfer physics fundamentals to real-world applications establishes a deeper understanding of underlying concepts while enhancing student interest. Forensic science offers a great opportunity for students to apply physics to highly engaging, real-world contexts. Integrating these opportunities into inquiry-based problem solving in a team environment provides a terrific backdrop for fostering communication, analysis, and critical thinking skills. One such activity, inspired jointly by the museum exhibit "CSI: The Experience"2 and David Bonner's TPT article "Increasing Student Engagement and Enthusiasm: A Projectile Motion Crime Scene,"3 provides students with three different crime scenes, each requiring an analysis of projectile motion. In this lesson students socially engage in higher-order analysis of two-dimensional projectile motion problems by collecting information from 3-D scale models and collaborating with one another on its interpretation, in addition to diagramming and mathematical analysis typical to problem solving in physics.

  1. Flight trajectory simulation of fluid payload projectiles

    NASA Astrophysics Data System (ADS)

    Vaughn, H. R.; Wolfe, W. P.; Oberkampf, W. L.

    A flight trajectory simulation method has been developed for calculating the six degree-of-freedom motion of fluid filled projectiles. Numerically calculated internal fluid moments and experimentally known aerodynamic forces and moments are coupled to the projectile motion. Comparisons of predicted results with flight test data of an M483 155mm artillery projectile with a highly viscous payload confirm the accuracy of the simulation. This simulation clearly shows that the flight instability is due to the growth of the nutation component of angular motion caused by the viscous effects of the fluid payload. This simulation procedure, when used in conjunction with the previously developed method for calculating internal fluid moments, allows the designer to examine the effects of various liquid payloads and container geometries on the dynamic behavior of flight vehicles.

  2. Human body projectiles implantation in victims of suicide bombings and implications for health and emergency care providers: the 7/7 experience.

    PubMed

    Patel, H D L; Dryden, S; Gupta, A; Stewart, N

    2012-07-01

    On 7 July 2005 four suicide bombings occurred on the London transport systems. In some of the injured survivors, bone fragments were embedded as biological foreign bodies. The aim of this study was to revisit those individuals who had sustained human projectile implantation injuries as a result of the bomb blasts at all scenes, review the process of body parts mapping and DNA identification at the scene, detail the management of such injuries and highlight the protocols that have been put in place for protection against blood borne pathogens. We retrospectively reviewed 12 instances of victims who sustained human body projectile implantation injuries. The Metropolitan Police and forensic scientists identified the human projectiles using DNA profiling and mapped these on the involved carriages and those found outside. All human projectiles included were greater than 3 cm(2). Twelve cases had human projectile implantation injuries. Of these, two died at the scene and ten were treated in hospital. Projectiles were mapped at three of the four bomb blast sites. Our findings show that victims within a 2m radius of the blast had human projectile injuries. Eight of the allogenic bony fragments that were identified in the survivors originated from the suicide bomber. All victims with an open wound should have prophylaxis against hepatitis B and serum stored for appropriate action against HIV and hepatitis C infection. All victims following a suicide bombing should be assumed to have human body projectile implantation injuries with blood products or bony fragments. All immediate care providers should receive prophylaxis against hepatitis B virus and appropriate action should be taken against HIV and hepatitis C infection.

  3. Optical Flow-Based State Estimation for Guided Projectiles

    DTIC Science & Technology

    2015-06-01

    ARL-TR-7321 ● JUNE 2015 US Army Research Laboratory Optical Flow-Based State Estimation for Guided Projectiles by Moshe... Guided Projectiles by Moshe Hamaoui Weapons and Materials Research Directorate, ARL Approved for public release...

  4. Computation of Viscous Flow about Advanced Projectiles.

    DTIC Science & Technology

    1983-09-09

    4.1ZEDZED .<, m’, o ,,, , =, s , AA CFD 83-2 COMPUTATION OF VISCOUS FLOW ABOUT ADVANCED PROJECTILES Final Report t . Joseph L. Steger September 9, 1983 U. S...rF, Ira ASF,; VMSTRI &UTION j\\h I U OTC IFLL COP!94 AA CFD 83-2 COMPUTATION OF VISCOUS FLOW ABOUT ADVANCED PROJECTILES Final Report Joseph L. Steger...segments. First, the grid in the outer region A more critical check of the computational is obtained using an elliptic solver 9 for the results is

  5. Numerical simulations of gun-launched kinetic energy projectiles subjected to asymmetric projectile base pressure

    SciTech Connect

    Rabern, D.A.

    1991-12-31

    Three-dimensional numerical simulations were performed to determine the effect of an asymmetric base pressure on kinetic energy projectiles during launch. A matrix of simulations was performed in two separate launch environments. One launch environment represented a severe lateral load environment, while the other represented a nonsevere lateral load environment based on the gun tube straightness. The orientation of the asymmetric pressure field, its duration, the projectile`s initial position, and the tube straightness were altered to determine the effects of each parameter. The pressure asymmetry translates down the launch tube to exit parameters and is washed out by tube profile. Results from the matrix of simulations are presented.

  6. Fragmentation of ice by low velocity impact

    NASA Technical Reports Server (NTRS)

    Lange, M. A.; Ahrens, T. J.

    1982-01-01

    Low-velocity impact experiments (0.14 to 1 km/s) carried out in polycrystalline water ice targets at 257 and 81 K reveal interactions which are assigned to four fragmentation classes: cratering, erosion, disruption, and total fragmentation. The specific kinetic energies for the transitions between these classes are found to be about one to two orders of magnitude below those for silicate rocks. The mass vs. cumulative number distribution of fragments in the experiments is described by a simple power law, similar to that observed in fragmented rocks both in the laboratory and in nature. The logarithmic slopes of cumulative number vs. fragment weight range from -0.9 to -1.8; they decrease with increasing projectile energy and are approximately independent of target temperature. The shapes of fragments resulting from erosion and disruption of ice targets are found to be significantly less spherical for 257 K targets than for 81 K targets. Fragment sphericity increases with increasing projectile energy at 257 K; however, no similar trend is observed for 81 K ice.

  7. Properties of largest fragment produced by hypervelocity impact of aluminum spheres with thin aluminum sheets

    NASA Technical Reports Server (NTRS)

    Piekutowski, Andrew J.

    1992-01-01

    Results are presented from hypervelocity impact tests in which 1.275 g spheres of 2017-T4 Al alloy were fired at normal incidence at eight thicknesses of 6061-T6 Al alloy sheets, with impact velocity of about 6.7 km/sec; additional data are presented for smaller and larger spheres than these, in the cases of other Al alloy impact bumpers. A large fragment of the projectile is observable at the center of the debris clouds generated upon impact. The velocity of these large fragments decreased continuously with increasing bumper thickness/projectile diameter ratio, from 99 percent to less than 80 percent of impact velocity; there is a linear increase in the size of the central projectile fragment with decreasing shock-induced stress in the projectile.

  8. Observation of different isoscaling behavior between emitted fragments and residues

    NASA Astrophysics Data System (ADS)

    Youngs, M.; McIntosh, A. B.; Hagel, K.; Heilborn, L.; Huang, M.; Jedele, A.; Kohley, Z.; May, L. W.; McCleskey, E.; Zarrella, A.; Yennello, S. J.

    2017-06-01

    The traditional isoscaling technique has been used to analyze all isotopically identified particles from 70Zn+70Zn and 64Zn+64Zn collisions at 35 MeV/u. Two additional techniques, using an energy-averaged ratio and using the data present in the tail of energy spectra, are compared to the traditional method and show similar results. Isoscaling fit parameters α and β are found both globally and for each individual series of constant Z and N. The data are then split up between emitted fragments and projectile-like fragments. Isoscaling values for the two different types of fragments are shown to be different, emphasizing the importance of experimentally distinguishing between projectile-like fragments and emitted fragments in order to achieve accurate isoscaling parameters.

  9. Theory, Guidance, and Flight Control for High Maneuverability Projectiles

    DTIC Science & Technology

    2014-01-01

    flight systems, including nonlinear equations of motion for projectile flight, aerodynamic modeling, actuator dynamics, and measurement modeling, is...distributed around the projectile as well as the numbering scheme and sign convention 4 associated with the trailing edge. The moveable aerodynamic surfaces...deflection sign convention (viewed from projectile base). Individual moveable aerodynamic surfaces combine to yield effective roll, pitch, and yaw

  10. High School Students' Understanding of Projectile Motion Concepts

    ERIC Educational Resources Information Center

    Dilber, Refik; Karaman, Ibrahim; Duzgun, Bahattin

    2009-01-01

    The aim of this study was to investigate the effectiveness of conceptual change-based instruction and traditionally designed physics instruction on students' understanding of projectile motion concepts. Misconceptions related to projectile motion concepts were determined by related literature on this subject. Accordingly, the Projectile Motion…

  11. High School Students' Understanding of Projectile Motion Concepts

    ERIC Educational Resources Information Center

    Dilber, Refik; Karaman, Ibrahim; Duzgun, Bahattin

    2009-01-01

    The aim of this study was to investigate the effectiveness of conceptual change-based instruction and traditionally designed physics instruction on students' understanding of projectile motion concepts. Misconceptions related to projectile motion concepts were determined by related literature on this subject. Accordingly, the Projectile Motion…

  12. Speciation of sodium nitrate and sodium nitrite using kiloelectronvolt energy atomic and polyatomic and megaelectronvolt energy atomic projectiles with secondary ion mass spectrometry

    PubMed

    Van Stipdonk MJ; Justes; Force; Schweikert

    2000-06-01

    The negative-ion mass spectra produced by kiloelectronvolt energy (CsI)nCs+ (n = 0-2) and megaelectronvolt energy 252Cf fission fragment projectile impacts on NaNO3 and NaNO2 were collected and compared. The mass spectra generated by impacts of the kiloelectronvolt polyatomic primary ions on NaNO3 were markedly different from those derived from the fission fragment impacts, featuring higher relative intensities of nitrate (NO3-) specific secondary ions (those that reflect the sample stoichiometry). The most prominent secondary ion (SI) peaks produced from NaNO3 by the kiloelectronvolt energy projectiles were NO3- and Na(NO3)2-, both of which relate directly back to the chemical composition of the staring material. Likewise, the most prominent peaks produced by the kiloelectronvolt energy polyatomic projectile impacts on NaNO2 were NO2- and Na(NO2)2-. The fission fragment projectiles produced SI spectra from NaNO3 that were dominated by signals characteristic more of NaNO2, indicating that the megaelectronvolt energy ions induce considerable degradation of the nitrate solid. In addition, the fission fragment projectile produced relative negative SI intensity distributions that are remarkably similar to those reported in earlier studies of the use of laser desorption to produce SI signals from NaNO3. Of the projectiles examined in this study, the 20 keV (CsI)Cs+ projectile generated negative-ion mass spectra that best differentiated NaNO3 and NaNO2, primarily by producing a base peak in the NaNO3 spectrum that was unambiguously representative of the original sample stoichiometry.

  13. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    ERIC Educational Resources Information Center

    Planinsic, Gorazd; Likar, Andrej

    2012-01-01

    The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

  14. Maximizing the Range of a Projectile.

    ERIC Educational Resources Information Center

    Brown, Ronald A.

    1992-01-01

    Discusses solutions to the problem of maximizing the range of a projectile. Presents three references that solve the problem with and without the use of calculus. Offers a fourth solution suitable for introductory physics courses that relies more on trigonometry and the geometry of the problem. (MDH)

  15. Batch Computed Tomography Analysis of Projectiles

    DTIC Science & Technology

    2016-05-01

    error calculation. Projectiles are then grouped together according to the similarity of their components. Also discussed is graphical- cluster analysis...ballistic, armor, grouping, clustering 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF...Fig. 10 Graphical structure of 15 clusters of the jacket/core radii profiles with plots of the profiles contained within each cluster . The size of

  16. Ballistics projectile image analysis for firearm identification.

    PubMed

    Li, Dongguang

    2006-10-01

    This paper is based upon the observation that, when a bullet is fired, it creates characteristic markings on the cartridge case and projectile. From these markings, over 30 different features can be distinguished, which, in combination, produce a "fingerprint" for a firearm. By analyzing features within such a set of firearm fingerprints, it will be possible to identify not only the type and model of a firearm, but also each and every individual weapon just as effectively as human fingerprint identification. A new analytic system based on the fast Fourier transform for identifying projectile specimens by the line-scan imaging technique is proposed in this paper. This paper develops optical, photonic, and mechanical techniques to map the topography of the surfaces of forensic projectiles for the purpose of identification. Experiments discussed in this paper are performed on images acquired from 16 various weapons. Experimental results show that the proposed system can be used for firearm identification efficiently and precisely through digitizing and analyzing the fired projectiles specimens.

  17. Ballistic Similitude Design Criterion for artillery projectiles

    SciTech Connect

    Hodapp, A.E. Jr.; LaFarge, R.A.

    1982-01-01

    A Sandia National Laboratories analytically derived and experimentally verified Ballistic Similitude Design Criterion (BSDC) is described herein. This BSDC, for projectiles of identical external shape, was used to guide development of the M753 8-inch Artillery Fired Atomic Projectile (AFAP) as a ballistically similar counterpart to the M650 8-inch rocket assisted conventional high explosive (HE) projectile. As required for similitude, the mean impact point of the M753 falls within the precision error region about the M650 mean impact point when the M753 is fired with standard equipment and M650 firing data. The M753 is the first AFAP that has been developed and proven to be ballistically similar to a conventional HE projectile. Since gross internal differences between the M753 and M650 make complete duplication of M650 mass properties impossible, a BSDC was required to identify which properties were necessary to match in order to achieve similitude. The effects of internal vibrating bodies, rotating band characteristics, muzzle exit conditions, the basic mass properties, and the effects of mass asymmetries were all considered in the development of the BSDC.

  18. Teaching Projectile Motion to Eliminate Misconceptions

    ERIC Educational Resources Information Center

    Prescott, Anne; Mitchelmore, Michael

    2005-01-01

    Student misconceptions of projectile motion are well documented, but their effect on the teaching and learning of the mathematics of motion under gravity has not been investigated. An experimental unit was designed that was intended to confront and eliminate misconceptions in senior secondary school students. The approach was found to be…

  19. Trajectory And Heating Of A Hypervelocity Projectile

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.

    1992-01-01

    Technical paper presents derivation of approximate, closed-form equation for relationship between velocity of projectile and density of atmosphere. Results of calculations based on approximate equation agree well with results from numerical integrations of exact equations of motion. Comparisons of results presented in series of graphs.

  20. Bulldozing Your Way Through Projectile Motion.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1983-01-01

    Presents two models and two demonstrations targeted at student understanding of projectile motion as the sum of two independent, perpendicular vectors. Describes materials required, construction, and procedures used. Includes a discussion of teaching points appropriate to each demonstration or model. (JM)

  1. Trajectory And Heating Of A Hypervelocity Projectile

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.

    1992-01-01

    Technical paper presents derivation of approximate, closed-form equation for relationship between velocity of projectile and density of atmosphere. Results of calculations based on approximate equation agree well with results from numerical integrations of exact equations of motion. Comparisons of results presented in series of graphs.

  2. Bulldozing Your Way Through Projectile Motion.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1983-01-01

    Presents two models and two demonstrations targeted at student understanding of projectile motion as the sum of two independent, perpendicular vectors. Describes materials required, construction, and procedures used. Includes a discussion of teaching points appropriate to each demonstration or model. (JM)

  3. An Inexpensive Mechanical Model for Projectile Motion

    ERIC Educational Resources Information Center

    Kagan, David

    2011-01-01

    As experienced physicists, we see the beauty and simplicity of projectile motion. It is merely the superposition of uniform linear motion along the direction of the initial velocity vector and the downward motion due to the constant acceleration of gravity. We see the kinematic equations as just the mathematical machinery to perform the…

  4. Excalibur Precision 155mm Projectiles (Excalibur)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-366 Excalibur Precision 155mm Projectiles (Excalibur) As of FY 2017 President’s Budget...Program Office Estimate RDT&E - Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be

  5. Launching a Projectile into Deep Space

    ERIC Educational Resources Information Center

    Maruszewski, Richard F., Jr.

    2004-01-01

    As part of the discussion about Newton's work in a history of mathematics course, one of the presentations calculated the amount of energy necessary to send a projectile into deep space. Afterwards, the students asked for a recalculation with two changes: First the launch under study consisted of a single stage, but the students desired to…

  6. An Inexpensive Mechanical Model for Projectile Motion

    ERIC Educational Resources Information Center

    Kagan, David

    2011-01-01

    As experienced physicists, we see the beauty and simplicity of projectile motion. It is merely the superposition of uniform linear motion along the direction of the initial velocity vector and the downward motion due to the constant acceleration of gravity. We see the kinematic equations as just the mathematical machinery to perform the…

  7. Launching a Projectile into Deep Space

    ERIC Educational Resources Information Center

    Maruszewski, Richard F., Jr.

    2004-01-01

    As part of the discussion about Newton's work in a history of mathematics course, one of the presentations calculated the amount of energy necessary to send a projectile into deep space. Afterwards, the students asked for a recalculation with two changes: First the launch under study consisted of a single stage, but the students desired to…

  8. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    ERIC Educational Resources Information Center

    Planinsic, Gorazd; Likar, Andrej

    2012-01-01

    The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

  9. Method of and apparatus for accelerating a projectile

    DOEpatents

    Goldstein, Yeshayahu S. A.; Tidman, Derek A.

    1986-01-01

    A projectile is accelerated along a confined path by supplying a pulsed high pressure, high velocity plasma jet to the rear of the projectile as the projectile traverses the path. The jet enters the confined path at a non-zero angle relative to the projectile path. The pulse is derived from a dielectric capillary tube having an interior wall from which plasma forming material is ablated in response to a discharge voltage. The projectile can be accelerated in response to the kinetic energy in the plasma jet or in response to a pressure increase of gases in the confined path resulting from the heat added to the gases by the plasma.

  10. Apparatus and method for the acceleration of projectiles to hypervelocities

    DOEpatents

    Hertzberg, Abraham; Bruckner, Adam P.; Bogdanoff, David W.

    1990-01-01

    A projectile is initially accelerated to a supersonic velocity and then injected into a launch tube filled with a gaseous propellant. The projectile outer surface and launch tube inner surface form a ramjet having a diffuser, a combustion chamber and a nozzle. A catalytic coated flame holder projecting from the projectile ignites the gaseous propellant in the combustion chamber thereby accelerating the projectile in a subsonic combustion mode zone. The projectile then enters an overdriven detonation wave launch tube zone wherein further projectile acceleration is achieved by a formed, controlled overdriven detonation wave capable of igniting the gaseous propellant in the combustion chamber. Ultrahigh velocity projectile accelerations are achieved in a launch tube layered detonation zone having an inner sleeve filled with hydrogen gas. An explosive, which is disposed in the annular zone between the inner sleeve and the launch tube, explodes responsive to an impinging shock wave emanating from the diffuser of the accelerating projectile thereby forcing the inner sleeve inward and imparting an acceleration to the projectile. For applications wherein solid or liquid high explosives are employed, the explosion thereof forces the inner sleeve inward, forming a throat behind the projectile. This throat chokes flow behind, thereby imparting an acceleration to the projectile.

  11. First-principles molecular dynamics simulations of the interaction of ionic projectiles with liquid water and ice

    NASA Astrophysics Data System (ADS)

    Kohanoff, Jorge; Artacho, Emilio

    2008-12-01

    We first present results of first-principles molecular dynamics simulations of the passage of Carbon projectiles through water in the liquid state in the adiabatic regime, where the electrons are always in the instantaneous ground state. We study a range of projectile velocities up to the estimated upper limit for the adiabatic approximation and analyze the different types of collision events. We show that for high projectile velocities collisions are mostly binary, but at lower velocities most trajectories exhibit a continuous energy loss to the medium, which cannot be properly described as a sequence of independent binary collisions. For the slowest projectiles we observe the formation of new chemical species such as hydronium, H5O2+ and hydrogen peroxide. When C-atoms are completely stopped, then we also see the formation of species like formic acid. By analyzing the generation of secondary fragments, we observe that these are mostly hyperthermal and their spatial rate of generation increases with decreasing projectile energy. The two most numerous species are H and OH. In the second part we study, via electronic dynamics with fixed nuclei, the opposite regime of very fast protons producing only electronic excitation in ice, under channeling conditions. We observe the existence of a threshold velocity for electronic excitation of about 0.2 a.u. By monitoring the rate of increase of the total energy, we calculate the electronic stopping power.

  12. Investigating the Sources and Timing of Projectiles Striking the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Joy, K. H.; Kring, D. A.; Zolensky, M. E.; McKay, D. S.; Ross, D. K.

    2011-01-01

    The lunar surface is exposed to bombardment by asteroids, comets, and debris from them. Surviving fragments of those projectiles in the lunar regolith provide a direct measure of the sources of exogenous material delivered to the Moon. Con-straining the temporal flux of their delivery will directly address key questions about the bombardment history of the inner Solar System. Regolith breccias, which are consolidated samples of the lunar regolith, were closed to further impact processing at the time they were assembled into rocks [1]. They are, therefore, time capsules of impact bombardment at different times through lunar history. Here we investigate the impact archive preserved in the Apollo 16 regolith breccias and compare this record to evidence of projectile species in other lunar samples.

  13. Occupational deaths due to penetrating chest injuries from sledgehammer fragments: two case reports and review of the literature.

    PubMed

    Smith, Michael E; Zumwalt, Ross

    2004-03-01

    Occupational deaths due to projectiles from hand tools are rare. We report 2 unusual cases of individuals killed by metallic projectiles produced by the fragmentation of the head of a sledgehammer. At initial examination, these wounds appear similar to atypical gunshot or stab wounds. Proper evaluation requires radiographic examination, scene correlation, and, when possible, comparison of metallic fragments retrieved at autopsy and tools from the scene.

  14. Initiation of Gaseous Detonation by Conical Projectiles

    NASA Astrophysics Data System (ADS)

    Verreault, Jimmy

    Initiation and stabilization of detonation by hypersonic conical projectiles launched into combustible gas mixtures is investigated. This phenomenon must be understood for the design and optimization of specific hypersonic propulsion devices, such as the oblique detonation wave engine and the ram accelerator. The criteria for detonation initiation by a projectile is also related to fundamental aspects of detonation research, such as the requirement for direct initiation of a detonation by a blast wave. Experimental results of this problem also offer useful references for validation of numerical and theoretical modeling. Projectiles with cone half angles varying from 15° to 60° were launched into stoichiometric mixtures of hydrogen/oxygen with 70% argon dilution at initial pressures between 10 and 200 kPa. The projectiles were launched from a combustion-driven gas gun at velocities up to 2.2 km/s (corresponding to 133% of the Chapman Jouguet velocity). Pictures of the flowfields generated by the projectiles were taken via Schlieren photography. Five combustion regimes were observed about the projectile ranging from prompt and delayed oblique detonation wave formation, combustion instabilities, a wave splitting, and an inert shock wave. Two types of transition from the prompt oblique detonation wave regime to the inert shock regime were observed. The first (the delayed oblique detonation wave regime) showed an inert shock attached to the tip of the projectile followed by a sharp kink at the onset of an oblique detonation wave; this regime occurred by decreasing the cone angle at high mixture pressures. The second (the combustion instabilities regime) exhibited large density gradients due to combustion ignition and quenching phenomena; this regime occurred by decreasing the mixture pressure at large cone angles. A number of theoretical models were considered to predict critical conditions for the initiation of oblique detonations. The Lee-Vasiljev model agreed

  15. Nuclear fragmentation and the number of particle tracks in tissue.

    PubMed

    Ponomarev, A L; Cucinotta, F A

    2006-01-01

    For high energy nuclei, the number of particle tracks per cell is modified by local nuclear reactions that occur, with large fluctuations expected for heavy ion tracks. Cells near the interaction site of a reaction will experience a much higher number of tracks than estimated by the average fluence. Two types of reaction products are possible and occur in coincidence; projectile fragments, which generally have smaller charge and similar velocity to that of the projectile, and target fragments, which are produced from the fragmentation of the nuclei of water atoms or other cellular constituents with low velocity. In order to understand the role of fragmentation in biological damage a new model of human tissue irradiated by heavy ions was developed. A box of the tissue is modelled with periodic boundary conditions imposed, which extrapolates the technique to macroscopic volumes of tissue. The cross sections for projectile and target fragmentation products are taken from the quantum multiple scattering fragmentation code previously developed at NASA Johnson Space Center. Statistics of fragmentation pathways occurring in a cell monolayer, as well as in a small volume of 10 x 10 x 10 cells are given. A discussion on approaches to extend the model to describe spatial distributions of inactivated or other cell damage types, as well as highly organised tissues of multiple cell types, is presented.

  16. Energy distributions of atomic and molecular ions sputtered by C 60+ projectiles

    NASA Astrophysics Data System (ADS)

    Delcorte, A.; Poleunis, C.; Bertrand, P.

    2006-07-01

    In the process of investigating the interaction of fullerene projectiles with adsorbed organic layers, we measured the kinetic energy distributions (KEDs) of fragment and parent ions sputtered from an overlayer of polystyrene (PS) oligomers cast on silver under 15 keV C 60+ bombardment. These measurements have been conducted using our TRIFT™ spectrometer, recently equipped with the C 60+ source developed by Ionoptika, Ltd. For atomic ions, the intensity corresponding to the high energy tail decreases in the following order: C +( E-0.4) > H +( E-1.5) > Ag +( E-3.5). In particular, the distribution of Ag + is not broader than those of Ag 2+ and Ag 3+ clusters, in sharp contrast with 15 keV Ga + bombardment. On the other hand, molecular ions (fragments and parent-like species) exhibit a significantly wider distribution using C 60+ instead of Ga + as primary ions. For instance, the KED of Ag-cationized PS oligomers resembles that of Ag + and Ag n+ clusters. A specific feature of fullerene projectiles is that they induce the direct desorption of positively charged oligomers, without the need of a cationizing metal atom. The energy spectrum of these PS + ions is significantly narrower then that of Ag-cationized oligomers. For characteristic fragments of PS, such as C 7H 7+ and C 15H 13+ and polycyclic fragments, such as C 9H 7+ and C 14H 10+, the high energy decay is steep ( E-4 - E-8). In addition, reorganized ions generally show more pronounced high energy tails than characteristic ions, similar to the case of monoatomic ion bombardment. This observation is consistent with the higher excitation energy needed for their formation. Finally, the fraction of hydrocarbon ions formed in the gas phase via unimolecular dissociation of larger species is slightly larger with gallium than with fullerene projectiles.

  17. A Unique Presentation of an Intracranial Abscess Secondary to Retained Projectile after Debridement with Dural Closure

    PubMed Central

    Awuor, Victor

    2017-01-01

    Patients with penetrating head trauma with retained projectiles develop intracranial abscesses as a common complication. The most common presentation is a suddenly worsening headache. The most common pathogen identified is staphylococcus. Outcomes are related to adherence of Matson’s tenets. This case study details the presentation of a 19-year-old patient that presented to the neurological surgery clinic without neurologic deficits. Further questioning revealed complaints of intermittent diffuse headaches with bilateral upper extremity shock-like sensation for two weeks. Eight weeks prior he had undergone right craniotomy, after a gunshot wound, for debridement and watertight dural closure. The patient denied symptoms of fever, chills, nausea, vomiting, diarrhea, or seizure. The patient presented with a noncontrast head computed tomography (CT) which revealed retained projectile fragments without clear evidence of abscess. On physical exam, the patient was without any neurological deficit. Laboratory investigation revealed normal white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and negative blood cultures. Head CT with contrast revealed a large intracerebral abscess adjacent to the thalamus. The patient was taken to the operating room for repeat craniotomy with resection of the abscess and removal of the intracranial projectile fragments. Post-operatively, the patient remained neurology intact. Intraoperative cultures were not significant for the growth of any bacteria. In eight weeks time, the patient returned to his employment and his baseline level of activity. This case underscores the importance of thorough assessment in patients with retained intracranial projectiles as well as the need to routine follow-up. The unique presentation of this patient prompted further investigation which elucidated a lesion which correlated to his symptoms although laboratory assessment was without abnormality. PMID:28690961

  18. A Unique Presentation of an Intracranial Abscess Secondary to Retained Projectile after Debridement with Dural Closure.

    PubMed

    Milton, Jason; Awuor, Victor

    2017-06-09

    Patients with penetrating head trauma with retained projectiles develop intracranial abscesses as a common complication. The most common presentation is a suddenly worsening headache. The most common pathogen identified is staphylococcus. Outcomes are related to adherence of Matson's tenets. This case study details the presentation of a 19-year-old patient that presented to the neurological surgery clinic without neurologic deficits. Further questioning revealed complaints of intermittent diffuse headaches with bilateral upper extremity shock-like sensation for two weeks. Eight weeks prior he had undergone right craniotomy, after a gunshot wound, for debridement and watertight dural closure. The patient denied symptoms of fever, chills, nausea, vomiting, diarrhea, or seizure. The patient presented with a noncontrast head computed tomography (CT) which revealed retained projectile fragments without clear evidence of abscess. On physical exam, the patient was without any neurological deficit. Laboratory investigation revealed normal white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and negative blood cultures. Head CT with contrast revealed a large intracerebral abscess adjacent to the thalamus. The patient was taken to the operating room for repeat craniotomy with resection of the abscess and removal of the intracranial projectile fragments. Post-operatively, the patient remained neurology intact. Intraoperative cultures were not significant for the growth of any bacteria. In eight weeks time, the patient returned to his employment and his baseline level of activity. This case underscores the importance of thorough assessment in patients with retained intracranial projectiles as well as the need to routine follow-up. The unique presentation of this patient prompted further investigation which elucidated a lesion which correlated to his symptoms although laboratory assessment was without abnormality.

  19. X-ray tomography to measure size of fragments from penetration of high-velocity tungsten rods

    NASA Astrophysics Data System (ADS)

    Stone, Zach; Bless, Stephan; Tolman, John; McDonald, Jason; Levinson, Scott; Hanna, R.

    2012-03-01

    Behind-armor debris that results from tungsten rods penetrating armor steel at 2 km/s was studied by analysis of recovered fragments. Fragment recovery was by means of particle board. Individual fragments were analyzed by x-ray tomography, which provides information for fragment identification, mass, shape, and penetration down to masses of a few milligrams. The experiments were complemented by AUTODYN and EPIC calculations. Fragments were steel or tungsten generated from the channel or from the breakout through the target rear surface. Channel fragment motions were well described by Tate theory. Breakout fragments had velocities from the projectile remnant to the channel velocity, apparently depending on where in the projectile a fragment originated. The fragment size distribution was extremely broad and did not correlate well with simple uniform-fragment-size models.

  20. X-Ray Tomography to Measure Size of Fragments from Penetration of High-Velocity Tungsten Rods

    NASA Astrophysics Data System (ADS)

    Stone, Zach; Hanna, Romy; Bless, Stephan; Levinson, Scott; InstituteAdvanced Technology Collaboration; Department of Geological Sciences-UT Austin Collaboration

    2011-06-01

    Behind-armor debris that results from tungsten rods penetrating armor steel at 2 km/s was studied by analysis of recovered fragments. Fragment recovery was by means of particleboard. Individual fragments were analyzed by x-ray tomography, which provides information for fragment identification, mass, shape, and penetration down to masses of a few milligrams. The experiments were complemented by AUTODYN SPH calculations to provide the exit velocity and the strain rate at the time of particle formation. There were four types of fragments: steel or tungsten, and generated from the channel or from the breakout through the target rear surface. Channel fragment motions were well described by Tate theory. Breakout fragments had velocities from the projectile remnant to the channel velocity, apparently depending on where in the projectile a fragment originated. The fragment size distribution was extremely broad and did not correlate well with simple uniform-fragment-size models, e.g., Grady Kipp.

  1. Fragmentation of relativistic nuclei in a hydrogen target

    SciTech Connect

    Knott, C.N.

    1993-04-01

    Beams of relativistic Ne, Mg, S, Ar, Ca, Cr, Fe and Ni with energies between 400 and 900 MeV/n accelerated at the LBL Bevalac have been studied fragmenting in a liquid hydrogen target. The detectors used are capable of determining both the mass and charge of the leading fragment produced in these interactions. The most striking result from the measured elemental cross sections is the well defined differences in yields as a function of the neutron excess in the projectile nucleus. Projectiles with no neutron excess, such as {sup 40}Ca {sup 36}Ar and {sup 32}S, show a strong odd-even dependence of the partial cross sections. However, those with a neutron excess, such as {sup 40}Ar, {sup 26}Mg and {sup 22}Ne have this effect completely suppressed, with the cross sections smoothly decreasing with decreasing fragment charge. The magnitudes of the odd-even effects show a significant energy dependence, whereas the yields for the projectiles with neutron excesses are relatively independent of the energy. The heavier {sup 52}Cr, {sup 56}Fe and {sup 58}Ni projectiles all have neutron excesses and the partial cross sections show the same relatively smooth decrease with decreasing fragment charge. A preliminary analytical representation of these features will be presented.

  2. Radio Frequency Fragment Separator at NSCL

    NASA Astrophysics Data System (ADS)

    Bazin, D.; Andreev, V.; Becerril, A.; Doléans, M.; Mantica, P. F.; Ottarson, J.; Schatz, H.; Stoker, J. B.; Vincent, J.

    2009-07-01

    A new device has been designed and built at NSCL which provides additional filtering of radioactive beams produced via projectile fragmentation. The Radio Frequency Fragment Separator (RFFS) uses the time micro structure of the beams accelerated by the cyclotrons to deflect particles according to their time-of-flight, in effect producing a phase filtering. The transverse RF (Radio Frequency) electric field of the RFFS has superior filtering performance compared to other electrostatic devices, such as Wien filters. Such filtering is critical for radioactive beams produced on the neutron-deficient side of the valley of stability, where strong contamination occurs at intermediate energies from 50 to 200 MeV/u.

  3. Electromagnetic force, jerk, and electric gun projectiles

    NASA Astrophysics Data System (ADS)

    Zowarka, R. C.; Kajs, J. P.

    1993-01-01

    The electromagnetic forces that affect the mechanical loading of railgun projectiles are examined. Jerk is defined in terms of electromagnetic parameters, and examples of stress amplification with increasing acceleration rate are given. Maps of ideal performance are presented on the basis of idealized current waveforms modified to observe railgun and projectile structural limitations. In a railgun system driven with inductive stores, the opening switch function has to be modified to produce the desired acceleration profile. A modification to explosive opening switches which allows the control of the developed voltage of the switch and therefore the rate of rise of current in the railgun is described. Experimental data demonstrating this capability on the Balcones 60 MJ power supply are presented.

  4. Modeling projectile impact onto prestressed ceramic targets

    NASA Astrophysics Data System (ADS)

    Holmquist, T. J.; Johnson, G. R.

    2003-09-01

    This work presents computed results for the responses of ceramic targets, with and without prestress, subjected to projectile impact. Also presented is a computational technique to include prestress. Ceramic materials have been considered for armor applications for many years because of their high strength and low density. Many researchers have demonstrated that providing confinement enhances the ballistic performance of ceramic targets. More recently, prestressing the ceramic is being considered as an additional enhancement technique. This work investigates the effect of prestressing the ceramic for both thin and thick target configurations subjected to projectile impact. In all cases the targets with ceramic prestress provided enhanced ballistic performance. The computed results indicate that prestressed ceramic reduces and/or delays failure, resulting in improved ceramic performance and ballistic efficiency.

  5. The aerodynamics of some guided projectiles

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1984-01-01

    Some characteristic projectile shapes are considered with various added components intended to provide lift, stability, and control. The intent of the additions is to provide some means for altering the normal ballistic flight path of a projectile for various purposes such as: achieving greater accuracy at the impact point, selecting alternate impact points, extending range, improved evasion, and so on. The configurations presented illustrate the effects of a flare, wings, and tails for providing stability and lift, and the effects of aft-tails, a close-coupled flap, and all-moving forward wings for control. The relative merits of the various configurations, all of which provided for flight path alterations, are discussed.

  6. Projectile Density Effects on Shield Performance

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L.; Lear, Dana; Lyons, Frankel; Davis, Alan

    2009-01-01

    In the past, the orbital debris environment was modeled as consisting entirely of aluminum particles. As a consequence, most of the impact test database on spacecraft micro-meteoroid and orbital debris (MMOD) shields, and the resulting ballistic limit equations used to predict shielding performance, has been based on using aluminum projectiles. Recently, data has been collected from returned spacecraft materials and other sources that indicate higher and lower density components of orbital debris also exist. New orbital debris environment models such as ORDEM2008 provide predictions of the fraction of orbital debris in various density bins (high = 7.9 g/cu cm, medium = 2.8 g/cu cm, and low = 0.9-1.1 g/cu cm). This paper describes impact tests to assess the effects of projectile density on the performance capabilities of typical MMOD shields. Updates to shield ballistic limit equations are provided based on results of tests and analysis.

  7. The aerodynamics of some guided projectiles

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1984-01-01

    Some characteristic projectile shapes are considered with various added components intended to provide lift, stability, and control. The intent of the additions is to provide some means for altering the normal ballistic flight path of a projectile for various purposes such as: achieving greater accuracy at the impact point, selecting alternate impact points, extending range, improved evasion, and so on. The configurations presented illustrate the effects of a flare, wings, and tails for providing stability and lift, and the effects of aft-tails, a close-coupled flap, and all-moving forward wings for control. The relative merits of the various configurations, all of which provided for flight path alterations are discussed.

  8. An Inexpensive Mechanical Model for Projectile Motion

    NASA Astrophysics Data System (ADS)

    Kagan, David

    2011-05-01

    As experienced physicists, we see the beauty and simplicity of projectile motion. It is merely the superposition of uniform linear motion along the direction of the initial velocity vector and the downward motion due to the constant acceleration of gravity. We see the kinematic equations as just the mathematical machinery to perform the calculations. What do our students see? Likely, most see no deeper than the operational understanding needed to use the kinematic equations. Described below is a device (shown in Fig. 1) that illustrates the physicist's view of projectile motion. It can be used as a classroom demonstration or as a project for your students, and it costs less than three dollars to make.

  9. Electrical parameters of projectile stun guns.

    PubMed

    McDaniel, Wayne C; Benwell, Andrew; Kovaleski, Scott

    2009-01-01

    Projectile stun guns have been developed as less-lethal devices that law enforcement officers can use to control potentially violent subjects, as an alternative to using firearms. These devices apply high voltage, low amperage, pulsatile electric shocks to the subject, which causes involuntary skeletal muscle contraction and renders the subject unable to further resist. In field use of these devices, the electric shock is often applied to the thorax, which raises the issue of cardiac safety of these devices. An important determinant of the cardiac safety of these devices is their electrical output. Here the outputs of three commercially available projectile stun guns were evaluated with a resistive load and in a human-sized animal model (a 72 kg pig).

  10. Reliability Estimates for Flawed Mortar Projectile Bodies

    DTIC Science & Technology

    2009-12-01

    Monte Carlo simulations were used to estimate reliability. Measured distributions of wall thickness, defect rate, material strength, and applied loads...element analysis Case study Monte Carlo simulation a b s t r a c t The Army routinely screens mortar projectiles for defects in safety-critical parts. In...of a safety-critical failure. Limit state functions and Monte Carlo simulations were used to estimate reliability. Measured distributions of wall

  11. Energy loss of hydrogen projectiles in gases

    SciTech Connect

    Schiefermueller, A.; Golser, R.; Stohl, R.; Semrad, D. )

    1993-12-01

    The stopping cross sections of H[sub 2], D[sub 2], He, and Ne for hydrogen projectiles in the energy range 3--20 keV per nucleon have been measured by time of flight. We compare our experimental result to the sum of the individual contributions due to excitation and ionization of the target and of the projectile, respectively, and due to charge exchange, using published cross-section data. Satisfactory agreement is found only for the He target and only at moderate projectile velocities, whereas for H[sub 2] and D[sub 2] the calculated values are about 30% too low. A Monte Carlo program allows us to simulate the measured time-of-flight spectra and to explain minor trends in the experimental data: for increased Ne gas pressure, an increased specific energy loss has been found that can be traced to different regions of impact parameters selected in our transmission geometry. This also explains, in part, the increased specific energy loss for deuterons compared to protons of equal velocity that is most evident for Ne. In contrast, a decrease of the specific energy loss with increasing pressure for He may be explained by impurities in the target gas. If we correct for the effect of impurities, the stopping cross section of He at 4 keV per nucleon is slightly smaller (0.60[times]10[sup [minus]15] eV cm[sup 2]) than published earlier (0.72[times]10[sup [minus]15] eV cm[sup 2]) and depends on the 3.8th power of projectile velocity.

  12. Migrating intrathecal high-velocity projectile.

    PubMed

    Chan, Yuen T C; Al-Mahfoudh, Rafid; Thennakon, Shymica; Eldridge, Paul; Pillay, Robin

    2015-01-01

    Bullet injuries to the spine can cause significant damage to surrounding tissues and cause serious neurological sequelae. These cases are often associated with neurological deficits. We present a case of a gunshot injury to the spine with a migrating intrathecal bullet which subsequently developed neurological deficits. Initially, the patient did not exhibit any neurological symptoms when first assessed soon after the injury. Subsequently, the patient developed signs of neurological injury as a result of spinal intrathecal migration of the projectile.

  13. Field Artillery Projectile Pallet (FAPP) Prototype

    DTIC Science & Technology

    1993-10-01

    impact the steel plate . There was no additional damage to the pallet other than scratches and abrasions. The loose cargo test was conducted in...accordance with ARDEC drawing 8837375. The pallet was tested at 300 rpm on a loose cargo machine with a steel 0 plate floor. There was a wood fence around the...loose cargo machine was prepared with 2 x 4 lumber walls and a steel plate floor. The pallets were packed out with projectiles and then conditioned

  14. Projectile Ullage Inspection Technique: Laboratory Demonstration Apparatus.

    DTIC Science & Technology

    1983-08-01

    inspection of projectiles was feasible. The mercury manometer was used because it was the only gauge readily available in the laboratory that was...pres- sure. It is suggested that the mercury manometer be replaced by a panel-mounted diaphragm or Bourdon tube gauge. The full-scale pressure range of...When the mercury manometer is used, the volume of the pressure indicator changes linearly with pres- sure (it is assumed that the manometer tube

  15. Fatal lawn mower related projectile injury.

    PubMed

    Colville-Ebeling, Bonnie; Lynnerup, Niels; Banner, Jytte

    2014-06-01

    Fatal lawn mower related injuries are a relatively rare occurrence. In a forensic setting, the primary aim is to reconstruct the injury mechanism and establish the cause of death. A relatively rare, but characteristic type of injury is a so-called projectile or missile injury. This occurs when the operator or a bystander is impacted by an object mobilized from the grass by the rotating mower blades. This type of injury often leaves only modest external trauma, which increases the risk of overlooking an entry wound. In this paper we present a case of a fatal lawn mower related projectile injury which was initially overlooked, later interpreted as a possible gunshot homicide, and finally identified as a lawn mower related projectile injury when autopsy revealed a piece of metal thread in the main bronchus to the right middle lobe, hemopericardium, and right-sided hemothorax. To our knowledge, this injury mechanism has not previously been reported as a cause of death. This case illustrates the importance of postmortem radiological imaging and interdisciplinary cooperation when establishing manner and cause of death in unusual cases.

  16. Modelling of the Pele Fragmentation Dynamics

    NASA Astrophysics Data System (ADS)

    Verreault, Jimmy

    2013-06-01

    The Penetrator with Enhanced Lateral Effect (PELE) is a type of explosive-free projectile that undergoes radial fragmentation upon an impact with a target plate. This type of projectile is composed of a brittle cylindrical shell (the jacket) filled in its core with a material characterized with a large Poisson's ratio. Upon an impact with a target, the axial compression causes the filling to expand in the radial direction. However, due to the brittleness of the jacket material, very little radial deformation can occur which creates a radial stress between the two materials and a hoop stress in the jacket. Fragmentation of the jacket occurs if the hoop stress exceeds the material's ultimate stress. The PELE fragmentation dynamics is explored via Finite-Element Method (FEM) simulations using the AUTODYN explicit dynamics hydrocode. The numerical results are compared with an analytical model based on wave interactions, as well as with the experimental investigation of Paulus and Schirm (1996). The comparison is based on the mechanical stress in the filling, the resulting radial velocity of the fragments, the number of fragments generated and their mass distribution.

  17. Hign-speed penetration of projectile with cavitator into sand

    NASA Astrophysics Data System (ADS)

    Daurskikh, Anna; Veldanov, Vladislav

    2011-06-01

    Cavitators are used in underwater projectiles design to form a cavern in which projectile could move with no or significantly reduced drag. An investigation of possible application of this structural element for penetration into porous media was conducted. High-speed impact of a conical-shaped head projectile with cavitator was studied in terms of its influence on penetration capacity and projectile stability in sand for impact velocity about 1500 m/s. Cavitators were manufactured of steel with different strength moduli, and thus two penetration regimes (with eroding/non-eroding cavitator) were compared. Numerical simulations showing wave propagation in target and projectile were performed in AUTODYN with Johnson-Cook model for projectile and granular model for sand.

  18. Design and fabrication of projectiles for round bore railguns

    SciTech Connect

    Susoeff, A.R.; Hawke, R.S.

    1985-03-07

    A hypervelocity railgun system which operates in a vacuum and uses a gas gun injector to pre-accelerate the projectiles required that the projectile seal operate over wide pressure and velocity ranges. In our case, the helium gas gun injector operated at up to 35 MPa (5 ksi) while the railgun, using a plasma arc armature, operated at up to 150 MPa (22 ksi). In addition to gas and arc sealing, it was necessary that a metal fuse be attached to the rear of the projectile in order to electrically commutate the rails upon entry to the railgun. This paper discusses procedures and techniques in the design and fabrication of projectiles for a round bore railgun. It is divided into three sections: (1) machining the projectile; (2) fuse fabrication; and (3) assembly of the projectile/fuse package.

  19. Railgun using plasma initiation separated from the projectile

    SciTech Connect

    Katsuki, S.; Akiyama, H.; Yamada, T.; Eguchi, N.; Maeda, S.; Sato, K.N.

    1993-12-01

    Preacceleration of a projectile is quite important to reduce the erosion of the bore surface in a railgun. Gas guns, electrothermal guns and other railguns have been used to preaccelerate the projectile. Here, the new method using Plasma Initiation Separated from the Projectile (PISP method) is proposed, and its effectiveness is confirmed experimentally. A thin copper is placed near the edge of the railgun, which explodes and forms a plasma that has a fast flow velocity due to the Lorentz force. This fast flowing plasma collides with the projectile which obtains an initial velocity mainly by the momentum transfer. Since the current increases while only the plasma is accelerated, the driving force of the projectile just after the collision of the plasma with the projectile is large. In other words, the PISP method works as an inductive energy storage circuit with an opening switch.

  20. Photon emission from massive projectile impacts on solids

    PubMed Central

    Fernandez-Lima, F. A.; Pinnick, V. T.; Della-Negra, S.; Schweikert, E. A.

    2011-01-01

    First evidence of photon emission from individual impacts of massive gold projectiles on solids for a number of projectile-target combinations is reported. Photon emission from individual impacts of massive Aun+q (1 ≤ n ≤ 400; q = 1–4) projectiles with impact energies in the range of 28–136 keV occurs in less than 10 ns after the projectile impact. Experimental observations show an increase in the photon yield from individual impacts with the projectile size and velocity. Concurrently with the photon emission, electron emission from the impact area has been observed below the kinetic emission threshold and under unlikely conditions for potential electron emission. We interpret the puzzling electron emission and correlated luminescence observation as evidence of the electronic excitation resulting from the high-energy density deposited by massive cluster projectiles during the impact. PMID:21603128

  1. Photon emission from massive projectile impacts on solids.

    PubMed

    Fernandez-Lima, F A; Pinnick, V T; Della-Negra, S; Schweikert, E A

    2011-01-01

    First evidence of photon emission from individual impacts of massive gold projectiles on solids for a number of projectile-target combinations is reported. Photon emission from individual impacts of massive Au(n) (+q) (1 ≤ n ≤ 400; q = 1-4) projectiles with impact energies in the range of 28-136 keV occurs in less than 10 ns after the projectile impact. Experimental observations show an increase in the photon yield from individual impacts with the projectile size and velocity. Concurrently with the photon emission, electron emission from the impact area has been observed below the kinetic emission threshold and under unlikely conditions for potential electron emission. We interpret the puzzling electron emission and correlated luminescence observation as evidence of the electronic excitation resulting from the high-energy density deposited by massive cluster projectiles during the impact.

  2. Dissociative ionization of the H 2O molecule induced by medium-energy singly charged projectiles

    NASA Astrophysics Data System (ADS)

    Kovács, S. T. S.; Herczku, P.; Juhász, Z.; Sarkadi, L.; Gulyás, L.; Sulik, B.

    2017-09-01

    We report on the fragmentation of the water molecule by 1 MeV H+ and He+ and 650 keV N+ ion impact. The fragment-ion energy spectra were measured by an electrostatic spectrometer at different observation angles. The obtained double-differential fragmentation cross sections for N+ are found to be more than an order of magnitude higher than that for H+. The relative ratios of the fragmentation channels are also different for the three projectiles. Additional fragmentation channels were observed in the spectra for He+ and for N+ impact, which are missing in the case of H+. From the analysis of the kinetic energy of the fragments, the maximum observed degree of ionization was found to be qmax=3 , 4, and 5 for H + , He + , and N + impact, respectively. Absolute multiple-ionization cross sections have been determined. They are compared with the predictions of the classical trajectory Monte Carlo and continuum-distorted-wave eikonal-initial-state theories. At lower degrees of ionization, theories provide reasonable agreement with experiment. The systematic overestimation of the cross section by the theories towards higher degrees of ionization indicates the failure of the independent particle model.

  3. Numerical simulations of gun-launched kinetic energy projectiles subjected to asymmetric projectile base pressure

    SciTech Connect

    Rabern, D.A.

    1991-01-01

    Three-dimensional numerical simulations were performed to determine the effect of an asymmetric base pressure on kinetic energy projectiles during launch. A matrix of simulations was performed in two separate launch environments. One launch environment represented a severe lateral load environment, while the other represented a nonsevere lateral load environment based on the gun tube straightness. The orientation of the asymmetric pressure field, its duration, the projectile's initial position, and the tube straightness were altered to determine the effects of each parameter. The pressure asymmetry translates down the launch tube to exit parameters and is washed out by tube profile. Results from the matrix of simulations are presented.

  4. An Approximate Analysis of Balloting Motion of Railgun Projectiles

    DTIC Science & Technology

    1991-07-01

    projecile/ barrel clearance. To simplify the fri-oddelinci, a plane motion configuration is assumed. Though the pro- jectile ;s moving with a varying yaw...angle, the axee of the barrel and the projectile pactia~f, and the projectile center oi gravity are always considered in a plane containing the...The lateral forces and lateral projectile/ barrel impact affects muzzle jump, intermediate and terminai ballistics and, consequently, weapon system

  5. Design and testing of high-pressure railguns and projectiles

    SciTech Connect

    Peterson, D.R.; Fowler, C.M.

    1984-03-01

    The results of high-pressure tests of four railgun designs and four projectile types are presented. All tests were conducted at the Los Alamos explosive magnetic-flux compression facility in Ancho Canyon. The data suggest that the high-strength projectiles have lower resistance to acceleration than the lowstrength projectiles, which expand against the bore during acceleration. The railguns were powered by explosive magneticflux compression generators. Calculations to predict railgun and power supply performance were performed by Kerrisk.

  6. Interface Defeat of Long-Rod Projectiles by Ceramic Armor

    DTIC Science & Technology

    2005-09-01

    Interface Defeat of Long-Rod Projectiles by Ceramic Armor by George E. Hauver, Edward J. Rapacki, Jr., Paul H. Netherwood, and Ralph F. Benck...21005-5066 ARL-TR-3590 September 2005 Interface Defeat of Long-Rod Projectiles by Ceramic Armor George E. Hauver, Edward J. Rapacki, Jr...NUMBER 4. TITLE AND SUBTITLE Interface Defeat of Long-Rod Projectiles by Ceramic Armor 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER

  7. A Study of Projectile Response to Ballistics Environment

    DTIC Science & Technology

    2005-11-01

    solid-propellant charges used to launch projectiles from guns. Modern solid mechanics codes such as DYNA3D and EPIC can complement the ARL-NGEN3...Results 3 4. EPIC/ DYNA3D Comparison 4 5. Further EPIC Results – 1.25-in Wall Projectile 6 6. Initial Rotation of Projectile 7 7. Propellant With...simulation (left) and the DYNA3D simulation (right).....................................................3 Figure 3. Pressure-time curves predicted

  8. Flight dynamics of a spinning projectile descending on a parachute

    SciTech Connect

    Benedetti, G.A.

    1989-02-01

    During the past twenty years Sandia National Laboratories and the US Army have vertically gun launched numerous 155mm and eight-inch diameter flight test projectiles. These projectiles are subsequently recovered using an on-board parachute recovery system which is attached to the forward case structure of the projectile. There have been at least five attempts to describe, through analytical and numerical simulations, the translational and rotational motions of a spinning projectile descending on a parachute. However, none of these investigations have correctly described the large nutational motion of the projectile since all of them overlooked the fundamental mechanism which causes these angular motions. Numerical simulations as well as a closed form analytical solution show conclusively that the Magnus moment is responsible for the large nutational motion of the projectile. That is, when the center of pressure for the Magnus force is aft of the center of mass for the projectile, the Magnus moment causes an unstable (or large) nutational motion which always tends to turn the spinning projectile upside down while it is descending on the parachute. Conversely, when the center of mass for the projectile is aft of the center of pressure for the Magnus force, the Magnus moment stabilizes the nutational motion tending to always point the base of the spinning projectile down. The results of this work are utilized to render projectile parachute recovery systems more reliable and to explain what initially may appear to be strange gyrodynamic behavior of a spinning projectile descending on a parachute. 14 refs., 20 figs.

  9. Microcraters formed in glass by low density projectiles

    NASA Technical Reports Server (NTRS)

    Mandeville, J.-C.; Vedder, J. F.

    1971-01-01

    Microcraters were produced in soda-lime glass by the impact of low density projectiles of polystyrene with masses between 0.7 and 62 picograms and velocities between 2 and 14 kilometers per second. The morphology of the craters depends on the velocity and angle of incidence of the projectiles. The transitions in morphology of the craters formed by polystyrene spheres occur at higher velocities than they do for more dense projectiles. For oblique impact, the craters are elongated and shallow with the spallation threshold occuring at higher velocity. For normal incidence, the total displaced mass of the target material per unit of projectile kinetic energy increases slowly with the energy.

  10. Electric rail gun projectile acceleration to high velocity

    NASA Technical Reports Server (NTRS)

    Bauer, D. P.; Mccormick, T. J.; Barber, J. P.

    1982-01-01

    Electric rail accelerators are being investigated for application in electric propulsion systems. Several electric propulsion applications require that the rail accelerator be capable of launching projectiles at velocities above 10 km/s. An experimental program was conducted to develop rail accelerator technology for high velocity projectile launch. Several 6 mm bore, 3 m long rail accelerators were fabricated. Projectiles with a mass of 0.2 g were accelerated by plasmas, carrying currents up to 150 kA. Experimental design and results are described. Results indicate that the accelerator performed as predicted for a fraction of the total projectile acceleration. The disparity between predicted and measured results are discussed.

  11. Continuous measurements of in-bore projectile velocity

    SciTech Connect

    Asay, J.R.; Konrad, C.H.; Hall, C.A. ); Shahinpoor, M. . Dept. of Mechanical Engineering); Hickman, R. )

    1989-01-01

    The application of velocity interferometry to the continuous measurement of in-bore projectile velocity in a small-bore three-stage railgun is described. These measurements are useful for determining projectile acceleration and for evaluating gun performance. The launcher employed in these studies consists of a two-stage light gas gun used to inject projectiles into a railgun for additional acceleration. Results obtained for projectile velocities to 7.4 km/s with the two-stage injector are reported and potential improvements for railgun applications are discussed.

  12. Projectile development for railguns using hypervelocity preacceleration. Revision 1

    SciTech Connect

    Susoeff, A.R.; Hawke, R.S.; Ang, J.A.; Asay, J.R.; Hall, C.A.; Konrad, C.H.; Sauve, G.L.; Hickman, R.J.

    1992-03-20

    The STARFIRE Project is a joint Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL) effort to achieve hypervelocity projectile launches up to 15 km/s. The apparatus used to achieve this goal is a three stage acceleration system made up of a two-stage light-gas gun (2SLGG) coupled to a railgun. The 2SLGG is used as a preaccelerator capable of injecting 2 gram projectiles at velocities of 6 km/s or more. Projectiles used in this environment are subject to many conditions. Some of these which effect projectile design include: acceleration loading, structural response, barrel condition and alignment. Development of a projectile to satisfy the programmatic requirements is underway. This report covers the evolution of design and fabrication for railgun projectiles from previous experiment at LLNL to the replenished plasma armature and projectile now used on STARFIRE. Projectile design, development and fabrication methods which use off-the-shelf materials and standard techniques to meet the operational criteria of the experimental program are discussed in this paper. Initial work involving the design and fabrication of skirted projectiles, which are expected to further reduce interaction phenomena between the plasma armature and railgun barrel, is also described.

  13. Projectile target combination to synthesis superheavy nuclei Z = 126

    NASA Astrophysics Data System (ADS)

    Manjunatha, H. C.; Sridhar, K. N.

    2017-06-01

    We have studied the fusion cross section, survival cross section, fission cross section, compound nucleus formation probability (PCN) and survival probability (PSurv) of superheavy nuclei 307126, 318126, 319126, and 320126. Hence, we have identified the most probable projectile-target combination to synthesis these superheavy nuclei. From the detail study of these parameters, it is clear that for the superheavy nuclei 307126, the projectile target combinations such as 54Fe + 253Fm and 58Ni + 249Cf are most probable projectile target combination for synthesis. The projectile target combinations such as 64Ni + 254Cf and 80Se + 238U are most probable projectile target combination for the synthesis of 318126. The projectile target combinations such as 72Zn + 247Cm and 66Ni + 253Cf are most probable projectile target combination for synthesis the superheavy nuclei 319126. The projectile target combinations such as 66Ni + 254Cf and 82Se + 238U are most probable projectile target combination for synthesis the superheavy nuclei 320126. Thus, we hope that our predictions may be guide for the future experiments in the synthesis of superheavy nuclei Z = 126.

  14. Prediction of projectile ricochet behavior after water impact.

    PubMed

    Baillargeon, Yves; Bergeron, Guy

    2012-11-01

    Although not very common, forensic investigation related to projectile ricochet on water can be required when undesirable collateral damage occurs. Predicting the ricochet behavior of a projectile is challenging owing to numerous parameters involved: impact velocity, incident angle, projectile stability, angular velocity, etc. Ricochet characteristics of different projectiles (K50 BMG, 0.5-cal Ball M2, 0.5-cal AP-T C44, 7.62-mm Ball C21, and 5.56-mm Ball C77) were studied in a pool. The results are presented to assess projectile velocity after ricochet, ricochet angle, and projectile azimuth angle based on impact velocity or incident angle for each projectile type. The azimuth ranges show the highest variability at low postricochet velocity. The critical ricochet angles were ranging from 15 to 30°. The average ricochet angles for all projectiles were pretty close for all projectiles at 2.5 and 10° incident angles for the range of velocities studied. © 2012 Her Majesty the Queen in Right of Canada 2012. Reproduced with the permission of the Minister of the Department of National Defence.

  15. Design and testing of high-pressure railguns and projectiles

    NASA Technical Reports Server (NTRS)

    Peterson, D. R.; Fowler, C. M.; Cummings, C. E.; Kerrisk, J. F.; Parker, J. V.; Marsh, S. P.; Adams, D. F.

    1984-01-01

    Attention is given to the results of high-pressure tests involving four railgun designs and four projectile types. Explosive magnetic-flux compression generators were employed to power the railguns. On the basis of the experimental data, it appears that the high-strength projectiles have lower resistance to acceleration than low-strength projectiles, which expand against the bore during acceleration. While confined in the bore, polycarbonate projectiles can be subjected to pressures as high as 1.3 GPa without shattering. In multishot railguns, it is important to prevent an accumulation of sooty material from the plasma armature in railgun seams.

  16. Approximate analysis of balloting motion of railgun projectiles. Technical report

    SciTech Connect

    Chu, S.H.

    1991-07-01

    This is the final of three reports dealing with the in-bore balloting motion of a projectile fired from an electromagnetic railgun. Knowledge of projectile in-bore motion is important to its design and the design of the railgun. It is a complicated problem since many parameters are involved and it is not easy to determine the interacting relationships between them. To make the problem easier to understand it was analyzed on several levels. Beginning from the basic simple model which computed only the axial motion, more complicated models were introduced in upper levels that included the more significant lateral forces and gun tube vibration effects. This report deals with the approximate analysis of balloting motion. This model considers the effects of the propulsion force, the friction force of the projectile package (projectile and armature), air resistance, gravity, the elastic forces, and the projectile/barrel clearance. To simplify the modeling, a plane motion configuration is assumed. Though the projectile is moving with a varying yaw angle, the axes of the barrel and the projectile package, and the projectile center of gravity are always considered in a plane containing the centerlines of the rails. Equations of motion are derived and solved. A sample computation is performed and the results plotted to give a clearer understanding of projectile in-bore motion.

  17. Work on Sabot-Projectiles and Supplements, 1942-1944

    DTIC Science & Technology

    1946-10-01

    Projectiles by C. L. Critchfield. NDRC Report A-233 (OSRD No. 2067), "Development of Subcaliber Projectiles for the Hispano- Suiza Gun" by C. L. Critchfield...Millar, "Development of Subcaliber Projectiles for the Hispano- Suiza Gun," NDRC Report A-233 (OSRD No. 2067). C 0 N F I D F N T I A L - 18 - however...jectiles for the Hisnano- Suiza Gun," by C. L. Critchfield snd J. -McG. Millnr. * Projectile Test Report AD-P99 Ordnance Research Center, A.P.G. Report on

  18. Electric rail gun projectile acceleration to high velocity

    NASA Technical Reports Server (NTRS)

    Bauer, D. P.; Mccormick, T. J.; Barber, J. P.

    1982-01-01

    Electric rail accelerators are being investigated for application in electric propulsion systems. Several electric propulsion applications require that the rail accelerator be capable of launching projectiles at velocities above 10 km/s. An experimental program was conducted to develop rail accelerator technology for high velocity projectile launch. Several 6 mm bore, 3 m long rail accelerators were fabricated. Projectiles with a mass of 0.2 g were accelerated by plasmas, carrying currents up to 150 kA. Experimental design and results are described. Results indicate that the accelerator performed as predicted for a fraction of the total projectile acceleration. The disparity between predicted and measured results are discussed.

  19. Penetration into limestone targets with ogive-nose steel projectiles

    SciTech Connect

    Frew, D.J.; Green, M.L.; Forrestal, M.J.; Hanchak, S.J.

    1996-12-01

    We conducted depth of penetration experiments into limestone targets with 3.0 caliber-radius-head, 4340 Rc 45 steel projectiles. Powder guns launched two projectiles with length-to-diameter ratios of ten to striking velocities between 0.4 and 1.5 km/s. Projectiles had diameters and masses of 12.7 mm, 0. 117 kg and 25.4 mm, 0.610 kg. Based on data sets with these two projectile scales, we proposed an empirical penetration equation that described the target by its density and an empirical strength constant determined from penetration depth versus striking velocity data.

  20. Continuous measurements of in-bore projectile velocity

    SciTech Connect

    Asay, J.R.; Konrad, C.H.; Hall, C.A.; Shahinpoor, M.; Hickman, R.

    1988-01-01

    The application of velocity interferometry to the continuous measurement of in-bore projectile velocity in a small-bore three-stage railgun is described. These measurements are useful for determining projectile acceleration and for evaluating gun performance. The launcher employed in these studies consists of a two-stage light gas gun used to inject projectiles into a railgun for additional acceleration. Results obtained for projectile velocities to 7.4 km/s with the two-stage injector are reported and potential improvements for railgun applications are discussed. 12 refs., 7 figs.

  1. Forensic imaging of projectiles using cone-beam computed tomography.

    PubMed

    von See, Constantin; Bormann, Kai-Hendrik; Schumann, Paul; Goetz, Friedrich; Gellrich, Nils-Claudius; Rücker, Martin

    2009-09-10

    In patients with gunshot injuries, it is easy to detect a projectile within the body due to the high-density of the object, but artefacts make it difficult to obtain information about the deformation and the exact location of the projectile in surrounding tissues. Cone-beam computed tomography (CBCT) is a new radiological imaging modality that allows radio-opaque objects to be localised and assessed in three dimensions. The full potential of the use of CBCT in forensic medicine has not yet been explored. In this study, three different modern projectiles were fired into the heads of pig cadavers (n=6) under standardised conditions. Tissue destruction and the location of the projectiles were analysed separately using CBCT and multi-slice computed tomography (MDCT). The projectiles had the same kinetic energy but showed considerable differences in deformation behaviour. Within the study groups, tissue destruction was reproducible. CBCT is less severely affected by metallic artefacts than MDCT. Therefore CBCT is superior in visualising bone destruction in the immediate vicinity of the projectile and projectile deformation, whereas MDCT allows soft tissue to be evaluated in more detail. CBCT is an improved diagnostic tool for the evaluation of gunshot injuries. In particular, it is superior to MDCT in detecting structural hard-tissue damage in the immediate vicinity of high-density metal projectiles and in identifying the precise location of a projectile in the body.

  2. A New Ballistic Limit Equation of Projectiles Hypervelocity Impacting on Dual Wall Structures

    NASA Astrophysics Data System (ADS)

    Ding, L.; Zhang, W.; Pang, B. J.

    The potential threat from meteoroid and orbital debris particles impacting on pressurized spacecraft prompted a study of ballistic limit equations The ballistic limits can be subdivided into three phases ballistic shatter and melt vaporization The present paper is devoted to a new ballistic limit equation of sphere projectiles impacting on dual wall structures Compared with existed equations the proposed equation has clearer theoretical bases and more convenient form for engineering design In ballistic phase forward velocity of projectiles after impacting bumpers is presented as a non-dimensional function from results of numerical simulations by a multivariate linear least squares regression analysis Materials used for bumpers in these numerical simulations consisted of aluminum copper and steel Because of little effect the spacing between the walls was not considered in ballistic phase The response of rear walls is modeled following a single wall crater equation In shatter phase the approach for obtaining the equation is similar to that in ballistic phase The forward velocity of the biggest fragments of chattered projectiles after impacting bumpers was analyzed in shatter phase In melt vaporization phase since accelerated facilities can hardly reach so high velocity experimental data are relatively less than the other two phases An initial equation form based on dynamic mechanics analysis was assumed firstly and the equation was obtained by a regression analysis for a single variable lastly Tresca criterion was used to define the critical penetration

  3. Numerical and experimental study of the impact of small caliber projectiles on ballistic soap

    NASA Astrophysics Data System (ADS)

    Dyckmans, G.; Ndompetelo, N.; Chabotier, A.

    2003-09-01

    Terminal ballistic deals with interactions between targets and projectiles. One of the areas of interest is wound ballistics, where one studies the interaction between a projectile (a bullet or a fragment) and the human body. Soap and gelatin are commonly used materials for simulating soft human body tissue in wound ballistics experiments. They are to be considered as tools for comparing the effectiveness of different projectiles. The department of weapon systems & ballistics of the Belgian Royal Military Academy is examining to what extent the Autodyn hydrocode can be used as a numerical tool for simulating the penetration of military bullets into ballistic soap. This article presents the philosophy and the results of the project's first phase i.e. the use of Autodyn for simulating the penetration of a steel sphere into a block of ballistic soap as a result of a normal impact at different velocities. A series of experiments (real firings) have been performed in the laboratory of the department. They serve as a reference and validation tool for the numerical approach. The latter is characterized by the specific problem of accurate material modeling of the soap. The application of a stepwise parametric study of material models and parameters has resulted in numerical simulations which fit quite well with experiments.

  4. Molecular depth profiling in ice matrices using C 60 projectiles

    NASA Astrophysics Data System (ADS)

    Wucher, A.; Sun, S.; Szakal, C.; Winograd, N.

    2004-06-01

    The prospects of molecular sputter depth profiling using C 60+ projectiles were investigated on thick ice layers prepared by freezing aqueous solutions of histamine onto a metal substrate. The samples were analyzed in a ToF-SIMS spectrometer equipped with a liquid metal Ga + ion source and a newly developed fullerene ion source. The C 60+ beam was used to erode the surface, while static ToF-SIMS spectra were taken with both ion beams alternatively between sputtering cycles. We find that the signals both related to the ice matrix and to the histamine are about two orders of magnitude higher under 20-keV C 60 than under 15-keV Ga bombardment. Histamine related molecular signals are found to increase drastically if the freshly introduced surface is pre-sputtered with C 60 ions, until at a total ion fluence of about 10 13 cm -2 the spectra are completely dominated by the molecular ion and characteristic fragments of histamine. At larger fluence, the signal is found to decrease with a disappearance cross section of approximately 10 -14 cm 2, until at total fluences of about 10 14 cm -2 a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga + ions were used to erode the surface.

  5. Modelling of the PELE fragmentation dynamics

    NASA Astrophysics Data System (ADS)

    Verreault, J.

    2014-05-01

    The Penetrator with Enhanced Lateral Effect (PELE) is a type of explosive-free projectile that undergoes radial fragmentation upon an impact with a target plate. This type of projectile is composed of a brittle cylindrical shell (the jacket) filled in its core with a material characterized with a large Poisson's ratio. Upon an impact with a target, the axial compression causes the filling to expand in the radial direction. However, due to the brittleness of the jacket material, very little radial deformation can occur which creates a radial stress between the two materials and a hoop stress in the jacket. Fragmentation of the jacket occurs if the hoop stress exceeds the material's ultimate stress. The PELE fragmentation dynamics is explored via Finite-Element Method (FEM) simulations using the Autodyn explicit dynamics hydrocode. The numerical results are compared with an analytical model based on wave interactions, as well as with the experimental investigation of Paulus and Schirm (1996). The comparison is based on the mechanical stress in the filling and the qualitative fragmentation of the jacket.

  6. Fundamental Aerodynamic Investigations for Development of Arrow-Stabilized Projectiles

    NASA Technical Reports Server (NTRS)

    Kurzweg, Hermann

    1947-01-01

    The numerous patent applications on arrow-stabilized projectiles indicate that the idea of projectiles without spin is not new, but has appeared in various proposals throughout the last decades. As far as projectiles for subsonic speeds are concerned, suitable shapes have been developed for sometime, for example, numerous grenades. Most of the patent applications, though, are not practicable particularly for projectiles with supersonic speed. This is because the inventor usually does not have any knowledge of aerodynamic flow around the projectile nor any particular understanding of the practical solution. The lack of wind tunnels for the development of projectiles made it necessary to use firing tests for development. These are obviously extremely tedious or expensive and lead almost always to failures. The often expressed opinion that arrow-stabilized projectiles cannot fly supersonically can be traced to this condition. That this is not the case has been shown for the first time by Roechling on long projectiles with foldable fins. Since no aerodynamic investigations were made for the development of these projectiles, only tedious series of firing tests with systematic variation of the fins could lead to satisfactory results. These particular projectiles though have a disadvantage which lies in the nature cf foldable fins. They occasionally do not open uniformly in flight, thus causing unsymmetry in flow and greater scatter. The junctions of fins and body are very bad aerodynamically and increase the drag. It must be possible to develop high-performance arrow-stabilized projectiles based on the aerodynamic research conducted during the last few years at Peenemuende and new construction ideas. Thus the final shape, ready for operational use, could be developed in the wind tunnel without loss of expensive time in firing tests. The principle of arrow-stabilized performance has been applied to a large number of caliburs which were stabilized by various means Most

  7. Tailoring Laminates For Protection Against Projectiles

    NASA Technical Reports Server (NTRS)

    Gassner, John J.; Boyce, Joseph S.; Smirlock, Martin E.; Evans, David A.

    1992-01-01

    Fiber/matrix composite laminates developed to protect military land vehicles against projectiles and spacecraft against impacts by micrometeroids. Although types, sizes, and velocities of expected incident objects differ between terrestrial and outer-space cases, general protection problems and solutions exhibit some common features. Configurations of fibers and matrices optimized with respect to protection, bulk, and weight, to obtain shield that breaks rapidly moving incident object into harmless smaller, more-slowly-moving pieces, containing debris, vaporizes debris, and/or otherwise absorbs kinetic energy of object to prevent harm to vehicle and occupants.

  8. Tailoring Laminates For Protection Against Projectiles

    NASA Technical Reports Server (NTRS)

    Gassner, John J.; Boyce, Joseph S.; Smirlock, Martin E.; Evans, David A.

    1992-01-01

    Fiber/matrix composite laminates developed to protect military land vehicles against projectiles and spacecraft against impacts by micrometeroids. Although types, sizes, and velocities of expected incident objects differ between terrestrial and outer-space cases, general protection problems and solutions exhibit some common features. Configurations of fibers and matrices optimized with respect to protection, bulk, and weight, to obtain shield that breaks rapidly moving incident object into harmless smaller, more-slowly-moving pieces, containing debris, vaporizes debris, and/or otherwise absorbs kinetic energy of object to prevent harm to vehicle and occupants.

  9. On high explosive launching of projectiles for shock physics experiments

    NASA Astrophysics Data System (ADS)

    Swift, Damian C.; Forest, Charles A.; Clark, David A.; Buttler, William T.; Marr-Lyon, Mark; Rightley, Paul

    2007-06-01

    The hydrodynamic operation of the "Forest Flyer" type of explosive launching system for shock physics projectiles was investigated in detail using one and two dimensional continuum dynamics simulations. The simulations were numerically converged and insensitive to uncertainties in the material properties; they reproduced the speed of the projectile and the shape of its rear surface. The most commonly used variant, with an Al alloy case, was predicted to produce a slightly curved projectile, subjected to some shock heating and likely exhibiting some porosity from tensile damage. The curvature is caused by a shock reflected from the case; tensile damage is caused by the interaction of the Taylor wave pressure profile from the detonation wave with the free surface of the projectile. The simulations gave only an indication of tensile damage in the projectile, as damage is not understood well enough for predictions in this loading regime. The flatness can be improved by using a case of lower shock impedance, such as polymethyl methacrylate. High-impedance cases, including Al alloys but with denser materials improving the launching efficiency, can be used if designed according to the physics of oblique shock reflection, which indicates an appropriate case taper for any combination of explosive and case material. The tensile stress induced in the projectile depends on the relative thickness of the explosive, expansion gap, and projectile. The thinner the projectile with respect to the explosive, the smaller the tensile stress. Thus if the explosive is initiated with a plane wave lens, the tensile stress is lower than that for initiation with multiple detonators over a plane. The previous plane wave lens designs did, however, induce a tensile stress close to the spall strength of the projectile. The tensile stress can be reduced by changes in the component thicknesses. Experiments verifying the operation of explosively launched projectiles should attempt to measure

  10. On high explosive launching of projectiles for shock physics experiments.

    PubMed

    Swift, Damian C; Forest, Charles A; Clark, David A; Buttler, William T; Marr-Lyon, Mark; Rightley, Paul

    2007-06-01

    The hydrodynamic operation of the "Forest Flyer" type of explosive launching system for shock physics projectiles was investigated in detail using one and two dimensional continuum dynamics simulations. The simulations were numerically converged and insensitive to uncertainties in the material properties; they reproduced the speed of the projectile and the shape of its rear surface. The most commonly used variant, with an Al alloy case, was predicted to produce a slightly curved projectile, subjected to some shock heating and likely exhibiting some porosity from tensile damage. The curvature is caused by a shock reflected from the case; tensile damage is caused by the interaction of the Taylor wave pressure profile from the detonation wave with the free surface of the projectile. The simulations gave only an indication of tensile damage in the projectile, as damage is not understood well enough for predictions in this loading regime. The flatness can be improved by using a case of lower shock impedance, such as polymethyl methacrylate. High-impedance cases, including Al alloys but with denser materials improving the launching efficiency, can be used if designed according to the physics of oblique shock reflection, which indicates an appropriate case taper for any combination of explosive and case material. The tensile stress induced in the projectile depends on the relative thickness of the explosive, expansion gap, and projectile. The thinner the projectile with respect to the explosive, the smaller the tensile stress. Thus if the explosive is initiated with a plane wave lens, the tensile stress is lower than that for initiation with multiple detonators over a plane. The previous plane wave lens designs did, however, induce a tensile stress close to the spall strength of the projectile. The tensile stress can be reduced by changes in the component thicknesses. Experiments verifying the operation of explosively launched projectiles should attempt to measure

  11. Microcraters formed in glass by projectiles of various densities

    NASA Technical Reports Server (NTRS)

    Vedder, J. F.; Mandeville, J.-C.

    1974-01-01

    An experiment was conducted investigating the effect of projectile density on the structure and size of craters in soda lime glass and fused quartz. The projectiles were spheres of polystyrene-divinylbenzene (PS-DVB), aluminum, and iron with velocities between 0.5 and 15 km/sec and diameters between 0.4 and 5 microns. The projectile densities spanned the range expected for primary and secondary particles of micrometer size at the lunar surface, and the velocities spanned the lower range of micrometeoroid velocities and the upper range of secondary projectile velocities. There are changes in crater morphology as the impact velocity increases, and the transitions occur at lower velocities for the projectiles of higher density. The sequence of morphological features of the craters found for PS-DVB impacting soda lime glass for increasing impact velocity, described in a previous work (Mandeville and Vedder, 1971), also occurs in fused quartz and in both targets with the more dense aluminum and iron projectiles. Each transition in morphology occurs at impact velocities generating a certain pressure in the target. High density projectiles require a lower velocity than low-density projectiles to generate a given shock pressure.

  12. Theoretical Design and Modeling of an Infantry Railgun Projectile

    DTIC Science & Technology

    2005-12-01

    element computer models. The modeling results validated fundamental railgun equations. The final projectile design concluded with a 3 m barrel and is...equations. The final projectile design concluded with a 3 m barrel and is characterized by the following parameters: conducting rails with an inductance...CONSIDERATIONS ......................................................60 C. BARREL OPTIMIZATION

  13. Microcraters formed in glass by projectiles of various densities

    NASA Technical Reports Server (NTRS)

    Vedder, J. F.; Mandeville, J.-C.

    1974-01-01

    An experiment was conducted investigating the effect of projectile density on the structure and size of craters in soda lime glass and fused quartz. The projectiles were spheres of polystyrene-divinylbenzene (PS-DVB), aluminum, and iron with velocities between 0.5 and 15 km/sec and diameters between 0.4 and 5 microns. The projectile densities spanned the range expected for primary and secondary particles of micrometer size at the lunar surface, and the velocities spanned the lower range of micrometeoroid velocities and the upper range of secondary projectile velocities. There are changes in crater morphology as the impact velocity increases, and the transitions occur at lower velocities for the projectiles of higher density. The sequence of morphological features of the craters found for PS-DVB impacting soda lime glass for increasing impact velocity, described in a previous work (Mandeville and Vedder, 1971), also occurs in fused quartz and in both targets with the more dense aluminum and iron projectiles. Each transition in morphology occurs at impact velocities generating a certain pressure in the target. High density projectiles require a lower velocity than low-density projectiles to generate a given shock pressure.

  14. Corrected Launch Speed for a Projectile Motion Laboratory

    ERIC Educational Resources Information Center

    Sanders, Justin M.; Boleman, Michael W.

    2013-01-01

    At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range…

  15. Corrected Launch Speed for a Projectile Motion Laboratory

    ERIC Educational Resources Information Center

    Sanders, Justin M.; Boleman, Michael W.

    2013-01-01

    At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range…

  16. ’Fused-on’ Rotating Bands for Projectiles

    DTIC Science & Technology

    1974-12-01

    casting alloys, might be preferable for the procese or as rotating band materials depending on projectile requirements. METHODS AND PROCEDURES In this in...has fractured on impact (left projectile) all parts of the band have remained attached to the steel. Problem Areas One of the problems encountered in

  17. Flight Performance of a Man Portable Guided Projectile Concept

    DTIC Science & Technology

    2014-02-01

    computational aerodynamics techniques were applied. Aerodynamic models and projectile flight mechanics were derived to enable flight simulation. Assessment of... Computational mesh on symmetry plane and projectile surfaces. ...............................15 Figure 14. Mach number contours on vertical...the basis of this new maneuver concept. The novel contributions are the flight concept, theoretical modeling of the concept, computational and

  18. Use of monoatomic and polyatomic projectiles for the characterisation of polylactic acid by static secondary ion mass spectrometry.

    PubMed

    Boschmans, Bart; Van Royen, Pieter; Van Vaeck, Luc

    2005-01-01

    The application of polyatomic primary ions is a strongly developing branch of static secondary ion mass spectrometry (S-SIMS), since these projectiles allow a significant increase in the secondary ion yields to be achieved. However, the different limitations and possibilities of certain polyatomic primary ions for use on specific functional classes of samples are still not completely known. This paper compares the use of monoatomic and polyatomic primary ions in S-SIMS for thin layers of polylactic acid (PLA), obtained by spin-coating solutions on silicon wafers. Bombardment with Ga+, Xe+ and SF5+ primary ions allowed the contribution of the projectile mass and number of atoms in the gain in ion yield and molecular specificity (relative importance of high m/z and low m/z signals) to be assessed. Samples obtained by spin-coating solutions with increasing concentration showed that optimal layer thickness depended on the primary ion used. In comparison with the use of Ga+ projectiles, the yield of structural ions increased by a factor of about 1.5 to 2 and by about 7 to 12 when Xe+ and SF5+ primary ion bombardment were applied, respectively. A detailed fragmentation pattern was elaborated to interpret ion signal intensity changes for different projectiles in terms of energy deposition and collective processes in the subsurface, and the internal energy of radical and even-electron precursor ions.

  19. Locating the source of projectile fluid droplets

    NASA Astrophysics Data System (ADS)

    Varney, Christopher R.; Gittes, Fred

    2011-08-01

    The ill-posed projectile problem of finding the source height from spattered droplets of viscous fluid is a longstanding obstacle to accident reconstruction and crime-scene analysis. It is widely known how to infer the impact angle of droplets on a surface from the elongation of their impact profiles. However, the lack of velocity information makes finding the height of the origin from the impact position and angle of individual drops not possible. From aggregate statistics of the spatter and basic equations of projectile motion, we introduce a reciprocal correlation plot that is effective when the polar launch angle is concentrated in a narrow range. The vertical coordinate depends on the orientation of the spattered surface and equals the tangent of the impact angle for a level surface. When the horizontal plot coordinate is twice the reciprocal of the impact distance, we can infer the source height as the slope of the data points in the reciprocal correlation plot. If the distribution of launch angles is not narrow, failure of the method is evident in the lack of linear correlation. We perform a number of experimental trials, as well as numerical calculations and show that the height estimate is relatively insensitive to aerodynamic drag. Besides its possible relevance for crime investigation, reciprocal-plot analysis of spatter may find application to volcanism and other topics and is most immediately applicable for undergraduate science and engineering students in the context of crime-scene analysis.

  20. Penetration of projectiles into granular targets.

    PubMed

    Ruiz-Suárez, J C

    2013-06-01

    Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point.

  1. Powder metallurgy process for manufacturing core projectile

    NASA Astrophysics Data System (ADS)

    Akbar, Taufik; Setyowati, Vuri Ayu; Widyastuti

    2013-09-01

    Bullets are part of the defense equipment which the development is very rapid. There are a variety of forms but the bullet Lead is a metal that has always been used for applications projectiles. Lead core constituent materials are combined with antimony. In this research will be conducted by making the material for the core projectile with Tin Lead. The addition of Tin will increase the stiffness of Lead which is soft in nature. The Lead Tin composition variation was given in 10% weight of Sn. The manufacturing process using powder metallurgy using temperature and holding time variations of sintering at 100, 150, and 200°C for 1,2, and 3 hours. XRD samples will be tested to determine the form and phase morphology was observed using SEM-EDX. These results revealed that Pb-10%wtSn Composite which is sintered in temperature 200°C for 3 hours has the greatest density, 10.695 g/cm3 as well as the smallest porosity, 2.2%. In agreement with theoretical analysis that increasing higher temperature and longer holding time give decrease in porosity level due to activation energy which further promotes grain growth. Moreover, there is no intermetallic phase formation as well as no oxide found on composites.

  2. The added mass of a spherical projectile

    NASA Astrophysics Data System (ADS)

    Pantaleone, J.; Messer, J.

    2011-12-01

    When a ball moves through the air, the air exerts a force on the ball. For a sphere moving at constant velocity with respect to the air, this force is called the drag force and it has been well measured. If the sphere moves with a nonconstant velocity there are additional forces. These "unsteady" forces depend on the sphere's acceleration and, in principle, also on higher derivatives of the motion. The force equal to a constant times the acceleration is called the "added mass" because it increases the effective inertia of the sphere moving through the fluid. We measure the unsteady forces on a sphere by observing the one- and two-dimensional projectile motion of light spheres around the highest point. The one-dimensional motion is well described by just the usual buoyant force and the added mass as calculated in the ideal fluid model. This measurement is an excellent experiment for introductory physics students. For spheres in two-dimensional projectile motion the downward vertical acceleration at the highest point increases with the horizontal velocity. This effect can be described by an additional force proportional to the speed times the acceleration.

  3. Penetration of projectiles into granular targets

    NASA Astrophysics Data System (ADS)

    Ruiz-Suárez, J. C.

    2013-06-01

    Energetic collisions of subatomic particles with fixed or moving targets have been very valuable to penetrate into the mysteries of nature. But the mysteries are quite intriguing when projectiles and targets are macroscopically immense. We know that countless debris wandering in space impacted (and still do) large asteroids, moons and planets; and that millions of craters on their surfaces are traces of such collisions. By classifying and studying the morphology of such craters, geologists and astrophysicists obtain important clues to understand the origin and evolution of the Solar System. This review surveys knowledge about crater phenomena in the planetary science context, avoiding detailed descriptions already found in excellent papers on the subject. Then, it examines the most important results reported in the literature related to impact and penetration phenomena in granular targets obtained by doing simple experiments. The main goal is to discern whether both schools, one that takes into account the right ingredients (planetary bodies and very high energies) but cannot physically reproduce the collisions, and the other that easily carries out the collisions but uses laboratory ingredients (small projectiles and low energies), can arrive at a synergistic intersection point.

  4. Operation of polycarbonate projectiles in the ram accelerator

    NASA Astrophysics Data System (ADS)

    Elder, Timothy

    The ram accelerator is a hypervelocity launcher with direct space launch applications in which a sub-caliber projectile, analogous to the center-body of a ramjet engine, flies through fuel and oxidizer that have been premixed in a tube. Shock interactions in the tube ignite the propellant upon entrance of the projectile and the combustion travels with it, creating thrust on the projectile by stabilizing a high pressure region of gas behind it. Conventional ram accelerator projectiles consist of aluminum, magnesium, or titanium nosecones and bodies. An experimental program has been undertaken to determine the performance of polycarbonate projectiles in ram accelerator operation. Experimentation using polycarbonate projectiles has been divided into two series: determining the lower limit for starting velocity (i.e., less than 1100 m/s) and investigating the upper velocity limit. To investigate the influence of body length and starting velocity, a newly developed "combustion gun" was used to launch projectiles to their initial velocities. The combustion gun uses 3-6 m of ram accelerator test section as a breech and 4-6 m of the ram accelerator test section as a launch tube. A fuel-oxidizer mix is combusted in the breech using a spark plug or electric match and bursts a diaphragm, accelerating the ram projectile to its entrance velocity. The combustion gun can be operated at modest fill pressures (20 bar) but can only launch to relatively low velocities (approximately 1000 m/s) without destroying the projectile and obturator upon launch. Projectiles were successfully started at entrance velocities as low as 810 m/s and projectile body lengths as long as 91 mm were used. The tests investigating the upper Mach number limits of polycarbonate projectiles used the conventional single-stage light-gas gun because of its ability to reach higher velocities with a lower acceleration launch. It was determined that polycarbonate projectiles have an upper velocity limit in the

  5. Modified point mass trajectory simulation for base-burn projectiles

    NASA Astrophysics Data System (ADS)

    Lieske, R. F.; Danberg, J. E.

    1992-03-01

    An addition to the Modified Point Mass Trajectory Model for Rocket-Assisted Projectiles is presented for the exterior ballistic simulation of base-burn projectiles. The addition models the change in aerodynamic base-drag based on the change in base pressure due to the base-burn motor's ejection of hot gas into the wake of the projectile. The mass flow rate of the remaining fuel of the base-burn motor is modeled as a function of the instantaneous projectile spin rate and atmospheric air pressure. HAWK Doppler radar data collected at Yuma Proving Ground, Arizona, for the 155mm, M1864 base-burn projectile were used to verify the modeling approach for a variety of test conditions.

  6. Impact effects of explosively formed projectiles on normal strength concrete

    NASA Astrophysics Data System (ADS)

    Bookout, Laurin; Baird, Jason

    2012-03-01

    This paper will address the experimental results of the impact of 101.6 mm (4 in) explosively formed projectiles on normal strength concrete targets. Five projectiles were recovered using a soft recovery system to determine the average mass and nose shape of the projectiles. Velocity data for each test was measured with a high speed camera. The average projectile nose shape and mass plus the striking velocity, and the penetration depths from ten tests were compared to existing penetration equations to see if one or more of the equations is applicable for this type of projectile impact. The coarse aggregate gradation used in the concrete mix has Hugoniot data available. The Hugoniot data allows comparison of any observed spalling with the theoretical predictions.

  7. Impact effects of explosively formed projectiles on normal strength concrete

    NASA Astrophysics Data System (ADS)

    Bookout, Laurin; Baird, Jason

    2011-06-01

    This paper will address the experimental results of the impact of four-inch explosively formed projectiles on normal strength concrete targets. Five projectiles will be recovered using a soft recovery system to determine the average mass and nose shape of the projectiles. Velocity data for each test will be measured with a high speed camera. The average projectile nose shape and mass plus the striking velocity, and the penetration depths from ten tests will then be compared to existing penetration equations to see if one or more of the equations are applicable for this type of projectile impact. The coarse aggregate gradation used in the concrete mix has Hugoniot data available. If spalling occurs on any of the targets, the Hugoniot data will allow comparison of the observed spalling with the theoretical predictions.

  8. Shape Effect Analysis of Aluminum Projectile Impact on Whipple Shields

    NASA Technical Reports Server (NTRS)

    Carrasquilla, Maria J.; Miller, Joshua E.

    2017-01-01

    respect to their mass, size, and material composition needs to be summarized in a form that can be used in MMOD analysis. The mechanism that brings these fragment traits into MMOD analysis is through ballistic limit equations (BLE) that have been developed largely for a few types of materials1. As a BLE provides the failure threshold for a shield or spacecraft component based on parameters such as the projectile impact velocity and size, and the target's materials, thickness, and configuration, it is used to design protective shields for spacecraft such as Whipple shields (WS) to an acceptable risk level. The majority of experiments and simulations to test shields and validate BLEs have, heretofore, largely used spheres as the impactor, not properly reflecting the irregular shapes of MMOD. This shortfall has motivated a numerical impact analysis study of HVI involving non-spherical geometries to identify key parameters that environment models should provide.

  9. Double differential cross section for light mass fragment production on tens of MeV proton, deuteron, helium and carbon induced reactions

    NASA Astrophysics Data System (ADS)

    Sanami, Toshiya; Yamaguchi, Yuji; Uozumi, Yusuke; Hagiwara, Masayuki; Koba, Yusuke

    2017-09-01

    Double differential cross sections (DDXs) of light mass fragment (LMFs - Li,Be,B,C,N and O) productions were measured for tens of MeV proton, deuteron helium and carbon induced reactions on Be, C, Al, Ti and Cu targets. The incident energies for the measurements were chosen to allow us to compare DDXs with same incident energy but different projectiles on various targets. Systematic data were obtained to see the differences between projectile energies, particles, targets and emitted particles. From the comparison, reaction processes of not only evaporation from complete fusion nucleus, but also scattering, pickup, stripping and projectile fragmentation were observed.

  10. A Methodology for the Development of Direct Fired Flight Projectiles

    NASA Astrophysics Data System (ADS)

    Farina, Anthony P.

    This thesis addresses shortcomings in flight projectile design by describing the creation of an improved product development methodology for direct fired flight projectiles. At the outset, platform based flight projectile design and the requirements for direct fired flight projectiles are considered. The traditional methods and tools used in flight projectile design and development are presented and the improved methodology for the design and development of direct fired flight projectiles is introduced. This methodology improves upon the traditional design methodology for flight projectiles by addressing the difference in fidelity levels of the applicable design tools, classifying designs and components by families and their characteristics, and applying the tools of IPD in a three phased approach for the low, medium and high fidelity models of each discipline to create an efficient design methodology for flight projectiles. This includes an evaluation of the relationship between the number of alternatives at each fidelity level and the time to evaluate each configuration. Early on in the design process, there may be many configurations under evaluation, therefore it will be advantageous to use faster running low fidelity models to reduce the number to only those in the feasible design space, and to use medium fidelity models populated with data from the low fidelity codes as the field narrows, and to use the more time consuming and computationally expensive models with the fewer final design candidates. This new design methodology improves upon the traditional development methods by the use of models of appropriate fidelity levels at each stage of development, and the design process is also improved by proper and timely integration between predictive codes of varying fidelity levels. The utilization of such a highly desirable methodology enables the efficient design of flight projectiles that meets the customer needs of increased levels of performance against new

  11. Fragmentation of water on swift 3He 2+ ion impact

    NASA Astrophysics Data System (ADS)

    Sabin, John R.; Cabrerra-Trujillo, Remigio; Stolterfoht, Nikolaus; Deumens, Erik; Öhrn, Yngve

    2009-01-01

    Charge exchange and fragmentation are the usual results in ion-molecule collision systems, and the specifics of the fragmentation process determine the chemical destiny of the target system. In this paper, we report recent progress on calculations of the fragmentation patterns for the model system He2+ + H2O for projectile energies of a few keV. The calculations are obtained using the electron-nuclear dynamics (END) method for solution of the time-dependent Schrödinger equation.

  12. Chameleon fragmentation

    SciTech Connect

    Brax, Philippe

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  13. A New Mechanism of Sediment Attachment to Oil in Turbulent Flows: Projectile Particles.

    PubMed

    Zhao, Lin; Boufadel, Michel C; Katz, Joseph; Haspel, Gal; Lee, Kenneth; King, Thomas; Robinson, Brian

    2017-09-20

    The interaction of oil and sediment in the environment determines, to a large extent, the trajectory and fate of oil. Using confocal microscope imaging techniques to obtain detailed 3D structures of oil-particle aggregates (OPAs) formed in turbulent flows, we elucidated a new mechanism of particle attachment, whereby the particles behave as projectiles penetrating the oil droplets to depths varying from ∼2 to 10 μm due to the hydrodynamic forces in the water. This mechanism results in a higher attachment of particles on oil in comparison with adsorption, as commonly assumed. The projectile hypothesis also explains the fragmentation of oil droplets with time, which occurred after long hours of mixing, leading to the formation of massive OPA clusters. Various lines of inquiry strongly suggested that protruding particles get torn from oil droplets and carry oil with them, causing the torn particles to be amphiphillic so that they contribute to the formation of massive OPAs of smaller oil droplets (<∼5-10 μm). Low particle concentration resulted in large, irregularly shaped oil blobs over time, the deformation of which without fragmentation could be due to partial coverage of the oil droplet surface by particles. The findings herein revealed a new pathway for the fate of oil in environments containing non-negligible sediment concentrations.

  14. Direct detection of projectile relics from the end of the lunar basin-forming epoch.

    PubMed

    Joy, Katherine H; Zolensky, Michael E; Nagashima, Kazuhide; Huss, Gary R; Ross, D Kent; McKay, David S; Kring, David A

    2012-06-15

    The lunar surface, a key proxy for the early Earth, contains relics of asteroids and comets that have pummeled terrestrial planetary surfaces. Surviving fragments of projectiles in the lunar regolith provide a direct measure of the types and thus the sources of exogenous material delivered to the Earth-Moon system. In ancient [>3.4 billion years ago (Ga)] regolith breccias from the Apollo 16 landing site, we located mineral and lithologic relics of magnesian chondrules from chondritic impactors. These ancient impactor fragments are not nearly as diverse as those found in younger (3.4 Ga to today) regolith breccias and soils from the Moon or that presently fall as meteorites to Earth. This suggests that primitive chondritic asteroids, originating from a similar source region, were common Earth-Moon-crossing impactors during the latter stages of the basin-forming epoch.

  15. Interactions in hydrogen of relativistic neon to nickel projectiles: Total charge-changing cross sections

    NASA Astrophysics Data System (ADS)

    Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Jones, F. C.; Knott, C. N.; Lindstrom, P. J.; Mitchell, J. W.; Potenza, R.; Romanski, J.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.; Zhang, X.

    1994-06-01

    A liquid hydrogen target was used to study the nuclear fragmentation of beams of relativistic heavy ions, 22Ne to 58Ni, over an energy range 400 to 900 MeV/nucleon. The experiments were carried out at the Lawrence Berkeley Laboratory Bevalac HISS facility, using the charge-velocity-rigidity method to identify the charged fragments. Here we describe the general concept of the experiment and present total charge-changing cross sections obtained from 17 separate runs. These new measured cross sections display an energy dependence which follows semiempirical model predictions. The mass dependence of the cross sections behaves as predicted by optical models, but within the experimental energy range, the optical model parameters display a clear energy dependence. The isospin of the projectile nuclei also appears to be an important factor in the interaction process.

  16. Interactions in hydrogen of relativistic neon to nickel projectiles: Total charge-changing cross sections

    SciTech Connect

    Chen, C.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T.G.; Insolia, A.; Jones, F.C.; Knott, C.N.; Lindstrom, P.J.; Mitchell, J.W.; Potenza, R.; Romanski, J.; Russo, G.V.; Soutoul, A.; Testard, O.; Tull, C.E.; Tuve, C.; Waddington, C.J.; Webber, W.R.; Wefel, J.P.; Zhang, X. Space Science Laboratory, University of California, Berkeley, California 94720 Service d'Astrophysique, Centre d'Etudes de Saclay, 91191 Gif-sur-Yvette, Cedex Dipartimento di Fisica, Universita di Catania, Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia 57, I 95129-Catania NASA

    1994-06-01

    A liquid hydrogen target was used to study the nuclear fragmentation of beams of relativistic heavy ions, [sup 22]Ne to [sup 58]Ni, over an energy range 400 to 900 MeV/nucleon. The experiments were carried out at the Lawrence Berkeley Laboratory Bevalac HISS facility, using the charge-velocity-rigidity method to identify the charged fragments. Here we describe the general concept of the experiment and present total charge-changing cross sections obtained from 17 separate runs. These new measured cross sections display an energy dependence which follows semiempirical model predictions. The mass dependence of the cross sections behaves as predicted by optical models, but within the experimental energy range, the optical model parameters display a clear energy dependence. The isospin of the projectile nuclei also appears to be an important factor in the interaction process.

  17. Heavy ion fragmentation experiments at the bevatron

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.

    1976-01-01

    Collaborative research efforts to study the fragmentation processes of heavy nuclei in matter using heavy ion beams of the Bevatron/Bevalac are described. The goal of the program is to obtain the single particle inclusive spectra of secondary nuclei produced at 0 deg by the fragmentation of heavy ion beam projectiles. The process being examined is B+T yields F + anything, where B is the beam nucleus, T is the target nucleus, and F is the detected fragment. The fragments F are isotopically identified by experimental procedures involving magnetic analysis, energy loss and time-of-flight measurements. Effects were also made to: (a) study processes of heavy nuclei in matter, (b) measure the total and partial production cross section for all isotopes, (c) test the applicability of high energy multiparticle interaction theory to nuclear fragmentation, (d) apply the cross section data and fragmentation probabilities to cosmic ray transport theory, and (e) search for systematic behavior of fragment production as a means to improve existing semi-empirical theories of cross-sections.

  18. A comparison of finite element analysis to smooth particle hydrodynamics for application to projectile impact on cementitious material

    NASA Astrophysics Data System (ADS)

    Nordendale, Nikolas A.; Heard, William F.; Sherburn, Jesse A.; Basu, Prodyot K.

    2016-03-01

    The response of structural components of high-strength cementitious (HSC) materials to projectile impact is characterized by high-rate fragmentation resulting from strong compressive shock waves coupled with reflected tensile waves. Accurate modeling of armor panels of such brittle materials under high-velocity projectile impact is a complex problem requiring meticulous experimental characterization of material properties. In a recent paper by the authors, an approach to handle such problems based on a modified Advanced Fundamental Concrete (AFC) constitutive model was developed. In the HSC panels considered in this study, an analogous approach is applied, and the predictions are verified with ballistic impact test data. Traditional Lagrangian finite element analysis (FEA) of these problems tends to introduce errors and suffers from convergence issues resulting from large deformations at free surfaces. Also, FEA cannot properly account for the issues of secondary impact of spalled fragments when multiple armor panels are used. Smoothed particle hydrodynamics (SPH) is considered to be an attractive alternative to resolve these and other issues. However, SPH-based quantitative results have been found to be less accurate than the FEA-based ones when the deformations are not sufficiently large. This paper primarily focuses on a comparison of FEA and SPH models to predict high-velocity projectile impact on single and stacked HSC panels. Results are compared to recent ballistic experiments performed as a part of this research, and conclusions are drawn based on the findings.

  19. Projectile impact Hugoniot parameters for selected materials

    SciTech Connect

    Vigil, M G

    1989-08-01

    The Rankine Hugoniot equation relating the conversion of momentum across a shock front and the empirical relationship for shock velocity as a function of particle velocity are used to calculate the impact pressures for selected materials. The shock velocity and particle velocities are then calculated as a function of impact pressures. The calculated data are graphically presented sets of three figures for the selected materials as follows: Impact pressure as a function of impact velocity, impact pressure as a function of particle velocity, impact pressure as a function of shock velocity. Given the projectile impact velocity and material Hugoniot information, this graphical representation of the data allows for a fast approximation of the impact pressure particle velocity, and shock velocity in the target material. 9 refs., 1 fig., 3 tabs.

  20. Turbulent Flow Past Projectiles: A Computational Investigation

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Donald; Buckley, Liam; Carlucci, Pasquale; Thangam, Siva

    2010-11-01

    Projectiles with free spinning bases are often used for smart munitions to provide effective control, stability and terminal guidance. Computational investigations are performed for flow past cylinders aligned along their axis where a base freely spins while attached to and separated at various distances from a non-spinning fore-body. The energy spectrum is modified to incorporate the effects of swirl and rotation using a parametric characterization of the model coefficients. An efficient finite-volume algorithm is used to solve the time-averaged equations of motion and energy along with the modeled form of transport equations for the turbulence kinetic energy and the scalar form of turbulence dissipation. Computations are performed for both rigid cylinders as well as cylinders with free-spinning bases. Experimental data for a range of spin rates and free stream flow conditions obtained from subsonic wind tunnel with sting-mounted spinning cylinders is used for validating the computational findings.

  1. [Traumatology due to ancient lead missile projectiles].

    PubMed

    Moog, Ferdinand Peter

    2002-01-01

    The lead missiles of slingers in antiquity, known as glans or molybdis, are widely considered to have been very dangerous projectiles of the ancient armies. Ballistic investigations and results of experimental archaeology seem to confirm this. However, the findings of medical history concerning these missiles disagree with this view. In ancient medical texts these missiles are only mentioned sporadically, as in Celsus or Paul of Aigina, and wounds caused by them are merely discussed incidentally. There is so far no evidence at all on them in palaeopathology. It is undisputed however that in individual cases these missiles were able to cause serious injuries, especially when they hit unprotected parts of the body. Accordingly, their main effect seems to have consisted in the intimidation of the enemy.

  2. Veterinary Forensics: Firearms and Investigation of Projectile Injury.

    PubMed

    Bradley-Siemens, N; Brower, A I

    2016-09-01

    Projectile injury represents an estimated 14% of reported animal cruelty cases in the United States. Cases involving projectiles are complicated by gross similarities to other common types of injury, including bite wounds and motor vehicle injuries, by weapons and ammunition not commonly recognized or understood by veterinary medical professionals, and by required expertise beyond that employed in routine postmortem examination. This review describes the common types of projectile injuries encountered within the United States, as well as firearms and ammunition associated with this form of injury. The 3 stages of ballistics-internal, external, and terminal-and wounding capacity are discussed. A general understanding of firearms, ammunition, and ballistics is necessary before pursuing forensic projectile cases. The forensic necropsy is described, including gunshot wound examination, projectile trajectories, different imaging procedures, collection and storage of projectile evidence, and potential advanced techniques for gunpowder analysis. This review presents aspects of projectile injury investigation that must be considered in tandem with standard postmortem practices and procedures to ensure reliable conclusions are reached for medicolegal as well as diagnostic purposes. © The Author(s) 2016.

  3. Trajectory Control of Small Rotating Projectiles by Laser Sparks

    NASA Astrophysics Data System (ADS)

    Starikovskiy, Andrey; Limbach, Christopher; Miles, Richard

    2015-09-01

    The possibility of controlling the trajectory of the supersonic motion of a rotating axisymmetric projectile using a remotely generated laser spark was investigated. The dynamic images of the interaction of thermal inhomogeneity created by the laser spark with the bow shock in front of the projectile were obtained. The criterion for a strong shock wave interaction with the thermal inhomogeneity at different angles of a shock wave was derived. Significant changes in the configuration of the bow shock wave and changes in the pressure distribution over the surface of the rotating projectile can appear for laser spark temperature of T' = 2500-3000 K. The experiment showed that strong interaction takes place for both plane and oblique shock waves. The measurement of the velocity of the precession of the rotating projectile axis from the initial position in time showed that the angle of attack of the projectile deviates with a typical time of perturbation propagation along the projectile's surface. Thus the laser spark can change the trajectory of the rotating projectile, moving at supersonic speed, through the creation of thermal heterogeneity in front of it.

  4. Projectile transverse motion and stability in electromagnetic induction launchers

    SciTech Connect

    Shokair, I.R.

    1993-08-01

    The transverse motion of a projectile in an electromagnetic induction launcher is considered. The equations of motion for translation and rotation are derived assuming a rigid projectile and a flyway restoring force per unit length that is proportional to the local displacement. Transverse forces and torques due to energized coils are derived for displaced or tilted projectile elements based on a first order perturbation method. The resulting equations of motion for a rigid projectile composed of multiple elements in a multi-coil launcher are analyzed as a coupled oscillator system of equations and a simple stability condition is derived. The equations of motion are incorporated into the 2-D Slingshot code and numerical solutions for the transverse motion are obtained. For the 20 meter navy launcher parameters we find that stability is achieved with a flyway spring constant of k {approx} 1{times} 10{sup 8} N/m{sup 2}. For k {approx} 1.5 {times} 10{sup 8} N/m{sup 2} and sample coil misalignment modeled as a sine wave of I mm amplitude at wavelengths of one or two meters, the projectile displacement grows to a maximum of 4 mm. This growth is due to resonance between the natural frequency of the Projectile transverse motion and the coil displacement wavelength. This resonance does not persist because of the changing axial velocity. Random coil displacement is also found to cause roughly the same projectile displacement. For the maximum displacement a rough estimate of the transverse pressure is 50 bars.

  5. Scattering-angle dependence of doubly differential cross sections for fragmentation of H{sub 2} by proton impact

    SciTech Connect

    Egodapitiya, K. N.; Sharma, S.; Laforge, A. C.; Schulz, M.

    2011-01-15

    We have measured double differential cross sections (DDCS) for proton fragment formation for fixed projectile energy losses as a function of projectile scattering angle in 75 keV p + H{sub 2} collisions. An oscillating pattern was observed in the angular dependence of the DDCS with a frequency about twice as large as what we found earlier for nondissociative ionization. Possible origins for this frequency doubling are discussed.

  6. Microcraters formed in glass by low density projectiles

    NASA Technical Reports Server (NTRS)

    Mandeville, J.-C.; Vedder, J. F.

    1971-01-01

    Microcraters were produced in soda-lime glass by the impact of low density projectiles of polystyrene (p = 1.06 g/cu cm) with masses between 0.7 and 62 picograms and velocities between 2 and 14 km/s. The morphology of the craters depended on the velocity and the angle of incidence of the projectiles and these are discussed in detail. It was found that the transitions in morphology of the craters formed by polystyrene spheres occurred at higher velocities than they did for more dense projectiles.

  7. Dynamic impact analysis of the M1 105mm projectile

    SciTech Connect

    Walls, J.C.; Webb, D.S.

    1993-06-01

    Evaluation of the effects of [open quotes]rough-handling[close quotes]-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.

  8. Dynamic impact analysis of the M1 105mm projectile

    SciTech Connect

    Walls, J.C.; Webb, D.S.

    1993-06-01

    Evaluation of the effects of {open_quotes}rough-handling{close_quotes}-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.

  9. Response of spacecraft window materials to hypervelocity projectile impact

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1991-01-01

    This paper presents the results of an investigation of the response of window materials to hypervelocity projectile impact. Window impact damage is characterized according to the nature and extent of surface and internal damage. Analysis of the test data indicates that, for single-pane specimens, the extent of the damage to the test specimens can be written as functions of the impact parameters of the original projectile and the geometric and material properties of the projectile/ window system. These functions can be used to perform parameter-sensitivity studies and to evaluate hypothetical design applications and configurations.

  10. Corrected Launch Speed for a Projectile Motion Laboratory

    NASA Astrophysics Data System (ADS)

    Sanders, Justin M.; Boleman, Michael W.

    2013-09-01

    At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range calculated using the speed as determined by the photogates. In this paper, we will discuss the origin of this systematic error and derive a simple formula to correct it. In particular, we find that the launch speed given by our instrument is significantly different from the actual launch speed of our projectile.

  11. Uniform Projectile Motion: Dynamics, Symmetries and Conservation Laws

    NASA Astrophysics Data System (ADS)

    Swaczyna, Martin; Volný, Petr

    2014-04-01

    A geometric nonholonomic theory is applied to the problem of uniform projectile motion, i.e. motion of a projectile with constant instantaneous speed. The problem is investigated from the kinematic and dynamic point of view. Corresponding kinematic parameters of classical and uniform projectile motion are compared, nonholonomic Hamilton equations are derived and their solvability is discussed. Symmetries and conservation laws of the considered system are studied, the nonholonomic formulation of a conservation law of generalized energy is found as one of the corresponding Noetherian first integrals of this nonholonomic system.

  12. The projectile-wall interface in rail launchers

    NASA Astrophysics Data System (ADS)

    Thio, Y. C.; Huerta, M. A.; Boynton, G. C.; Tidman, D. A.; Wang, S. Y.; Winsor, N. K.

    1993-01-01

    At sufficiently high velocity, an energetic gaseous interface is formed between the projectile and the gun wall. We analyze the flow in this interface in the regime of moderately high velocity. The effect of this gaseous interface is to push the gun wall radially outward and shrink the projectile radially inward. Our studies show that significant plasma blow-by can be expected in most experimental railguns in which organic polymers are used as insulators. Since plasma leakage may result in the reduction of propulsion pressure and possibly induce the separation of the primary, the results point to the importance of having sufficiently stiff barrels and structurally stiff but 'ballistically compliant' projectile designs.

  13. Neutron-rich rare-isotope production from projectile fission of heavy nuclei near 20 MeV/nucleon beam energy

    NASA Astrophysics Data System (ADS)

    Vonta, N.; Souliotis, G. A.; Loveland, W.; Kwon, Y. K.; Tshoo, K.; Jeong, S. C.; Veselsky, M.; Bonasera, A.; Botvina, A.

    2016-12-01

    We investigate the possibilities of producing neutron-rich nuclides in projectile fission of heavy beams in the energy range of 20 MeV/nucleon expected from low-energy facilities. We report our efforts to theoretically describe the reaction mechanism of projectile fission following a multinucleon transfer collision at this energy range. Our calculations are mainly based on a two-step approach: The dynamical stage of the collision is described with either the phenomenological deep-inelastic transfer model (DIT) or with the microscopic constrained molecular dynamics model (CoMD). The de-excitation or fission of the hot heavy projectile fragments is performed with the statistical multifragmentation model (SMM). We compared our model calculations with our previous experimental projectile-fission data of 238U (20 MeV/nucleon) + 208Pb and 197Au (20 MeV/nucleon) + 197Au and found an overall reasonable agreement. Our study suggests that projectile fission following peripheral heavy-ion collisions at this energy range offers an effective route to access very neutron-rich rare isotopes toward and beyond the astrophysical r-process path.

  14. Dynamics of dust-free cavities behind fast projectiles in a dusty plasma under microgravity conditions

    SciTech Connect

    Caliebe, D.; Arp, O.; Piel, A.

    2011-07-15

    The penetration of a dusty plasma by fast charged projectiles is studied under microgravity conditions. The mass and charge of the projectiles are larger than those of the target particles. A projectile generates a dust-free cavity in its wake, whose shape strongly depends on the projectile velocity. The faster the projectile the more elongated becomes the cavity while its cross-section decreases. The opening time of the cavity is found independent of the projectile velocity. For supersonic projectiles, the dynamics of the cavity can be decomposed into an initial impulse and a subsequent elastic response that can be modeled by a damped harmonic oscillator.

  15. Fragmentation Processes

    NASA Astrophysics Data System (ADS)

    Whelan, Colm T.

    2012-12-01

    Preface; 1. Direct and resonant double-photoionization: from atoms to solids L. Avaldi and G. Stefani; 2. The application of propagation exterior complex scaling to atomic collisions P. L. Bartlett and A. T. Stelbovics; 3. Fragmentation of molecular-ion beams in intense ultra-short laser pulses I. Ben-Itzhak; 4. Atoms with one and two active electrons in strong laser fields I. A. Ivanov and A. S. Kheifets; 5. Experimental aspects of ionization studies by positron and positronium impact G. Laricchia, D. A. Cooke, Á. Kövér and S. J. Brawley; 6. (e,2e) spectroscopy using fragmentation processes J. Lower, M. Yamazaki and M. Takahashi; 7. A coupled pseudostate approach to the calculation of ion-atom fragmentation processes M. McGovern, H. R. J. Walters and C. T. Whelan; 8. Electron Impact Ionization using (e,2e) coincidence techniques from threshold to intermediate energies A. J. Murray; 9. (e,2e) processes on atomic inner shells C. T. Whelan; 10. Spin resolved atomic (e,2e) processes J. Lower and C. T. Whelan; Index.

  16. A high-speed study of the dynamic bullet-body interactions produced by grazing gunshots with full metal jacketed and lead projectiles.

    PubMed

    Thali, M J; Kneubuehl, B P; Zollinger, U; Dirnhofer, R

    2003-03-27

    Experimenting upon a synthetic, non-biological Skull-Brain Model, our goal was to document and study the bullet-body interaction of grazing (glancing, tangential) gunshots. Thanks to the high-speed study of the dynamic bullet-body interaction it was possible to document the glancing behavior of projectiles with a resolution of 50 million pictures per second. It was possible to demonstrate the differing deformation and fragmentation patterns between the 9mm Luger full metal jacketed projectile and the 38 Smith & Wesson (S & W) lead round nose projectile. In a true-to-life manner the morphologic fracture systems could be documented by utilization of the model in dependence of the projectile's behavior, deformation, and fragmentation. Based on these experimental studies with body models, conclusions could be drawn for surgical and reconstructive forensic questions in real cases. In summary, model substitutes offer a suitable basis for the study of the bullet-body interaction because the experiments are reproducible, totally independent of the biological variances of corpse and animal experiments, and are harmless from the ethical perspective.

  17. Penetration analysis of projectile with inclined concrete target

    NASA Astrophysics Data System (ADS)

    Kim, S. B.; Kim, H. W.; Yoo, Y. H.

    2015-09-01

    This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction) and CONCRETE_DAMAGE (K&C concrete) models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.

  18. Determination of atmospheric density using a space-launched projectile

    NASA Technical Reports Server (NTRS)

    Menees, G. P.; Park, C.; Brown, K. G.; Wilson, J. F.

    1985-01-01

    A method is proposed that provides advance information about unpredictable atmospheric density dispersions that must be accommodated during random operations of aeroassisted-orbital-transfer vehicles (AOTVs). The principal feature is that a test or 'scout' projectile precedes the AOTV through the same region of the atmosphere as that of the predicted transatmospheric flight trajectory. The atmospheric density structure is determined from the vehicle's aerodynamic deceleration characteristics by on-board or ground-based tracking equipment. The time lag between passage of the projectile and the AOTV can be adjusted to only that time necessary to implement required guidance, navigation, and control (GN&C) corrections. The various strategies available to control the projectile's flight characteristics are analyzed in detail. The results are correlated with aerothermodynamic heating and materials requirements to ensure the survival of the projectile and, consequently, the capability of the AOTV to navigate a variable upper atmosphere within specified limits.

  19. 35. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. 6 POWDER MAGAZINE AND MELT LOADING), GENERAL VIEW, SHOWING SOUTHWEST ELEVATION. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  20. 2. VAL CONCRETE 'A' FRAME STRUCTURE SHOWING CAMERA TOWER, PROJECTILE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VAL CONCRETE 'A' FRAME STRUCTURE SHOWING CAMERA TOWER, PROJECTILE LOADING DECK AND BREECH END OF LAUNCHER BRIDGE LOOKING SOUTH. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  1. 34. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. 6 POWDER MAGAZINE AND MELT LOADING), LOOKING SOUTH ALONG EAST SIDE OF BUILDING. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  2. 15. VAL, DETAIL OF SUPPORT CARRIAGE, PROJECTILE LOADING DECK AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VAL, DETAIL OF SUPPORT CARRIAGE, PROJECTILE LOADING DECK AND THE BREECH END OF THE LAUNCHER BRIDGE LOOKING NORTHWEST. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  3. 36. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. 6 POWDER MAGAZINE AND MELT LOADING), GENERAL VIEW SHOWING NORTHEAST WALL. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  4. 32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER SLAB AND UNDERSIDE OF LAUNCHER BRIDGE LOOKING SOUTHWEST. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  5. 17. VAL PROJECTILE LOADING DECK AND BREECH END OF LAUNCHER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VAL PROJECTILE LOADING DECK AND BREECH END OF LAUNCHER BRIDGE LOOKING SOUTH. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  6. 22. Emplacement no. 1 showing well for projectile hoist at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Emplacement no. 1 showing well for projectile hoist at right. at left is passage toward the shot gallery. View looking northwest - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

  7. 3. VAL PROJECTILE LOADING DECK, SUPPORT CARRIAGE AND LAUNCHING BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VAL PROJECTILE LOADING DECK, SUPPORT CARRIAGE AND LAUNCHING BRIDGE LOOKING SOUTHWEST. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  8. Oblique impact: Projectile richochet, concomitant ejecta and momentum transfer

    NASA Technical Reports Server (NTRS)

    Gault, Donald E.; Schultz, Peter H.

    1987-01-01

    Experimental studies of oblique impact indicate that projectile richochet occurs for trajectory angles less than 30 deg and that the richocheted projectile, accompanied by some target material, are ejected at velocities that are a large fraction of the impact velocity. Because the probability of occurrence of oblique impact less than 30 deg on a planetary body is about one out of every four impact events, oblique impacts would seem to be a potential mechanism to provide a source of meteorites from even the largest atmosphere-free planetary bodies. Because the amount of richocheted target material cannot be determined from previous results, additional experiments in the Ames Vertical Gun laboratory were undertaken toward that purpose using pendulums; one to measure momentum of the richocheted projectile and concomitant target ejecta, and a second to measure the momentum transferred from projectile to target. These experiments are briefly discussed.

  9. 23. Emplacement no. 1, view looking up projectile hoist well ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Emplacement no. 1, view looking up projectile hoist well from magazine level, showing the rear of the delivery table - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

  10. 16. VAL PROJECTILE LOADING DECK AND VIEW OF RESERVOIR LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VAL PROJECTILE LOADING DECK AND VIEW OF RESERVOIR LOOKING SOUTHWEST WITH MORRIS DAM IN THE DISTANCE. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  11. Measurement of sound emitted by flying projectiles with aeroacoustic sources

    NASA Technical Reports Server (NTRS)

    Cho, Y. I.; Shakkottai, P.; Harstad, K. G.; Back, L. H.

    1988-01-01

    Training projectiles with axisymmetric ring cavities that produce intense tones in an airstream were shot in a straight-line trajectory. A ground-based microphone was used to obtain the angular distribution of sound intensity produced from the flying projectile. Data reduction required calculation of Doppler and attenuation factors. Also, the directional sensitivity of the ground-mounted microphone was measured and used in the data reduction. A rapid angular variation of sound intensity produced from the projectile was found that can be used to plot an intensity contour map on the ground. A full-scale field test confirmed the validity of the aeroacoustic concept of producing a relatively intense whistle from the projectile, and the usefulness of short-range flight tests that yield acoustic data free of uncertainties associated with diffraction, reflection, and refraction at jet boundaries in free-jet tests.

  12. 19. Emplacement no. 1, interior of projectile magazine or shot ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Emplacement no. 1, interior of projectile magazine or shot room, view to south, line overhead crane shown on ceiling - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

  13. 46. BUILDING NO. 477, ORDNANCE FACILITY (NONGASEOUS PROJECTILE LOADING), LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. BUILDING NO. 477, ORDNANCE FACILITY (NON-GASEOUS PROJECTILE LOADING), LOOKING WEST AT NORTHEAST AND SOUTHEAST SIDES. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  14. Guiding supersonic projectiles using optically generated air density channels

    NASA Astrophysics Data System (ADS)

    Johnson, Luke A.; Sprangle, Phillip

    2015-09-01

    We investigate the feasibility of using optically generated channels of reduced air density to provide trajectory correction (guiding) for a supersonic projectile. It is shown that the projectile experiences a force perpendicular to its direction of motion as one side of the projectile passes through a channel of reduced air density. A single channel of reduced air density can be generated by the energy deposited from filamentation of an intense laser pulse. We propose changing the laser pulse energy from shot-to-shot to build longer effective channels. Current femtosecond laser systems with multi-millijoule pulses could provide trajectory correction of several meters on 5 km trajectories for sub-kilogram projectiles traveling at Mach 3.

  15. Projectile-power-compressed magnetic-field pulse generator

    SciTech Connect

    Barlett, R.H.; Takemori, H.T.; Chase, J.B.

    1983-03-17

    Design considerations and experimental results are presented of a compressed magnetic field pulsed energy source. A 100-mm-diameter, gun-fired projectile of approx. 2MJ kinetic energy was the input energy source. An initial magnetic field was trapped and compressed by the projectile. With a shorted load, a magajoule in a nanohenry was the design goal, i.e., 50 percent energy transformation from kinetic to magnetic. Five percent conversion was the highest recorded before gauge failure.

  16. a Study of Ricochet Phenomenon for Inclined Impact of Projectile

    NASA Astrophysics Data System (ADS)

    Jo, Jong-Hyun; Lee, Young-Shin

    In this study, the numerical simulation using AUTODYN-3D program was investigated for trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate(PC) plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile's trajectory in the PC plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The numerical analyses were used to study the effect of the angle of inclination on the trajectory and kinetic energy of the projectile. The dynamic deformation behaviors tests of PC were compared with numerical simulation results which can be used for predictive purpose. Ricochet phenomenon for angles of inclination of 0° ≤ θ ≤ 20° in the analysis. The projectile perforated the plate for θ > 30°, thus defined a failure envelope for numerical configuration. The numerical analyses was used to study the effect under the projectile impact velocity on the depth of penetration(DOP).

  17. Universality in fragment inclusive yields from Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Insolia, A.; Tuvè, C.; Albergo, S.; Bieser, F.; Brady, F. P.; Caccia, Z.; Cebra, D.; Chacon, A. D.; Chance, J. L.; Choi, Y.; Costa, S.; Elliott, J. B.; Gilkes, M.; Hauger, J. A.; Hirsch, A. S.; Hjort, E. L.; Justice, M.; Keane, D.; Kintner, J.; Lisa, M.; Matis, H. S.; McMahan, M.; McParland, C.; Olson, D. L.; Partlan, M. D.; Porile, N. T.; Potenza, R.; Rai, G.; Rasmussen, J.; Ritter, H. G.; Romero, J. L.; Russo, G. V.; Scharenberg, R.; Scott, A.; Shao, Y.; Srivastava, B. K.; Symons, T. J. M.; Tincknell, M. L.; Wang, S.; Warren, P. G.; Wieman, H. H.; Wolf, K. L.

    2001-11-01

    The inclusive light fragment (Z⩽7) yield data in Au+Au reactions, measured by the EOS Collaboration at the LBNL Bevalac, are presented and discussed. For peripheral collisions the measured charge distributions develop progressively according to a power law which can be fitted by a single τ exponent independently of the bombarding energy in the range 250-1200 A MeV. In addition to this universal feature, we observe that the location of the maximum in the individual yields of different charged fragments shift towards lower multiplicity as the fragment charge increases from Z=3 to Z=7. This trend is common to all six measured beam energies. Moments of charge distributions and correlations among different moments are reported. Finally, the THe,DT thermometer has been constructed for central and peripheral collisions using the double yield ratios of He and D, T projectile fragments. The measured nuclear temperatures are in agreement with experimental findings in other fragmentation reactions.

  18. Perforation of woven fabric by spherical projectiles

    SciTech Connect

    Shim, V.P.W.; Tan, V.B.C.; Tay, T.E.

    1995-12-31

    Rectangular specimens of Twaron{reg_sign} fabric, clamped on two opposite sides, are subjected to impact perforation by 9.5 mm diameter spherical steel projectiles at speeds ranging from 140 m/s to 420 m/s. This plain woven fabric, comprising PPTA (poly-paraphenylene terepthalamide) fibers, is commonly employed in flexible an-nor applications. Its perforation response is examined in terms of residual velocity, energy absorbed and resulting deformation patterns. The existence of a critical or transition impact velocity, beyond which there is a significant reduction in energy absorbed by perforation, is observed. Differences in creasing and deformation induced in specimens are also demarcated by this transition impact velocity. Effects of difference in boundary conditions (clamped and free) on yarn breakage are also noted. A numerical model, based on an initially orthogonal network of pin-jointed bars interconnected at nodes, is formulated to simulate the fabric. Fiber yam mechanical properties are represented via a three-element spring-dashpot model which encapsulates viscoelastic behavior and fiber failure. Numerical results exhibit good correlation with experimental observations in terms of prediction of threshold perforation velocity, energy absorbed, occurrence of a transition critical velocity and fabric deformation characteristics.

  19. Impact Behaviour of Soft Body Projectiles

    NASA Astrophysics Data System (ADS)

    Kalam, Sayyad Abdul; Rayavarapu, Vijaya Kumar; Ginka, Ranga Janardhana

    2017-04-01

    Bird strike analysis is a common type of analysis done during the design and analysis of primary structures such as engine cowlings or fuselage panels. These simulations are done in order to predict whether various designs will pass the necessary certification tests. Composite materials are increasingly being used in aerospace industry and bird strike is a major threat which may lead to serious structural damage of those materials. Such phenomenon may arise from numerous impact scenarios. The focus of current study is on the finite element modeling for composite structures and simulation of high velocity impact loads from soft body projectiles with an explicit dynamics code AUTODYN. This paper investigates the methodology which can be utilized to certify an aircraft for bird strike resistance using computational technique by first demonstrating the accuracy of the method for bird impact on rigid target modeling and then applies the developed model to a more complex problem. The model developed for bird strike threat assessment incorporates parameters of bird number (bird density), bird body mass, equation of state (EOS) and bird path during impact.

  20. Heavy-ion fragmentation studies in thick water absorbers

    NASA Astrophysics Data System (ADS)

    Shavers, M. R.; Miller, J.; Schimmerling, W.; Wilson, J. W.; Townsend, L. W.

    Proposed long-term space missions could expose crewmembers to significant fluxes of galactic cosmic radiation (GCR) particles and secondary particles created from nuclear collisions. An assessment of radiobiological risks is dependent upon an accurate description of the charged-particle radiation field inside the human body. As shield thickness increases and the incident ions are slowed, the production of secondary particles contributes an increasingly significant fraction of the total dose until eventually secondary particles become more important than the primary particles. The nuclear mean free path of the GCR ions (which usually have nuclear charge between 1 (protons) and 26 (iron), both inclusive) are comparable with thicknesses typical of spacecraft structures and the human body. Collisions in these media will create projectile and target fragments with charge less than that of the primary particle, and each interaction event can have a multiplicity of more than one emerging interaction product. Projectile fragments usually continue on with very nearly the velocity of the primary ion (the so-called straightahead approximation). Having sufficient energy, the fragments may collide with atomic nuclei in thick shields and create a second generation of fragments, and so on. Target fragments are emitted from a struck nucleus, usually with much lower energy than projectile fragments and nearly isotropically in the rest frame of the absorbing medium. The resulting spectrum of particles and their energy loss rates will be very different from that in the unshielded environment, will determine the radiobiological impact on exposed living tissues -- whether in space or in ground-based radiobiology experiments -- and will play an important role in radiation effects on microelectronics.

  1. Relativistic heavy ion fragmentation at HISS (Heavy Ion Spectrometer System)

    SciTech Connect

    Tull, C.E.

    1990-10-01

    An experiment was conducted at the Lawrence Berkeley Laboratory to measure projectile fragmentation of relativistic heavy ions. Charge identification was obtained by the use of a Cerenkov Hodoscope operating above the threshold for total internal reflection, while velocity measurement was performed by use of a second set of Cerenkov radiators operating at the threshold for total internal reflection. Charge and mass resolution for the system was {sigma}{sub Z} = 0.2 e and {sigma}{sub A} = 0.2 u. Measurements of the elemental and isotopic production cross sections for the fragmentation of {sup 40}Ar at 1.65{center dot}A GeV have been compared with an Abrasion-Ablation Model based on the evaporation computer code GEMINI. The model proves to be an accurate predictor of the cross sections for fragments between Chlorine and Boron. The measured cross section were reproduced using simple geometry with charge dispersions induced by zero-point vibrations of the giant dipole resonance for the prompt abrasion stage, and injecting an excitation energy spectrum based on a final state interaction with scaling factor E{sub fsi} = 38.8 MeV/c. Measurement of the longitudinal momentum distribution widths for projectile fragments are consistent with previous experiment and can be interpreted as reflecting the Fermi momentum distribution in the initial projectile nucleus. Measurement of the transverse momentum indicate an additional, unexplained dependence of the reduced momentum widths on fragment mass. This dependence has the same sign and similar slope to previously measured fragments of {sup 139}La, and to predictions based on phase-space constraints on the final state of the system.

  2. Heavy-ion fragmentation studies in thick water absorbers

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Miller, J.; Schimmerling, W.; Wilson, J. W.; Townsend, L. W.

    1993-01-01

    Proposed long-term space missions could expose crewmembers to significant fluxes of galactic cosmic radiation (GCR) particles and secondary particles created from nuclear collisions. An assessment of radiobiological risks is dependent upon an accurate description of the charged-particle radiation field inside the human body. As shield thickness increases and the incident ions are slowed, the production of secondary particles contributes an increasingly significant fraction of the total dose until eventually secondary particles become more important than the primary particles. The nuclear mean free path of the GCR ions (which usually have nuclear charge between 1 (protons) and 26 (iron), both inclusive) are comparable with thicknesses typical of spacecraft structures and the human body. Collisions in these media will create projectile and target fragments with charge less than that of the primary particle, and each interaction event can have a multiplicity of more than one emerging interaction product. Projectile fragments usually continue on with very nearly the velocity of the primary ion (the so-called straightahead approximation). Having sufficient energy, the fragments may collide with atomic nuclei in thick shields and create a second generation of fragments, and so on. Target fragments are emitted from a struck nucleus, usually with much lower energy than projectile fragments and nearly isotropically in the rest frame of the absorbing medium. The resulting spectrum of particles and their energy loss rates will be very different from that in the unshielded environment, will determine the radiobiological impact on exposed living tissues -- whether in space or in ground-based radiobiology experiments -- and will play an important role in radiation effects on microelectronics.

  3. Grain to continuum considering mesoscale: computational framework for projectile penetration through granular material

    NASA Astrophysics Data System (ADS)

    Turner, Anne; Penumadu, Dayakar; Herbold, Eric

    2015-06-01

    High-speed projectile penetration through granular materials is governed by the particle or grain level (meso-scale) physics including inter-granular contact forces, particle reorientation, deformation and fragmentation. In this work, we investigate a method for numerically capturing the initial meso-structure of the assembly and morphology of individual particles using high resolution computed X-ray and neutron tomography. Using the finite element code, GEODYN-L, Ottawa sand specimen assembly directly measured from high resolution computed radiation based tomography non-invasively are numerically simulated to represent the initial state of compaction and subsequently subjected to one-dimensional compression. The effects of selected finite element formulations and grain discretization approaches are investigated to maximize the ability to capture high stress concentrations at contact points between grains, where fracture is likely to initiate, yet maintaining computational efficiency. The effect of coordination number on the contact forces and resulting stress distribution within a grain is also examined. This ``grain to continuum considering meso-scale'' computational framework is being developed to for realistic representation of deformation and damage mechanics associated with projectile penetration through granular materials. DTRA Grant HDTRA1-12-1-0045 managed by Dr. Suhiti Peiris.

  4. Projectile and rail launcher design analysis for electromagnetic propulsion to velocities exceeding 10 km/s

    SciTech Connect

    Buckingham, A.C.

    1981-02-24

    Hypersonic projectile launch was achieved using thrust exerted by an expanding electromagnetic field acting on the projectile base. Previous designs were confined to simple parallel-opposing flat rails. The rails carried the induction current used to launch rectangular projectiles. The projectiles weighed up to several grams and were launched at nearly 10 km/s. Here, a revised design for the launcher and projectiles using a more conventional cylindrical bore is described. Projectile spin-stabilization was considered together with the associated added-stress loads to projectile and launcher. In addition, both the design of the projectile configuration and materials capable of withstanding earth orbital, earth- and solar-system-escape launch loads, aerodynamic loads, and ablation and erosion penalties were studied. Projectile masses of ten to several hundred kilograms and launch speeds from 20 to 50 km/s are included in the analysis and discussion.

  5. Decay analysis of compound nuclei with masses A ≈30 - 200 formed in reactions involving loosely bound projectiles

    NASA Astrophysics Data System (ADS)

    Kaur, Mandeep; Singh, BirBikram; Sharma, Manoj K.; Gupta, Raj K.

    2015-08-01

    The dynamics of compound nuclei formed in the reactions using loosely bound projectiles are analyzed within the framework of the dynamical cluster-decay model (DCM) of Gupta and Collaborators. We have considered the reactions with neutron-rich and neutron-deficient projectiles, respectively, as 7Li , 9Be , and 7Be , on various targets at three different Elab energies, forming compound nuclei in the mass region A ˜30 - 200. For these reactions, the contributions of light-particle (LP, A ≤4 ) cross sections σLP, energetically favored intermediate-mass-fragment (IMF, 5 ≤A2≤20 ) cross sections σIMF, as well as the fusion-fission ff cross sections σff constitute the σfus(=σLP+σIMF+σff ), i.e., the contributions of the emitted LPs, IMFs, and ff fragments are added for all the angular momenta up to the ℓmax value for the respective reactions. Interestingly, we find that the empirically fitted neck-length parameter Δ Remp , the only parameter of the DCM, is uniquely fixed to address σfus for all the reactions having the same loosely bound projectile at a chosen incident laboratory energy. It may be noted that, in DCM, the dynamical collective mass motion of preformed LPs, IMFs, and ff fragments or clusters, through the modified interaction potential barrier, are treated on parallel footing. The modification of the barrier is due to nonzero Δ Remp , and the values of corresponding modified interaction-barrier heights Δ VBemp for such reactions are almost of the same order, specifically at the respective ℓmax value.

  6. Comparisons of cross-section predictions for relativistic iron and argon beams with semiempirical fragmentation models

    NASA Technical Reports Server (NTRS)

    Townsend, Lawrence W.; Tripathi, Ram K.; Khan, Ferdous

    1993-01-01

    Cross-section predictions with semi-empirical nuclear fragmentation models from the Langley Research Center and the Naval Research Laboratory are compared with experimental data for the breakup of relativistic iron and argon projectile nuclei in various targets. Both these models are commonly used to provide fragmentation cross-section inputs into galactic cosmic ray transport codes for shielding and exposure analyses. Overall, the Langley model appears to yield better agreement with the experimental data.

  7. Fragmentation of N-14 nuclei at 29 GeV - Inclusive isotope spectra at 0 deg.

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.; Greiner, D. E.; Lindstrom, P. J.; Bieser, F. S.

    1972-01-01

    We report the first results of a Bevatron heavy-ion experiment on the inclusive spectra of isotopically identified nuclei 3(Z-range between 3 and 7), produced by the fragmentation of 29-GeV N-14 ions in carbon and hydrogen. The preliminary values of the partial differential cross sections at 0 deg give evidence that the modes of fragmentation of N-14 projectiles are independent of the target nucleus.

  8. Quantum suppression of fluctuations and temperatures of reconstructed A ˜ 30 quasi-projectiles

    NASA Astrophysics Data System (ADS)

    Stein, B. C.; Bonasera, A.; Souliotis, G. A.; Zheng, H.; Cammarata, P. J.; Echeverria, A. J.; Heilborn, L.; Keksis, A. L.; Kohley, Z.; Mabiala, J.; Marini, P.; May, L. W.; McIntosh, A. B.; Richers, C.; Shetty, D. V.; Soisson, S. N.; Tripathi, R.; Wuenschel, S.; Yennello, S. J.

    2014-02-01

    Suppression of multiplicity fluctuations has been observed for three light fermions (protons, tritons and 3He) in the multifragmentation of reconstructed hot quasi-projectiles produced in collisions of 32S (45 MeV/nucleon) with 112Sn. This suppression, predicted by recent calculations, is attributed to Pauli blocking and has also been observed in experiments with trapped Fermi gases. Experimental results on nuclear temperature and density employing a quantal approach based on momentum and multiplicity fluctuations are also presented. The extracted temperatures show a noticeable reduction when compared to a similarly derived classical method. This reduction in temperature is in agreement with previous predictions indicating that classically derived methods overpredict nuclear temperature as they do not take into account the Fermi motion of the nucleons. The present results underline the role of quantum statistics in nuclear disassembly and suggest the need for proper quantum treatment when dealing with the thermodynamic properties of fragmenting heavy ions.

  9. Plasma guiding and deflection of high speed projectiles

    NASA Astrophysics Data System (ADS)

    Starikovskiy, Andrey; Miles, Richard; PU Team

    2016-09-01

    The deposition of energy in the air in front of a high-speed projectile can lead to both the reduction of drag and the production of steering moments. Modeling has shown that the major contributor to the drag reduction and the steering moment is the high temperature, low density region that is produced by the energy addition. If the energy addition is off axis, it leads to a non symmetric pressure distribution on the projectile as it passes through this region, producing steering control authority that increases nonlinearly with Mach number. Experiments with a tethered projectile and subsequently with a rotating projectile using pulsed laser energy addition were reported. More recent experiments with a 30-mm diameter projectile in M =3.5 flow have been undertaken using a nozzle driven by a pulsed shock tunnel 9.5 m in length and 100 mm internal diameter. Energy was deposited by Nd-YAG laser with pulse energy of about 3 Joules at 1064nm. The laser pulse duration was 5-6 ns. Preliminary results indicate that the laser spark - flow interaction changes the angular momentum of the model for with a laser pulse energy of 2.85 J, the angle between laser spark axis and the flow 30-0 and a flow speed 1100 m/s.

  10. Injury Risk Assessment of Non-Lethal Projectile Head Impacts

    PubMed Central

    Oukara, Amar; Nsiampa, Nestor; Robbe, Cyril; Papy, Alexandre

    2014-01-01

    Kinetic energy non-lethal projectiles are used to impart sufficient effect onto a person in order to deter uncivil or hazardous behavior with a low probability of permanent injury. Since their first use, real cases indicate that the injuries inflicted by such projectiles may be irreversible and sometimes lead to death, especially for the head impacts. Given the high velocities and the low masses involved in such impacts, the assessment approaches proposed in automotive crash tests and sports may not be appropriate. Therefore, there is a need of a specific approach to assess the lethality of these projectiles. In this framework, some recent research data referred in this article as “force wall approach” suggest the use of three lesional thresholds (unconsciousness, meningeal damages and bone damages) that depend on the intracranial pressure. Three corresponding critical impact forces are determined for a reference projectile. Based on the principle that equal rigid wall maximal impact forces will produce equal damage on the head, these limits can be determined for any other projectile. In order to validate the consistence of this innovative method, it is necessary to compare the results with other existing assessment methods. This paper proposes a comparison between the “force wall approach” and two different head models. The first one is a numerical model (Strasbourg University Finite Element Head Model-SUFEHM) from Strasbourg University; the second one is a mechanical surrogate (Ballistics Load Sensing Headform-BLSH) from Biokinetics. PMID:25400712

  11. Experimental study on oblique water entry of projectiles

    NASA Astrophysics Data System (ADS)

    Zhao, Chenggong; Wang, Cong; Wei, Yingjie; Zhang, Xiaoshi; Sun, Tiezhi

    2016-10-01

    An experimental study of oblique water entry of projectiles with different noses has been conducted using high-speed photography technology. The images of the initial water entry impact, cavity evolution, and the closure and shedding of vortices of cavity are presented in the paper. The results reveal that for high-speed oblique water entry (the initial impact velocity >50 m/s), the cavity attached to the projectile is symmetrical and free from the influence of gravity. The shedding of the water-vapor-air mixture in the tail of the cavity produces vortices which disappear in the rear of the projectile trajectory. Particular attention is given to the velocity attenuation of the projectile after water entry. The results show that there is a transition point at the time corresponding to the surface seal of the cavity during the velocity attenuation after oblique water entry, and the rates of velocity attenuation are different before and after this transition point. Additionally, the chronophotography of the cavity evolution shows that the time when the surface seal of the cavity occurs decreases with the increase of the initial impact velocity of the projectile.

  12. Dependence of debris cloud formation on projectile shape

    NASA Astrophysics Data System (ADS)

    Konrad, C. H.; Chhabildas, L. C.; Boslough, M. B.; Piekutowski, A. J.; Poormon, K. L.; Mullin, S. A.; Littlefield, D. L.

    1994-07-01

    A two-stage lights-gas gun has been used to impact thin zinc bumpers by zinc projectiles over the velocity range of 2.4 km/s to 6.7 km/s to determine the propagation characteristics of the impact generated debris. Constant-mass projectiles in the form of spheres, discs, cylinders, and rods were used in these studies. Radiographic techniques were employed to record the debris cloud generated upon impact and the dynamic formation of the resulting rupture in an aluminum backing plate resulting from the loading of the debris cloud. The characteristics of the debris cloud generated upon impact is found to depend on the projectile shape. The data indicate that the debris front velocity is independent of the shape of the projectile, whereas the debris lateral/radial velocity is strongly dependent on projectile geometry. Spherical impactors generate the most radially dispersed debris cloud while the normal plate impactors result in column-like debris. It has been observed that the debris generated by the impact of thin plates on a thin bumper shield is considerably more damaging to a backwall than the debris generated by an equivalent-mass sphere.

  13. Projectile Remnants in Central Peaks of Lunar Impact Craters

    NASA Astrophysics Data System (ADS)

    Johnson, B.; Yue, Z.; Minton, D.; Melosh, H. J.; Di, K.; Hu, W.; Liu, Y.

    2012-12-01

    It is generally assumed that during the formation of a large impact crater the projectile is largely melted or vaporized and that only traces remain in the final crater. However, using the finite difference hydrocode iSALE, we show that at impact velocities below about 12 km/sec the projectile, while crushed and strongly deformed, may largely survive the impact. In small craters the projectile is nevertheless widely dispersed across the crater floor. But in complex craters much of the projectile debris is swept back into the central peak area by the collapse flow. Furthermore, on the Moon approximately 30% of asteroid impacts occur at velocities less than 12 km/sec, so that the central peaks of many lunar craters should retain a recognizable signature of the projectile. This observation may explain recent observations of exotic Mg-rich spinels and olivine in the central peaks of craters too small to have excavated the deep crust or mantle of the Moon. Similar conclusions apply to central peaks of complex craters on Mars and Rheasilvia crater on Vesta.

  14. Injury risk assessment of non-lethal projectile head impacts.

    PubMed

    Oukara, Amar; Nsiampa, Nestor; Robbe, Cyril; Papy, Alexandre

    2014-01-01

    Kinetic energy non-lethal projectiles are used to impart sufficient effect onto a person in order to deter uncivil or hazardous behavior with a low probability of permanent injury. Since their first use, real cases indicate that the injuries inflicted by such projectiles may be irreversible and sometimes lead to death, especially for the head impacts. Given the high velocities and the low masses involved in such impacts, the assessment approaches proposed in automotive crash tests and sports may not be appropriate. Therefore, there is a need of a specific approach to assess the lethality of these projectiles. In this framework, some recent research data referred in this article as "force wall approach" suggest the use of three lesional thresholds (unconsciousness, meningeal damages and bone damages) that depend on the intracranial pressure. Three corresponding critical impact forces are determined for a reference projectile. Based on the principle that equal rigid wall maximal impact forces will produce equal damage on the head, these limits can be determined for any other projectile. In order to validate the consistence of this innovative method, it is necessary to compare the results with other existing assessment methods. This paper proposes a comparison between the "force wall approach" and two different head models. The first one is a numerical model (Strasbourg University Finite Element Head Model-SUFEHM) from Strasbourg University; the second one is a mechanical surrogate (Ballistics Load Sensing Headform-BLSH) from Biokinetics.

  15. Mass and charge distributions in iron-induced reactions and excitation energy division between the fragments of the 672-MeV 56Fe + 165Ho reaction

    SciTech Connect

    Madani, Houria

    1993-01-01

    The projectile-like and target-like fragments produced by the 12-MeV/nucleon 56Fe + 165Ho reaction were detected in coincidence. The measured parameters were the mass, charge, kinetic energy scattering angle of the projectile-like fragments, and the scattering angle of the target-like fragments. The mass and charge distributions of the projectile-like fragments were generated as a function of energy loss, and characterized by their centroids, variances, and correlation coefficients. The neutron drift of the measured projectile-like products is mostly due to evaporative processes, while the charge drift is a result of a net transfer of protons from the projectile-like fragment to the target-like fragment. The result is a weak drift of the system towards mass asymmetry. The predictions of two nucleon exchange models are compared to the experimental results of the 672-MeV 56Fe + 165Ho reaction and other Fe-induced reactions. The fairly good agreement between the experimental and theoretical variances verifies the prevalence of a nucleon exchange mechanism in these reactions. The information from the coincidence measurement and two-body kinematics are used to reconstruct the pre-evaporation masses of the projectile-like and target-like fragments of the reaction. Statistical evaporation calculations are used to translate these masses into excitation energies of the primary fragments. The ratio of excitation energy stored in the projectile-Mm fragment decreases with increasing energy loss, in qualitative agreement with previous measurements; however, higher ratios are observed for the 672-MeV 56Fe on 165Ho system.

  16. Mass and charge distributions in iron-induced reactions and excitation energy division between the fragments of the 672-MeV [sup 56]Fe + [sup 165]Ho reaction

    SciTech Connect

    Madani, H.

    1993-01-01

    The projectile-like and target-like fragments produced by the 12-MeV/nucleon [sup 56]Fe + [sup 165]Ho reaction were detected in coincidence. The measured parameters were the mass, charge, kinetic energy scattering angle of the projectile-like fragments, and the scattering angle of the target-like fragments. The mass and charge distributions of the projectile-like fragments were generated as a function of energy loss, and characterized by their centroids, variances, and correlation coefficients. The neutron drift of the measured projectile-like products is mostly due to evaporative processes, while the charge drift is a result of a net transfer of protons from the projectile-like fragment to the target-like fragment. The result is a weak drift of the system towards mass asymmetry. The predictions of two nucleon exchange models are compared to the experimental results of the 672-MeV [sup 56]Fe + [sup 165]Ho reaction and other Fe-induced reactions. The fairly good agreement between the experimental and theoretical variances verifies the prevalence of a nucleon exchange mechanism in these reactions. The information from the coincidence measurement and two-body kinematics are used to reconstruct the pre-evaporation masses of the projectile-like and target-like fragments of the reaction. Statistical evaporation calculations are used to translate these masses into excitation energies of the primary fragments. The ratio of excitation energy stored in the projectile-Mm fragment decreases with increasing energy loss, in qualitative agreement with previous measurements; however, higher ratios are observed for the 672-MeV [sup 56]Fe on [sup 165]Ho system.

  17. Optical model analyses of 1.65 A GeV argon fragmentation: cross sections and momentum distributions.

    PubMed

    Townsend, L W; Khan, F; Tripathi, R K

    1993-12-01

    An optical potential fragmentation model capable of predicting fragmentation cross sections and fragment momentum distributions is used to analyze recent measurements of 1.65 A GeV argon projectiles fragmenting in carbon and potassium-chloride targets obtained with the Heavy Ion Spectrometer System (HISS) at the Lawrence Berkeley Laboratory Bevalac. The theoretical model uses an abrasion-ablation-FSI (frictional spectator interaction) collision formalism to estimate elemental and isotopic production cross sections for comparison with the measured values. The collision momentum transfer model is incorporated into a Goldhaber formalism to analyze measured transverse and longitudinal distributions of the projectile fragments. Good agreement between theory and experiment is obtained for all observables.

  18. Electron emission in collisions between atoms and dressed projectiles

    NASA Astrophysics Data System (ADS)

    Mondal, A.; Ghosh, T. K.; Mandal, C. R.; Purkait, M.

    2016-12-01

    We present theoretical results for electron emission in collisions between helium atoms and dressed projectiles at high energies. Double-differential cross sections (DDCSs) as a function of the emitted electron energies and angles are calculated. In our study we have applied the three-body formalism using the three-Coulomb wave (3CW-3B) model. The interaction between the dressed projectile and the active electron in the target has been approximated by a model potential having both a long-range Coulomb potential part and a short-range part. However, the active electron in the target has been treated as hydrogenic. We have also studied the projectile charge state dependence of the DDCS. Our theoretical results are compared with available experimental data as well as other theoretical calculations. The comparison shows a good agreement between the present calculations and the measurements. The obtained results are also compatible with other theoretical findings.

  19. Surgical management of a projectile within the temporomandibular joint.

    PubMed

    Grossmann, Eduardo; Silva, Aurelício Novaes; Collares, Marcus Vinicius Martins

    2012-03-01

    Facial gunshot wounds pose a challenge for head and neck surgeons as it is usually accompanied by significant soft and bone tissue loss and impairment of the stomatognathic system. This article reports the case of a patient who had sustained facial gunshot wound and had the projectile lodged at the upper disk space of the right-side temporomandibular joint, which caused mandible function impairment and pain. The projectile was surgically removed via endaural access, and the patient was later submitted to physiotherapy. After treatment, the function of the joint was reestablished, the pain disappeared, and the aesthetics results were considered excellent, with no sequels. The surgical removal of the projectile of the temporomandibular joint combined with the postsurgical physiotherapy showed to be an efficient treatment to the present case.

  20. In situ characterization of projectile penetration into sand targets

    NASA Astrophysics Data System (ADS)

    Borg, John P.; Sable, Peter; Sandusky, Harold; Felts, Joshua

    2017-01-01

    This work presents the results from dynamic penetration experiments in which long rod projectiles were launched into Ottawa sand at velocities ranging from 90 m/s to 350 m/s. A unique aspect of these experiments was that the sand targets were visually accessible, which allowed for the penetration event recorded using high-speed digital photography. The images were processed using two different correlation methods. In addition, stress measurements of the transmitted waveforms were simultaneously collected from a piezoelectric load cell that was buried in the sand at various locations relative to the shot line. The results indicate that impact results in two waves: one similar to a detached bow shock and one near the projectile that forms force chains. Grains are damaged and broken by the force chains which allows the projectile to penetrate the target.

  1. The traumatic potential of a projectile shot from a sling.

    PubMed

    Borovsky, Igor; Lankovsky, Zvi; Kalichman, Leonid; Belkin, Victor

    2017-03-01

    Herein, we analyze the energy parameters of stones of various weights and shapes shot from a sling and based on this data evaluate its traumatic potential. Four police officers proficient in the use of a sling participated in the trials. The following projectile types, shot using an overhead technique at a target 100m away were: round steel balls of different sizes and weights (24mm, 57g; 32mm, 135g; 38mm, 227g); different shaped stones weighing 100-150g and 150-200g and a golf ball (47g). Our data indicated that projectiles shot from unconventional weapons such as a sling, have serious traumatic potential for unprotected individuals and can cause blunt trauma of moderate to critical severity such as fractures of the trunk, limb, and facial skull bone, depending on the weight and shape of the projectile and the distance from the source of danger. Asymmetrically shaped projectiles weighing more than 100g were the most dangerous. Projectiles weighing more than 100g can cause bone fractures of the trunk and limbs at distances of up to 60m from the target and may cause serious head injuries to an unprotected person (Abbreviated Injury Scale 4-5) at distances up to 200m from the target. Due to the traumatic potential of projectiles shot from a sling, the police must wear full riot gear and keep at a distance of at least 60m from the source of danger in order to avoid serious injury. Furthermore, given the potential for serious head injuries, wearing a helmet with a visor is mandatory at distances up to 200m from the source of danger. Copyright © 2016. Published by Elsevier B.V.

  2. Projectile transverse motion and stability in electromagnetic induction launchers

    SciTech Connect

    Shokair, I.R.

    1993-12-31

    The transverse motion of a projectile in an electromagnetic induction launcher is considered. The equations of motion for translation and rotation are derived assuming a rigid projectile and a flyway restoring force per unit length that is proportional to the local displacement. Linearized transverse forces and torques due to energized coils are derived for displaced or tilted armature elements based on a first order perturbation method. The resulting equations of motion for a rigid projectile composed of multiple elements in a multi-coil launcher are analyzed as a coupled oscillator system of equations and a simple linear stability condition is derived. The equations of motion are incorporated into the 2-D Slingshot circuit code and numerical solutions for the transverse motion are obtained. For a launcher with a 10 cm bore radius with a 40 cm long solid armature, we find that stability is achieved with a restoring force (per unit length) constant of k {approx} 1 {times} 10{sup 8} N/m{sup 2}. For k = 1.5 {times} 10{sup 8} N/m{sup 2} and sample coil misalignment modeled as a sine wave of 1 mm amplitude at wavelengths of one or two meters, the projectile displacement grows to a maximum of 4 mm. This growth is due to resonance between the natural frequency of the projectile transverse motion and the coil displacement wavelength. This resonance does not persist because of the changing axial velocity. Random coil displacement is also found to cause roughly the same projectile displacement. For the maximum displacement a rough estimate of the transverse pressure is 50 bars. Results for a wound armature with uniform current density throughout show very similar displacements.

  3. Saturation Effect of Projectile Excitation in Ion-Atom Collisions

    NASA Astrophysics Data System (ADS)

    Mukoyama, Takeshi; Lin, Chii-Dong

    Calculations of projectile K-shell electron excitation cross sections for He-like ions during ion-atom collisions have been performed in the distortion approximation by the use of Herman-Skillman wave functions. The calculated results are compared with the experimental data for several targets. The excitation cross sections deviate from the first-Born approximation and show the saturation effect as a function of target atomic number. This effect can be explained as the distortion of the projectile electronic states by the target nucleus.

  4. Projectile general motion in a vacuum and a spreadsheet simulation

    NASA Astrophysics Data System (ADS)

    Benacka, Jan

    2015-01-01

    This paper gives the solution and analysis of projectile motion in a vacuum if the launch and impact heights are not equal. Formulas for the maximum horizontal range and the corresponding angle are derived. An Excel application that simulates the motion is also presented, and the result of an experiment in which 38 secondary school students developed the application and investigated the system is given. A questionnaire survey was carried out to find out whether the students found the lessons interesting, learned new skills and wanted to model projectile motion in the air as an example of more realistic motion. The results are discussed.

  5. Thrusters Pairing Guidelines for Trajectory Corrections of Projectiles

    DTIC Science & Technology

    2011-01-12

    distance traveled along flight path, cal V = projectile velocity, m s1 = pitch angle , rad = total incidence angle , rad = yaw angle , rad S, F...3) M Ad 3 2Iy CM (4) T Ad 2m CL md2 Ix CMp (5) Figure 1 shows that the complex incidence angle is the plane projection of the total... angle of attack. As the projectile travels along the trajectory, the complex incidence traces out a series of loops in the pitch-yaw plane, which is

  6. Cantilever Beam Design for Projectile Internal Moving Mass Systems

    DTIC Science & Technology

    2010-09-01

    25 30 35 40 45 50 55 60 Beam Length (in) M ax im um A ng ul ar D is pl ac em en t ( de g ) 2 3 4 5 6 7 8 9 10 130 140 150 160 170 180 190 200 Beam...Actuated Kinetic Warheads. J. Guid. Control Dynam. 2004, 27 (1), 118–127. 8. Frost, G .; Costello, M . Linear Theory of a Projectile with a Rotating...Internal Part in Atmospheric Flight. J. Guid. Control Dynam. 2004, 27 (5), 898–906. 9. Frost, G .; Costello, M . Control Authority of a Projectile

  7. Infinite penetration of a projectile into a granular medium.

    PubMed

    Pacheco-Vázquez, F; Caballero-Robledo, G A; Solano-Altamirano, J M; Altshuler, E; Batista-Leyva, A J; Ruiz-Suárez, J C

    2011-05-27

    An object falling in a fluid reaches a terminal velocity when the drag force and its weight are balanced. Contrastingly, an object impacting into a granular medium rapidly dissipates all its energy and comes to rest always at a shallow depth. Here we study, experimentally and theoretically, the penetration dynamics of a projectile in a very long silo filled with expanded polystyrene particles. We discovered that, above a critical mass, the projectile reaches a terminal velocity and, therefore, an endless penetration. © 2011 American Physical Society

  8. Numerical simulation of fluid flow around a scramaccelerator projectile

    NASA Technical Reports Server (NTRS)

    Pepper, Darrell W.; Humphrey, Joseph W.; Sobota, Thomas H.

    1991-01-01

    Numerical simulations of the fluid motion and temperature distribution around a 'scramaccelerator' projectile are obtained for Mach numbers in the 5-10 range. A finite element method is used to solve the equations of motion for inviscid and viscous two-dimensional or axisymmetric compressible flow. The time-dependent equations are solved explicitly, using bilinear isoparametric quadrilateral elements, mass lumping, and a shock-capturing Petrov-Galerkin formulation. Computed results indicate that maintaining on-design performance for controlling and stabilizing oblique detonation waves is critically dependent on projectile shape and Mach number.

  9. Numerical simulation of fluid flow around a scramaccelerator projectile

    NASA Technical Reports Server (NTRS)

    Pepper, Darrell W.; Humphrey, Joseph W.; Sobota, Thomas H.

    1991-01-01

    Numerical simulations of the fluid motion and temperature distribution around a 'scramaccelerator' projectile are obtained for Mach numbers in the 5-10 range. A finite element method is used to solve the equations of motion for inviscid and viscous two-dimensional or axisymmetric compressible flow. The time-dependent equations are solved explicitly, using bilinear isoparametric quadrilateral elements, mass lumping, and a shock-capturing Petrov-Galerkin formulation. Computed results indicate that maintaining on-design performance for controlling and stabilizing oblique detonation waves is critically dependent on projectile shape and Mach number.

  10. Tethers as Debris: Simulating Impacts of Tether Fragments on Shuttle Tiles

    NASA Technical Reports Server (NTRS)

    Evans, Steven W.

    2004-01-01

    The SPHC hydrodynamic code was used to simulate impacts of Kevlar and aluminum projectiles on a model of the LI-900 type insulating tiles used on Space Shuffle Orbiters The intent was to examine likely damage that such tiles might experience if impacted by orbital debris consisting of tether fragments. Projectile speeds ranged from 300 meters per second to 10 kilometers per second. Damage is characterized by penetration depth, tile surface-hole diameter, tile body-cavity diameter, coating fracture diameter, tether and cavity wall material phases, and deformation of the aluminum backwall.

  11. Charge Radii of Neutron Deficient Fe,5352 Produced by Projectile Fragmentation

    NASA Astrophysics Data System (ADS)

    Minamisono, K.; Rossi, D. M.; Beerwerth, R.; Fritzsche, S.; Garand, D.; Klose, A.; Liu, Y.; Maaß, B.; Mantica, P. F.; Miller, A. J.; Müller, P.; Nazarewicz, W.; Nörtershäuser, W.; Olsen, E.; Pearson, M. R.; Reinhard, P.-G.; Saperstein, E. E.; Sumithrarachchi, C.; Tolokonnikov, S. V.

    2016-12-01

    Bunched-beam collinear laser spectroscopy is performed on neutron deficient Fe,5352 prepared through in-flight separation followed by a gas stopping. This novel scheme is a major step to reach nuclides far from the stability line in laser spectroscopy. Differential mean-square charge radii δ ⟨r2⟩ of Fe,5352 are determined relative to stable 56Fe as δ ⟨r2⟩56 ,52=-0.034 (13 ) fm2 and δ ⟨r2⟩56 ,53=-0.218 (13 ) fm2 , respectively, from the isotope shift of atomic hyperfine structures. The multiconfiguration Dirac-Fock method is used to calculate atomic factors to deduce δ ⟨r2⟩. The values of δ ⟨r2⟩ exhibit a minimum at the N =28 neutron shell closure. The nuclear density functional theory with Fayans and Skyrme energy density functionals is used to interpret the data. The trend of δ ⟨r2⟩ along the Fe isotopic chain results from an interplay between single-particle shell structure, pairing, and polarization effects and provides important data for understanding the intricate trend in the δ ⟨r2⟩ of closed-shell Ca isotopes.

  12. Charge radii of neutron deficient Fe52,53 produced by projectile fragmentation

    DOE PAGES

    Minamisono, K.; Rossi, D. M.; Beerwerth, R.; ...

    2016-12-15

    Bunched-beam collinear laser spectroscopy is performed on neutron deficient 52,53Fe prepared through in-flight separation followed by a gas stopping. This novel scheme is a major step to reach nuclides far from the stability line in laser spectroscopy. Differential mean-square charge radii δmore » $$\\langle$$r2$$\\rangle$$ of 52,53Fe are determined relative to stable 56Fe as δ$$\\langle$$r2$$\\rangle$$56,52=$-$0.034(13) fm2 and δ$$\\langle$$r2$$\\rangle$$56,53=$-$0.218(13) fm2, respectively, from the isotope shift of atomic hyperfine structures. The multiconfiguration Dirac-Fock method is used to calculate atomic factors to deduce δ$$\\langle$$r2$$\\rangle$$. The values of δ$$\\langle$$r2$$\\rangle$$ exhibit a minimum at the N=28 neutron shell closure. The nuclear density functional theory with Fayans and Skyrme energy density functionals is used to interpret the data. As a result, the trend of δ$$\\langle$$r2$$\\rangle$$ along the Fe isotopic chain results from an interplay between single-particle shell structure, pairing, and polarization effects and provides important data for understanding the intricate trend in the δ$$\\langle$$r2$$\\rangle$$ of closed-shell Ca isotopes« less

  13. Charge Radii of Neutron Deficient ^{52,53}Fe Produced by Projectile Fragmentation.

    PubMed

    Minamisono, K; Rossi, D M; Beerwerth, R; Fritzsche, S; Garand, D; Klose, A; Liu, Y; Maaß, B; Mantica, P F; Miller, A J; Müller, P; Nazarewicz, W; Nörtershäuser, W; Olsen, E; Pearson, M R; Reinhard, P-G; Saperstein, E E; Sumithrarachchi, C; Tolokonnikov, S V

    2016-12-16

    Bunched-beam collinear laser spectroscopy is performed on neutron deficient ^{52,53}Fe prepared through in-flight separation followed by a gas stopping. This novel scheme is a major step to reach nuclides far from the stability line in laser spectroscopy. Differential mean-square charge radii δ⟨r^{2}⟩ of ^{52,53}Fe are determined relative to stable ^{56}Fe as δ⟨r^{2}⟩^{56,52}=-0.034(13)  fm^{2} and δ⟨r^{2}⟩^{56,53}=-0.218(13)  fm^{2}, respectively, from the isotope shift of atomic hyperfine structures. The multiconfiguration Dirac-Fock method is used to calculate atomic factors to deduce δ⟨r^{2}⟩. The values of δ⟨r^{2}⟩ exhibit a minimum at the N=28 neutron shell closure. The nuclear density functional theory with Fayans and Skyrme energy density functionals is used to interpret the data. The trend of δ⟨r^{2}⟩ along the Fe isotopic chain results from an interplay between single-particle shell structure, pairing, and polarization effects and provides important data for understanding the intricate trend in the δ⟨r^{2}⟩ of closed-shell Ca isotopes.

  14. Small-Caliber Projectile Target Impact Angle Determined From Close Proximity Radiographs

    DTIC Science & Technology

    2006-10-01

    of M855 projectile . ....................................................................3 Figure 3. Projectile geometry template...angular orientation relative to the line of fire at the four orthogonal stations. Figure 2. Example of radiograph of M855 projectile . For...of the M855 projectile from the same barrel. The result is presented as a distribution from 0 to 5 deg in 0.5 deg increments. For the relative

  15. Analytical and experimental evaluation of a proposed self-forging fragment munition

    SciTech Connect

    Tuft, D.B.; Folsom, E.N.

    1982-12-27

    Analytical and experimental tools have been used to study the formation of a proposed self-forging fragment projectile. The primary objective of this study is the determination of the interior and exterior shape of the fully formed fragment, and to determine if the fragment tumbles in flight. In addition, it is of interest to compare computer predictions to experimental results. An experiment was performed using high speed photography and high-energy flash x-ray radiography to study liner and case motion and projectile formation. Fabrication and assembly tolerances were closely controlled in an effort to eliminate tolerances as a possible source of fragment instability. X-ray film-density contours were analyzed to determine the fully formed fragment interior and exterior shape. Down-range yaw screens showed fragment tumbling in flight. The computed fragment shape was compared to experimental results and it was found that a retaining ring in the computational model near the liner periphery had a significant effect on the final computed fragment shape. With the retaining ring in the computational model and full two-way sliding between all material interfaces, the final computed fragment showed very good agreement with the experiment on both exterior and interior shapes.

  16. HZEFRG1 - SEMIEMPIRICAL NUCLEAR FRAGMENTATION MODEL

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1994-01-01

    The high charge and energy (HZE), Semiempirical Nuclear Fragmentation Model, HZEFRG1, was developed to provide a computationally efficient, user-friendly, physics-based program package for generating nuclear fragmentation databases. These databases can then be used in radiation transport applications such as space radiation shielding and dosimetry, cancer therapy with laboratory heavy ion beams, and simulation studies of detector design in nuclear physics experiments. The program provides individual element and isotope production cross sections for the breakup of high energy heavy ions by the combined nuclear and Coulomb fields of the interacting nuclei. The nuclear breakup contributions are estimated using an energy-dependent abrasion-ablation model of heavy ion fragmentation. The abrasion step involves removal of nucleons by direct knockout in the overlap region of the colliding nuclei. The abrasions are treated on a geometric basis and uniform spherical nuclear density distributions are assumed. Actual experimental nuclear radii obtained from tabulations of electron scattering data are incorporated. Nuclear transparency effects are included by using an energy-dependent, impact-parameter-dependent average transmission factor for the projectile and target nuclei, which accounts for the finite mean free path of nucleons in nuclear matter. The ablation step, as implemented by Bowman, Swiatecki, and Tsang (LBL report no. LBL-2908, July 1973), was treated as a single-nucleon emission for every 10 MeV of excitation energy. Fragmentation contributions from electromagnetic dissociation (EMD) processes, arising from the interacting Coulomb fields, are estimated by using the Weiszacker-Williams theory, extended to include electric dipole and electric quadrupole contributions to one-nucleon removal cross sections. HZEFRG1 consists of a main program, seven function subprograms, and thirteen subroutines. Each is fully commented and begins with a brief description of its

  17. HZEFRG1 - SEMIEMPIRICAL NUCLEAR FRAGMENTATION MODEL

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1994-01-01

    The high charge and energy (HZE), Semiempirical Nuclear Fragmentation Model, HZEFRG1, was developed to provide a computationally efficient, user-friendly, physics-based program package for generating nuclear fragmentation databases. These databases can then be used in radiation transport applications such as space radiation shielding and dosimetry, cancer therapy with laboratory heavy ion beams, and simulation studies of detector design in nuclear physics experiments. The program provides individual element and isotope production cross sections for the breakup of high energy heavy ions by the combined nuclear and Coulomb fields of the interacting nuclei. The nuclear breakup contributions are estimated using an energy-dependent abrasion-ablation model of heavy ion fragmentation. The abrasion step involves removal of nucleons by direct knockout in the overlap region of the colliding nuclei. The abrasions are treated on a geometric basis and uniform spherical nuclear density distributions are assumed. Actual experimental nuclear radii obtained from tabulations of electron scattering data are incorporated. Nuclear transparency effects are included by using an energy-dependent, impact-parameter-dependent average transmission factor for the projectile and target nuclei, which accounts for the finite mean free path of nucleons in nuclear matter. The ablation step, as implemented by Bowman, Swiatecki, and Tsang (LBL report no. LBL-2908, July 1973), was treated as a single-nucleon emission for every 10 MeV of excitation energy. Fragmentation contributions from electromagnetic dissociation (EMD) processes, arising from the interacting Coulomb fields, are estimated by using the Weiszacker-Williams theory, extended to include electric dipole and electric quadrupole contributions to one-nucleon removal cross sections. HZEFRG1 consists of a main program, seven function subprograms, and thirteen subroutines. Each is fully commented and begins with a brief description of its

  18. Computations of Projectile Magnus Effect at Transonic Velocities

    DTIC Science & Technology

    1983-08-01

    memory , the use of computational methods in design becomes more of a reality. The means to compute projectile aerodynamics for all Mach number regimes...ray is shown as a oressions which occur near tne ogive-cy i muci anu vj -„HH iind in ;fd"has Jlen^^pTn^ded.’The a^reemf wUh tje

  19. Characterization of Concrete Material Flow During Projectile Penetration

    NASA Astrophysics Data System (ADS)

    Sobeski, Robert

    The Department of Defense (DoD) has an operational requirement to predict, quickly and accurately, the depth of penetration that a projectile can achieve for a given target and impact scenario. Fast-running analytical models can provide reliable predictions, but they often require the use of one or more dimensionless parameters that are derived from experimental data. These analytical models are continually evolving, and the dimensionless parameters are often adjusted to obtain new analytical models without a true understanding of the change in characteristics of material flow across targets of varying strength and projectile impact velocities. In this dissertation, the penetration of ogive-nose projectiles into concrete targets is investigated using finite element analyses. The Elastic-Plastic Impact Computation (EPIC) code is used to examine the velocity vector fields and their associated direction cosines for high and low-strength concrete target materials during projectile penetration. Two methodologies, referred as Normal Expansion Comparison Methodology (NECM) and Spherical Expansion Comparison Methodology (SECM), are developed in MATLAB to quantify the change in concrete material flow during this short-duration dynamic event. Improved velocity profiles are proposed for better characterization of cavity expansion stresses based on the application of NECM and SECM to EPIC outputs. Structural engineers and model developers working on improving the accuracy of current analytical concrete penetration models and potentially reducing their reliance on fitting parameters will benefit from the findings of this research.

  20. Projectile General Motion in a Vacuum and a Spreadsheet Simulation

    ERIC Educational Resources Information Center

    Benacka, Jan

    2015-01-01

    This paper gives the solution and analysis of projectile motion in a vacuum if the launch and impact heights are not equal. Formulas for the maximum horizontal range and the corresponding angle are derived. An Excel application that simulates the motion is also presented, and the result of an experiment in which 38 secondary school students…

  1. Projectile Motion in the "Language" of Orbital Motion

    ERIC Educational Resources Information Center

    Zurcher, Ulrich

    2011-01-01

    We consider the orbit of projectiles launched with arbitrary speeds from the Earth's surface. This is a generalization of Newton's discussion about the transition from parabolic to circular orbits, when the launch speed approaches the value [image omitted]. We find the range for arbitrary launch speeds and angles, and calculate the eccentricity of…

  2. Using Statcast to lift the discussion of projectile motion

    NASA Astrophysics Data System (ADS)

    Siegel, P. B.

    2017-04-01

    Home run data from Major League Baseball's Statcast can be described by adding a lift force to the equations of projectile motion commonly used in undergraduate computational physics courses. We discuss how the Statcast data can be implemented in the classroom.

  3. 78. PHOTO OF A PROJECTILE FIRING USING A SABOT TAKEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    78. PHOTO OF A PROJECTILE FIRING USING A SABOT TAKEN WITH A 70 MM MITCHEL MOTION PICTURE CAMERA, Date unknown, circa 1950. (Original photograph in possession of Dave Willis, San Diego, California.) Photograph represents central frame of negative. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  4. On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts

    ERIC Educational Resources Information Center

    Stewart, Sean M.

    2012-01-01

    Motivated by quaint woodcut depictions often found in many late 16th and 17th century ballistic manuals of cannonballs fired in air, a comparison of their shapes with those calculated for the classic case of a projectile moving in a linear resisting medium is made. In considering the asymmetrical nature of such trajectories, the initial launch…

  5. Projectile attitude and position determination using magnetometer sensor only

    NASA Astrophysics Data System (ADS)

    Changey, Sebastien; Fleck, Volker; Beauvois, Dominique

    2005-03-01

    A priori information given by the complete modelling of the ballistic behavior (trajectory, attitude) of the projectile is simplified to give a pertinent reduced evolution model. An algorithm based on extended Kalman filters is designed to determinate: " position: x,y,z references in earth frame. " value and direction of the velocity vector; its direction is given by 2 angles (η and θ). " attitude around velocity vector given by 3 angles: roll angle in the range [0, 2π], angle of attack α and side-slip angle β in the range of few milliradians. The estimation is based on the measures of the magnetic field of the earth given by a three-axis magnetometer sensor embedded on the projectile. The algorithm also needs the knowledge of the direction of the earth magnetic fields in the earth frame and aerodynamics coefficients of the projectile. The algorithm has been tested on simulation, using real evolution of attitude data for a shot with a 155 mm rotating projectile over a distance of 16 km, with wind and measurement noise. The results show that we can estimate milliradians with non-linear equations and approximations, with good precision.

  6. [Arthroscopic removal of an intraarticular projectile from the knee].

    PubMed

    Díaz-Martín, A A; Guerrero-Moyano, N; Salinas-Sánchez, P; Guerado-Parra, E

    2011-01-01

    We present the case of a patient who sustained a gunshot wound; the projectile was located in the knee and was arthroscopically removed. A 31 year-old patient sustained a gunshot wound in the right thigh, right hand and left knee. X-rays revealed the presence of a projectile in the knee, thigh and hand. The projectile was arthroscopically removed. Traumas causing articular wounds of the knee are infrequent. Excluding the most frequent causes of articular wounds, a small percentage of them are due to gunshot wounds. There is consensus around arthroscopy as a technique useful to remove articular foreign bodies; it has advantages over open surgery. This procedure minimizes surgical morbidity, reduces the risk of septic arthritis, synovitis, arthropathy or systemic lead toxicity, and it also hastens the patient's functional recovery. Knee arthroscopy allows physicians to provide a definitive treatment of these injuries, explore the joint, diagnose associated injuries and perform debridement and articular lavage. Arthroscopy is an effective tool for the extraction of articular projectiles; it also allows diagnosing and treating associated lesions.

  7. 37. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. BUILDING NO. 276, MAJOR CALIBER PROJECTILE LOADING (ORIGINALLY NO. 6 POWDER MAGAZINE AND MELT LOADING), GENERAL VIEW SHOWING SOUTHEAST WALL. BUILDING NO. 276-D IN BACKGROUND LEFT BEHIND CHUTES. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  8. 22. VAL, VIEW OF PROJECTILE LOADING DECK LOOKING NORTHEAST TOWARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. VAL, VIEW OF PROJECTILE LOADING DECK LOOKING NORTHEAST TOWARD TOP OF CONCRETE 'A' FRAME STRUCTURE SHOWING DRIVE CABLES, DRIVE GEAR, BOTTOM OF CAMERA TOWER AND 'CROWS NEST' CONTROL ROOM. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  9. 73. DETAIL OF 'A' FRAME STRUCTURE LOOKING NORTH SHOWING PROJECTILE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. DETAIL OF 'A' FRAME STRUCTURE LOOKING NORTH SHOWING PROJECTILE CAR, CAMERA TOWER, CANTILEVERED WALKWAYS AND ELECTRICAL GEAR, August 17, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  10. Apparatus for Teaching Physics: A Versatile Projectile Motion Board.

    ERIC Educational Resources Information Center

    Prigo, Robert B.; Korda, Anthony

    1984-01-01

    Describes the design and use of a projectile motion apparatus to illustrate a variety of projective motion results typically discussed in an introductory course. They include independence of horizontal (constant speed) and vertical (constant acceleration) motions, parabolic path shape, and other types of motion. (JN)

  11. The Long Decay Model of One-Dimensional Projectile Motion

    ERIC Educational Resources Information Center

    Lattery, Mark Joseph

    2008-01-01

    This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo ("in De Motu") and by contemporary students. Implications for instruction are…

  12. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    ERIC Educational Resources Information Center

    Wee, Loo Kang; Chew, Charles; Goh, Giam Hwee; Tan, Samuel; Lee, Tat Leong

    2012-01-01

    This article reports on the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When a computer model building learning process is supported and driven by video analysis data, this free Open Source Physics tool can provide opportunities for students to engage in active enquiry-based…

  13. On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts

    ERIC Educational Resources Information Center

    Stewart, Sean M.

    2012-01-01

    Motivated by quaint woodcut depictions often found in many late 16th and 17th century ballistic manuals of cannonballs fired in air, a comparison of their shapes with those calculated for the classic case of a projectile moving in a linear resisting medium is made. In considering the asymmetrical nature of such trajectories, the initial launch…

  14. Apparatus for Teaching Physics: A Versatile Projectile Motion Board.

    ERIC Educational Resources Information Center

    Prigo, Robert B.; Korda, Anthony

    1984-01-01

    Describes the design and use of a projectile motion apparatus to illustrate a variety of projective motion results typically discussed in an introductory course. They include independence of horizontal (constant speed) and vertical (constant acceleration) motions, parabolic path shape, and other types of motion. (JN)

  15. The Long Decay Model of One-Dimensional Projectile Motion

    ERIC Educational Resources Information Center

    Lattery, Mark Joseph

    2008-01-01

    This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo ("in De Motu") and by contemporary students. Implications for instruction are…

  16. Projectile - Mass asymmetry systematics for low energy incomplete fusion

    NASA Astrophysics Data System (ADS)

    Singh, Pushpendra P.; Yadav, Abhishek; Sharma, Vijay R.; Sharma, Manoj K.; Kumar, Pawan; Sahoo, Rudra N.; Kumar, R.; Singh, R. P.; Muralithar, S.; Singh, B. P.; Bhowmik, R. K.; Prasad, R.

    2015-06-01

    In the present work, low energy incomplete fusion (ICF) in which only a part of projectile fuses with target nucleus has been investigated in terms of various entrance channel parameters. The ICF strength function has been extracted from the analysis of experimental excitation functions (EFs) measured for different projectile-target combinations from near- to well above- barrier energies in 12C,16O(from 1.02Vb to 1.64Vb)+169Tm systems. Experimental EFs have been analysed in the framework statistical model code PACE4 based on the idea of equilibrated compound nucleus decay. It has been found that the value of ICF fraction (FICF) increases with incident projectile energy. A substantial fraction of ICF (FICF ≈ 7 %) has been accounted even at energy as low as ≈ 7.5% above the barrier (at relative velocity νrel ≈0.027) in 12C+169Tm system, and FICF ≈ 10 % at νrel ≈0.014 in 16O+169Tm system. The probability of ICF is discussed in light of the Morgenstern's mass-asymmetry systematics. The value of FICF for 16O+169Tm systems is found to be 18.3 % higher than that observed for 12C+169Tm systems. Present results together with the re-analysis of existing data for nearby systems conclusively demonstrate strong competition of ICF with CF even at slightly above barrier energies, and strong projectile dependence that seems to supplement the Morgenstern's systematics.

  17. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    ERIC Educational Resources Information Center

    Wee, Loo Kang; Chew, Charles; Goh, Giam Hwee; Tan, Samuel; Lee, Tat Leong

    2012-01-01

    This article reports on the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When a computer model building learning process is supported and driven by video analysis data, this free Open Source Physics tool can provide opportunities for students to engage in active enquiry-based…

  18. The tubular "cookie cutter" bullet: a unique projectile.

    PubMed

    Nolte, K B

    1990-11-01

    Recently marketed PMC (Pan Metal Corporation) Ultramag tubular hollow point ammunition is uniquely constructed with a two-part projectile composed of a tubular copper bullet and a Teflon wad. A fatal gunshot wound with this ammunition is described. A unique radiographic pattern and the results of test firing are also presented.

  19. High performance projectile seal development for non perfect railgun bores

    SciTech Connect

    Wolfe, T.R.; Vine, F.E. Le; Riedy, P.E.; Panlasigui, A.; Hawke, R.S.; Susoeff, A.R.

    1997-01-01

    The sealing of high pressure gas behind an accelerating projectile has been developed over centuries of use in conventional guns and cannons. The principal concern was propulsion efficiency and trajectory accuracy and repeatability. The development of guns for use as high pressure equation-of-state (EOS) research tools, increased the importance of better seals to prevent gas leakage from interfering with the experimental targets. The development of plasma driven railguns has further increased the need for higher quality seals to prevent gas and plasma blow-by. This paper summarizes more than a decade of effort to meet these increased requirements. In small bore railguns, the first improvement was prompted by the need to contain the propulsive plasma behind the projectile to avoid the initiation of current conducting paths in front of the projectile. The second major requirements arose from the development of a railgun to serve as an EOS tool where it was necessary to maintain an evacuated region in front of the projectile throughout the acceleration process. More recently, the techniques developed for the small bore guns have been applied to large bore railguns and electro-thermal chemical guns in order to maximize their propulsion efficiency. Furthermore, large bore railguns are often less rigid and less straight than conventional homogeneous material guns. Hence, techniques to maintain seals in non perfect, non homogeneous material launchers have been developed and are included in this paper.

  20. Projectile Motion in the "Language" of Orbital Motion

    ERIC Educational Resources Information Center

    Zurcher, Ulrich

    2011-01-01

    We consider the orbit of projectiles launched with arbitrary speeds from the Earth's surface. This is a generalization of Newton's discussion about the transition from parabolic to circular orbits, when the launch speed approaches the value [image omitted]. We find the range for arbitrary launch speeds and angles, and calculate the eccentricity of…

  1. Projectile General Motion in a Vacuum and a Spreadsheet Simulation

    ERIC Educational Resources Information Center

    Benacka, Jan

    2015-01-01

    This paper gives the solution and analysis of projectile motion in a vacuum if the launch and impact heights are not equal. Formulas for the maximum horizontal range and the corresponding angle are derived. An Excel application that simulates the motion is also presented, and the result of an experiment in which 38 secondary school students…

  2. Aerodynamic Validation of Emerging Projectile and Missile Configurations

    DTIC Science & Technology

    2010-12-01

    VALIDATION OF EMERGING PROJECTILE AND MISSILE CONFIGURATIONS by Tan Wei Chieh December 2010 Thesis Advisor: Max F. Platzer Second Reader...SCHOOL December 2010 Author: Tan Wei Chieh Approved by: Max F. Platzer Thesis Advisor Garth V. Hobson Second Reader... Platzer , for his dedication, guidance and support in the development of this thesis. His phenomenal knowledge and experience in this field of studies

  3. Evaluation of different projectiles in matched experimental eye impact simulations.

    PubMed

    Weaver, Ashley A; Kennedy, Eric A; Duma, Stefan M; Stitzel, Joel D

    2011-03-01

    Eye trauma results in 30,000 cases of blindness each year in the United States and is the second leading cause of monocular visual impairment. Eye injury is caused by a wide variety of projectile impacts and loading scenarios with common sources of trauma being motor vehicle crashes, military operations, and sporting impacts. For the current study, 79 experimental eye impact tests in literature were computationally modeled to analyze global and localized responses of the eye to a variety of blunt projectile impacts. Simulations were run with eight different projectiles (airsoft pellets, baseball, air gun pellets commonly known as BBs, blunt impactor, paintball, aluminum, foam, and plastic rods) to characterize effects of the projectile size, mass, geometry, material properties, and velocity on eye response. This study presents a matched comparison of experimental test results and computational model outputs including stress, energy, and pressure used to evaluate risk of eye injury. In general, the computational results agreed with the experimental results. A receiver operating characteristic curve analysis was used to establish the stress and pressure thresholds that best discriminated for globe rupture in the matched experimental tests. Globe rupture is predicted by the computational simulations when the corneoscleral stress exceeds 17.21 MPa or the vitreous pressure exceeds 1.01 MPa. Peak stresses were located at the apex of the cornea, the limbus, or the equator depending on the type of projectile impacting the eye. A multivariate correlation analysis revealed that area-normalized kinetic energy was the best single predictor of peak stress and pressure. Additional incorporation of a relative size parameter that relates the projectile area to the area of the eye reduced stress response variability and may be of importance in eye injury prediction. The modeling efforts shed light on the injury response of the eye when subjected to a variety of blunt projectile

  4. Small-angle fragmentation of carbon ions at 0.6 GeV/n. A comparison with models of ion-ion interactions

    SciTech Connect

    Krutenkova, Anna P.; Abramov, B. M.; Alekseev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Dukhovskoy, I. A.; Khanov, A. I.; Kulikov, V. V.; Martemianov, M. A.; Mashnik, Stepan Georgievich; Matsyuk, M. A.; Turdakina, E. N.

    2015-05-29

    The momentum distributions of hydrogen and helium isotopes from 12C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. Moreover, the differential cross sections cover six orders of magnitude. The distributions measured are compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters.

  5. Small-angle fragmentation of carbon ions at 0.6 GeV/n: A comparison with models of ion-ion interactions

    SciTech Connect

    Krutenkova, A. P.; Abramov, B. M.; Alekseev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Dukhovskoy, I. A.; Khanov, A. I.; Kulikov, V. V.; Martemianov, M. A.; Mashnik, S. G.; Matsyuk, M. A.; Turdakina, E. N.; Bravina, L.; Foka, Y.; Kabana, S.

    2015-05-29

    Momentum distributions of hydrogen and helium isotopes from ¹²C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. The differential cross sections cover six orders of magnitude. The distributions measured are compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters.

  6. Small-angle fragmentation of carbon ions at 0.6 GeV/n. A comparison with models of ion-ion interactions

    DOE PAGES

    Krutenkova, Anna P.; Abramov, B. M.; Alekseev, P. N.; ...

    2015-05-29

    The momentum distributions of hydrogen and helium isotopes from 12C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. Moreover, the differential cross sections cover six orders of magnitude. The distributions measured aremore » compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters.« less

  7. Small-angle fragmentation of carbon ions at 0.6 GeV/n: A comparison with models of ion-ion interactions

    DOE PAGES

    Krutenkova, A. P.; Abramov, B. M.; Alekseev, P. N.; ...

    2015-05-29

    Momentum distributions of hydrogen and helium isotopes from ¹²C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. The differential cross sections cover six orders of magnitude. The distributions measured are compared tomore » the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters.« less

  8. Quantum molecular dynamics approach to heavy ion collisions: Description of the model, comparison with fragmentation data, and the mechanism of fragment formation

    NASA Astrophysics Data System (ADS)

    Aichelin, J.; Peilert, G.; Bohnet, A.; Rosenhauer, A.; Stöcker, H.; Greiner, W.

    1988-06-01

    We present a detailed microscopic quantum molecular dynamic analysis of fragment formation in the reaction Ne(1.05 GeV/nucleon) + Au. The theoretical predictions of the total mass yield, the multiplicity distribution of clusters, their average momentum, and their angular distribution agree well with the available data. We find a rather localized hot participant zone, which predominantly emits protons and neutrons. The multiplicity of light clusters depends strongly on the impact parameter whereas the heavier fragments A>=40 result from the decay of spectator residues. Their yield can provide a good measure for the impact parameter. The hypothesis of a compound system of AP and AT nucleons which is globally heated and equilibrated is not supported by our results. Light and massive fragments occupy different regions in phase space. Semiperipheral reactions do not lead to a stopping of the projectile. We observe a power law behavior of the inclusive mass yield distribution. Its form, however, is caused by averaging over different impact parameters. This rules out inclusive mass yield distributions as candidates for revealing a possible liquid gas phase transition. Light and intermediate mass fragments are formed during the early compressional stage of the reaction. We find that the projectile causes a high density wave to travel through the target. It causes the target to fragment and transfers transverse momentum to the intermediate mass fragments. Lighter fragments receive additional momentum transfer due to n-n collisions.

  9. Centrifuge Modeling of Projectile Penetration in Granular Soils.

    NASA Astrophysics Data System (ADS)

    Taylor, Teresa Ann

    1988-12-01

    Investigations of the projectile penetration phenomenon in granular soils have been impeded by the difficulty in adequately quantifying and characterizing soil targets, and by the inability to directly scale results of 1-g penetration tests to full-scale conditions. The former is largely due to the failure to adequately prepare and quantify laboratory test samples, and the inherent limitations involved with testing and quantifying in situ soils. The latter is associated with an incomplete understanding of the soil parameters involved in the projectile penetration event. A series of laboratory tests on dry sands was conducted to assess the influence of confining pressure on projectile penetration depth, using a centrifuge to simulate full-scale stress levels in the soil targets. Projectiles were fired from a Thompson Contender^circler pistol at impact velocities of approximately 305 m/s into the rotating soil samples. Corresponding tests were conducted under 1-g conditions. The targets were prepared using a pluviation technique that resulted in uniform, reproducible samples of known density; this sample preparation technique contributed to the reproducibility of penetration test results that was observed in the test program. Significant differences in projectile penetration depths were obtained for different soils and for the same soils prepared at different densities. The penetration depths obtained in the test samples subjected to accelerated g-levels were compared to those obtained in corresponding 1-g tests. The test results indicate a gravity-dependence for the penetration event in granular soils. In addition, the magnitudes of penetration depths predicted by the centrifuge test results compare well to results from full-scale field tests. Thus, the centrifuge testing technique appears well-suited to further investigation of the penetration phenomenon in granular soils.

  10. Simplified method for evaluating the flight stability of liquid-filled projectiles

    NASA Astrophysics Data System (ADS)

    Weber, Daniel J.

    1994-01-01

    This paper describes a modification to the tricyclic theory to include the effect of a liquid payload on the motion and stability of the projectile. The influence on the projectile's motion by the liquid payload is similar to the Magnus effect. A computer program has been developed that determines the complex projectile motion using either theoretical estimates of liquid-fill characteristics or experimental results obtained from a test fixture for nonrigid payloads. Preliminary stability assessments for liquid-filled projectile can be made rapidly and provide a means of determining the relative importance between the aerodynamic and liquid-fill characteristics on the projectiles flight stability.

  11. Experimental Research on Aeroelasticity of a Large Length to Diameter Ratio Projectile

    NASA Astrophysics Data System (ADS)

    Yi, Wenjun; Sun, Dongyang; Tan, Junjie; Yuan, Dandan

    In order to investigate the aeroelastic influences on the aerodynamic performance and flight stability of a large length to diameter ratio projectile, free-flight experiments on both the flexible and rigid projectile model are performed in our ballistic range. Many groups of shadowgraphs for these two kinds of projectiles during flight tests were taken and one of those typical results is shown. The projectile flight velocity, angle of attack and precession are obtained after the data procession. Moreover, the aerodynamic force and moment coefficients of two kinds of projectiles are presented, their aerodynamic performances and flight stability are compared and analyzed. Our results show that the flexible projectile has larger drag coefficient than the rigid. After the deformation, its lift to drag ratio decreases and its rotation moment increases obviously. The elastic deformation of the flexible projectile has remarkable influence on its flight stability which can induce the flight instability.

  12. Experimental studies of collision and fragmentation phenomena

    NASA Technical Reports Server (NTRS)

    Hartmann, William K.; Davis, D. R.; Weidenschilling, S. J.

    1987-01-01

    The reduction and publication of an extensive data set collected in experiments over several years at Ames and PSI is briefly examined. Hartmann has been assembling data sets from his experiments on catastrophic fragmentation of various materials, including basalt, other igneous rock, ice, and weak dirt clods. Weidenschilling and Davis have continued to gather and reduce data on oblique impacts. The data indicate a power law distribution of ejecta mass vs. velocity, with a slope that is independent of azimuth, and does not vary with impact angle from normal impacts to at least 75 deg from vertical. In order to improve models of coagulation of dust aggregates in the solar nebula, SJW developed an apparatus for drop tests of fragile projectiles. Davis and Weidenschilling continued to collect and analyze experimental data on collisional catastrophic disruption at the Ames Vertical Gun Range.

  13. Impact melt- and projectile-bearing ejecta at Barringer Crater, Arizona

    NASA Astrophysics Data System (ADS)

    Osinski, Gordon R.; Bunch, Ted E.; Flemming, Roberta L.; Buitenhuis, Eric; Wittke, James H.

    2015-12-01

    Our understanding of the impact cratering process continues to evolve and, even at well-known and well-studied structures, there is still much to be learned. Here, we present the results of a study on impact-generated melt phases within ejecta at Barringer Crater, Arizona, one of the first impact craters on Earth to be recognized and arguably the most famous. We report on previously unknown impact melt-bearing breccias that contain dispersed fragments of the projectile as well as impact glasses that contain a high proportion of projectile material - higher than any other glasses previously reported from this site. These glasses are distinctly different from so-called ;melt beads; that are found as a lag deposit on the present-day erosion surface and that we also study. It is proposed that the melts in these impact breccias were derived from a more constrained sub-region of the melt zone that was very shallow and that also had a larger projectile contribution. In addition to low- and high-Fe melt beads documented previously, we document Ca-Mg-rich glasses and calcite globules within silicate glass that provide definitive evidence that carbonates underwent melting during the formation of Barringer Crater. We propose that the melting of dolomite produces Ca-Mg-rich melts from which calcite is the dominant liquidus phase. This explains the perhaps surprising finding that despite dolomite being the dominant rock type at many impact sites, including Barringer Crater, calcite is the dominant melt product. When taken together with our estimate for the amount of impact melt products dispersed on, and just below, the present-day erosional surface, it is clear that the amount of melt produced at Barringer Crater is higher than previously estimated and is more consistent with recent numerical modeling studies. This work adds to the growing recognition that sedimentary rocks melt during hypervelocity impact and do not just decompose and/or devolatilize as was previously thought

  14. Experimental determination of drag coefficient for volcanic materials: Calibration and application of a model to Popocatépetl volcano (Mexico) ballistic projectiles

    NASA Astrophysics Data System (ADS)

    Alatorre-Ibargüengoitia, Miguel A.; Delgado-Granados, Hugo

    2006-06-01

    This study shows the results of experiments performed in a subsonic wind tunnel to measure drag coefficients (Cd) for volcanic particles emitted by Popocatépetl volcano (Mexico). The results indicate that volcanic projectiles move in a range of Reynolds number (Re) values where Cd is independent of Re. Drag coefficients of volcanic fragments were found between the values of spheres and cubes with low values. In this study, initial conditions of the ballistic equations were calibrated with the ``launching'' kinetic energy from ballistics expelled by Popocatépetl volcano during the eruptive event of December 17, 1998. The maximum range of the projectiles calculated with the experimentally measured drag coefficient is in better agreement with the field and observational data reported here than using the values of geometrical bodies as in previous studies. Our study can be useful for definition of safety zones around volcanoes to protect people and infrastructure adequately.

  15. Structural Damage Prediction and Analysis for Hypervelocity Impact: Properties of Largest Fragment Produced by Hypervelocity Impact of Aluminum Spheres with Thin Aluminum Sheets

    NASA Technical Reports Server (NTRS)

    Piekutowski, Andrew J.

    1995-01-01

    Results of a series of hypervelocity impact tests are presented. In these tests, 1.275-g, 9.53-mm-diameter, 2017-T4 aluminum spheres were fired at normal incidence at eight thicknesses of 6061-T6 aluminum sheet. Bumper thickness to projectile diameter (t/D) ratio ranged from 0.026 to 0.424. Nominal impact velocity was 6.7 km/s. Results of five tests using 6.35, 9.53, and 12.70-mm-diameter aluminum spheres and other aluminum alloy bumpers are also given. A large chunky fragment of projectile was observed at the center of the debris clouds produced by the impacts. The equivalent diameter of this large fragment ranged from 5.5 mm for the lowest t/D ratio to a minimum of 0.6 mm for the case where maximum breakup of the projectile occurred (t/D approximately 0.2 to 0.3). When the t/D ratio was 0.42, numerous large flaky fragments were evenly distributed in the external bubble of bumper debris. Velocity of the large central fragments decreased continuously with increasing t/D ratio, ranging from about 99 percent to less than 80 percent of the impact velocity. The change in the velocity of small fragments spalling from the rear of the projectile was used to obtain a relationship showing a linear increase in the size of the central projectile fragment with decrease in the shock-induced stress in the projectile.

  16. Apparatus and method for producing fragment-free openings

    DOEpatents

    Cherry, Christopher R.

    2001-01-01

    An apparatus and method for explosively penetrating hardened containers such as steel drums without producing metal fragmentation is disclosed. The apparatus can be used singularly or in combination with water disrupters and other disablement tools. The apparatus is mounted in close proximity to the target and features a main sheet explosive that is initiated at least three equidistant points along the sheet's periphery. A buffer material is placed between the sheet explosive and the target. As a result, the metallic fragments generated from the detonation of the detonator are attenuated so that no fragments from the detonator are transferred to the target. As a result, an opening can be created in containers such as steel drums through which access to the IED is obtained to defuse it with projectiles or fluids.

  17. Phenomenological Investigation of Rapid Projectile Penetration in Granular Media

    NASA Astrophysics Data System (ADS)

    Omidvar, Mehdi

    There has been a recent flurry of research in rapid penetration into granular media, motivated by military and civilian applications including underground target penetration, design of fortifications, drilling for resource extraction, offshore foundations and anchors, probing of in situ mechanical properties, and study of high strain rate response of granular media, among others. The present study contributes to the state of the art in rapid penetration into granular media, by producing data at the macro and meso scales. In-house projectile accelerators are used to launch projectiles into laboratory scale physical models. The experimental program is divided into two sections. In the first section, penetration tests are performed at impact velocities in the range of 60-300 m/s. High-speed imaging and photonic Doppler velocimetry are used to record time history of penetration. In the second section, low velocity penetration tests are performed in refractive index matched transparent soils. Images are acquired form a mid plane within the sample. Digital image correlation is employed to describe granular kinematics. Macro scale test results point to the existence of at least two transition regimes in penetration resistance. The first, occurring at penetration velocities of approximately 60- 80 m/s, may be due the role of particle crushing, while the second is linked to frictional resistance dominating over inertial resistance at penetration velocities below approximately 15 m/s. It is also found that the role of nose shape is related to particle crushing. An attached false cone forms ahead of the projectile due to significant particle crushing, rendering nose shape effects less significant. Packing density and saturation are also found to affect penetration characteristics. Penetration tests in transparent soils reveal significant differences between quasi-static and dynamic penetration. Greater vertical displacements occur ahead of the projectile in dynamic

  18. Ballistics considerations for small-caliber, low-density projectiles

    SciTech Connect

    Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Milora, S.L.; Qualls, A.L.

    1993-11-01

    One major application for single- and two-stage light gas guns is for fueling magnetic fusion confinement devices. Powder guns are not a feasible alternative due to possible plasma contamination by residual powder gases and the eventual requirement of steady-state operation at {approximately} 1 Hz, which will dictate a closed gas handling system where propellant gases are recovered, processed and recompressed. Interior ballistic calculations for single-stage light gas guns, both analytical and numerical, are compared to an extensive data base for low density hydrogenic projectiles (pellets). Some innovative range diagnostics are described for determining the size and velocity of these small (several mm) size projectiles. A conceptual design of a closed cycle propellant gas system is presented including tradeoffs between different light propellant gases.

  19. Computational fluid dynamics capability for the solid fuel ramjet projectile

    NASA Astrophysics Data System (ADS)

    Nusca, Michael J.; Chakravarthy, Sukumar R.; Goldberg, Uriel C.

    1988-12-01

    A computational fluid dynamics solution of the Navier-Stokes equations has been applied to the internal and external flow of inert solid-fuel ramjet projectiles. Computational modeling reveals internal flowfield details not attainable by flight or wind tunnel measurements, thus contributing to the current investigation into the flight performance of solid-fuel ramjet projectiles. The present code employs numerical algorithms termed total variational diminishing (TVD). Computational solutions indicate the importance of several special features of the code including the zonal grid framework, the TVD scheme, and a recently developed backflow turbulence model. The solutions are compared with results of internal surface pressure measurements. As demonstrated by these comparisons, the use of a backflow turbulence model distinguishes between satisfactory and poor flowfield predictions.

  20. Autoionizing states of He: Projectile-velocity-dependent lifetime

    NASA Astrophysics Data System (ADS)

    Otranto, S.; Garibotti, C. R.; Colavecchia, F. D.; Gasaneo, G.

    2001-02-01

    In this work, we study the dependence of the lifetime (τ) of an autoionizing state with the velocity (vP) of an ionic projectile of charge Z. We use a C2 model to represent the final state of the autoionized electron in the continuum of two centers. Explicit calculations for the helium autoionizing states 2s2(1S), 2p2(1D), and 2s2p(1P) are analyzed. We evaluate the decay law for the metastable initial state and find that τ increases as the projectile becomes faster and converges to the photoionization lifetime for high impact energies. A scaling law for τ is obtained in terms of the Sommerfeld parameter (Z/vP). Finally, we evaluate the transition probability for the autoionized electron and show that the mean half-width of the focusing peak decreases as vP increases.

  1. Study on miss distance based on projectile shock wave sensor

    NASA Astrophysics Data System (ADS)

    Gu, Guohua; Cheng, Gang; Zhang, Chenjun; Zhou, Lei

    2017-05-01

    The paper establishes miss distance models based on physical characteristic of shock-wave. The aerodynamic theory shows that the shock-wave of flying super-sonic projectile is generated for the projectile compressing and expending its ambient atmosphere. It advances getting miss distance according to interval of the first sensors, which first catches shock-wave, to solve the problem such as noise filtering on severe background, and signals of amplifier vibration dynamic disposal and electromagnetism compatibility, in order to improves the precision and reliability of gathering wave N signals. For the first time, it can identify the kinds of pills and firing units automatically, measure miss distance and azimuth when pills are firing. Application shows that the tactics and technique index is advanced all of the world.

  2. Investigation of shock-induced combustion past blunt projectiles

    NASA Technical Reports Server (NTRS)

    Ahuja, J. K.; Tiwari, S. N.

    1996-01-01

    A numerical study is conducted to simulate shock-induced combustion in premixed hydrogen-air mixtures at various free-stream conditions and parameters. Two-dimensional axisymmetric, reacting viscous flow over blunt projectiles is computed to study shock-induced combustion at Mach 5.11 and Mach 6.46 in hydrogen-air mixture. A seven-species, seven reactions finite rate hydrogen-air chemical reaction mechanism is used combined with a finite-difference, shock-fitting method to solve the complete set of Navier-Stokes and species conservation equations. The study has allowed an improved understanding of the physics of shock-induced combustion over blunt projectiles and the numerical results can now be explained more readily with one-dimensional wave-interaction model.

  3. [Computer simulation of projectile injuries to pig mandibular angle].

    PubMed

    Lei, Tao; Chen, Yu-Bin; Xie, Liang-Xian; Zhang, Gang; Tan, Ying-Hui

    2012-11-01

    To investigate the feasibility of computer simulation in maxillofacial firearm injury. The three-dimensional finite element models and simulations of 7.62 mm, 5.56 mm standard bullets projectile injuries to pig mandibular angle were established by using MIMICS, ANSA, LS-DYNA and LS-POST software. Based on the simulation results, the bullet hole diameters, energy loss values, energy loss rates, von Mises stress, effective strain, effective strain rate dynamic contours at different time points were used for biomechanical analysis. The damage processe of 7.62 mm, 5.56 mm standard bullets projectile injury to pig mandibular angle were simulated successfully. The injury rate of 7.62 mm standard bullet and injury severity of the mandible were higher than that of 5.56 mm standard bullet. Computer simulation can simulate maxillofacial firearm injuries effectively and may become an important method for oral and maxillofacial firearm injuries analysis.

  4. Developmental changes of misconception and misperception of projectiles.

    PubMed

    Kim, In-Kyeong

    2012-12-01

    This study investigated the developmental changes of perceptual and cognitive commonsense physical knowledge. Children 4 to 9 years old (N = 156; 79 boys, 77 girls) participated. Each child was asked to predict the landing positions of balls that rolled down and fell off a virtual ramp and to choose the most natural-looking motion from different projectile motions depicted. The landing position of the most natural-looking projectile was compared with the predicted landing position and also compared with the actual landing position. The results showed children predicted the ball's landing position closer to the ramp than the actual position. Children also chose the depiction in which the ball fell closer to the ramp than the accurate position, although the error in the prediction task was larger than in the perception task and decreased with age. The results indicated the developmental convergence of explicit reasoning and implicit perception, which suggest a single knowledge system with representational re-description.

  5. Electron loss of fast projectiles in collisions with molecules

    SciTech Connect

    Matveev, V. I.; Makarov, D. N.; Rakhimov, Kh. Yu.

    2011-07-15

    The single- and multiple-electron loss of fast highly charged projectiles in collisions with neutral molecules is studied within the framework of a nonperturbative approach. The cross sections for single-, double-, and triple-electron losses are calculated for the collision system Fe{sup q+}{yields}N{sub 2} (q=24, 25, 26) at the collision energies 10, 100, and 1000 MeV/nucleon. The effects caused by the collision multiplicity and the orientation of the axis of the target molecule are treated. It is shown that the collision multiplicity effect leads to considerable differences for the cases of perpendicular and parallel orientations of the molecular axes with respect to the direction of the projectile motion, while for chaotic orientation such an effect is negligible.

  6. Two dimensional fractional projectile motion in a resisting medium

    NASA Astrophysics Data System (ADS)

    Rosales, Juan; Guía, Manuel; Gómez, Francisco; Aguilar, Flor; Martínez, Juan

    2014-07-01

    In this paper we propose a fractional differential equation describing the behavior of a two dimensional projectile in a resisting medium. In order to maintain the dimensionality of the physical quantities in the system, an auxiliary parameter k was introduced in the derivative operator. This parameter has a dimension of inverse of seconds (sec)-1 and characterizes the existence of fractional time components in the given system. It will be shown that the trajectories of the projectile at different values of γ and different fixed values of velocity v 0 and angle θ, in the fractional approach, are always less than the classical one, unlike the results obtained in other studies. All the results obtained in the ordinary case may be obtained from the fractional case when γ = 1.

  7. Two dimensional fractional projectile motion in a resisting medium

    NASA Astrophysics Data System (ADS)

    Rosales, Juan J.; Guía, Manuel; Gómez, Francisco; Aguilar, Flor; Martínez, Juan

    2014-07-01

    In this paper we propose a fractional differential equation describing the behavior of a two dimensional projectile in a resisting medium. In order to maintain the dimensionality of the physical quantities in the system, an auxiliary parameter k was introduced in the derivative operator. This parameter has a dimension of inverse of seconds ( sec)-1 and characterizes the existence of fractional time components in the given system. It will be shown that the trajectories of the projectile at different values of γ and different fixed values of velocity v 0 and angle θ, in the fractional approach, are always less than the classical one, unlike the results obtained in other studies. All the results obtained in the ordinary case may be obtained from the fractional case when γ = 1.

  8. Computational and Experimental Investigations of Turbulent Flow Past Projectiles

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Carlucci, Pasquale; Carlucci, Donald; Thangam, Siva

    2008-11-01

    Experimental and computational investigations of turbulent flow past projectiles is modeled as axial flow past a cylinder with a free-spinning base. A subsonic wind tunnel with a forward-sting mounted spinning cylinder is used for experiments. In addition, a free-jet facility is used for benchmarking the experimental set up. Experiments are performed for a range of spin rates and free stream flow conditions. An anisotropic two-equation Reynolds-stress model that incorporates the effect of rotation-modified energy spectrum and swirl is used to perform computations for the flow past axially rotating cylinders. Both rigid cylinders as well as that of cylinders with free-spinning base are considered from a computational point of view. Applications involving the design of projectiles are discussed.

  9. a Theoretical Study of Projectile Delta Excitations in

    NASA Astrophysics Data System (ADS)

    Jo, Yung

    1995-01-01

    An approach is proposed for the investigation of the projectile Delta excitations induced by charge exchange reactions in the intermediate energy region. The nuclear structure part of the formalism is based on the particle-hole model and the nuclear reaction part is treated within the plane-wave impulse approximation (PWIA). In the nuclear structure part, all important nuclear medium effects are included. We take into account the nucleon knock-out mode and the related nucleon particle -nucleon hole (NN^{-1}) correlations. In order to perform the calculations, we first set up coupled-channel (CC) equations for the excited nucleons. The Lanczos method is adopted to solve this CC equations. In this dissertation we study the contribution of the projectile delta excitation process to (p, n) reaction spectra from a nuclear target. The spin observables are also calculated and discussed.

  10. Reconnection launcher projectile heating using the modified REGGIE code

    SciTech Connect

    Freemen, J.R.

    1989-01-01

    Modified REGGIE is a variant of the REGGIE reconnection launcher code. It was written to provide a more economical tool for studying multi-stage projectile heating. The validity of the approximations made in modified REGGIE was determined by comparisons with both full REGGIE and WARP-10 computations. Modified REGGIE runs about seven times faster than full REGGIE. Modified REGGIE was used to study projectile heating for a specific force profile proposed by M. Cowan. The total energy dissipated after seven stages was reduced by a factor of about eight compared to the present day conventional discrete coil system. This reduction would allow higher peak velocities to be achieved prior to ablation. 5 refs., 4 figs., 3 tabs.

  11. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  12. Structural Analysis of a Kinetic Energy Projectile During Launch

    DTIC Science & Technology

    1981-07-01

    Fracture i,,wei~ I w~emeduu mda Ideftf dr h block rnuwbbev rhis pa2per presents the results of a thro~e pliasti effort. to quantify the i3trut.I,. fli ... 1 .ua ’iitegrity ()f a long rod kinWLetZ nEry punetraLor projectile during lai),t!.. Te fErst plmanc iised thr- f ln .t~e ... nwo rrn’t.nor to

  13. Control Mechanism Strategies for Spin-Stabilized Projectiles

    DTIC Science & Technology

    2008-09-01

    maneuver footprint shape was dictated by the angle -of-fall and yaw of repose . Shallow angles -of-fall produced footprint ellipses, with a major axis...Magnus moments and yaw of repose . Adding a control mechanism such as fins to guide a spin- stabilized projectile further complicates the resulting...ratio), and the roll window over which the pulsed controller operated. The metrics of this analysis were the maneuver footprint, total angle of attack

  14. Measuring the Effects of Lift and Drag on Projectile Motion

    ERIC Educational Resources Information Center

    Cross, Rod

    2012-01-01

    The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces. The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms[superscript -1] (89.5 mph), it experiences a drag force of about 1.5 N.…

  15. Transportation Vibration Analysis of the XM982 Projectile

    DTIC Science & Technology

    2007-02-01

    Interactions, and Damping 3 Preloads and Applied Loads 5 Analysis Results 9 Contact Force 9 Angular Displacement 10 Torque 12 Discussion 12...Conclusions 13 References 15 Appendix A - Calculation of Angular Displacement , Angular Acceleration, and Torque 17 Distribution List 21 FIGURES Page 1 XM982... displacement (radians) versus time(s) for projectile secured in one strap 11 configuration with 0.173 in. strap preload and 0.183 in. strap preload 12

  16. Wave propagation in a plate after impact by a projectile

    NASA Technical Reports Server (NTRS)

    El-Raheb, M.; Wagner, P.

    1987-01-01

    The wave propagation in a circular plate after impact by a cylindrical projectile is studied. In the vicinity of impact, the pressure is computed numerically. An intense pressure pulse is generated that peaks 0.2 microns after impact, then drops sharply to a plateau. The response of the plate is determined adopting a modal solution of Mindlin's equations. Velocity and acceleration histories display both propagating and dispersive features.

  17. Wave propagation in a plate after impact by a projectile

    NASA Technical Reports Server (NTRS)

    El-Raheb, M.; Wagner, P.

    1987-01-01

    The wave propagation in a circular plate after impact by a cylindrical projectile is studied. In the vicinity of impact, the pressure is computed numerically. An intense pressure pulse is generated that peaks 0.2 microns after impact, then drops sharply to a plateau. The response of the plate is determined adopting a modal solution of Mindlin's equations. Velocity and acceleration histories display both propagating and dispersive features.

  18. Measuring the Effects of Lift and Drag on Projectile Motion

    ERIC Educational Resources Information Center

    Cross, Rod

    2012-01-01

    The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces. The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms[superscript -1] (89.5 mph), it experiences a drag force of about 1.5 N.…

  19. Microadaptive Flow Control Applied to a Spinning Projectile

    DTIC Science & Technology

    2005-09-01

    yaw vs. range. 2.5 In-bore Launch Modeling and Validation Testing In order to understand the launch behavior of the projectile, DYNA3D was used to...rate is modeled in DYNA3D . Head Batter Battery Support Bore Body Back Cover Steel Sleeve Tungsten Ring Sensor board Processor board GTRItm...Livermore National Laboratory code, DYNA3D (11), was adopted for the analysis. The input required includes geometric data, mechanical data, and

  20. Design of Kinetic Energy Projectiles for Structural Integrity

    DTIC Science & Technology

    1981-09-01

    phase of flight . A great deal of design effort must be expended to ensure launchability of the projectile, i.e. in-bore structural integrity. Since the...travel and, sub- sequently, discard at the muzzle in such a manner as to impart low yaw and yaw rate to the flight body. These latter requirements may be...requirements. The basic flight configuration of the subprojectile is assumed to be specified by terminal ballistic and aerodynamic considerations. Thus the

  1. Effects of Mixtures on Liquid and Solid Fragment Size Distributions

    DTIC Science & Technology

    2016-05-01

    treated steel ; 67.0/ mn Table 11 gives examples of size distributions taken from the research literature on atomization and sprays where mn...impact (0.5–2.0 km/s) on thin steel plates.” More specifically, he studied “spherical porous aluminum projectiles 2.51 cm in diameter … cut from a...Effects of Mixtures on Liquid and Solid Fragment Size Distributions Distribution Statement A. Approved for public release; distribution is unlimited

  2. Doubly differential cross sections for galactic heavy-ion fragmentation

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Norbury, John W.; Khandelwal, Govind S.; Townsend, Lawrence W.

    1987-01-01

    An abrasion-ablation T-matrix formulation is applied to the calculation of double differential-cross sections in projectile fragmentation of 2.1 GeV/nucleon O-16 on Be-9 and 86 MeV/nucleon C-12 on C-12 and Ag-108. An exponential parameterization of the ablation T-matrix is used and the total width of the intermediate states is taken as a parameter. Fitted values of the total width to experimental results are used to predict the lifetime of the ablation stage and indicate a decay time on the order of 10 to the -19th power sec.

  3. Destabilization and intracranial fragmentation of a full metal jacket bullet.

    PubMed

    Farrugia, A; Raul, J S; Geraut, A; Tortel, M C; Ludes, B

    2009-10-01

    We report a case with an atypical entrance wound as a result of a destabilized full metal jacket bullet penetration. The destabilized bullet by an impact with the dorsal hand experiences a yawing to tumbling motion in flight. The large angle of yaw induces a larger presenting profile upon impact that contributes, associated to a rapid deceleration, to a greater mechanical force on the projectile structure and a fragmentation into core and jacket. Forensic pathologists have to be aware that the metal jacket bullet could tend to break up outside or inside the body particularly after a shooting through a target. This phenomenon induces atypical entrance wounds and atypical X-ray presentation.

  4. Impact ionisation spectra from hypervelocity impacts using aliphatic poly(methyl methacrylate) microparticle projectiles.

    PubMed

    Burchell, Mark J; Armes, Steven P

    2011-02-28

    We report impact ionisation spectra from spherical poly(methyl methacrylate) (PMMA) microparticles of 724 nm diameter impacting a rhodium target. These projectiles were coated with an ultrathin (~11 nm) overlayer of polypyrrole, an electrically conducting organic polymer; this enabled the accumulation of sufficient surface charge to allow electrostatic acceleration up to speeds of 4 to 8 km s(-1) using a high-voltage Van de Graaff instrument. A grid above the target (held at 3.33 kV cm(-1) with respect to the target) accelerated the cations that were generated during the hypervelocity impacts, and these ions then drifted to a charge detector. By measuring the collected charge vs. time and assuming only single ionisation events, time-of-flight mass spectra were obtained. Strong signals were observed for cationic species with ions of m/z 41, 65 and 115. There were also minor contributions from cations with masses ranging from m/z 29 to 142. The three major signals are assigned to fragment ions (C(3)H(5)(+), C(4)H(5)O(+)/C(5)H(9)(+) and C(6)H(11)O(2)(+)) which are known to be associated with the decomposition of PMMA. These impact ionisation spectra differ significantly from those reported earlier using polystyrene (PS) microparticles. The aliphatic PMMA microparticles generate small (m/z <100) fragment ions more readily at lower speeds than the predominantly aromatic PS microparticles, where speeds of at least 10 km s(-1) are typically required for substantial yields of low-mass fragment ions. This correlates well with the well-known greater chemical and thermal fragility of PMMA compared to PS. The PMMA microparticles should prove useful synthetic mimics for aliphatic carbonaceous micrometeorites. Copyright © 2011 John Wiley & Sons, Ltd.

  5. GPU-enabled projectile guidance for impact area constraints

    NASA Astrophysics Data System (ADS)

    Rogers, Jonathan

    2013-05-01

    Guided projectile engagement scenarios often involve impact area constraints, in which it may be less desirable to incur miss distance on one side of a target or within a specified boundary near the target area. Current projectile guidance schemes such as impact point predictors cannot handle these constraints within the guidance loop, and may produce dispersion patterns that are insensitive to these constraints. In this paper, a new projectile guidance law is proposed that leverages real-time Monte Carlo impact point prediction to continually evaluate the probability of violating impact area constraints. The desired aim point is then adjusted accordingly. Real-time Monte Carlo simulation is enabled within the feedback loop through use of graphics processing units (GPU's), which provide parallel pipelines through which a dispersion pattern can routinely be predicted. The result is a guidance law that can achieve minimum miss distance while avoiding impact area constraints. The new guidance law is described and formulated as a nonlinear optimization problem which is solved in real-time through massively-parallel Monte Carlo simulation. An example simulation is shown in which impact area constraints are enforced and the methodology of stochastic guidance is demonstrated. Finally, Monte Carlo simulations are shown which demonstrate the ability of the stochastic guidance scheme to avoid an arbitrary set of impact area constraints, generating an impact probability density function that optimally trades miss distance within the restricted impact area. The proposed guidance scheme has applications beyond smart weapons to include missiles, UAV's, and other autonomous systems.

  6. Dynamics of drag force for projectile impact in granular media

    NASA Astrophysics Data System (ADS)

    Behringer, Lauren; Stevens Bester, Cacey; Behringer, Robert

    2016-11-01

    We study the way in which momentum is dissipated as a free-falling projectile impacts a dense granular target. An empirical force law has been widely accepted to describe this process, defining the stopping force as the sum of depth-dependent static force and velocity-dependent inertial drag. However, a complete understanding of the stopping force, incorporating grain-scale interactions during impact, remains unresolved. Using direct force measurements by way of a photoelastic imaging technique, we explore the complex fluctuating behavior of the forces acting on the projectile decelerating through a granular medium. Our results are used to study the static drag as the projectile comes to rest, as well as its connection to the effect of the container boundary of the granular target. We additionally vary the shape of the impeding object to infer intruder-grain interactions from force measurements. Supported by Duke University Provost's Postdoctoral Program, NASA Grant NNX15AD38G, NSF-DMR-1206351.

  7. Effect of projectile mass on amorphization of CuTi

    SciTech Connect

    Koike, J.; Okamoto, P.R.; Meshii, M.

    1988-09-01

    Various intermetallic compounds are shown to be amorphized by electron and ion irradiations below a critical temperature. the critical temperature for amorphization is higher for ion irradiation than for electron irradiation. In the present work, the effect of projectile mass is studied in amorphization of CuTi with electron, Ne , Kr and Xe . The critical temperature was found to increase monotonically with projectile mass from 185K for electron to 543K for Kr and Xe . The kinetics of crystalline to amorphous transition was studied by measuring the integrated intensity of diffuse rings on electron diffraction patterns. The analysis of the results of this measurement by Gibbons model indicated that the direct amorphization occurs in a single damage zone with Kr , while overlapping of three damage zones is required for amorphization with Ne . In the light of these observations, the relation between the structure of irradiation damage and the crystalline to amorphous transition, and the projectile mass dependence of the critical temperature for irradiation-induced amorphization will be discussed. 14 refs., 5 figs.

  8. Dual mode fracture of composite laminates penetrated by spherical projectiles

    NASA Astrophysics Data System (ADS)

    Czarnecki, G. J.

    The basic for delamination initiation and propagation within an impacted laminate was studied, with an explanation provided for the fracture mode transformation along the projectile's path. Post-impact observations of graphite/epoxy (AS4/3501-6) laminates penetrated by steel spheres (0.5-inch diameter) reveal a fracture mode, similar to shear plugging adjacent to the impacted surface. This fracture mode is contrasted with that of delamination adjacent to the rear surface. The sudden transition from shear plugging to delamination is believed to occur when the projectile interacts with the returning impact-generated tensile wave. To demonstrate the transition, results are presented from ballistically impacted laminates containing a series of imbedded carbon stress and constantan strain gages. Results are based on impact velocities of 1300, 1850, and 2380 f/s. Transverse stress waves are shown capable of creating delamination until attenuated by a local zone of compressed material associated with the on-coming projectile. Based on experimental results, the location of the fracture mode transition plane is predicted both graphically and through a simple equation of motion.

  9. Molecular target and projectile angular scattering effects in stopping power and charge exchange at low-to-intermediate projectile energies

    NASA Astrophysics Data System (ADS)

    Cabrera-Trujillo, R.; Öhrn, Y.; Sabin, John R.; Deumens, E.

    2002-02-01

    We analyze the implications of the molecular structure of a target and the angular scattering effects on projectile-target collisions within the Electron-Nuclear Dynamics (END) approach. We show the suitability of the END method for the analysis of molecular scattering processes such as differential cross sections, charge exchange, and energy loss as required for the study of the stopping cross section. As a consequence of these effects, we show that the rovibronic energy loss becomes of greatest importance at low projectile energies. Furthermore, we find that the Bragg additivity rule and the linear-velocity dependence of the stopping cross section are not fulfilled at low projectile energies. Finally, we analyze the differences in the scattering processes for molecular and atomic targets, and show that in a transmission experiment with small exit window, the acceptance angle corresponds to different impact parameter selection for molecular targets than for atomic ones. Thus, the measured stopping cross section becomes a function of the acceptance angle of the experimental setup. We present results for hydrogen beams on H2 and N2 gas targets.

  10. Numerical study on the high-speed water-entry of hemispherical and ogival projectiles

    NASA Astrophysics Data System (ADS)

    Guo, Zitao; Zhang, Wei; Wei, Gang; Ren, Peng

    2012-03-01

    The water entry problem is considered as a classic problem which has a long research history; however, projectile water entry is still a difficult problem that has not been completely solved. In this paper, the effects of the projectile nose shape on laws of velocity attenuations for all projectiles were studied by a series of numerical simulations using the AUTODYN-2D. The result showed that the drag coefficient increases monotonically with the initial velocities for an identical projectile and decreases with the CRH values for projectiles at the same velocity. A simple and effective model was proposed to determine the relations between the drag coefficients, nose shape coefficient and initial velocities of projectiles.

  11. Characteristics and measurement of supersonic projectile shock waves by a 32-microphone ring array.

    PubMed

    Chang, Ho; Wu, Yan-Chyuan; Tsung, Tsing-Tshih

    2011-08-01

    This paper discusses about the characteristics of supersonic projectile shock wave in muzzle region during firing of high explosive anti-tank (HEAT) and high explosive (HE) projectiles. HEAT projectiles are fired horizontally at a muzzle velocity of Mach 3.5 from a medium caliber tank gun equipped with a newly designed multi-perforated muzzle brake, whereas HE projectiles are fired at elevation angles at a muzzle velocity of Mach 2 from a large caliber howitzer equipped with a newly designed double-baffle muzzle brake. In the near field, pressure signatures of the N-wave generated from projectiles are measured by 32-microphone ring array wrapped by cotton sheath. Records measured by the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements made in this study can be a significant reference for developing guns, tanks, or the chassis of fighting vehicles.

  12. Characteristics and measurement of supersonic projectile shock waves by a 32-microphone ring array

    NASA Astrophysics Data System (ADS)

    Chang, Ho; Wu, Yan-Chyuan; Tsung, Tsing-Tshih

    2011-08-01

    This paper discusses about the characteristics of supersonic projectile shock wave in muzzle region during firing of high explosive anti-tank (HEAT) and high explosive (HE) projectiles. HEAT projectiles are fired horizontally at a muzzle velocity of Mach 3.5 from a medium caliber tank gun equipped with a newly designed multi-perforated muzzle brake, whereas HE projectiles are fired at elevation angles at a muzzle velocity of Mach 2 from a large caliber howitzer equipped with a newly designed double-baffle muzzle brake. In the near field, pressure signatures of the N-wave generated from projectiles are measured by 32-microphone ring array wrapped by cotton sheath. Records measured by the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements made in this study can be a significant reference for developing guns, tanks, or the chassis of fighting vehicles.

  13. Aeroballistic Performance of the 25mm M910 TPDS-T Range Limited Training Projectile

    DTIC Science & Technology

    1991-01-01

    stands for " armor -piercing target-practice - traced." The specified maximum range of the projectile is 8000 meters. During prototype testing at Fort Bliss...35 vii INTENTONALLY LEFT BLANK. viii I. INTRODUCTION The armor -piercing target-practice - traced M910 TPDS-T projectile was developed by the...service projectile is the armor -piercing discarding-sabot - traced M791 APDS-T, which is a spin-stabilized sabot-launched tungsten al- loy penetrator. The

  14. Evaluation of CAPEL (Confined Armature Projectile Experimental Launcher), A Novel Railgun Concept,

    DTIC Science & Technology

    1986-09-01

    bore immediately behind the projectile confine the high pressure plasma as it accelerates the projectile forward due to the Lorentz J x B forces...a barrel to contain the transverse forces of a high pressure plasma armature, a cavity is introduced into the projectile itself. This then contains...confining barrel . It also provides many other advantages over the conventional railgun (using a plasma armature). These are discussed In the later

  15. The drag force on a subsonic projectile in a fluid complex plasma

    SciTech Connect

    Ivlev, A. V.; Zhukhovitskii, D. I.

    2012-09-15

    The incompressible Navier-Stokes equation is employed to describe a subsonic particle flow induced in complex plasmas by a moving projectile. Drag forces acting on the projectile in different flow regimes are calculated. It is shown that, along with the regular neutral gas drag, there is an additional force exerted on the projectile due to dissipation in the surrounding particle fluid. This additional force provides significant contribution to the total drag.

  16. A Synopsis of Yaw-Induction Techniques Used During Projectile Free-Flight Aerodynamics Experiments

    DTIC Science & Technology

    2013-03-01

    A Synopsis of Yaw-Induction Techniques Used During Projectile Free-Flight Aerodynamics Experiments by Bradford S. Davis and Bernard J...Synopsis of Yaw-Induction Techniques Used During Projectile Free-Flight Aerodynamics Experiments Bradford S. Davis and Bernard J. Guidos Weapons and...October 2012 4. TITLE AND SUBTITLE A Synopsis of Yaw-Induction Techniques Used During Projectile Free-Flight Aerodynamics Experiments 5a. CONTRACT

  17. Analytical Approach to Ballistic Dispersion of Projectile Weapons Based on Variant Launch Velocity

    DTIC Science & Technology

    2013-04-01

    projectiles , the coefficient of variation of vz0 is as small as 0.5% through rigorous studies of 225 distinct barrel shapes and varying in-bore pressure due to...Analytical Approach to Ballistic Dispersion of Projectile Weapons Based on Variant Launch Velocity by Michael M. Chen ARL-RP-437 April... Projectile Weapons Based on Variant Launch Velocity Michael M. Chen Weapons and Materials Research Directorate, ARL A reprint from

  18. A Study of the Engraving of the M855 5.56-mm Projectile

    DTIC Science & Technology

    2009-03-01

    A Study of the Engraving of the M855 5.56-mm Projectile by Joseph South, Aristedes Yiournas, Jordan Wagner, John Brown, and Robert Kaste...ARL-TR-4743 March 2009 A Study of the Engraving of the M855 5.56-mm Projectile Joseph South, Aristedes Yiournas, Jordan Wagner, John Brown...approach to evaluate the effect of engraving on the M855 projectile as a function of propellant charge. The result of this combined approach is the

  19. A Terminal Guidance Model for Smart Projectiles Employing a Semi-Active Laser Seeker

    DTIC Science & Technology

    2011-08-01

    A Terminal Guidance Model for Smart Projectiles Employing a Semi-Active Laser Seeker by Luke S. Strohm ARL-TR-5654 August 2011...Terminal Guidance Model for Smart Projectiles Employing a Semi-Active Laser Seeker Luke S. Strohm Weapons and Materials Research Directorate...January 2010–31 March 2011 4. TITLE AND SUBTITLE A Terminal Guidance Model for Smart Projectiles Employing a Semi-Active Laser Seeker 5a. CONTRACT

  20. Considerations of Nose Shape for Thin-Walled Projectile Penetrating Double Reinforced Concrete

    DTIC Science & Technology

    2008-07-01

    experiments were fabricated by ARL from Vascomax 300 maraging steel [6]. A photograph of this projectile is shown in Figure 1. Six projectiles...Experiments The CRH=2 projectiles used in the second set of experiments were also fabricated from Vascomax 300 maraging steel . A photograph of the CRH=2...In the Zapotec simulations, the concrete target material was modeled with a brittle fracture kinetics model [4]. The experiments included steel