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Sample records for binary projectile fragmentation

  1. Binary projectile fragmentation of 12C at an incident energy of 33.3 MeV/nucleon

    CERN Document Server

    Förtsch, S V; Gadioli, E; Bassini, R; Buthelezi, E Z; Cerutti, F; Connell, S H; Cowley, A A; Fujita, H; Mabiala, J; Mairani, A; Mira, J; Papka, P; Neveling, R; Smit, F D

    2010-01-01

    Direct binary projectile fragmentation is being investigated for the case where a 400 MeV 12C projectile breaks up into an particle and a 8Be fragment in the interaction with a thin 93Nb and 197Au target. While the 8Be fragments were measured at 9 , the correlated particles were detected in an angular range between 16 and 30 on the opposite side of the beam. From the preliminary results presented here one may obtain information on the amount of quasi-elastic fragmentation (both fragments do not suffer any further interactions after they are produced). These experimental results indicate that the quasi-elastic break-up process is the dominant contribution to the measured correlation spectra. As was also observed in earlier work, the most forward quasi-elastically emitted particles have energies exceeding the beam velocity.

  2. Isoscaling of projectile-like fragments

    Institute of Scientific and Technical Information of China (English)

    Zhong Chen; Chen Jin-Hui; Guo Wei; Ma Chun-Wang; Ma Guo-Liang; Su Qian-Min; Yan Ting-Zhi; Zuo Jia-Xu; Ma Yu-Gang; Fang De-Qing; Cai Xiang-Zhou; Chen Jin-Gen; Shen Wen-Qing; Tian Wen-Dong; Wang Kun; Wei Yi-Bin

    2006-01-01

    In this paper, the isotopic and isotonic distributions of projectile fragmentation products have been simulated by a modified statistical abrasion-ablation model and the isoscaling behaviour of projectile-like fragments has been discussed. The isoscaling parameters α andβ have been extracted respectively, for hot fragments before evaporation and cold fragments after evaporation. It looks that the evaporation has stronger effect on α than β. For cold fragments,a monotonic increase of α and |β| with the increase of Z and N is observed. The relation between isoscaling parameter and the change of isospin content is discussed.

  3. Angular Momentum Population in Projectile Fragmentation

    Science.gov (United States)

    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.

  4. N/Z Dependence of Projectile Fragmentation

    CERN Document Server

    Trautmann, W; Aumann, T; Bacri, C O; Barczyk, T; Bassini, R; Bianchin, S; Boiano, C; Botvina, A S; Boudard, A; Brzychczyk, J; Chbihi, A; Cibor, J; Czech, B; De Napoli, M; Ducret, J -E; Emling, H; Frankland, J D; Hellström, M; Henzlova, D; Imme, G; Iori, I; Johansson, H; Kezzar, K; Lafriakh, A; Le Fèvre, A; Gentil, E Le; Leifels, Y; Lühning, J; Lukasik, J; Lynch, W G; Lynen, U; Majka, Z; Mocko, M; Müller, W F J; Mykulyak, A; Orth, H; Otte, A N; Palit, R; Pawlowski, P; Pullia, A; Raciti, G; Rapisarda, E; Sann, H; Schwarz, C; Sfienti, C; Simon, H; Sümmerer, K; Tsang, M B; Verde, G; Volant, C; Wallace, M; Weick, H; Wiechula, J; Wieloch, A; Zwieglinski, B

    2007-01-01

    The N/Z dependence of projectile fragmentation at relativistic energies has been studied in a recent experiment at the GSI laboratory with the ALADiN forward spectrometer coupled to the LAND neutron detector. Besides a primary beam of 124Sn, also secondary beams of 124La and 107Sn delivered by the FRS fragment separator have been used in order to extend the range of isotopic compositions of the produced spectator sources. With the achieved mass resolution of \\Delta A/A \\approx 1.5%, lighter isotopes with atomic numbers Z \\le 10 are individually resolved. The presently ongoing analyses of the measured isotope yields focus on isoscaling and its relation to the properties of hot fragments at freeze-out and on the derivation of chemical freeze-out temperatures which are found to be independent of the isotopic composition of the studied systems. The latter result is at variance with the predictions for limiting temperatures as obtained with finite-temperature Hartree-Fock calculations.

  5. Experimental and numerical study on fragmentation of steel projectiles

    Directory of Open Access Journals (Sweden)

    Hopperstad O.S.

    2012-08-01

    Full Text Available 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. Fragmentation of Pb-Projectiles at SPS Energies

    CERN Multimedia

    2002-01-01

    % EMU17 \\\\ \\\\ We have exposed stacks consisting of solid state nuclear track detectors (CR-39 plastic and BP-1 glass) and different target materials at the SPS to beams of Pb projectiles. Our detectors record tracks of relativistic nuclei with charge numbers of Z~$\\geq$~6 for CR-39 and Z~$\\geq$75 for BP-1. After development of the tracks by etching they are detected and measured using completely automated microscope systems. Thus experiments with high statistics are possible. \\\\ \\\\BP-1 detectors were exposed to measure total charge changing cross sections and elemental production cross sections for heavy projectile fragments. These experiments were performed for different targets CH$ _{2} $, C, Al, Cu, Ag and Pb. Comparison of the results for different targets allows to investigate contributions to charge changing reactions by electromagnetic dissociation. Multifragmentation events in which several intermediate mass fragments are emitted from the heavy Pb projectile are studied using stacks containing CR-39 d...

  7. Bimodal pattern in the fragmentation of Au quasi-projectiles

    CERN Document Server

    Bruno, M; D'Agostino, M; Gramegna, F; Gulminelli, F; Vannini, G

    2006-01-01

    Signals of bimodality have been investigated in experimental data of quasi-projectile decay produced in Au+Au collisions at 35 AMeV. This same data set was already shown to present several signals characteristic of a first order, liquid-gas-like phase transition. For the present analysis, events are sorted in bins of transverse energy of light charged particles emitted by the quasi-target source. A sudden change in the fragmentation pattern is observed from the distributions of the asymmetry of the two largest fragments, and the charge of the largest fragment. This latter distribution shows a bimodal behavior. The interpretation of this signal is discussed.

  8. Predicting the fragmentation onset velocity for different metallic projectiles using numerical simulations

    NARCIS (Netherlands)

    Livingstone, I.H.G.; Verolme, K.; Hayhurst, C.J.

    2001-01-01

    For cubes and spheres under high velocity impact there exists for each system of projectile and target, a threshold velocity that is just sufficient to shatter the projectile. This velocity, usually above 2km/s for metallic projectiles, is known as the fragmentation onset velocity. To determine the

  9. Effect of neutron skin thickness on projectile fragmentation

    CERN Document Server

    Dai, Z T; Ma, Y G; Cao, X G; Zhang, G Q; Shen, W Q

    2015-01-01

    The fragment production in collisions of $^{48,50}$Ca+$^{12}$C at 50 MeV/nucleon are simulated via the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model followed by the {GEMINI code}. {By changing the diffuseness parameter of neutron density distribution to obtain different neutron skin size, the effects of neutron skin thickness (${\\delta}_{np}$) on projectile-like fragments (PLF) are investigated. The sensitivity of isoscaling behavior to neutron skin size is studied, from which it is found that the isoscaling parameter $\\alpha$ has a linear dependence on ${\\delta}_{np}$. A linear dependence between ${\\delta}_{np}$ and the mean $N/Z$ [N(Z) is neutron(proton) number] of PLF is obtained as well.} The results show that thicker neutron skin will lead to smaller {isoscaling parameter} $\\alpha$ and N/Z. Therefore, it may be probable to extract information of neutron skin thickness from {isoscaling parameter} $\\alpha$ and N/Z.

  10. Nuclear Fragmentation Induced by Relativistic Projectiles Studied in the 4$\\pi$ Configuration of Plastic Track Detectors

    CERN Multimedia

    2002-01-01

    % EMU19 \\\\ \\\\ The collisions of heavy ions at relativistic energies have been studied to explore a number of questions related with hot and dense nuclear matter in order to extend our knowledge of nuclear equation-of-state. There are other aspects of these interactions which are studied to expound the process of projectile and/or target disintegrations. The disintegrations in question could be simply binary fissions or more complex processes leading to spallation or complete fragmentation. These important aspects of nuclear reactions are prone to investigations with nuclear track detectors. \\\\ \\\\One of the comparatively new track detector materials, CR-39, is sensitive enough to record particles of Z~$\\geq$~6 with almost 100\\% efficiency up to highly relativistic energies. The wide angle acceptance and exclusive measurements possible with plastic track detectors offer an opportunity to use them in a variety of situations in which high energy charged fragments are produced. The off-line nature of measuring tra...

  11. Two source emission behaviour of alpha fragments of projectile having energy around 1 GeV per nucleon

    CERN Document Server

    Singh, V; Pathak, Ramji

    2010-01-01

    The emission of projectile fragments alpha has been studied in ^{84}Kr interactions with nuclei of the nuclear emulsion detector composition at relativistic energy below 2 GeV per nucleon. The angular distribution of projectile fragments alpha in terms of transverse momentum could not be explained by a straight and clean-cut collision geometry hypothesis of Participant - Spectator (PS) Model. Therefore, it is assumed that projectile fragments alpha were produced from two separate sources that belong to the projectile spectator region differing drastically in their temperatures. It has been clearly observed that the emission of projectile fragments alpha are from two different sources. The contribution of projectile fragments alpha from contact layer or hot source is a few percent of the total emission of projectile fragments alphas. Most of the projectile fragments alphas are emitted from the cold source. It has been noticed that the temperature of hot and cold regions are dependent on the projectile mass num...

  12. Formation of wide binaries by turbulent fragmentation

    Science.gov (United States)

    Lee, Jeong-Eun; Lee, Seokho; Dunham, Michael M.; Tatematsu, Ken'ichi; Choi, Minho; Bergin, Edwin A.; Evans, Neal J.

    2017-08-01

    Understanding the formation of wide-binary systems of very low-mass stars (M ≤ 0.1 solar masses, M⊙) is challenging 1,2,3 . The most obvious route is through widely separated low-mass collapsing fragments produced by turbulent fragmentation of a molecular core4,5. However, close binaries or multiples from disk fragmentation can also evolve to wide binaries over a few initial crossing times of the stellar cluster through tidal evolution6. Finding an isolated low-mass wide-binary system in the earliest stage of formation, before tidal evolution could occur, would prove that turbulent fragmentation is a viable mechanism for (very) low-mass wide binaries. Here we report high-resolution ALMA observations of a known wide-separation protostellar binary, showing that each component has a circumstellar disk. The system is too young7 to have evolved from a close binary, and the disk axes are misaligned, providing strong support for the turbulent fragmentation model. Masses of both stars are derived from the Keplerian rotation of the disks; both are very low-mass stars.

  13. Research on critical behaviour during fragmentation of the projectile in the Xe+Sn (at 50 MeV/A) reaction; Recherche d`un comportement critique dans la fragmentation du projectile dans la reaction Xe+Sn a 50 MeV/A

    Energy Technology Data Exchange (ETDEWEB)

    Benlliure, J.

    1995-03-01

    The study of moments of fragments charge distributions produced in heavy ions collisions can give us evidence of a critical behavior of nuclear matter which could explain the multifragmentation pattern. From an experimental point of view, in order to perform this capabilities of the INDRA detector has made it possible to identify all these particles and to reconstruct the initial projectile-like fragment coming from binary collisions in the reaction Xe+Sn at 50 MeV/A. We have selected events where the initial projectile-like fragments keep their entire charge in a large range of excitation energy. The study of these fragment`s characteristics show clearly a change in the deexcitation pattern. The evolution of moments of the fragment charge distributions has been reproduced within a percolation model, in this sense we can interpreter this change in the deexcitation pattern as a function of the initial projectile-like fragment`s size shows the existence of finite-size effects. However, the signature of a phase transition remains independent on the projectile-like fragment`s size. (author). 74 refs., 58 figs., 9 tabs.

  14. Cq+-induced excitation and fragmentation of uracil : effects of the projectile electronic structure

    NARCIS (Netherlands)

    de Vries, J.; Hoekstra, R.A.; Morgenstern, R.W.H.; Schlathölter, T.A.

    2002-01-01

    Ionization and fragmentation of the RNA base uracil (C4H4N2O2) by means of Cq+ ions (q = 1-6) has been studied for ion kinetic energies ranging from ;2 to 120 keV. Whereas for Cq+ (q = 1, 3, 4, 5, 6) very similar fragmentation yields are observed which increase with the projectile velocity v, C2+

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

    CERN Document Server

    Thies, R; 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; Caamano, M; Caesar, C; Casarejos, E; Catford, W; Cederkäll, J; Chakraborty, S; Chartier, M; Chulkov, L V; Cortina-Gil, D; Crespo, R; Datta, U; Fernández, P Díaz; 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; Diaz, D Gonzalez; 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; Kelic-Heil, A; Knöbel, R; Kröll, T; Krücken, R; Kurcewicz, J; Kurz, N; Labiche, M; Langer, C; Bleis, T Le; 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; del Rio, J Sanchez; 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

    2016-01-01

    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 to reach 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 10-15B isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent dataset. We compare our data to model calculations. Results: One-proton removal cross sec...

  16. Signature of fractionally charged projectile fragments in /sup 24/Mg-emulsion interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, D.; Roy, J.; Mukherjee, A.; Ghosh, A.

    1987-07-01

    From the measurement of charge of the projectile fragments produced in /sup 24/Mg-emulsion nuclei at 4.5 (GeV/c)/N, an indication of the existence of charges Z = 8/3 and 5/3 among the projectile fragments was obtained. The measurement was based on the lacunarity study of the linear structure of the ionizing track, and the percentage abundance of Z = 8/3 and 5/3 has found to be consistent with the relative abundance of anomalons.

  17. Production of helium projectile fragments in 16O-emulsion interactions at 4.5 A GeV/c

    Institute of Scientific and Technical Information of China (English)

    Zhang Dong-Hai; Li Zhen-Yu; Li Jun-Sheng; Wu Feng-Juan

    2004-01-01

    The measurements of partial production cross sections of the multiple helium projectile fragments emitted at 4.5A GeV/c 16O-Em interactions are reported. We have studied the production rate of helium projectile fragments due to fragmentation of 16O ions and compared it with that obtained from different projectiles at various energies. The dependence of on the mass number of the incident beams is formulated. The multiplicity distributions of the helium fragments produced in 16O-Em interactions at different energies exhibit Koba-Nielson-Olesen (KNO) scaling.The correlation of helium projectile fragments and target fragments is also investigated and it is found that the average of target fragments is increased with the decrease of the number of helium fragments in peripheral interactions.

  18. Scaling invariance of spherical projectile fragmentation upon high-velocity impact on a thin continuous shield

    Energy Technology Data Exchange (ETDEWEB)

    Myagkov, N. N., E-mail: nn-myagkov@mail.ru [Russian Academy of Sciences, Institute of Applied Mechanics (Russian Federation)

    2017-01-15

    The problem of aluminum projectile fragmentation upon high-velocity impact on a thin aluminum shield is considered. A distinctive feature of this description is that the fragmentation has been numerically simulated using the complete system of equations of deformed solid mechanics by a method of smoothed particle hydrodynamics in three-dimensional setting. The transition from damage to fragmentation is analyzed and scaling relations are derived in terms of the impact velocity (V), ratio of shield thickness to projectile diameter (h/D), and ultimate strength (σ{sub p}) in the criterion of projectile and shield fracture. Analysis shows that the critical impact velocity V{sub c} (separating the damage and fragmentation regions) is a power function of σ{sub p} and h/D. In the supercritical region (V > V{sub c}), the weight-average fragment mass asymptotically tends to a power function of the impact velocity with exponent independent of h/D and σ{sub p}. Mean cumulative fragment mass distributions at the critical point are scale-invariant with respect to parameters h/D and σ{sub p}. Average masses of the largest fragments are also scale-invariant at V > V{sub c}, but only with respect to variable parameter σ{sub p}.

  19. Modeling Fragment Simulating Projectile Penetration into Steel Plates Using Finite Elements and Meshfree Particles

    Directory of Open Access Journals (Sweden)

    James O’Daniel

    2011-01-01

    Full Text Available Simulating fragment penetration into steel involves complicated modeling of severe behavior of the materials through multiple phases of response. Penetration of a fragment-like projectile was simulated using finite element (FE and meshfree particle formulations. Extreme deformation and failure of the material during the penetration event were modeled with several approaches to evaluate each as to how well it represents the actual physics of the material and structural response. A steel Fragment Simulating Projectile (FSP – designed to simulate a fragment of metal from a weapon casing – was simulated for normal impact into a flat square plate. A range of impact velocities was used to examine levels of exit velocity ranging from relatively small to one on the same level as the impact velocity. The numerical code EPIC, used for all the simulations presented herein, contains the element and particle formulations, as well as the explicit methodology and constitutive models needed to perform these simulations. These simulations were compared against experimental data, evaluating the damage caused to the projectile and the target plates, as well as comparing the residual velocity when the projectile perforated the target.

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

    Energy Technology Data Exchange (ETDEWEB)

    Engelage, J.; Crawford, H.J.; Greiner, L.; Kuo, C. [and others

    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.

  1. Cq+-induced excitation and fragmentation of uracil : effects of the projectile electronic structure

    NARCIS (Netherlands)

    Hoekstra, R; Morgenstern, R; Schlatholter, T

    2002-01-01

    Ionization and fragmentation of the RNA base uracil (C4H4N2O2) by means of Cq+ ions (q = 1-6) has been studied for ion kinetic energies ranging from ;2 to 120 keV. Whereas for Cq+ (q = 1, 3, 4, 5, 6) very similar fragmentation yields are observed which increase with the projectile velocity v, C2+ io

  2. Signals of bimodality in the fragmentation of Au quasi-projectiles

    CERN Document Server

    Bruno, M; Cannata, F; D'Agostino, M; Gramegna, F; Vannini, G

    2008-01-01

    Signals of bimodality have been investigated in experimental data of quasi-projectile decay produced in Au+Au collisions at 35 AMeV. This same data set was already shown to provide several signals characteristic of a first order, liquid-gas-like phase transition. Different event sortings proposed in the recent literature are analyzed. A sudden change in the fragmentation pattern is revealed by the distribution of the charge of the largest fragment, compatible with a bimodal behavior.

  3. Source size scaling of fragment production in projectile breakup

    CERN Document Server

    Beaulieu, L; Fox, D; Das-Gupta, S; Pan, J; Ball, G C; Djerroud, B; Doré, D; Galindo-Uribarri, A; Guinet, D; Hagberg, E; Horn, D; Laforest, R; Larochelle, Y; Lautesse, P; Samri, M; Roy, R; Saint-Pierre, C

    1996-01-01

    Fragment production has been studied as a function of the source mass and excitation energy in peripheral collisions of $^{35}$Cl+$^{197}$Au at 43 MeV/nucleon and $^{70}$Ge+$^{nat}$Ti at 35 MeV/nucleon. The results are compared to the Au+Au data at 600 MeV/nucleon obtained by the ALADIN collaboration. A mass scaling, by $A_{source} \\sim$ 35 to 190, strongly correlated to excitation energy per nucleon, is presented, suggesting a thermal fragment production mechanism. Comparisons to a standard sequential decay model and the lattice-gas model are made. Fragment emission from a hot, rotating source is unable to reproduce the experimental source size scaling.

  4. Extrapolation of neutron-rich isotope cross-sections from projectile fragmentation

    CERN Document Server

    Mocko, M; Sun, Z Y; Andronenko, L; Andronenko, M; Delaunay, F; Famiano, M; Friedman, W A; Henzl, V; Henzlova, D; Hui, H; Liu, X D; Lukyanov, S; Lynch, W G; Rogers, A M; Wallace, M S

    2007-01-01

    Using the measured fragmentation cross sections produced from the 48Ca and 64Ni beams at 140 MeV per nucleon on 9Be and 181Ta targets, we find that the cross sections of unmeasured neutron rich nuclei can be extrapolated using a systematic trend involving the average binding energy. The extrapolated cross-sections will be very useful in planning experiments with neutron rich isotopes produced from projectile fragmentation. The proposed method is general and could be applied to other fragmentation systems including those used in other radioactive ion beam facilities.

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

    Directory of Open Access Journals (Sweden)

    Aizik F.

    2012-08-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  10. INTERACTION MEAN FREE PATH OF He PROJECTILE FRAGMENTS FROM 16O-EM COLLISION AT 60 A GeV

    Institute of Scientific and Technical Information of China (English)

    ZHANG DONG-HA1; SUN HAN-CHENG; G.GHARIBI

    2001-01-01

    The interaction mean free path of He projectile fragments, produced by the collisions of 16O at 60 A GeV in a nuclear emulsion, has been investigated. In the present analysis, 1555 He projectile fragments, giving rise to 320 secondary interactions, have been used. At a level of 3% a very weak signal of anomalons is observed, which comes mainly from the 3×He channel.

  11. Projectile fragmentation of 40,48Ca and isotopic scaling in a transport approach

    Science.gov (United States)

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

    2016-07-01

    We investigate theoretically projectile fragmentation in reactions of 40,48Ca on 9Be and 181Ta 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 40,48Ca pair. The symmetry energy determined in this way depends on these structure effects.

  12. Fragmentation of Millimeter-Size Hypervelocity Projectiles on Combined Mesh-Plate Bumpers

    Directory of Open Access Journals (Sweden)

    Aleksandr Cherniaev

    2017-01-01

    Full Text Available This numerical study evaluates the concept of a combined mesh-plate bumper as a shielding system protecting unmanned spacecraft from small (1 mm orbital debris impacts. Two-component bumpers consisting of an external layer of woven mesh (aluminum or steel directly applied to a surface of the aluminum plate are considered. Results of numerical modeling with a projectile velocity of 7 km/s indicate that, in comparison to the steel mesh-combined bumper, the combination of aluminum mesh and aluminum plate provides better fragmentation of small hypervelocity projectiles. At the same time, none of the combined mesh/plate bumpers provide a significant increase of ballistic properties as compared to an aluminum plate bumper. This indicates that the positive results reported in the literature for bumpers with metallic meshes and large projectiles are not scalable down to millimeter-sized particles. Based on this investigation’s results, a possible modification of the combined mesh/plate bumper is proposed for the future study.

  13. Comparison of mid-velocity fragment formation with projectile-like decay

    CERN Document Server

    Hudan, S; Davin, B; Larochelle, Y; Xu, H; Beaulieu, L; Lefort, T; Yañez, R; De Souza, R T; Charity, R J; Sobotka, L G; Liu, T X; Liu, X D; Lynch, W G; Shomin, R; Tan, W P; Tsang, M B; Molen, A V; Wagner, A; Xi, H F

    2005-01-01

    The characteristics of intermediate mass fragments (IMFs: 3<=Z<=20) produced in mid-peripheral and central collisions are compared. We compare IMFs detected at mid-velocity with those evaporated from the excited projectile-like fragment (PLF*). On average, the IMFs produced at mid-velocity are larger in atomic number, exhibit broader transverse velocity distributions, and are more neutron-rich as compared to IMFs evaporated from the PLF*. In contrast, comparison of mid-velocity fragments associated with mid-peripheral and central collisions reveals that their characteristics are remarkably similar despite the difference in impact parameter. The characteristics of mid-velocity fragments are consistent with low-density formation of the fragments. Neutron deficient isotopes of even Z elements manifest higher kinetic energies than heavier isotopes of the same element for both PLF* and mid-velocity emission. This result may be due to the decay of long-lived excited states in the field of the emitting system.

  14. Singly and Doubly Charged Projectile Fragments in Nucleus-Emulsion Collisions at Dubna Energy in the Framework of the Multi-Source Model

    Institute of Scientific and Technical Information of China (English)

    WANG Er-Qin; LIU Fu-Hu; Magda A.Rahim; S.Fakhraddin; SUN Jian-Xin

    2011-01-01

    @@ The multiplicity distributions of projectile fragments emitted in interactions of different nuclei with emulsion are studied by using a multi-source model.Our calculated results show that the projectile fragments can be described by the model and each source contributes an exponential distribution.As the weighted sum of the folding result of many exponential distributions,a multi-component Erlang distribution is used to describe the experimental data.The relationship between the height(or width)of the distribution and the mass of the incident projectile,as well as the dependence of projectile fragments on target groups,are investigated too.

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

    Science.gov (United States)

    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

  16. Strange baryon production and projectile fragmentation in p-A collisions at the AGS

    CERN Document Server

    Cole, B A

    2003-01-01

    Experiment 910 (E910) has studied proton-nucleus collisions at 12.3 and 17.5 GeV incident energies using a variety of targets. Centrality selection is provided via 'grey' track multiplicity which can be statistically related to nu, the number of scatterings of the proton in the target nucleus. Previously published semi-inclusive measurements of LAMBDA production are discussed and preliminary measurements of 'leading' LAMBDA production in 17.5 GeV p-Au collisions are presented as a function of nu. The data indicate that the probability for the projectile to fragment into a strange baryon increases significantly with increasing nu for nu <= 3; an extrapolation of the E910 data to nucleus-nucleus collisions can reproduce most of the enhancement in LAMBDA production observed in Pb-Pb collisions at 40, 80 and 160 A x GeV. Preliminary measurements of XI sup - production in 17.5 GeV p-Au collisions show a rapid increase in yield with increasing nu. The data are discussed in the context of the Van Hove fragmentati...

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

    Science.gov (United States)

    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.

  18. Study of events in absence of target/projectile fragments in interactions of nuclei with emulsion at 4.5 and 4.1 AGeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Magda A., E-mail: dr.magda2006@hotmail.co [Physics Department, Faculty of Science, Sana' s University (Yemen); Fakhraddin, S., E-mail: sakinafa1@hotmail.co [Physics Department, Faculty of Science, Sana' s University (Yemen)

    2009-12-01

    This work is devoted to study two types of events. Type (a): events with no target fragments, the incident nucleus is dissociated in emulsion accompanied with the pions. Type (b): events with no projectile fragments, total break-up of the two colliding nuclei into relatively small fragments. Case of central collisions. The main characteristics of these reactions, that is multiplicity distributions of projectile and target fragments have been studied and compared for interactions of {sup 4}He, {sup 12}C, {sup 16}O, {sup 22}Ne and {sup 28}Si nuclei with emulsion at almost same momentum. The dependence of the mean multiplicity of different PFs on the projectile mass is investigated. Also the percentage of occurrence of these two events for different projectiles are analyzed.

  19. Binary star formation: gravitational fragmentation followed by capture

    Science.gov (United States)

    Turner, J. A.; Chapman, S. J.; Bhattal, A. S.; Disney, M. J.; Pongracic, H.; Whitworth, A. P.

    1995-11-01

    We describe in detail one of a sequence of numerical simulations which realize the mechanism of binary star formation proposed by Pringle. In these simulations, collisions between stable molecular cloud clumps produce dense shocked layers, which cool radiatively and fragment gravitationally. The resulting fragments then condense to form protostellar discs, which at the same time fall together and, as a result of tidal and viscous interactions, capture one another to form binary systems. We refer to this mechanism as shock-induced gravitational fragmentation followed by capture, or SGF+C. When the initial clumps are sufficiently massive and/or the Mach number of the collision is sufficiently high, a large number (>~10) of protostellar discs is produced; under these circumstances, the layer fragments first into filaments, and then into beads along the filaments. The marriage of two protostellar discs in this way is `arranged' in the sense that the protostellar discs involved do not form independently. First, they both condense out of the same layer, and probably also out of the same filament within this layer; this significantly increases the likelihood of them interacting dynamically. Secondly, there tends to be alignment between the orbital and spin angular momenta of the interacting protostellar discs, reflecting the fact that these angular momenta derive mainly from the systematic global angular momentum of the off-axis collision which produced the layer; this alignment of the various angular momenta pre-disposes the discs to very dissipative interactions, thereby increasing the probability of producing a strongly bound, long-lasting union. It is a marriage because the binary orbit stabilizes itself rather quickly. Any subsequent orbit evolution, as the protostellar discs `mop up' the surrounding residual gas and interact tidally, tends to harden the orbit. Therefore, as long as a third body does not intervene, the union is binding. Even if a third body does

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

    Science.gov (United States)

    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.

  1. Interactions of $^{16}$O Projectile and its Fragments in Nuclear Emulsion at about 60 and 200 GeV/nucleon

    CERN Multimedia

    2002-01-01

    The aim of the experiment is to measure the multiplicity ``$ n _{s} $'' and pseudo-rapidity ``$\\eta$'' of the shower particles ($\\beta$~$\\geq$~0.7) produced in different types of collisions (peripheral, semi-central and central), of $^{16}$O and $^{32}$S in nuclear emulsions. The multiplicities and angular distributions of both the grey ``$ n _{g} $'' (mainly due to knock- on and recoil protons), and black ``$ n _{b} $'' (slow evaporated target fragments) particles, and the inter-correlation between them are studied. \\\\ \\\\ The yield, charge and angular distributions of produced relativistic projectile fragments P.F.S., for $ Z _{P} . _{F} . $ $\\geq$~2 are measured and their interactions in emulsions are investigated. \\\\ \\\\ The study of the mean free paths for the projectile fragments with Z $\\geq$ 3 produced from 200~A~GeV $^{16}$ 0 interactions were performed, which show the absence of the anomalous phenomena. \\\\ \\\\ The possible production of zero-spin light neutral scaler bosons and pseudoscaler bosons from...

  2. Projectile atomic-number effect on ion-induced fragmentation and ionization of fullerenes

    NARCIS (Netherlands)

    Hadjar, O; Hoekstra, R; Morgenstern, R; Schlatholter, T

    2001-01-01

    The delocalized pi electrons of a C-60 cluster can be well described as an electron gas. Electronic friction experienced by a multicharged ion colliding with a fullerene might then be modeled in terms of the electronic stopping power. We investigated such collisions for projectile atomic numbers Z r

  3. Energy distribution of projectile fragment particles in heavy ion therapeutic beam

    Energy Technology Data Exchange (ETDEWEB)

    Matsufuji, Naruhiro; Tomura, Hiromi; Futami, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)] [and others

    1998-03-01

    Production of fragment particles in a patient`s body is one of important problems for heavy charged particle therapy. It is required to know the yield and the energy spectrum for each fragment element - so called `beam quality` to understand the effect of therapeutic beam precisely. In this study, fragment particles produced by practical therapeutic beam of HIMAC were investigated with using tissue-equivalent material and a detector complex. From the results, fragment particles were well identified by difference of their atomic numbers and the beam quality was derived. Responses of the detectors in this energy region were also researched. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Pilot experiments with relativistic uranium projectile and fission fragments thermalized in a cryogenic gas-filled stopping cell

    Energy Technology Data Exchange (ETDEWEB)

    Reiter, Moritz Pascal

    2015-07-01

    High precision experiments and decay spectroscopy of exotic nuclei are of great interest for nuclear structure and nuclear astro-physics. They allow for studies of the nuclear structure far from stability, test of fundamental interactions and symmetries and give important input for the understanding of the nuclear synthesis in the universe. In the context of this work a second generation stopping cell for the low energy branch of the Super-FRS was commissioned at the FRS at GSI and significant improvements were made to the device. The prototype stopping cell is designed as a cryogenic stopping cell (CSC), featuring enhanced cleanliness and high area density. The CSC was brought into full operation and its performance characteristics were investigated including the maximal area density, extraction times, cleanliness and extraction efficiencies. In three commissioning experiments at the current GSI FRS facility in 2011, 2012 and 2014 up to 22 isotopes from 14 elements produced by in-flight projectile fragmentation and fission of {sup 238}U could be thermalized and extracted with high efficiency. For the first time projectile and fission fragmentation produced at 1000 MeV/u could be thermalized in a stopping cell and provided as a low-energy beam of high brilliance for high precision experiments. The technical improvements of the CSC, such as an improved RF carpet, new cryocooler-based cooling system, a monitoring system of the cleanliness and the high density operation, made it possible to thermalize heavy {sup 238}U projectile fragments with total efficiencies of about 20% in the 2014 experiment. In addition the improvements lead to an increase in the stability and reliability of the CSC and the performance of the CSC during online experiments at the FRS Ion Catcher showed that the utilized techniques are ready for the final CSC for the low-energy branch of the Super-FRS at FAIR. The CSC was operated with an area density of up to 6.3 mg/cm{sup 2} helium during

  6. Multifragmentation vs. Evaporation vs. Binary-Decay in Fragment Production

    CERN Document Server

    Mashnik, S G; Baznat, M I

    2006-01-01

    This paper presents part of an internal LANL Progress Report on completion of the "S" and "G" versions of the improved Cascade-Exciton Model (CEM03.01) and the Los Alamos Quark-Gluon String Model (LAQGSM.03.01) codes. The "S" versions consider fragmentation of compound nuclei produced after the preequilibrium stage of reactions for excitation energies above 2A MeV using the Statistical Multifragmentation Model (SMM) by Botvina et al. ("S" stands for SMM), while the "G" versions describe evaporation/fission stages of reactions using the fission-like binary-decay model GEMINI of Charity et al. ("G" stands for GEMINI) instead of using the the Generalized Evaporation Model GEM2 of Furihata incorporated into the standard versions of these codes. We present here an analysis of the recent 660 MeV p + 129I and 3.65 GeV p + 112Sn JINR measurements, of the new COSY data on 1.2 GeV p + (13 nuclei from Al to Th), of the 300 MeV and 1 GeV p + 56Fe data measured at GSI in inverse kinematics, and of the new GSI data on 1 Ge...

  7. Multiplicity distributions of projectile fragments in interactions of nuclei with emulsion at 4.1-4.5 A GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Fakhraddin, S; Rahim, Magda A [Physics Department, Faculty of Science, Sana' a University, Republic of Yemen (Yemen)], E-mail: sakinafa1@hotmail.com, E-mail: dr.magda2006@hotmail.com

    2008-07-15

    The results of our systematic studies of projectile fragments (PFs) multiplicity distributions in interactions of {sup 4}He, {sup 12}C, {sup 16}O, {sup 22}Ne and {sup 28}Si with emulsion at 4.1-4.5 A GeV/c are presented in this paper. The mean values for the three different multiplicities of PFs at nearly the same energy are given. The dependence of these mean values on the projectile mass number A{sub p}, as well as the dependence of the PFs on target groups (H, CNO and AgBr), has been investigated.

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

    Science.gov (United States)

    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

  9. Study of projectile fragmentation in the reaction (158AGeV) Pb + Pb using CR-39

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, I.E. [Physics Research Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)]. E-mail: imtinan@pinstech.org.pk; Shahzad, M.I. [Physics Research Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Javed, M.T. [Centre for High Energy Physics, University of the Punjab, Lahore (Pakistan); Manzoor, S. [Physics Research Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Sher, G. [Physics Research Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Aleem, F. [Centre for High Energy Physics, University of the Punjab, Lahore (Pakistan); Khan, H.A. [COMSATS, Shahrah-e-Jamhuriyyat, G-5/2, Islamabad (Pakistan)

    2005-11-15

    The fragmentation of Pb ions at 158AGeV energy produced in the interaction with Pb target has been studied using a CR-39 track detector. A stack comprising of 64 detectors was prepared such that a target of 1cm thickness was sandwiched between the sheets of CR-39. The purpose of this exposure geometry was to calibrate CR-39 with respect to relativistic heavy ions as well as to study the fragmentation of Pb ions at 158AGeV energy. The exposure was carried out at the SPS beam facility of CERN at normal incidence with a fluence of {approx}1500ion/cm{sup 2}. Two detectors from the exposed stack have been selected for this study: one before and the other after the target material. After etching, the detectors were scanned using an optical microscope and the etched track lengths and the diameters of the track openings were measured manually. Considering that the lengths of tracks provide the best charge resolution for Z>65, we have measured track lengths for a sufficiently large number of fragments to identify individual charge states for 65

  10. SHAPING THE BROWN DWARF DESERT: PREDICTING THE PRIMORDIAL BROWN DWARF BINARY DISTRIBUTIONS FROM TURBULENT FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Jumper, Peter H.; Fisher, Robert T., E-mail: robert.fisher@umassd.edu [University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, MA 02747-2300 (United States)

    2013-05-20

    The formation of brown dwarfs (BDs) poses a key challenge to star formation theory. The observed dearth of nearby ({<=}5 AU) BD companions to solar mass stars, known as the BD desert, as well as the tendency for low-mass binary systems to be more tightly bound than stellar binaries, has been cited as evidence for distinct formation mechanisms for BDs and stars. In this paper, we explore the implications of the minimal hypothesis that BDs in binary systems originate via the same fundamental fragmentation mechanism as stars, within isolated, turbulent giant molecular cloud cores. We demonstrate analytically that the scaling of specific angular momentum with turbulent core mass naturally gives rise to the BD desert, as well as wide BD binary systems. Further, we show that the turbulent core fragmentation model also naturally predicts that very low mass binary and BD/BD systems are more tightly bound than stellar systems. In addition, in order to capture the stochastic variation intrinsic to turbulence, we generate 10{sup 4} model turbulent cores with synthetic turbulent velocity fields to show that the turbulent fragmentation model accommodates a small fraction of binary BDs with wide separations, similar to observations. Indeed, the picture which emerges from the turbulent fragmentation model is that a single fragmentation mechanism may largely shape both stellar and BD binary distributions during formation.

  11. Multiplicity distributions in the binary fragmenting with inhibition at the transition line

    Energy Technology Data Exchange (ETDEWEB)

    Botet, R. [Paris-11 Univ., 91 - Orsay (France); Ploszajczak, M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)

    1996-03-01

    Properties of the fragment multiplicity distribution obtained in the sequential binary fragmentation process at the transition line are investigated. It is shown that the multifragment cumulant correlation functions have the hierarchical, linked-pair structure. Several distinct classes of multiplicity domains are clearly identified, and the asymptotic appearance of the Koba - Nielsen - Olesen scaling is discussed. (author). 36 refs.

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

    Science.gov (United States)

    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

  13. Fragmentation properties of spherical projectiles impacting at hypervelocity%球形弹丸超高速碰撞破碎特性

    Institute of Scientific and Technical Information of China (English)

    汪庆桃; 吴克刚; 李必红; 陈志阳

    2014-01-01

    讨论超高速碰撞数值模拟方法,用 ANSYS /AUTODYN 程序的 SPH 方法对球形弹丸超高速撞击时弹丸破碎、碎片云形成过程进行数值模拟并与实验结果比较,验证计算方法及模型参数的正确性。在此基础上研究钨合金、轧制均质装甲(Rolled Homogeneous Armor,RHA)两种材料球形弹丸破碎的临界速度随比值(ts /dp,ts为靶板厚,dp为弹丸直径)的变化规律,给出两种材料超高速碰撞时应变率及平均碎片尺寸随撞击速度的变化曲线以及碎片质量分布规律。%The numerical simulation method for the process of hypervelocity impact was discussed.The damage mechanism and the process of debris cloud forming were studied with the SPH method in ANSYS /AUTODYN code when spherical projectiles at hypervelocity impact a thin shield.The hypervelocity impact of projectiles made of tungsten alloy and RHA(Rolled Homogeneous Armor)material with the given constitutive models was numerically simulated and the results are in good agreement with the experimental results.The fragmentation-initiation threshold velocity of the projectile,the average fragment size and the distribution of fragment size,together with their variation with the change of impacting velocity were investigated.

  14. Rotationally-Driven Fragmentation for the Formation of the Binary Protostellar System L1551 IRS 5

    CERN Document Server

    Lim, Jeremy; Hanawa, Tomoyuki; Takakuwa, Shigehisa; Matsumoto, Tomoaki; Saigo, Kazuya

    2016-01-01

    Either bulk rotation or local turbulence is widely invoked to drive fragmentation in collapsing cores so as to produce multiple star systems. Even when the two mechanisms predict different manners in which the stellar spins and orbits are aligned, subsequent internal or external interactions can drive multiple systems towards or away from alignment thus masking their formation process. Here, we demonstrate that the geometrical and dynamical relationship between the binary system and its surrounding bulk envelope provide the crucial distinction between fragmentation models. We find that the circumstellar disks of the binary protostellar system L1551 IRS 5 are closely parallel not just with each other but also with their surrounding flattened envelope. Measurements of the relative proper motion of the binary components spanning nearly 30 yr indicate an orbital motion in the same sense as the envelope rotation. Eliminating orbital solutions whereby the circumstellar disks would be tidally truncated to sizes smal...

  15. Binary formation and mass function variations in fragmenting discs with short cooling times

    CERN Document Server

    Alexander, R D; Cuadra, J

    2008-01-01

    Accretion discs at sub-pc distances around supermassive black holes are likely to cool rapidly enough that self-gravity results in fragmentation. Here, we use high-resolution hydrodynamic simulations of a simplified disc model to study how the outcome of fragmentation depends upon numerical resolution and cooling time, and to investigate the incidence of binary formation within fragmenting discs. We investigate a range of cooling times, from the relatively long cooling time-scales that are marginally unstable to fragmentation down to highly unstable cooling on a time-scale that is shorter than the local dynamical time. The characteristic mass of fragments decreases with reduced cooling time, though the effect is modest and dependent upon details of how rapidly bound clumps radiate. We observe a high incidence of capture binaries, though we are unable to determine their final orbits or probability of survival. The results suggest that faster cooling in the parent disc results in an increased binary fraction, a...

  16. Theoretical study of projectile fragmentation in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at 1 GeV/nucleon

    CERN Document Server

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

    2014-01-01

    We analyze the production cross sections and isotopic distributions of projectile-like residues in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. Calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters determined previously for similar reactions at 600 MeV/nucleon. The obtained good agreement with the experiment establishes the universal properties of the excited spectator systems produced during the dynamical stage of the reaction. It is furthermore confirmed that a significant reduction of the symmetry-energy term at the freeze-out stage of reduced density and high temperature is necessary to reproduce the experimental isotope distributions. A trend of decreasing symmetry energy for large neutron-rich fragments of low excitation energy is interpreted as a nuclear-structure effect.

  17. Partial cross section of projectile fragmentation in {sup 197}Au+{sup 27}Al interactions at 1.015 GeV/n

    Energy Technology Data Exchange (ETDEWEB)

    Battacharyya, D.P.; Saha, S.; Basu, B. [Indian Association for the Cultivation of Science, Calcutta (India)] [and others

    1996-02-01

    The large fragmentation of {sup 197}Au projectiles at BEVALAC energy 1.015 GeV/n in Al target has been studied using a stack consisting of CR-39 (DOP) plastic track detectors. The partial cross-sections for the production of large fragments of charge Z{sub F} = 75 to Z{sub F} = 78 in collisions of {sup 197}Au beam of nuclei at 0.930 GeV/n in {sup 27}Al target has been estimated from the cone length distribution. The authors data found comparable to the expected results from the latest semi empirical model of Tsao et al. and that from the abrasion-ablation model of Townsend et al. The present data is in approximate agreement with the active and passive experimental data of Binns et al., and Gerbier et al. in Al target, respectively.

  18. Shaping the Brown Dwarf Desert: Predicting the Primordial Brown Dwarf Binary Distributions from Turbulent Fragmentation

    CERN Document Server

    Jumper, Peter H

    2013-01-01

    The formation of brown dwarfs (BDs) poses a key challenge to star formation theory. The observed dearth of nearby ($\\leq 5$ AU) brown dwarf companions to solar-mass stars, known as the brown dwarf desert, as well as the tendency for low-mass binary systems to be more tightly-bound than stellar binaries, have been cited as evidence for distinct formation mechanisms for brown dwarfs and stars. In this paper, we explore the implications of the minimal hypothesis that brown dwarfs in binary systems originate via the same fundamental fragmentation mechanism as stars, within isolated, turbulent giant molecular cloud cores. We demonstrate analytically that the scaling of specific angular momentum with turbulent core mass naturally gives rise to the brown dwarf desert, as well as wide brown-dwarf binary systems. Further, we demonstrate analytically that the turbulent core fragmentation model also naturally predicts that very low-mass (VLM) binary and BD/BD systems are more tightly-bound than stellar systems. In addit...

  19. Direct mass measurements of neutron-rich $^{86}$Kr projectile fragments and the persistence of neutron magic number $N$ = 32 in Sc isotopes

    CERN Document Server

    Xu, Xing; Zhang, Yu-hu; Xu, Hu-shan; Shuai, Peng; Tu, Xiao-lin; Litvinov, Yuri A; Zhou, Xiao-hong; Sun, Bao-hua; Yuan, You-jin; Xia, Jia-wen; Yang, Jian-cheng; Blaum, KLaus; 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-ging; Xing, Yuan-ming; Yamaguchi, T; Yamaguchi, Y; Zeng, Qi; Yan, Xin-liang; Zhao, Hong-wei; Zhao, Tie-cheneg; Zhang, Wei; Zhan, Wen-long

    2016-01-01

    In this paper, we present direct mass measurements of neutron-rich $^{86}$Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of $^{52-54}$Sc 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, $^{53}$Sc and $^{54}$Sc 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.

  20. Study of projectile fragmentation in the reaction (158 A GeV) Pb + Pb using CR-39

    CERN Document Server

    Qureshi, I E; Javed, M T; Manzoor, S; Sher, G; Aleem, F; Khan, H A

    2005-01-01

    The fragmentation of Pb ions at 158 A GeV energy produced in the interaction with Pb target has been studied using a CR-39 track detector. A stack comprising of 64 detectors was prepared such that a target of 1 cm thickness was sandwiched between the sheets of CR-39. The purpose of this exposure geometry was to calibrate CR-39 with respect to relativistic heavy ions as well as to study the fragmentation of Pb ions at 158 A GeV energy. The exposure was carried out at the SPS beam facility of CERN at normal incidence with a fluence of . Two detectors from the exposed stack have been selected for this study: one before and the other after the target material. After etching, the detectors were scanned using an optical microscope and the etched track lengths and the diameters of the track openings were measured manually. Considering that the lengths of tracks provide the best charge resolution for Z>65, we have measured track lengths for a sufficiently large number of fragments to identify individual charge states...

  1. Mass measurements of {sup 238}U-projectile fragments for the first time with a multiple-reflection time-of-flight mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Jens

    2016-07-01

    Mass measurements of short-lived uranium projectile fragments were performed for the first time with a Multiple-Reflexion-Time-of-Flight Mass Spectrometer (MR-TOF-MS). A major part of this doctoral work was a novel development of a data analysis method for the MR-TOF-MS mass measurements of exotic nuclei at the fragment separator FRS at GSI. The developed method was successfully applied to the data obtained from two pilot experiments with the MR-TOF-MS at the FRS in 2012 and 2014. A substantial upgrade of the experimental setup of the MR-TOF-MS was also performed in the frame work of this doctoral thesis after the first run. In the experiments projectile fragments were created with 1000 MeV/u {sup 238}U ions in a Be/Nb target at the entrance of the in-flight separator FRS. The exotic nuclei were spatially separated, energy bunched and slowed down with the ion-optical system of the FRS combined with monoenergetic and homogeneous degraders. At the final focal plane of the FRS the fragments were completely slowed down and thermalized in a cryogenic stopping cell (CSC) filled with 3-5 mg/cm{sup 2} pure helium gas. The exotic nuclei were fast extracted from the CSC to enable mass measurements of very short-lived fragments with the MR-TOF-MS. The achievement of this goal was successfully demonstrated with the mass measurement of {sup 220}Ra ions with a half-life of 17.9 ms and 11 detected events. The mass measurements of the isobars {sup 211}Fr, {sup 211}Po and {sup 211}Rn have clearly demonstrated the scientific potential of the MR-TOF-MS for the investigation of exotic nuclei and the power of the data analysis system. Difficult measurements with overlapping mass distributions with only a few counts in the measured spectra were the challenge for the new data analysis method based on the maximum likelihood method. The drifts during the measurements were corrected with the developed time-resolved calibration method. After the improvements of the setup as a consequence of

  2. Fiber Composite Material Application on Prefabricated Fragment Projectile%复合纤维材料在预制破片弹上的应用

    Institute of Scientific and Technical Information of China (English)

    赵丽俊; 毛亮

    2013-01-01

    为提高预制破片弹丸携带的有效载荷量,增强其综合毁伤威力,采用理论与试验相结合的方法对复合纤维材料代替金属材料作为预制破片包覆层的发射强度进行了计算分析.结果表明,在高过载条件下,碳纤维T700S和钢材料作为包覆层材料均能满足强度要求,而E玻璃纤维作为包覆层材料则不能满足.此外,使用复合纤维材料的成本也比钢材料要低.研究结果对复合纤维材料在相关弹药上的应用前景具有重要的参考意义.%In order to increase the effective payload of the prefabricated fragment projectile and enhance the comprehensive damage power,this paper studies the launching strength of the prefabricated fragment covering layer using fiber composite materials instead of metal materials both theoretically and experimentally.The results show that the covering layer using the carbon fiber T700S and the steel can satisfy the strength requirements,but not by using the E glass fiber under the high overload.By the way,the cost of fiber composite materials is lower than that of the steel The research result can be used to evaluate the application prospect of the correlation ammunition using the fiber composite materials.

  3. Projectile spectator proton production in 84Kr- emulsion interactions at 1.7 A GeV%Projectile spectator proton production in 84Kr- emulsion interactions at 1.7 A GeV

    Institute of Scientific and Technical Information of China (English)

    BAI Cai-Yan; ZHANG Dong-Hai

    2011-01-01

    The multiplicity distribution of projectile protons and multiplicity correlations between black particles, grey particles, shower particles, compound particles, heavily ionized track particles, projectile helium fragments and projectile spectator protons

  4. Binary drop interaction on surfaces: onset and bounding ligaments of Crescent-Moon fragmentation

    Science.gov (United States)

    Bourouiba, Lydia; Wang, Yongji

    2016-11-01

    Drop impacts on surfaces can splash and create secondary droplets. These have important implications for industrial, environmental, and health processes such as air contamination by secondary pathogen-bearing droplets shaping disease transmission. Most studies of splash on surfaces have focused on the impact of one drop on a dry surface. Nevertheless, the outcome of impacts by spray or rain are shaped by the presence of adjacent sessile drops on the surface. Recently, in the context of rain and spray-induced disease transmission in crops, one particular binary drop interaction, the crescent-moon splash, was identified as a frequent and efficient source of secondary droplets (Gilet and Bourouiba ICB 2014 and JRSI 2015). The crescent-moon results from the interaction of an impacting drop with a sessile drop in the neighborhood of the impact point. Here, we report and rationalize the existence of a critical transition of impact parameters that enables the crescent-moon fragmentation to emerge. We also report and rationalize the peculiar, yet universal emergence of two bounding ligaments that are important in shaping the crescent-moon sheet.

  5. The Formation Mass of a Binary System via Fragmentation of a Rotating Parent Core with Increasing Total Mass

    CERN Document Server

    Arreaga-Garcia, Guillermo

    2016-01-01

    Recent VLA and CARMA observations have shown proto-stars in binaries with unprecedented resolution. Specifically, the proto-stellar masses of systems such as CB230 IRS1 and L1165-SMM1 have been detected in the range of $0.1-0.25 \\, M_{\\odot}$. These are much more massive than the masses generally obtained by numerical simulations of binary formation, around $0.01 \\, M_{\\odot}$. Motivated by these discrepancies in mass, in this paper we study the formation mass of a binary system as a function of the total mass of its parent core. To achieve this objective, we present a set of numerical simulations of the gravitational collapse of a uniform and rotating core, in which azimuthal symmetric mass seeds are initially implemented in order to favor the formation of a dense filament, out of which a binary system may be formed by direct fragmentation. We first observed that this binary formation process is diminished when the total mass of the parent core $M_0$ is increased; then we increased the level of the ratio of ...

  6. PLANET FORMATION IN STELLAR BINARIES. II. OVERCOMING THE FRAGMENTATION BARRIER IN α CENTAURI AND γ CEPHEI-LIKE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Rafikov, Roman R.; Silsbee, Kedron, E-mail: rrr@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States)

    2015-01-10

    Planet formation in small-separation (∼20 AU) eccentric binaries such as γ Cephei or α Centauri is believed to be adversely affected by the presence of the stellar companion. Strong dynamical excitation of planetesimals by the eccentric companion can result in collisional destruction (rather than growth) of 1-100 km objects, giving rise to the ''fragmentation barrier'' for planet formation. We revise this issue using a novel description of secular dynamics of planetesimals in binaries, which accounts for the gravity of the eccentric, coplanar protoplanetary disk, as well as gas drag. By studying planetesimal collision outcomes, we show, in contrast to many previous studies, that planetesimal growth and subsequent formation of planets (including gas giants) in AU-scale orbits within ∼20 AU separation binaries may be possible, provided that the protoplanetary disks are massive (≳ 10{sup –2} M {sub ☉}) and only weakly eccentric (disk eccentricity ≲ 0.01). These requirements are compatible with both the existence of massive (several M{sub J} ) planets in γ Cep-like systems and the results of recent simulations of gaseous disks in eccentric binaries. Terrestrial and Neptune-like planets can also form in lower-mass disks at small (sub-AU) radii. We find that the fragmentation barrier is less of a problem in eccentric disks that are apsidally aligned with the binary orbit. Alignment gives rise to special locations, where (1) relative planetesimal velocities are low and (2) the timescale of their drag-induced radial drift is long. This causes planetesimal pileup at such locations in the disk and promotes their growth locally, helping to alleviate the timescale problem for core formation.

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

    Science.gov (United States)

    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.

  8. 30-MM Tubular Projectile

    Science.gov (United States)

    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

  9. Projectile Motion Details.

    Science.gov (United States)

    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)

  10. Light charged particle and neutron velocity spectra in coincidence with projectile fragments in the reaction sup 4 sup 0 Ar(44 A MeV)+ sup 2 sup 7 Al

    CERN Document Server

    Lanzanò, G; Geraci, M; Pagano, A; Aiello, S; Cunsolo, A; Fonte, R; Foti, A; Sperduto, M L; Volant, C; Charvet, J L; Dayras, R; Legrain, R

    2001-01-01

    We present a three source analysis of velocity spectra of light charged particles (LCP) and neutrons emitted in the reaction sup 4 sup 0 Ar+ sup 2 sup 7 Al at 44 A MeV. The light particle (LP) velocity spectra are studied as a function of the detection angle (1.5 deg. projectile-like fragment (PLF). The temperature parameter, the velocity and the intensity of each source are extracted as a function of the PLF charge. While the temperature parameters for PLF and target-like fragments (TLF) are very similar and show a dependence on the PLF charge, the temperature parameter for the intermediate source is approximately 15 MeV, independent of the PLF charge. Comparison with temperature values extracted from double isotopic ratios, shows an agreement only between the temperature values extracted from formula involving sup 3 He, sup 4 He, d, t ratios and the PLF proton temperature parameter. The characteristics of the PLF sources are derived. Present ...

  11. VLA and CARMA observations of protostars in the Cepheus clouds: Sub-arcsecond proto-binaries formed via disk fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, John J.; Looney, Leslie W. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Chandler, Claire J. [National Radio Astronomy Observatory, Socorro, NM (United States); Wilner, David J.; Bourke, Tyler L. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Loinard, Laurent; D' Alessio, Paola [Centro de Radioastronomía y Astrofísica, UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán (Mexico); Chiang, Hsin-Fang [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii at Manoa, Hilo, HI 96720 (United States); Hartmann, Lee; Calvet, Nuria [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Kwon, Woojin, E-mail: jtobin@nrao.edu [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen (Netherlands)

    2013-12-20

    We present observations of three Class 0/I protostars (L1157-mm, CB230 IRS1, and L1165-SMM1) using the Karl G. Jansky Very Large Array (VLA) and observations of two (L1165-SMM1 and CB230 IRS1) with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The VLA observations were taken at wavelengths of λ = 7.3 mm, 1.4 cm, 3.3 cm, 4.0 cm, and 6.5 cm with a best resolution of ∼0.''06 (18 AU) at 7.3 mm. The L1165-SMM1 CARMA observations were taken at λ = 1.3 mm with a best resolution of ∼0.''3 (100 AU) and the CB230 IRS1 observations were taken at λ = 3.4 mm with a best resolution of ∼3'' (900 AU). We find that L1165-SMM1 and CB230 IRS1 have probable binary companions at separations of ∼0.''3 (100 AU) from detections of secondary peaks at multiple wavelengths. The position angles of these companions are nearly orthogonal to the direction of the observed bipolar outflows, consistent with the expected protostellar disk orientations. We suggest that these companions may have formed from disk fragmentation; turbulent fragmentation would not preferentially arrange the binary companions to be orthogonal to the outflow direction. For L1165-SMM1, both the 7.3 mm and 1.3 mm emission show evidence of a large (R > 100 AU) disk. For the L1165-SMM1 primary protostar and the CB230 IRS1 secondary protostar, the 7.3 mm emission is resolved into structures consistent with ∼20 AU radius disks. For the other protostars, including L1157-mm, the emission is unresolved, suggesting disks with radii <20 AU.

  12. The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin; Etude des quasi-projectiles produits dans les collisions Ni+Ni et Ni+Au: energie d'excitation et spin

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A

    2003-02-01

    During the collision between the projectile and the target nuclei in the intermediate energy regime (E < 100 MeV/nucleon) two excited nuclei are mainly observed in the exit channel, the quasi projectile (QP) and the quasi target. They disintegrate by particle emission. However, this binary picture is perturbed by the emission of particles and light fragments with velocities intermediate between the projectile velocity and the target one, all along the interaction (midrapidity component). This work aim to determine the excitation energy and the intrinsic angular momentum (or spin) of quasi-projectiles produced in the Ni+Ni and Ni+Au collisions at 52 and 90 MeV/nucleon. The excitation energy is deduced from the kinematical characteristics of particles emitted by the quasi-projectile. They have to be separated from midrapidity particles. Three different scenarios have been used for this purpose. The spin of the quasi-projectile has been extracted from the experimental data by mean of proton and alpha particles multiplicities emitted by the QP in the Ni+Au at 52 MeV/nucleon reaction. The results have been compared to the predictions of a theoretical model based on nucleon transfers. Their evolution is qualitatively reproduced as a function of the violence of the collision. (author)

  13. g-factors of isomers around N approx 40, Z approx 28 from time-dependent Larmor precession on spin-aligned projectile-like fragments

    CERN Document Server

    Neyens, G; Grzywacz, R; Hass, M; De Oliveira-Santos, F; Lewitowicz, M; Balabanski, D L; Bingham, C; Borcea, C; Coulier, N; Coussement, R; Daugas, J M; De France, G; Goldring, G; aGórska, M; Grawe, H; Oleari, C; Macovei, I; Mach, H; Page, R; Pfützner, M; Penionzhkevich, Yu E; Podolyák, Z; Regan, P H; Rykaczewski, K; Sawicka, M; Smirnova, N A; Sobolev, Y; Teughels, S; Vyvey, K

    2002-01-01

    First and preliminary results of an experiment aimed at measuring g-factors of isomeric states in neutron-rich nuclei in the vicinity of sup 6 sup 8 Ni are reported. Isomers near the predicted N=40 sub-shell closure in sup 6 sup 9 Cu, sup 6 sup 7 Ni and sup 6 sup 6 Co have been populated in the fragmentation of a sup 7 sup 6 Ge, 61.4 MeV/u beam onto a 145 mg/cm sup 2 sup 9 Be target at GANIL. Here we report the results for the 357(2) ns, I suppi=13/2 sup + isomer in sup 6 sup 9 Cu for which a preliminary gyromagnetic ratio of |g|=0.195(9) was derived. The Larmor precession of the spin-oriented isomeric ensemble was measured by recording gamma-ion correlations in a 20 mu s time window. This pioneering experiment has indicated interesting nuclear structure information and shows promising possibilities for future studies of this kind.

  14. Teaching Projectile Motion

    Science.gov (United States)

    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)

  15. Projectile Motion Revisited.

    Science.gov (United States)

    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)

  16. Hybrid armature projectile

    Science.gov (United States)

    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.

  17. Projectile spectator proton production in 84Kr-emulsion interactions at 1.7 A GeV

    Institute of Scientific and Technical Information of China (English)

    BAI Cai-Yan; ZHANG Dong-Hai

    2011-01-01

    The multiplicity distribution of projectile protons and multiplicity correlations between black particles, grey particles, shower particles, compound particles, heavily ionized track particles, projectile helium fragments and projectile spectator protons in Kr-emulsion collisions at 1.7 A GeV are investigated. It is found that the projectile spectator proton multiplicity distribution becomes broader with increasing target mass. The average multiplicity of shower particles and compound particles strongly depends on the number of projectile spectator protons, but the average multiplicity of black particles, grey particles and heavily ionized track particles weakly depends on the number of projectile spectator protons. The average multiplicity of projectile helium fragments increases linearly with increasing numbers of projectile spectator protons. Finally, the multiplicity distribution of projectile spectator protons obeys a KNO type of scaling law.

  18. [Large-scale fragmentation of dna and the death of tumor cells by the action of the binary system ascorbic acid-metallocomplexes of cobalt in vitro].

    Science.gov (United States)

    Medvedev, A I; Leshchenko, V V

    2012-01-01

    High-molecular-weight DNA fragments are the markers of the early stage of apoptosis induced in eukaryotic cells by cytotoxins of different nature. The dynamics of the development of large-scale DNA fragmentation in K-562 leukemia cells by the action of the antitumor drug, the binary system ascorbic acid--cobalt phthalocyanine within 48 h of incubation, which correspond to two periods of the doubling of cell number in growing control cultures, have been studied. It was shown that, within the first hours of incubation, hydrogen peroxide generated by the system induces the formation of DNA fragments from 2200 to 50 kbp long. Later on the cell death accompanied by a decrease in the content of fragmented DNA is observed. Within 24 h of incubation, part of fragmented DNA remains unrepaired; after 48 h of incubation, a delay or a slowed down proliferation of K-562 cells, which differ from control cells also by a high level of death and a higher content of high-molecular-weight DNA fragments, is observed.

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

    Science.gov (United States)

    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.

  20. Projectile Motion with Mathematica.

    Science.gov (United States)

    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)

  1. A Projectile Motion Bullseye.

    Science.gov (United States)

    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)

  2. Projectile Demilitarization Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Projectile Wash Out Facility is US Army Ammunition Peculiar Equipment (APE 1300). It is a pilot scale wash out facility that uses high pressure water and steam...

  3. Statistical and off-equilibrium production of fragments in heavy ion collisions at intermediate energies; Production statistique et hors-equilibre de fragments dans les collisions d`ions lourdes aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Bocage, Frederic [Lab. de Physique Corpusculaire, Caen Univ., 14 - Caen (France)

    1998-12-15

    The study of reaction products, fragments and light charged particles, emitted during heavy-ion collisions at intermediate energies has shown the dominant binary dissipative character of the reaction, which is persisting for almost all impact parameters. However, in comparison with this purely binary process, an excess of nuclear matter is observed in-between the quasi-projectile and the quasi-target. To understand the mechanisms producing such an excess, this work studies more precisely the breakup in two fragments of the quasi-projectile formed in Xe+Sn, from 25 to 50 MeV/u, and Gd+C and Gd+U at 36 MeV/u. The data were obtained during the first INDRA experiment at GANIL. The angular distributions of the two fragments show the competition between statistical fission and non-equilibrated breakup of the quasi-projectile. In the second case, the two fragments are aligned along the separation axis of the two primary partners. The comparison of the fission directions and probabilities with statistical models allows us to measure the fission time, as well as the angular momentum, temperature and size of the fissioning residue. The relative velocities are compatible with Coulomb and thermal effects in the case of statistical fission and are found much higher for the breakup of a non-equilibrated quasi-projectile, which indicates that the projectile was deformed during interaction with the target. Such deformations should be compared with dynamical calculations in order to constrain the viscosity of nuclear matter and the parameters of the nucleon-nucleon interaction, (author) 148 refs., 77 figs., 11 tabs.

  4. Phenomenological model for light-projectile breakup

    Science.gov (United States)

    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.

  5. More on Projectile Motion.

    Science.gov (United States)

    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)

  6. Projectile Base Flow Analysis

    Science.gov (United States)

    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

  7. Skirted projectiles for railguns

    Science.gov (United States)

    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).

  8. Isospin dependent multifragmentation of relativistic projectiles

    CERN Document Server

    Ogul, R; Atav, U; Buyukcizmeci, N; Mishustin, I N; Adrich, P; Aumann, T; Bacri, C O; Barczyk, T; Bassini, R; Bianchin, S; Boiano, C; Boudard, A; Brzychczyk, J; Chbihi, A; Cibor, J; Czech, B; De Napoli, M; Ducret, J -E; Emling, H; Frankland, J D; Hellstrom, M; Henzlova, D; Imme, G; Iori, I; Johansson, H; Kezzar, K; Lafriakh, A; Le Fèvre, A; Gentil, E Le; Leifels, Y; Luhning, J; Lukasik, J; Lynch, W G; Lynen, U; Majka, Z; Mocko, M; Muller, W F J; Mykulyak, A; Orth, H; Otte, A N; Palit, R; Pawlowski, P; Pullia, A; Raciti, G; Rapisarda, E; Sann, H; Schwarz, C; Sfienti, C; Simon, H; Summerer, K; Trautmann, W; Tsang, M B; Verde, G; Volant, C; Wallace, M; Weick, H; Wiechula, J; Wieloch, A; Zwieglinski, B

    2010-01-01

    The N/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. Stable and radioactive Sn and La beams with an incident energy of 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. For the interpretation of the data, calculations with the Statistical Multifragmentation Model for a properly chosen ensemble of excited sources were performed. The parameters of the ensemble, representing the variety of excited spectator nuclei expected in a participant-spectator scenario, are determined empirically by searching for an optimum reproduction of the measured fragment charge distributions and correlations. An overall very good agreement is obtained. The possible modification of the liquid-drop parameters of the fragment description in the hot freeze-out environment is studied, and a significant reduction of the symmetry-term coefficient is found necessary to reproduce the mean neutron-to-proton ratios /Z an...

  9. Measurement of Spin of Projectiles

    Directory of Open Access Journals (Sweden)

    S. R. Verma

    1989-01-01

    Full Text Available Hitherto the spin of the projectile has been measured with the help of spin loop method (for magnetised projectiles and Multishot Ballistic Synchro method (for magnetised and non-magnetised projectiles. This paper discusses the method of measurement of spinwith a single ballistic synchro picture; the advantage of this method is that it dispenses with elaborate and precise optical alignment, required for Multishot Ballistic Synchro method.

  10. Concrete structures under projectile impact

    CERN Document Server

    Fang, Qin

    2017-01-01

    In this book, the authors present their theoretical, experimental and numerical investigations into concrete structures subjected to projectile and aircraft impacts in recent years. Innovative approaches to analyze the rigid, mass abrasive and eroding projectile penetration and perforation are proposed. Damage and failure analyses of nuclear power plant containments impacted by large commercial aircrafts are numerically and experimentally analyzed. Ultra-high performance concrete materials and structures against the projectile impact are developed and their capacities of resisting projectile impact are evaluated. This book is written for the researchers, engineers and graduate students in the fields of protective structures and terminal ballistics.

  11. Modelling of the PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.

    2014-01-01

    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 la

  12. Modelling of the PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.

    2014-01-01

    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

  13. VLA and CARMA Observations of Protostars in the Cepheus Clouds: Sub-arcsecond Proto-Binaries Formed via Disk Fragmentation

    CERN Document Server

    Tobin, John J; Wilner, David J; Looney, Leslie W; Loinard, Laurent; Chiang, Hsin-Fang; Hartmann, Lee; Calvet, Nuria; D'Alessio, Paola; Bourke, Tyler L; Kwon, Woojin

    2013-01-01

    We present observations of three Class 0/I protostars (L1157-mm, CB230 IRS1, and L1165-SMM1) using the Karl G. Jansky Very Large Array (VLA) and observations of two (L1165-SMM1 and CB230 IRS1) with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The VLA observations were taken at wavelengths of $\\lambda = 7.3$ mm, 1.4 cm, 3.3 cm, 4.0 cm, and 6.5 cm with a best resolution of $\\sim$0\\farcs06 (18 AU) at 7.3 mm. The L1165-SMM1 CARMA observations were taken at $\\lambda = 1.3$ mm with a best resolution of $\\sim0\\farcs3$ (100 AU), and the CB230 IRS1 observations were taken at $\\lambda = 3.4$ mm with a best resolution of $\\sim$3\\arcsec\\ (900 AU). We find that L1165-SMM1 and CB230 IRS1 have probable binary companions at separations of $\\sim$0\\farcs3 (100 AU) from detections of secondary peaks at multiple wavelengths. The position angles of these companions are nearly orthogonal to the direction of the observed bipolar outflows, consistent with the expected protostellar disk orientations. We sugge...

  14. Equilibrium and non-equilibrium emission of complex fragments

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, D.R.

    1989-08-01

    Complex fragment emission (Z{gt}2) has been studied in the reactions of 50, 80, and 100 MeV/u {sup 139}La + {sup 12}C, and 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au. Charge, angle, and energy distributions were measured inclusively and in coincidence with other complex fragments, and were used to extract the source rapidities, velocity distributions, and cross sections. The experimental emission velocity distributions, charge loss distributions, and cross sections have been compared with calculations based on statistical compound nucleus decay. The binary signature of the coincidence events and the sharpness of the velocity distributions illustrate the primarily 2-body nature of the {sup 139}La + {sup 12}C reaction mechanism between 50 and 100 MeV/u. The emission velocities, angular distributions, and absolute cross sections of fragments of 20{le}Z{le}35 at 50 MeV/u, 19{le}Z{le}28 at 80 MeV/u, and 17{le}Z{le}21 at 100 MeV/u indicate that these fragments arise solely from the binary decay of compound nuclei formed in incomplete fusion reactions in which the {sup 139}La projectile picks up about one-half of the {sup 12}C target. In the 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au reactions, the disappearance of the binary signature in the total charge and velocity distributions suggests and increase in the complex fragment and light charged particle multiplicity with increasing target mass. As in the 80 and 100 MeV/u {sup 139}La + {sup 12}C reactions, the lighter complex fragments exhibit anisotropic angular distributions and cross sections that are too large to be explained exclusively by statistical emission. 143 refs., 67 figs.

  15. Breakup Conditions of Projectile Spectators from Dynamical Observables

    CERN Document Server

    Begemann-Blaich, M L

    1998-01-01

    Momenta and masses of heavy projectile fragments (Z >= 8), produced in collisions of 197Au with C, Al, Cu and Pb targets at E/A = 600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. An analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS-model. The data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. Classical trajectory calculations reproduce the dynamical observables. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, a good agreement with the data is found ...

  16. Modified Empirical Parametrization of Fragmentation Cross Sections

    CERN Document Server

    Sümmerer, K

    2000-01-01

    New experimental data obtained mainly at the GSI/FRS facility allow to modify the empirical parametrization of fragmentation cross sections, EPAX. It will be shown that minor modifications of the parameters lead to a much better reproduction of measured cross sections. The most significant changes refer to the description of fragmentation yields close to the projectile and of the memory effect of neutron-deficient projectiles.

  17. Water Entry of Projectiles

    Science.gov (United States)

    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.

  18. Protection from high-velocity projectiles

    Science.gov (United States)

    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.

  19. Projectile remnants in central peaks of lunar impact craters

    Science.gov (United States)

    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.

  20. Dynamical effects in nuclear collisions in the Fermi energy range: aligned breakup of heavy projectiles 24.75.+i; 25.70.Mn; 25.70.Pq; Heavy ions reactions at intermediate energy; Fragment correlations; Fission and aligned breakup; Deformation and neck instability

    CERN Document Server

    Bocage, F; Louvel, M; Auger, G; Bacri, C O; Bellaize, N; Borderie, B; Bougault, R; Brou, R; Buchet, P; Charvet, J L; Chbihi, A; Cussol, D; Dayras, R; De Cesare, N; Demeyer, A N; Doré, D; Durand, D; Frankland, J D; Galíchet, E; Genouin-Duhamel, E; Gerlic, E; Guinet, D; Lautesse, P; Laville, J L; Lecolley, J F; Legrain, R; Le Neindre, N; López, O; Maskay, A M; Nalpas, L; Nguyen, A D; Pârlog, M; Péter, J; Plagnol, E; Rivet, M F; Rosato, E; Saint-Laurent, F; Salou, S; Steckmeyer, J C; Stern, M; Tabacaru, G; Tamain, B; Tirel, O; Tassan-Got, L; Vient, E; Vigilante, M; Volant, C; Wieleczko, J P; Le Brun, C; Genoux-Lubain, A; Rudolf, G; Stuttgé, L

    2000-01-01

    Recent experimental results concerning heavy systems (Pb + Au, Pb + Ag, Pb + Al, Gd + C, Gd + U, Xe + Sn, etc) obtained at GANIL with the INDRA and NAUTILUS 4 pi arrays will be presented. The study of reaction mechanisms has shown the dominant binary and highly dissipative character of the process. The two heavy and excited fragments produced after the first stage of the interaction can decay into various decay modes from evaporation to multifragmentation including fission. However, deviations from this simple picture have been found by analyzing angular and velocity distributions of light charged particles, and fragments. Indeed, there is a certain amount of matter in excess emitted between the two primary sources suggesting either the existence of a mid-rapidity source similar to the one observed in the relativistic regime (participants) or a strong deformation induced by the dynamics of the collision (neck instability). This last possibility has been suggested by analyzing in detail the angular distributio...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  4. Sabot-Projectiles for Cannon

    Science.gov (United States)

    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

  5. First known terrestrial impact of a binary asteroid from a main belt breakup event.

    Science.gov (United States)

    Ormö, Jens; Sturkell, Erik; Alwmark, Carl; Melosh, Jay

    2014-10-23

    Approximately 470 million years ago one of the largest cosmic catastrophes occurred in our solar system since the accretion of the planets. A 200-km large asteroid was disrupted by a collision in the Main Asteroid Belt, which spawned fragments into Earth crossing orbits. This had tremendous consequences for the meteorite production and cratering rate during several millions of years following the event. The 7.5-km wide Lockne crater, central Sweden, is known to be a member of this family. We here provide evidence that Lockne and its nearby companion, the 0.7-km diameter, contemporaneous, Målingen crater, formed by the impact of a binary, presumably 'rubble pile' asteroid. This newly discovered crater doublet provides a unique reference for impacts by combined, and poorly consolidated projectiles, as well as for the development of binary asteroids.

  6. Formation of anions and cations via a binary-encounter process in OH$^+$ + Ar collisions: the role of dissociative excitation and statistical aspects

    CERN Document Server

    Lattouf, E; Chesnel, J -Y; Kovács, S T S; Bene, E; Herczku, P; Huber, B A; Méry, A; Poully, J -C; Rangama, J; Sulik, B

    2015-01-01

    Molecular fragmentation leading to the formation of negatively and positively charged hydrogen ions in 7-keV OH$^+$ + Ar collisions is investigated experimentally. The most striking finding is that negative and positive hydrogen ions are emitted with very similar angular dependences. Also, the kinetic energy distribution of the H$^+$ fragment shows strong similarities with that of the ejected H$^-$ ion. The kinematics of the emitted H core is found to be essentially driven by its scattering on the atomic target. However, in addition to this binary-encounter process, dissociative electronic excitation of the molecular projectile has to be invoked to explain the observed fragmentation patterns. Though the electron capture process is complex, it is shown that the relative population of the different final charge states of the outgoing fragments can be described by simple statistical laws.

  7. Systematics of the breakup probability function for {sup 6}Li and {sup 7}Li projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Capurro, O.A., E-mail: capurro@tandar.cnea.gov.ar [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); Pacheco, A.J.; Arazi, A. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Carnelli, P.F.F. [CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); Fernández Niello, J.O. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); and others

    2016-01-15

    Experimental non-capture breakup cross sections can be used to determine the probability of projectile and ejectile fragmentation in nuclear reactions involving weakly bound nuclei. Recently, the probability of both type of dissociations has been analyzed in nuclear reactions involving {sup 9}Be projectiles onto various heavy targets at sub-barrier energies. In the present work we extend this kind of systematic analysis to the case of {sup 6}Li and {sup 7}Li projectiles with the purpose of investigating general features of projectile-like breakup probabilities for reactions induced by stable weakly bound nuclei. For that purpose we have obtained the probabilities of projectile and ejectile breakup for a large number of systems, starting from a compilation of the corresponding reported non-capture breakup cross sections. We parametrize the results in accordance with the previous studies for the case of beryllium projectiles, and we discuss their systematic behavior as a function of the projectile, the target mass and the reaction Q-value.

  8. Projectile Motion Gets the Hose

    Science.gov (United States)

    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…

  9. Novice Rules for Projectile Motion.

    Science.gov (United States)

    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…

  10. Sensitivity of N/Z ratio in projectile break-up of isobaric systems

    Directory of Open Access Journals (Sweden)

    De Filippo E.

    2016-01-01

    Full Text Available The binary break-up of projectile-like fragments in non central heavy-ion collisions follows different decay patterns, from equilibrated emission towards dynamical (prompt fission. Recently, comparing two systems with different N/Z in the entrance channel, it has been shown that the dynamical emission cross-section is enhanced for the most neutron rich system while the statistical emission cross-section is independent from the isotopic composition. In order to understand this dependence and disentangle it from the initial size of the nuclei, we have studied the two isobaric systems 124Xe+64 Zn and 124Xe+64 Ni at 35 A MeV (InKiIsSy experiment, in comparison with the previous studied reactions (124Sn +64 Ni and 112Sn +58 Ni at the same bombarding energy. We present the first results evidencing a striking similar effect in the dynamical decay as a function of the N/Z of the target for equal size systems.

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

    Science.gov (United States)

    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.

  12. Emission of fragments in heavy ion-collisions at Fermi energy; Modes de production des fragments dans les collisions d'ions lourds aux energies intermediaires

    Energy Technology Data Exchange (ETDEWEB)

    Normand, J

    2001-10-01

    The study of reaction mechanisms in Fermi energy domain has shown the dominant binary character of the process. The two heavy sources produced after the first stage of the interaction (the quasi-projectile QP and the quasi-target QT) can experience various decay modes from evaporation to multifragmentation. However, the presence of light fragments at mid rapidity cannot be explained by the standard decay of the QP and the QT. To understand the mechanisms producing such a contribution, the break-up of the QP has been studied on the following systems: Xe+Sn from 25 to 50 MeV/A, Ta+Au and Ta+U at 33, 39.6 MeV/A and U+U at 24 MeV/A. The experiment has been performed at GANIL with the INDRA multidetector. The particular behaviour of the heaviest fragment and the correlation between the charge and the velocity of the fragments suggest a shape deformation followed by the rupture of a neck formed in between the two partners of the collision. The heaviest fragment could be the reminiscence of the projectile. A method based on the angular distribution of the heaviest fragment has allowed to separate the statistical break-up of the QP and the non equilibrated break-up. The statistical break-up ranges from 30 % to 75 % of the break-ups. The comparison of the statistical component with a statistical model gives information about the charge, the angular momentum and the temperature of the QP. The comparison of the non equilibrated component with dynamical models could give information about the parameters of the nuclear interaction in medium. (author)

  13. Distorted wave theories for dressed-ion-atom collisions with GSZ projectile potentials

    Energy Technology Data Exchange (ETDEWEB)

    Monti, J M; Rivarola, R D [Instituto de Fisica Rosario (CONICET-UNR) and Facultad de Ciencias Exactas, IngenierIa y Agrimensura, Universidad Nacional de Rosario, Avenida Pellegrini 250, 2000 Rosario (Argentina); Fainstein, P D, E-mail: monti@ifir-conicet.gov.ar [Comision Nacional de EnergIa Atomica, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina)

    2011-10-14

    The continuum distorted wave and the continuum distorted wave-eikonal initial state approximations for electron emission in ion-atom collisions are generalized to the case of dressed projectiles. The interaction between the dressed projectile and the active electron is represented by the analytic Green-Sellin-Zachor (GSZ) potential. Doubly differential cross sections as a function of the emitted electron energy and angle are computed. The region of the binary encounter peak is analysed in detail. Interference structures appear in agreement with the experimental data and are interpreted as arising from the coherent interference between short- and long-range scattering amplitudes.

  14. The Projectile inside the Loop

    OpenAIRE

    Varieschi, Gabriele U.

    2005-01-01

    In this paper we describe an alternative use of the loop-the-loop apparatus, which can be used to study an interesting case of projectile motion. We also present an effective way to perform and analyze these experiments, by using video capture software together with a digital video camera. These experiments can be integrated into classroom demonstrations for general physics courses, or become part of laboratory activities.

  15. Projectiles, pendula, and special relativity

    CERN Document Server

    Price, R H

    2005-01-01

    The kind of flat-earth gravity used in introductory physics appears in an accelerated reference system in special relativity. From this viewpoint, we work out the special relativistic description of a ballistic projectile and a simple pendulum, two examples of simple motion driven by earth-surface gravity. The analysis uses only the basic mathematical tools of special relativity typical of a first-year university course.

  16. Projectiles, pendula, and special relativity

    Science.gov (United States)

    Price, Richard H.

    2005-05-01

    The kind of flat-earth gravity used in introductory physics appears in an accelerated reference system in special relativity. From this viewpoint, we work out the special relativistic description of a ballistic projectile and a simple pendulum, two examples of simple motion driven by earth-surface gravity. The analysis uses only the basic mathematical tools of special relativity typical of a first-year university course.

  17. Wind-influenced projectile motion

    Science.gov (United States)

    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.

  18. Projectile Balloting Attributable to Gun Tube Curvature

    Directory of Open Access Journals (Sweden)

    Michael M. Chen

    2010-01-01

    Full Text Available Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive barrel centerline variations for the investigation of projectile balloting^1 motions. A modern projectile was adopted for this study. In-bore projectile responses at various locations of the projectile while traveling through the simulated gun tubes were obtained. The balloting was evaluated in both time and frequency domains. Some statistical quantities and the significance were outlined.

  19. Sequential injection gas guns for accelerating projectiles

    Science.gov (United States)

    Lacy, Jeffrey M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID

    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. keV fullerene interaction with hydrocarbon targets: Projectile penetration, damage creation and removal

    Energy Technology Data Exchange (ETDEWEB)

    Delcorte, Arnaud [PCPM Laboratory, Universite catholique de Louvain, Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium)]. E-mail: delcorte@pcpm.ucl.ac.be; Garrison, Barbara J. [Chemistry Department, Pennsylvania State University, University Park, PA (United States)

    2007-02-15

    The physics of energetic fullerene projectile penetration, damage creation and sputtering in organic solids is investigated via molecular dynamics simulations. Two models are used, the first one based on a full atomistic description of the target and the second one, using a coarse-grain prescription that was recently developed and tested for a benzene molecular crystal [E. Smiley, Z. Postawa, I.A. Wojciechowski, N. Winograd, B. J. Garrison, Appl. Surf. Sci. 252 (2006) 6436]. The results explore the mechanism of energy transfer from the C{sub 60} projectile to the organic target atoms/molecules through the comparison with significantly different projectiles (Argon) and samples (Ag crystal). The effects of the projectile energy on the penetration and fast energy transfer processes (200 fs) are also delineated. The second part of the results investigates the 'long term' consequences (20-50 ps) of fullerene impacts in hydrocarbon sample surfaces. In an icosane (C{sub 20}H{sub 42}) solid, a 5 keV C{sub 60} projectile induces a crater of {approx}10 nm diameter surrounded by a {approx}4 nm wide rim and ejects {approx}70 intact molecules. More than 75% of the fragments generated by the fullerene in the surface are also sputtered away by the end of the event. The perspective considers the capabilities of fullerene projectiles for depth profile analysis of molecular samples by particle-induced desorption mass spectrometry.

  1. Reliability estimates for flawed mortar projectile bodies

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, J.A. [US Army ARDEC, AMSRD-AAR-MEF-E, Analysis and Evaluation Division, Fuze and Precision Armaments Technology Directorate, US Army Armament Research Development and Engineering Center, Picatinny Arsenal, NJ 07806-5000 (United States)], E-mail: jennifer.cordes@us.army.mil; Thomas, J.; Wong, R.S.; Carlucci, D. [US Army ARDEC, AMSRD-AAR-MEF-E, Analysis and Evaluation Division, Fuze and Precision Armaments Technology Directorate, US Army Armament Research Development and Engineering Center, Picatinny Arsenal, NJ 07806-5000 (United States)

    2009-12-15

    The Army routinely screens mortar projectiles for defects in safety-critical parts. In 2003, several lots of mortar projectiles had a relatively high defect rate, 0.24%. Before releasing the projectiles, the Army reevaluated the chance of a safety-critical failure. Limit state functions and Monte Carlo simulations were used to estimate reliability. Measured distributions of wall thickness, defect rate, material strength, and applied loads were used with calculated stresses to estimate the probability of failure. The results predicted less than one failure in one million firings. As of 2008, the mortar projectiles have been used without any safety-critical incident.

  2. Stopping power: Effect of the projectile deceleration

    Energy Technology Data Exchange (ETDEWEB)

    Kompaneets, Roman, E-mail: kompaneets@mpe.mpg.de; Ivlev, Alexei V.; Morfill, Gregor E. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstr. 1, 85748 Garching (Germany)

    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.

  3. Chunk projectile launch using the Sandia Hypervelocity Launcher Facility

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Fragmentation and Plugging Failure of Projectile/Target System.

    Science.gov (United States)

    1987-03-01

    volume energy density inside the surface given in Figure 61, however, remains large and causes further fracture. A zig - zag fracture surface is...Materials and Structures, (Room 3D1089) Commander, U.S. Army Laboratory Command, 2800 Powder Mill Road, Adelphi, MD 20783-1145 1 ATTN : SLCIS-IM-TL

  5. Breakup conditions of projectile spectators from dynamical observables

    Energy Technology Data Exchange (ETDEWEB)

    Begemann-Blaich, M.; Lindenstruth, V.; Pochodzalla, J. [and others

    1998-03-01

    Momenta and masses of heavy projectile fragments (Z {>=} 8), produced in collisions of {sup 197}Au with C, Al, Cu and Pb targets at E/A=600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. Using these informations, an analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS-model. For a quantitative investigation, the data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. With classical trajectory calculations, where the charges and masses of the fragments are taken from a Monte Carlo sampling of the experimental events, the dynamical observables can be reproduced. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, a good agreement with the data is found with the exception that the fluctuation widths of the intrinsic fragment energies are significantly underestimated. A new version of the multifragmentation code MCFRAG was therefore used to investigate the potential role of angular momentum at the breakup stage. If a mean angular momentum of 0.75 {Dirac_h}/nucleon is added to the system, the energy fluctuations can be reproduced, but at the same time the charge partitions are modified and deviate from the data. (orig.)

  6. Asymmetry effects in fragment production

    Science.gov (United States)

    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).

  7. Inductiveless Rail Launchers for Long Projectiles

    Science.gov (United States)

    2001-04-26

    electromagnetic acceleration has remained unrealized. While long armatures could be readily designed for most projectiles, railguns cannot use them to... railgun concept is not readily applicable to tactical guns because it is hard to integrate sizable storage capacitors into the barrel. To circumvent...having substantially higher efficiency than railguns and much lower mechanical stresses in projectiles and launch tubes. Based on novel - inductiveless

  8. Graphical Method for Determining Projectile Trajectory

    Science.gov (United States)

    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,…

  9. Graphical Method for Determining Projectile Trajectory

    Science.gov (United States)

    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,…

  10. Efficient Calculation of Earth Penetrating Projectile Trajectories

    Science.gov (United States)

    2006-09-01

    CALCULATION OF EARTH PENETRATING PROJECTILE TRAJECTORIES by Daniel F . Youch September 2006 Thesis Advisor: Joshua Gordis... Daniel F . Youch 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING...EFFICIENT CALCULATION OF EARTH PENETRATING PROJECTILE TRAJECTORIES Daniel F . Youch Lieutenant Commander, United States Navy B.S., Temple

  11. ANALYTICAL MODEL OF CERAMIC/METAL ARMOR IMPACTED BY DEFORMABLE PROJECTILE

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new analytical model was established to describe the complex behavior of ceramic/metal armor under impact of deformable projectile by assuming some hypotheses.Three aspects were taken into account: the mushrooming deformation of the projectile,the fragment of ceramic tile and the formation and change of ceramic conoid and the deformation of the metal backup plate. Solving the set of equations, all the variables were obtained for the different impact velocities: the extent and particle velocity in rigid zone; the extent, cross-section area and particle velocity in plastic zone; the velocity and depth of penetration of projectile to the target; the reduction in volume and compressive strength of the fractured ceramic conoid; the displacement and movement velocity of the effective zone of backup plate. Agreement observed among analytical result, numerical simulation and experimental result confirms the validity of the model, suggesting the model developed can be a useful tool for ceramic/metal armor design.

  12. Plastic Guidance Fins for Long Rod Projectiles .

    Directory of Open Access Journals (Sweden)

    Mark L. Bundy

    1997-10-01

    Full Text Available Projectile tail fins on long rod kinetic energy (KE penetrators serve the same purpose as fletchings (feathers on an arrow, namely, they help align the projectile axis with its velocity vector. This reduces the projectile's yaw and hence reduces its aerodynamic drag. In addition, a low yaw angle at target impact helps to maximise the projectile's target penetration. It is typical for projectiles to exit the gun muzzle and enter free flight at some ndn-zero yaw angle. Aerodynamic forces acting on yawed tail fins create a stabilising torque about the projectile's centre of gravity (CG. This torque can be increased by making the fin material lighter. Most conventional long rod penetrators fired from high performance guns have tail fins made from aluminium. However, aluminium can undergo catastrophic oxidation (rapid burning in-bore. Coating aluminium with Al/sub 2/O/sub 3/ {hardcoat prevents ignition of the substrate, provided solid propellant grain impacts do not chip the brittle hardcoat off the surface. Plastic is lighter than aluminium and less exothermic when oxidized. Therefore, other factors aside, it is conceivable that plastic fins could increase projectile stability while incurring less thermal erosion than aluminium. However, thermal loads are not the only concern when considering plastic as an alternative tail fin material. The mechanical strength of plastic is also a critical factor. This paper discusses some of the successes and failures of plastic fins, at least relatively thin fins, for use as KE stabilisers.

  13. Geochemical identification of projectiles in impact rocks

    Science.gov (United States)

    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 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, this requires a set of impactite samples of various degree of projectile contamination.

  14. Isotopic Distributions of the l8N Fragmentation Products in Coincidence with Neutrons on Targets 197Au and 9Be

    Institute of Scientific and Technical Information of China (English)

    李湘庆; 江栋兴; 叶沿林; 华辉; 陈陶; 李智焕; 葛愉成; 王全进; 吴和宇; 靳根明; 段利敏; 肖志刚; 王宏伟; 李祖玉; 王素芳

    2002-01-01

    We present the experimental isotopic distributions of the 18 N projectile fragmentation products Li, Be,B and Cin coincidence with neutrons, as well as the inclusive ones on 197 Au and 9Be targets. In the framework of theabrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projec-tile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence withneutrons shows that the information on the nucleon density distribution of the 18N projectile can be extracted.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Hypervelocity High Speed Projectile Imagery and Video

    Science.gov (United States)

    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.

  18. Projectile Balloting Attributable to Gun Tube Curvature

    OpenAIRE

    Chen, Michael M.

    2010-01-01

    Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive...

  19. Batch Computed Tomography Analysis of Projectiles

    Science.gov (United States)

    2016-05-01

    component densities and their relative shapes and locations in space. Currently, surrogate BS41 projectiles are manufactured for the US Army Research...single core of an Intel Xeon X5650 processor operating at 2.67 GHz. To batch process the (210) projectiles, a Matlab script was written to parallelize...understand manufacturing variability, and to obtain a subgroup of the most similar for later ballistic testing, while omitting outliers. These

  20. Inclusive breakup of three-fragment weakly bound and Borromean nuclei

    CERN Document Server

    Carlson, Brett V; Hussein, Mahir S

    2016-01-01

    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, the theory is successfully generalized to Borromean 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 found to contain the contribution of a three-body absorption term that is also strongly influenced by the two-fragment correlations.

  1. Modeling and Experiments on Ballistic Impact into UHMWPE Yarns Using Flat and Saddle-Nosed Projectiles

    Directory of Open Access Journals (Sweden)

    Stuart Leigh Phoenix

    2017-03-01

    Full Text Available Yarn shooting experiments were conducted to determine the ballistically-relevant, Young’s modulus and tensile strength of ultra-high molecular weight polyethylene (UHMWPE fiber. Target specimens were Dyneema® SK76 yarns (1760 dtex, twisted to 40 turns/m, and initially tensioned to stresses ranging from 29 to 2200 MPa. Yarns were impacted, transversely, by two types of cylindrical steel projectiles at velocities ranging from 150 to 555 m/s: (i a reverse-fired, fragment simulating projectile (FSP where the flat rear face impacted the yarn rather than the beveled nose; and (ii a ‘saddle-nosed projectile’ having a specially contoured nose imparting circular curvature in the region of impact, but opposite curvature transversely to prevent yarn slippage off the nose. Experimental data consisted of sequential photographic images of the progress of the triangular transverse wave, as well as tensile wave speed measured using spaced, piezo-electric sensors. Yarn Young’s modulus, calculated from the tensile wave-speed, varied from 133 GPa at minimal initial tension to 208 GPa at the highest initial tensions. However, varying projectile impact velocity, and thus, the strain jump on impact, had negligible effect on the modulus. Contrary to predictions from the classical Cole-Smith model for 1D yarn impact, the critical velocity for yarn failure differed significantly for the two projectile types, being 18% lower for the flat-faced, reversed FSP projectile compared to the saddle-nosed projectile, which converts to an apparent 25% difference in yarn strength. To explain this difference, a wave-propagation model was developed that incorporates tension wave collision under blunt impact by a flat-faced projectile, in contrast to outward wave propagation in the classical model. Agreement between experiment and model predictions was outstanding across a wide range of initial yarn tensions. However, plots of calculated failure stress versus yarn pre

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

    Science.gov (United States)

    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.

  3. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya

    2016-04-19

    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.

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

    Science.gov (United States)

    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.

  5. Three Dimensional CAPP Technology of Projectile Based on MBD

    Directory of Open Access Journals (Sweden)

    Hongzhi Zhao

    2013-07-01

    Full Text Available This study aims at the research goal of three-dimensional digital process design of projectile, which adopts three-dimensional computer-aided process design technology based on MBD and uses MBD to conduct parametric modeling of projectile that can reduce the input of projectile’s process information and data conversion and produce reasonable, feasible and three-dimensional projectile manufacturing process to realize paperless three-dimensional process design of projectile. The application of three-dimensional computer-assisted process design technology of projectile based on model definition can shorten the design cycle of projectile, thus improving rapid manufacturing capacity of product and reducing cost.

  6. Isotopic distributions of the sup 1 sup 8 N fragmentation products in coincidence with neutrons on targets sup 1 sup 9 sup 7 Au and sup 9 Be

    CERN Document Server

    Li Xiang Qing; Ye Yan Lin; Hua Hui; Chen Tao; Li Zhi Huan; Ge Yuch Eng; Wang Quan Jin; Wu He Yu; Jin Ge; Duan Li Min; Xiao Zhi Gang; Wang Hong Wei; Li Zhu Yu; Wang Su Fang

    2002-01-01

    The authors present the experimental isotopic distributions of the sup 1 sup 8 N projectile fragmentation products Li, Be, B and C in coincidence with neutrons, as well as the inclusive ones on sup 1 sup 9 sup 7 Au and sup 9 Be targets. In the framework of the abrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projectile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence with neutrons shows that the information on the nucleon density distribution of the sup 1 sup 8 N projectile can be extracted

  7. The representational dynamics of remembered projectile locations.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Projectile-Borne Video Reconnaissance System

    Institute of Scientific and Technical Information of China (English)

    王海福; 张锋; 李向荣

    2004-01-01

    Aiming at applications as a projectile-borne video reconnaissance system, the overall design and prototype in principle of a mortar video reconnaissance system bomb were developed. Mortar launched test results show that the initial integrated system was capable of transmitting images through tens of kilometers with the image resolution identifying effectively tactical targets such as roads, hills, caverns, trees and rivers. The projectile-borne video reconnaissance system is able to meet the needs of tactical target identification and battle dage assessment for tactical operations. The study will provide significant technological support for further independent development.

  10. Grenade-launched imaging projectile system (GLIMPS)

    Science.gov (United States)

    Nunan, Scott C.; Coakley, Peter G.; Niederhaus, Gregory A.; Lum, Chris

    2001-09-01

    A system has been developed for delivering and attaching a sensor payload to a target using a standard 40-mm grenade launcher. The projectile incorporates an attachment mechanism, a shock mitigation system, a power source, and a video-bandwidth transmitter. Impact and launch g-loads have been limited to less than 10,000 g's, enabling sensor payloads to be assembled using Commercial Off-The-Shelf components. The GLIMPS projectile is intended to be a general-purpose delivery system for a variety of sensor payloads under the Unattended Ground Sensors program. Test results and development issues are presented.

  11. AB-Net Method of Protection from Projectiles (city, military base, battle-front, etc.)

    CERN Document Server

    Bolonkin, Alexander

    2008-01-01

    The author suggests a low cost special AB-Net from artificial fiber, which may protect cities and important objects from rockets, artillery and mortar shells, projectiles, bullets, and strategic weapons. The idea is as follows: The offered AB-Net joins an incoming projectile to a small braking parachute and this incoming projectile loses speed by air braking after a drag distance of 50 - 150 meters. A following interception net after the first may serve to collect the slowed projectiles and their fragments or bomblets so that they do not reach the aimpoint. The author offers the design of AB-Net, a developed theory of snagging with a small braking parachute by AB-Net; and sample computations. These nets may be used for defense of a town, city, military base, battle-front line, road (from terrorists), or any important objects or installations (for example nuclear electric station, government buildings, etc.). Computed projects are: Net to counter small rockets (for example, from Qassam), net to counter artille...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. High School Students' Understanding of Projectile Motion Concepts

    Science.gov (United States)

    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…

  14. A note on stability of motion of a projectile

    Indian Academy of Sciences (India)

    S D Naik

    2001-08-01

    A projectile is stabilised using either gyroscopic or aerodynamic stability. But subcalibre projectiles with sabot have both spin and fins. Separate stability criteria are researched generally for each type of projectile. In this paper a stability criterion which can be used for all such bodies has been developed through the Liapunov second method.

  15. Nuclear fragmentation for Xe+Au and Xe+Ag systems at an energy of 44 A.MeV, formation and decay of hot nuclei; Etude de la fragmentation nucleaire pour les systemes XE+AU et XE+AG a 44 A.MeV, production et decroissance de noyaux chauds

    Energy Technology Data Exchange (ETDEWEB)

    Meslin, C.

    1995-01-01

    A study of the formation and the decay of hot nuclear fragments produced in the reactions Xe+Au and Xe+Ag at an energy of 44 A.MeV is presented in this thesis. The 4{pi} experimental setup consisted of four multidetectors -two for the detection of the fragments (Z>7; DELF and XYZT) and two for the detection of the charged particles (Z<6; MUR and TONNEAU) and allowed an analysis using ``complete events`` (80 % of the total charge and the total parallel linear momentum of the entrance channel) to be carried out. The reaction mechanism is binary with as observed at low energy an almost complete relaxation of the incident energy. The collision results in two hot fragments at the beginning of the exit channel which decay by evaporation and/or fragmentation. In addition of these two body events, we have identified a new dynamic mechanism where we detect a small fragment, called the neck, coming form the overlap of the nuclei during the interaction, in coincidence with a projectile-like fragment and a target-like fragment. For the most dissipative collisions, the deep inelastic collision have allowed an estimation of the lifetime of the hot nuclear fragments to be made. This is possible using proximity effects and fragment-fragment space-time correlations of the decay of one or two primary partners from the deep inelastic collisions. This method is seen to reach its limits in the case of the reactions studied here. (authors). 61 refs.

  16. An Inexpensive Mechanical Model for Projectile Motion

    Science.gov (United States)

    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…

  17. Comment on "The envelope of projectile trajectories"

    CERN Document Server

    Butikov, E I

    2003-01-01

    Several simple alternative methods to obtain the equation of the envelope of the family of projectile trajectories corresponding to the same initial speed are suggested, including methods in which the boundary of the region occupied by the parabolic trajectories is found as an envelope of a set of circles. Two possible generalizations of the discussed problem are also suggested. (letters and comments)

  18. Teaching Projectile Motion to Eliminate Misconceptions

    Science.gov (United States)

    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. Bulldozing Your Way Through Projectile Motion.

    Science.gov (United States)

    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)

  20. Fatal lawn mower related projectile injury

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  1. Maximizing the Range of a Projectile.

    Science.gov (United States)

    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)

  2. Predicting the Accuracy of Unguided Artillery Projectiles

    Science.gov (United States)

    2016-09-01

    Unstable (right) Projectiles. Source: [4]..........................13 Figure 6. Direction of Lift and Gravitational Forces in a Spinning Top ...14 Figure 8. Precession of a Spinning Top . Source: [7...the gyroscopic effect, which tends to maintain the orientation of the axis of spin . This effect is commonly observed in spinning tops , which stay

  3. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    Science.gov (United States)

    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…

  4. Launching a Projectile into Deep Space

    Science.gov (United States)

    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…

  5. Effect of CFRP strengthening on the response of RC slabs to hard projectile impact

    Energy Technology Data Exchange (ETDEWEB)

    Almusallam, Tarek; Al-Salloum, Yousef; Alsayed, Saleh; Iqbal, Rizwan; Abbas, Husain, E-mail: abbas_husain@hotmail.com

    2015-05-15

    Highlights: • Studied response of CFRP-strengthened RC slabs under the impact load. • Slabs were tested under the strike of hemispherical steel projectiles at varying impact. • The slabs were analyzed numerically using LS-DYNA. • Strengthening increased the ballistic limit velocity by 18% and perforation energy by 56.7%. • CFRP sheet reduced the crater damage and contained the flying concrete fragments. - Abstract: In this paper impact response of CFRP-strengthened RC panels under the impact of non-deformable projectiles has been presented. The control and CFRP-strengthened RC slab panels were tested under the strike of hemispherical nosed steel projectiles at varying impact velocities. The response of these panels was investigated experimentally as well as numerically. The damage of the slab panels was measured in terms of the penetration depth, formation of cracks, spalling and scabbing areas and fracture of CFRP sheet. This study presents a practical and efficient numerical method for analyzing the impact response of CFRP-strengthened RC structures using LS-DYNA. The CFRP strengthening was found to increase the ballistic limit velocity by 18%, perforation energy of RC slabs by 56.7%, reduce the front crater damage and contains the flying of concrete fragments from the rear face. The maximum impact force occurs at almost same penetration depth for the control and CFRP-strengthened slabs but the restraint provided by CFRP increased the penetration depth by about 1/19.3 of the thickness of slab.

  6. Investigates on Aerodynamic Characteristics of Projectile with Triangular Cross Section

    Institute of Scientific and Technical Information of China (English)

    YI Wen-jun; WANG Zhong-yuan; LI Yan; QIAN Ji-sheng

    2009-01-01

    The aerodynamic characteristics of projectiles with triangular and circular cross sections are investigated respectively by use of free-flight experiment. Processed the experiment data, curves of flight velocity variation and nutation of both projectiles are obtained, based on the curves, their aerodynamic force and moment coefficients are found out by data fitting, and their aerodynamic performances are compared and analyzed. Results show that the projectile with triangular cross section has smaller resistance, higher lift-drag ratio, better static stability, higher stability capability and more excellent maneuverability than those of the projectile with circular cross section, therefore it can be used in the guided projectiles; under lower rotation speed, the triangular section projectile has greater Magnus moment leading to bigger projectile distribution.

  7. Radio Frequency Fragment Separator at NSCL

    Energy Technology Data Exchange (ETDEWEB)

    Bazin, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)], E-mail: bazin@nscl.msu.edu; Andreev, V. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Becerril, A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Doleans, M. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Mantica, P.F. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Schatz, H. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Stoker, J.B. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Vincent, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)

    2009-07-21

    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.

  8. Radio Frequency Fragment Separator at NSCL

    Science.gov (United States)

    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.

  9. Minimum and terminal velocities in projectile motion

    CERN Document Server

    Miranda, E N; Riba, R

    2012-01-01

    The motion of a projectile with horizontal initial velocity V0, moving under the action of the gravitational field and a drag force is studied analytically. As it is well known, the projectile reaches a terminal velocity Vterm. There is a curious result concerning the minimum speed Vmin; it turns out that the minimum velocity is lower than the terminal one if V0 > Vterm and is lower than the initial one if V0 < Vterm. These results show that the velocity is not a monotonous function. If the initial speed is not horizontal, there is an angle range where the velocity shows the same behavior mentioned previously. Out of that range, the volocity is a monotonous function. These results come out from numerical simulations.

  10. Electrical parameters of projectile stun guns.

    Science.gov (United States)

    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).

  11. Excalibur Precision 155mm Projectiles (Excalibur)

    Science.gov (United States)

    2015-12-01

    Acquisition Management Information Retrieval DoD - Department of Defense DSN - Defense Switched Network EMD - Engineering and Manufacturing Development...Inc Ia-2 projectile was delivered to inventory in April 2014. In total, PM Excalibur procured and delivered 2,132 Excalibur Inc Ia-1 ( Department of...funds are included in this report as Non- Treasury RDT&E (9999). Procurement Appn BA PE Army 2034 01 0210600A Line Item Name E80103 Excalibur

  12. The Envelope of Projectile Trajectories in Midair

    CERN Document Server

    Chudinov, P

    2005-01-01

    A classic problem of the motion of a point mass (projectile) thrown at an angle to the horizon is reviewed. The air drag force is taken into account with the drag factor assumed to be constant. Analytic approach is used for investigation. Simple analytical formulas are used for the constructing the envelope of the family of the point mass trajectories. The equation of envelope is applied for determination of maximum range of flight. The motion of a baseball is presented as an example.

  13. On the Stability of a Spinning Projectile

    Directory of Open Access Journals (Sweden)

    P. C. Rath

    1965-10-01

    Full Text Available Stability problem both for small and large yawing of a spinning projectile has been discussed. In the latter case criterion for stability of steady conically yawing motion has been obtained. Particularly it has been proved that with a tilting moment coefficient of the type micro(delta-betaohm/sup2/4[1-4qs(1-cosdelta] the motion of a shell in steady state is stable like an equivalent top only when q>=0.

  14. Projectile Ullage Inspection Technique: Laboratory Demonstration Apparatus.

    Science.gov (United States)

    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. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  16. Intuitive Mechanics: Inferences of Vertical Projectile Motion

    Directory of Open Access Journals (Sweden)

    Milana Damjenić

    2016-07-01

    Full Text Available Our intuitive knowledge of physics mechanics, i.e. knowledge defined through personal experience about velocity, acceleration, motion causes, etc., is often wrong. This research examined whether similar misconceptions occur systematically in the case of vertical projectiles launched upwards. The first experiment examined inferences of velocity and acceleration of the ball moving vertically upwards, while the second experiment examined whether the mass of the thrown ball and force of the throw have an impact on the inference. The results showed that more than three quarters of the participants wrongly assumed that maximum velocity and peak acceleration did not occur at the initial launch of the projectile. There was no effect of object mass or effect of the force of the throw on the inference relating to the velocity and acceleration of the ball. The results exceed the explanatory reach of the impetus theory, most commonly used to explain the naive understanding of the mechanics of object motion. This research supports that the actions on objects approach and the property transmission heuristics may more aptly explain the dissidence between perceived and actual implications in projectile motion.

  17. Binary and Ternary Fission Within the Statistical Model

    Science.gov (United States)

    Adamian, Gurgen G.; Andreev, Alexander V.; Antonenko, Nikolai V.; Scheid, Werner

    The binary and ternary nuclear fission are treated within the statistical model. At the scission point we calculate the potentials as functions of the deformations of the fragments in the dinuclear model. The potentials give the mass and charge distributions of the fission fragments. The ternary fission is assumed to occur during the binary fission.

  18. Determination of the excitation energy and angular momentum of the quasi-projectiles produced in the heavy ion collisions Xe + Sn; Determination de l'energie d'excitation et du moment angulaire des quasi-projectiles produits dans les collisions d'ions lourds Xe + Sn

    Energy Technology Data Exchange (ETDEWEB)

    Genouin-Duhamel, Emmanuel [Lab. de Physique Corpusculaire, Caen Univ., 14 Caen (France)

    1999-04-08

    This work is a contribution to the study of properties of hot nuclei formed in heavy ion collisions at intermediate energies. The experiment has been performed with the INDRA multidetector. It is shown that most of the reaction cross section is associated with binary dissipative collisions, accompanied by the production of particles from a region between the two reaction partners. This study is focussed on excitation energy and angular momentum of projectile-like fragment (PLF) in {sup 129}Xe + {sup nat}Sn reactions from 25 to 50 MeV per nucleon. Several methods are used to characterize hot nuclei (velocity, charge, mass and excitation energy). All these methods are compared between them and indicate that high energies are deposited in the nuclei during collision (it may exceed the nucleus binding energy). The angular momentum transferred into intrinsic spin to PLF in the peripheral collisions has been deduced from angular distributions and kinetic energies of the emitted light charged particles (atomic number smaller ar equal to 2). Both methods agree qualitatively. The spin values decrease with the violence of the collision. These values correspond to values averaged over the whole deexcitation chain of nuclei. The predictions of transport models reproduce qualitatively the most peripheral collisions and suggest that high spins are transferred to PLF (from 30 to 50 {Dirac_h}). Larger angular momentum values are observed at the lowest incident energy. The time hierarchy in the evaporation process and the role of mid-rapidity emission are also discussed.

  19. Quantum fragmentation

    CERN Document Server

    Peschanski, R

    1993-01-01

    Phenomenological and theoretical aspects of fragmentation for elementary particles (resp. nuclei) are discussed. It is shown that some concepts of classical fragmentation remain relevant in a microscopic framework, exhibiting non-trivial properties of quantum relativistic field theory (resp. lattice percolation). Email contact: pesch@amoco.saclay.cea.fr

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Oblique Impact of Projectile on Thin Aluminium Plates

    Directory of Open Access Journals (Sweden)

    W.U. Khan

    2003-04-01

    Full Text Available Experiments were performed, wherein cylindrical projectiles made of hardened steel were impacted on commercially available aluminium plates at different angles. Projectiles were of 12.8 mm diameter and plates were of 0.81 mm, 1.52mm and 1.91mm thicknesses. Based on the experimental results, an analytical model has been developed to predict the residual velocity of the projectile and the ballistic limit of the plate.

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

    Science.gov (United States)

    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.

  3. Dynamic analysis of a guided projectile during engraving process

    Institute of Scientific and Technical Information of China (English)

    Tao XUE; Xiao-bing ZHANG; Dong-hua CUI

    2014-01-01

    The reliability of the electronic components inside a guided projectile is highly affected by the launch dynamics of guided projectile. The engraving process plays a crucial role on determining the ballistic performance and projectile stability. This paper analyzes the dynamic response of a guided projectile during the engraving process. By considering the projectile center of gravity moving during the engraving process, a dynamics model is established with the coupling of interior ballistic equations. The results detail the stress situation of a guided projectile band during its engraving process. Meanwhile, the axial dynamic response of projectile in the several milliseconds following the engraving process is also researched. To further explore how the different performance of the engraving band can affect the dynamics of guided projectile, this paper focuses on these two aspects:(a) the effects caused by the different band geometry;and (b) the effects caused by different band materials. The time domain and frequency domain responses show that the dynamics of the projectile are quite sensitive to the engraving band width. A material with a small modulus of elasticity is more stable than one with a high modulus of elasticity.

  4. Microcraters formed in glass by low density projectiles

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  6. Electric rail gun projectile acceleration to high velocity

    Science.gov (United States)

    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.

  7. Dynamic analysis of a guided projectile during engraving process

    Directory of Open Access Journals (Sweden)

    Tao Xue

    2014-06-01

    Full Text Available The reliability of the electronic components inside a guided projectile is highly affected by the launch dynamics of guided projectile. The engraving process plays a crucial role on determining the ballistic performance and projectile stability. This paper analyzes the dynamic response of a guided projectile during the engraving process. By considering the projectile center of gravity moving during the engraving process, a dynamics model is established with the coupling of interior ballistic equations. The results detail the stress situation of a guided projectile band during its engraving process. Meanwhile, the axial dynamic response of projectile in the several milliseconds following the engraving process is also researched. To further explore how the different performance of the engraving band can affect the dynamics of guided projectile, this paper focuses on these two aspects: (a the effects caused by the different band geometry; and (b the effects caused by different band materials. The time domain and frequency domain responses show that the dynamics of the projectile are quite sensitive to the engraving band width. A material with a small modulus of elasticity is more stable than one with a high modulus of elasticity.

  8. Intermediate Mass Fragments Emission in Peripheral Heavy-Ion Collisions

    Science.gov (United States)

    Bini, M.; Casini, G.; Maurenzig, P. R.; Olmi, A.; Pasquali, G.; Piantelli, S.; Poggi, G.; Stefanini, A. A.; Taccetti, N.

    The collision 116Sn + 93Nb at 29.5 AMeV in direct and reverse kinematics has been studied at LNS in Catania. In particular the emission pattern in the νperp - νpar plane of Intermediate Mass Fragments with Z=3-7 (IMF's) shows that for peripheral reactions most of IMF's are emitted at velocities intermediate between those of the projectile- and target-like products. From coulomb trajectory calculations one can infere that these IMF's are produced mainly in the interaction zone, in a short time interval at the end of the target-projectile interaction.

  9. Electromagnetic Dissociation of Target Nuclei by $^{16}$O and $^{32}$S Projectiles

    CERN Multimedia

    2002-01-01

    We have measured the inclusive cross sections for electromagnetic dissociation (ED) of |1|9|7Au targets by 60 and 200~GeV/nucleon |1|6O and 200~ GeV/nucleon |3|2S projectiles. This is an extension of similar measurements carried out earlier at 2~GeV/nucleon. ED is a purely electromagnetic process occuring when a virtual photon is exchanged between projectile and target. The experiment emphasized precise measurement of total one-neutron-out cross sections. A secondary goal was to test the applicability of the concepts of factorization and limiting fragmentation at ultrarelativistic energies.\\\\ \\\\ Each individual target will be irradiated upstream and parasitic to experiment NA38 on the dimuon spectrometer. Cross sections for reactions of interest will be determined by off-line counting of the appropriate residual @g~ray activities in Ames, Iowa, USA. Preliminary results indicate an ED one-neutron removal cross section for 200~GeV/nucleon |1|6O projectiles on |1|9|7Au of approximately 0.45~barns. The result is ...

  10. Fragmented Authoritarianism or Integrated Fragmentation

    DEFF Research Database (Denmark)

    Brødsgaard, Kjeld Erik

    of these business leaders prompts the question of whether we are seeing the development of distinct interest groups that could challenge Party and state authority and create a fragmented polity. However, through the nomenklatura system the Party has an important instrument of control to wield over business groups...... and the Party-state, I suggest the notion of integrated fragmentation....

  11. Modelling of the PELE fragmentation dynamics

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  13. Corrected Launch Speed for a Projectile Motion Laboratory

    Science.gov (United States)

    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…

  14. ’Fused-on’ Rotating Bands for Projectiles

    Science.gov (United States)

    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

  15. Microcraters formed in glass by projectiles of various densities

    Science.gov (United States)

    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.

  16. Stability of Liquid-Filled Projectiles with Unusual Coning Frequencies.

    Science.gov (United States)

    1986-07-01

    INTRODUCTION .................. . .. ......... ... ...... 5 11. INVISCID LIQUID MOMENTo ......... s....................... 6 III. VISCOUS MODIFICATIONS...1966. (AD 489687) 3. Murphy, C. H., " Angular Motion of a Spinn Projectile inth a Viscous Liquid Payload," Ballistic Research Laboratory, Aberdeen...stability. II. INVISCID LIQUID MOMENT We will consider a spinning projectile** performing a coning or spiraling motion. In nonrolling coordinates the angular

  17. Locating the source of projectile fluid droplets

    CERN Document Server

    Varney, Christopher R

    2011-01-01

    The ballistically ill-posed projectile problem of finding 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. Due to missing velocity information, however, finding the height of origin from impact position and angle of individual drops is not possible. Turning to aggregate statistics of the spatter and basic equations of projectile motion familiar to physics students, we introduce a reciprocal correlation plot that is effective when the polar angle of launch is concentrated in a narrow range. The horizontal plot coordinate is twice the reciprocal of impact distance, and the vertical coordinate depends on the orientation of the spattered surface; for a level surface this is the tangent of impact angle. In all cases one infers source height as the slope of data points in the reciprocal correlation plot. Such plo...

  18. Penetration of projectiles into granular targets

    Science.gov (United States)

    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.

  19. Locating the source of projectile fluid droplets

    Science.gov (United States)

    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. Impact effects of explosively formed projectiles on normal strength concrete

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Metal-assisted secondary ion mass spectrometry using atomic (Ga+, In+) and fullerene projectiles.

    Science.gov (United States)

    Delcorte, A; Yunus, S; Wehbe, N; Nieuwjaer, N; Poleunis, C; Felten, A; Houssiau, L; Pireaux, J-J; Bertrand, P

    2007-05-15

    The advantages and drawbacks of using either monatomic or buckminsterfullerene primary ions for metal-assisted secondary ion mass spectrometry (MetA-SIMS) are investigated using a series of organic samples including additive molecules, polyolefins, and small peptides. Gold deposition is mostly performed by sputter-coating, and in some cases, the results are compared to those of thermal evaporation (already used in a previous article: Delcorte, A.; Médard, N.; Bertrand, P. Anal. Chem. 2002, 74, 4955). The microstructure of the gold-covered sample surfaces is assessed by scanning and transmission electron microscopies. The merits of the different sets of experimental conditions are established via the analysis of fragment and parent-like ion yields. For most of the analyzed samples, the highest yields of fragment and parent-like ions are already reached with the sole use of C60+ projectiles. Metallization of the sample does not lead to a significant additional enhancement. For polyethylene and polypropylene, however, gold metallization associated with Ga+/In+ projectiles appears to be the only way to observe large cationized, sample-specific chain segments (m/z approximately 1000-2000). A detailed study of the polypropylene mass spectra as a function of gold coverage shows that the dynamics of yield enhancement by metal nanoparticles is strongly dependent on the choice of the projectile, e.g., a pronounced increase with Ga+ and a slow decay with C60+. The cases of Irganox 1010, a polymer antioxidant, and leucine enkephalin, a small peptide, allow us to investigate the specific influence of the experimental conditions on the emission of parent(like) ions such as M+, (M + Na)+, and (M + Au)+. The results show a dependence on both the type of sample and the considered secondary ion. Using theoretical and experimental arguments, the discussion identifies some of the mechanisms underlying the general trends observed in the results. Guidelines concerning the choice of the

  3. Magma Fragmentation

    Science.gov (United States)

    Gonnermann, Helge M.

    2015-05-01

    Magma fragmentation is the breakup of a continuous volume of molten rock into discrete pieces, called pyroclasts. Because magma contains bubbles of compressible magmatic volatiles, decompression of low-viscosity magma leads to rapid expansion. The magma is torn into fragments, as it is stretched into hydrodynamically unstable sheets and filaments. If the magma is highly viscous, resistance to bubble growth will instead lead to excess gas pressure and the magma will deform viscoelastically by fracturing like a glassy solid, resulting in the formation of a violently expanding gas-pyroclast mixture. In either case, fragmentation represents the conversion of potential energy into the surface energy of the newly created fragments and the kinetic energy of the expanding gas-pyroclast mixture. If magma comes into contact with external water, the conversion of thermal energy will vaporize water and quench magma at the melt-water interface, thus creating dynamic stresses that cause fragmentation and the release of kinetic energy. Lastly, shear deformation of highly viscous magma may cause brittle fractures and release seismic energy.

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

    Science.gov (United States)

    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.

  5. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    , contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... into separate parts or systems: skeleton, skin, services, internal cladding, etc. Each building part/system is being conceived, produced, delivered and maintained by different construction companies. Basically the building is being fragmented into separate parts living their separate lives. The architect has...... to create architectural meaning and give character to an architecture of fragmentation. Layers are both seen as conceptual as well as material frames which define certain strong properties or meanings in the architectural work. Defining layers is a way of separating and organizing; it both defines...

  6. Fragmentation of Kozai–Lidov Disks

    Science.gov (United States)

    Fu, Wen; Lubow, Stephen H.; Martin, Rebecca G.

    2017-02-01

    We analyze the gravitational instability (GI) of a locally isothermal inclined disk around one component of a binary system. Such a disk can undergo global Kozai–Lidov (KL) cycles if the initial disk tilt is above the critical KL angle (of about 40◦). During these cycles, an initially circular disk exchanges its inclination for eccentricity, and vice versa. Self-gravity may suppress the cycles under some circumstances. However, with hydrodynamic simulations that include self-gravity, we show that for a sufficiently high initial disk tilts and for certain disk masses, disks can undergo KL oscillations and fragment due to GI, even when the Toomre Q value for an equivalent undisturbed disk is well within the stable regime (Q> 2). We suggest that KL triggered disk fragmentation provides a mechanism for the efficient formation of giant planets in binary systems and may enhance the fragmentation of disks in massive black hole binaries.

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

    Science.gov (United States)

    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.

  8. Interplay of mean field and nucleon-nucleon interactions in the production of carbon fragments in sup 1 sup 6 O induced reactions at incident energies up to 25 MeV/amu

    CERN Document Server

    Gadioli, E; Catarisano, C; Cavinato, M; Connell, S H; Cowley, A A; Fabrici, E; Förtsch, S V; Gadioli-Erba, E; Lawrie, J J; Sellschop, J P Friedel; Sideras-Haddad, E; Steyn, G F

    2002-01-01

    Two different reaction mechanisms (which both occur at very short interaction times) contribute to the emission of intermediate mass fragments in reactions induced by a light nucleus such as sup 1 sup 6 O. They are the binary fragmentation of the projectile and the coalescence of nucleons during the course of the nucleon-nucleon interaction cascade which starts as soon as the two ions (or part of them) come into contact. These two mechanisms are easily distinguished from each other because their contributions to measured emission spectra have different energy dependence, the first peaking at an energy not far from that corresponding to the beam velocity, the other to a much smaller energy about equal to the Coulomb barrier between the observed fragment and an heavy residue with mass and charge near to those of the target nucleus. These features are clearly observed in the spectra of carbon fragments produced in the interaction of sup 1 sup 6 O ions with sup 5 sup 9 Co and sup 9 sup 3 Nb at incident energies b...

  9. Key Techniques of Terminal Correction Mortar Projectiles

    Institute of Scientific and Technical Information of China (English)

    XU Jin-xiang

    2007-01-01

    The operational principle, the impulse force and terminal guidance laws of terminal correction mortar projectiles(TCMP) are researched in this paper, by using the TCMP simulation program, key techniques such as the miss distance influenced by the acting point of impulse force, the impulse force value, the correction threshold, and the number of impulse rockets are researched in this paper.And the dual pulse control scheme is also studied.Simulation results indicate that the best acting point is near the center of gravity, sufficient correction resources are needed, the miss distance is insentive to the correction threshold, increasing the number of impulse rockets properly is beneficial to increase the hit precision, the velocity pursuit guidance law has less miss distance, the change of the attack angle is milder and the transient time becomes less in the dual impulse control scheme.These conclusions are important for choosing parameters and impulse correction schemes designed for TCMP.

  10. Influence of projectile breakup on complete fusion

    Indian Academy of Sciences (India)

    A Mukherjee; M K Pradhan

    2010-07-01

    Complete fusion excitation functions for 11,10B+159Tb and 6,7Li+159Tb have been reported at energies around the respective Coulomb barriers. The measurements show significant suppression of complete fusion cross-sections at energies above the barrier for 10B+159Tb and 6,7Li+159Tb reactions, when compared to those for 11B+159Tb. The comparison shows that the extent of suppression of complete fusion cross-sections is correlated with the -separation energies of the projectiles. Also, the measured incomplete fusion cross-sections show that the -particle emanating channel is the favoured incomplete fusion process. Inclusive measurement of the -particles produced in 6Li+159Tb reaction has been carried out. Preliminary CDCC calculations carried out to estimate the - yield following 6Li breaking up into + fail to explain the measured -yield. Transfer processes seem to be important contributors.

  11. NUMERICAL SIMULATION FOR FORMED PROJECTILE OF DEPLETED URANIUM ALLOY

    Institute of Scientific and Technical Information of China (English)

    宋顺成; 高平; 才鸿年

    2003-01-01

    The numerical simulation for forming projectile of depleted uranium alloy with the SPH ( Smooth Particle Hydrodynamic ) algorithm was presented. In the computations the artificial pressures of detonation were used, i. e. , the spatial distribution and time distribution were given artificially. To describe the deformed behaviors of the depleted uranium alloy under high pressure and high strain rate, the Johnson-Cook model of materials was introduced. From the numerical simulation the formed projectile velocity,projectile geometry and the minimum of the height of detonation are obtained.

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

    Science.gov (United States)

    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.

  13. The projectile-wall interface in rail launchers

    Science.gov (United States)

    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.

  14. Neutron-rich rare isotope production from projectile fission of heavy beams in the energy range of 20 MeV/nucleon

    CERN Document Server

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

    2016-01-01

    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 deexcitation/fission of the hot heavy projectile fragments is performed with the Statistical Mul- tifragmentation 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 periph- eral heavy-ion collisions at this energy range of...

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Caliebe, D.; Arp, O.; Piel, A. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet, Kiel (Germany)

    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.

  17. A Direct-Fire Trajectory Model for Supersonic, Transonic, and Subsonic Projectile Flight

    Science.gov (United States)

    2014-07-01

    motions of the projectile about the trajectory due to the angular motion of the projectile . For a stable projectile , these motions are typically small...A Direct-Fire Trajectory Model for Supersonic, Transonic, and Subsonic Projectile Flight by Paul Weinacht ARL-TR-6998 July 2014...Direct-Fire Trajectory Model for Supersonic, Transonic, and Subsonic Projectile Flight Paul Weinacht Weapons and Materials Research Directorate, ARL

  18. Penetration analysis of projectile with inclined concrete target

    Science.gov (United States)

    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.

  19. Impact of Thin-Walled Projectiles with Concrete Targets

    Directory of Open Access Journals (Sweden)

    Rayment E. Moxley

    1995-01-01

    Full Text Available An experimental program to determine the response of thin-walled steel projectiles to the impact with concrete targets was recently conducted. The projectiles were fired against 41-MPa concrete targets at an impact velocity of 290 m/s. This article contains an outline of the experimental program, an examination of the results of a typical test, and predictions of projectile deformation by classical shell theory and computational simulation. Classical shell analysis of the projectile indicated that the predicted impact loads would result in circumferential buckling. A computational simulation of a test was conducted with an impact/penetration model created by linking a rigid-body penetration trajectory code with a general-purpose finite element code. Scientific visualization of the resulting data revealed that circumferential buckling was induced by the impact conditions considered.

  20. Penetration analysis of projectile with inclined concrete target

    Directory of Open Access Journals (Sweden)

    Kim S.B.

    2015-01-01

    Full Text Available 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.

  1. Light projectile scattering off the Color Glass Condensate

    CERN Document Server

    Fukushima, Kenji

    2007-01-01

    We systematically compute the expectation value of Wilson lines in the McLerran-Venugopalan model, which provides useful formulae for evaluation of the scattering aimplitude in the collision of a light projectile and a heavy target.

  2. Visualization Techniques Applied to 155-mm Projectile Analysis

    Science.gov (United States)

    2014-11-01

    demonstrated via these numerical calculations. The ability to understand the physics that impact the flight dynamics of the projectile through...properties Projectile Physical Properties Value Diameter, d (m) 0.155 Length, L (mm) 0.9814 Mass, m (kg) 44.197 Center of gravity, Xcg 0.5976 Axial...characteristics-based inflow/outflow boundary condition, which is based on solving a Riemann problem at the boundary. 2.3 Numerics Rolling/spinning is the

  3. Thrusters Pairing Guidelines for Trajectory Corrections of Projectiles

    Science.gov (United States)

    2011-01-12

    Gill, J., “Experimental Investigation of Super- and Hypersonic Jet Interaction on Missile Configurations,” Journal of Spacecraft and Rockets, Vol. 35...Thrusters Pairing Guidelines for Trajectory Corrections of Projectiles Daniel Corriveau∗ Canadian Department of National Defence , Quebec City, Quebec...course correction process for a 30-mm fin-stabilized air- defense projectile and a standard 105-mm spin-stabilized artillery shell are presented

  4. Numerical Prediction of Pitch Damping Stability Derivatives for Finned Projectiles

    Science.gov (United States)

    2013-11-01

    spinner rocket, but not to a finned projectile. This study presents the first combined application of these methods for finned projectiles in which...and the U.S. Air Force Research Laboratory (AFRL) Aeroballistic Research Facility (ARF) (29) at Eglin Air Force Base in Florida. 2. Theoretical...numerical convergence, the results of which are presented in section4.2.2. 2.2 Steady Lunar Coning Method Murphy (24), Schiff (15, 16), Tobak and Schiff

  5. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2016-01-01

    The Ph.D. -project Bespoke Fragments seeks to explore and utilise the space emerging between the potentials of digital drawing and fabrication and the field of materials and their properties and capacities. Within this span, the project is situated in a shuttling between the virtual and the actual......, the emergence of virtual space is no longer limited to the computer's digital world, but extends into the materials' world. Creation and uncertainty are allowed as virtual parameters in both the digital and reality. Based on this notion the project suggests utilising that exact potential to develop...

  6. Optimising LISA orbits: The projectile solution

    CERN Document Server

    Dhurandhar, S V; Vinet, J-Y

    2008-01-01

    LISA is a joint space mission of the NASA and the ESA for detecting low frequency gravitational waves (GW) in the band $10^{-5} - 0.1$ Hz. The proposed mission will use coherent laser beams which will be exchanged between three identical spacecraft forming a giant (almost) equilateral triangle of side $5 \\times 10^6$ kilometres. The plane of the triangle will make an angle of $\\sim 60^{\\circ}$ with the plane of the ecliptic. The spacecraft constituting LISA will be freely floating in the ambient gravitational field of the Sun and other celestial bodies. To achieve the requisite sensitivity, the spacecraft formation should remain stable, one requirement being, the distances between spacecraft should remain as constant as possible - that is the flexing of the arms should be minimal. In this paper we present a solution - the projectile solution - which constrains the flexing of the arms to below 5.5 metres/sec in a three year mission period. This solution is obtained in the field of the Sun and Earth only, which...

  7. Impact Behaviour of Soft Body Projectiles

    Science.gov (United States)

    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.

  8. Non-q sup 2 scaling of the ionization cross section near the binary peak

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.E.; Reinhold, C.O.; Schultz, D.R. (Missouri Univ., Rolla, MO (USA). Dept. of Physics)

    1990-08-28

    Cross sections differential in both the ionized electron energy and angle have been calculated using the classical trajectory Monte Carlo method to investigate the binary peak structure in collisions of 1.4 MeV u{sup -1} U{sup q+} ions with Ar for charge states 11 {le}q''<=92. To simulate the effects of the varying screening of the nuclear charge, model potentials have been utilized. At an ejection angle of zero degrees, the magnitude of the binary peak is found to rise at first with increasing projectile charge and then drop. The rise is due to the diminished screening of the projectile nuclear charge with increasing projectile charge state. The drop is ascribed to the influence of the varying screened projectile charge giving rise to a rapidly changing cross section at small angles. In fact, it is found that at 0{sup 0} the binary peak is 10 times larger for the partially stripped U{sup 32+} ion than for the fully stripped U{sup 92+} ion. (author).

  9. A Mass Loss Penetration Model to Investigate the Dynamic Response of a Projectile Penetrating Concrete considering Mass Abrasion

    OpenAIRE

    NianSong Zhang; Dong; Wang; Bei Peng; Yong He

    2015-01-01

    A study on the dynamic response of a projectile penetrating concrete is conducted. The evolutional process of projectile mass loss and the effect of mass loss on penetration resistance are investigated using theoretical methods. A projectile penetration model considering projectile mass loss is established in three stages, namely, cratering phase, mass loss penetration phase, and remainder rigid projectile penetration phase.

  10. Analysis of the Fragmentation of AlON and Spinel Under Ballistic Impact

    Science.gov (United States)

    2013-05-01

    Tests were conducted with each material at both impact veloc- ities, which were fully instrumented for high-speed photography. Three types of cameras...the projectile target interac- tion, crack propagation, and the onset of the ejection of fragments were visualized with an ultra-high-speed Shimadzu HPV

  11. Exploring the Birth of Binary Stars

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    More than half of all stars are thought to be in binary or multiple star systems. But how do these systems form? The misaligned spins of some binary protostars might provide a clue.Two Formation ModelsIts hard to tell how multiple-star systems form, since these systems are difficult to observe in their early stages. But based on numerical simulations, there are two proposed models for the formation of stellar binaries:Turbulent fragmentationTurbulence within a single core leads to multiple dense clumps. These clumps independently collapse to form stars that orbit each other.Disk fragmentationGravitational instabilities in a massive accretion disk cause the formation of a smaller, secondary disk within the first, resulting in two stars that orbit each other.Log column density for one of the authors simulated binary systems, just after the formation of two protostars. Diamonds indicate the protostar positions. [Adapted from Offner et al. 2016]Outflows as CluesHow can we differentiate between these formation mechanisms? Led by Stella Offner (University of Massachusetts), a team of scientists has suggested that the key isto examine the alignment of the stars protostellar outflows jets that are often emitted from the poles of young, newly forming stars.Naively, wed expect that disk fragmentation would produce binary stars with common angular momentum. As the stars spins would be aligned, they would therefore also launch protostellar jets that were aligned with each other. Turbulent fragmentation, on the other hand, would cause the stars to have independent angular momentum. This would lead to randomly oriented spins, so the protostellar jets would be misaligned.Snapshots from the authors simulations. Left panel of each pair: column density; green arrows giveprotostellar spin directions. Right panel: synthetic observations produced from the simulations; cyan arrows giveprotostellar outflow directions. [Offner et al. 2016]Simulations of FragmentationIn order to better

  12. Elastic recovery in targets impacted by low-velocity projectiles*%信息动态

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    By taking into account the whole plastic deformation and elastic deformation recovery of targets during the penetration of the rigid, sharp-nose projectiles, the ANSYS/LS-DYNA code was used to calculate the rebound velocities of the projectiles and targets in the cases that the projectiles at the same velocities penetrated into the targets with different widths and thicknesses. Influences of the sizes of the targets and the impact velocities of the projectiles on the elastic recovery of the targets and the rebound of the projectiles were analyzed. The researched results are helpful for the engineering and experimental designs of the projectiles with low velocities penetrating into the targets.

  13. Effects of projectile track charging on the H - secondary ion velocity distribution

    Science.gov (United States)

    Iza, P.; Farenzena, L. S.; da Silveira, E. F.

    2007-03-01

    The bombardment of insulating targets by MeV projectiles produces a positive track delivering secondary electrons to the solid. These electrons are eventually captured by adsorbed hydrogen-containing molecules, inducing fragmentation and initiating the H- secondary ion emission. The dynamics of this process is very sensitive to the track electric field and depends on the emission site and on the H- initial velocity. In this work, a model, based on a time-depending track potential followed by secondary electron induced desorption - SEID, is employed to describe the production and dynamics of H- secondary ion emission. It is shown that depending on how fast the track neutralization occurs, the movement of H- ions may be accelerated, decelerated or even aborted. Trajectories, angular distributions and energy distributions are predicted and compared with experimental data obtained for water ice bombarded by 1.7 MeV nitrogen ions.

  14. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary...... effectivity rule is regular if it is the effectivity rule of some regular binary SCR. We characterize completely the family of regular binary effectivity rules. Quite surprisingly, intrinsically defined von Neumann-Morgenstern solutions play an important role in this characterization...

  15. Set Down Study of Projectile in Flight Through Imaging

    Directory of Open Access Journals (Sweden)

    Suman Kumar Choudhury

    2014-11-01

    Full Text Available Deformation study of projectile immediately after firing is essential for its successful impact. A projectile that undergoes more than the tolerated amount of deformation in the barrel may not produce the requisite results. The study of projectile deformation before its impact requires it to be imaged in flight and perform some computation on the acquired image. Often the deformation tolerance is of the order of tens of micrometer and the acquired image cannot produce image with such accuracy because of photographic limitations. Therefore, it demands sub-pixel manipulation of the captured projectile image. In this work the diameter of a projectile is estimated from its image which became blur because of slow shutter speed. First the blurred image is restored and then various interpolation methods are used for sub-pixel measurement. Two adaptive geometrical texture based interpolation schemes are also proposed in this research. The proposed methods produce very good results as compared to the existing methods.Science Journal, Vol. 64, No. 6, November 2014, pp.530-535, DOI:http://dx.doi.org/10.14429/dsj.64.8114

  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

    Energy Technology Data Exchange (ETDEWEB)

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

    Energy Technology Data Exchange (ETDEWEB)

    Madani, Houria [Univ. of Maryland, College Park, MD (United States)

    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.

  18. Massive gaseous discs around SMBH binaries: Binary decay and tidal disruptions

    Directory of Open Access Journals (Sweden)

    Brem P.

    2012-12-01

    Full Text Available We investigate the evolution of black hole binaries embedded within geometrically thin gas discs. Our results imply that such discs can produce black hole mergers for relatively low-mass binaries, and that a significant population of eccentric binaries might exist at separations of a few 0.01 pc. These binaries may be detectable due to the time-variable accretion on to the black holes. If the disc fragments, then the newly-born stars will continue driving the binary to its coalescence, although at a slower rate. Interestingly, our preliminary analysis shows that these stars will be disrupted at a rate of ∼10−4–2 · 10−5 events per year per system.

  19. Study of Trajectory of Spin-Stabilised Artillery Projectiles

    Directory of Open Access Journals (Sweden)

    M. Krishnamurthy

    1991-10-01

    Full Text Available Equations of motion for conventional spin-stabilised artillery projectile have been derived using a pseudo-stability axes system in addition to body-fixed and space-fixed axes systems. The aerodynamic forces and moments have been represented by their respective coefficients and the effects of Mach number and Reynolds number have been suitably accounted. The magnus terms which are significant at high rates of spin are estimated using a simple model. The set of equations have been partly linearised and solved numerically for a typical projectile using NAG system routines. Various trajectory parameters are computed and compared with the range-table data for the projectile. A parametric study had been carried out varying the aerodynamic coefficients to understand the sensitivity of the results obtained.

  20. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    CERN Document Server

    Wee, Loo Kang; Goh, Giam Hwee; Tan, Samuel; Lee, Tat Leong

    2012-01-01

    This paper reports the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When computer model building learning processes is supported and driven by video analysis data, this free Open Source Physics (OSP) tool can provide opportunities for students to engage in active inquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions of projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modeling with traditional video analysis could be an innovative and effective way to learn projectile motion.

  1. Breakup reaction models for two- and three-cluster projectiles

    CERN Document Server

    Baye, D

    2010-01-01

    Breakup reactions are one of the main tools for the study of exotic nuclei, and in particular of their continuum. In order to get valuable information from measurements, a precise reaction model coupled to a fair description of the projectile is needed. We assume that the projectile initially possesses a cluster structure, which is revealed by the dissociation process. This structure is described by a few-body Hamiltonian involving effective forces between the clusters. Within this assumption, we review various reaction models. In semiclassical models, the projectile-target relative motion is described by a classical trajectory and the reaction properties are deduced by solving a time-dependent Schroedinger equation. We then describe the principle and variants of the eikonal approximation: the dynamical eikonal approximation, the standard eikonal approximation, and a corrected version avoiding Coulomb divergence. Finally, we present the continuum-discretized coupled-channel method (CDCC), in which the Schroed...

  2. In situ characterization of projectile penetration into sand targets

    Science.gov (United States)

    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.

  3. Oblique perforation of thick metallic plates by rigid projectiles

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Chen; Qingming Li; Saucheong Fan

    2006-01-01

    Oblique perforation of thick metallic plates by rigid Drojectiles with various nose shapes is studied in this paper.Two perforation mechanisms,i.e., the hole enlargement for a sharp projectile nose and the plugging formation for a blunt projectile nose,are considered in the proposed analytical model.It is shown that the perforation of a thick plate is dominated by several non-dimensional numbers,i.e., the impact function,the geometry function of projectile,the non-dimensional thickness of target and the impact obliquity.Explicit formulae are obtained to predict the ballistic limit.residual velocity and directional change for the oblique perforation of thick metallic plates.The proposed model is able to predict the critical condition for the occurrence of ricochet.The proposed model is validated by comparing the predictions with other existing models and independent experimental data.

  4. The traumatic potential of a projectile shot from a sling.

    Science.gov (United States)

    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.

  5. A Simple General Solution for Maximal Horizontal Range of Projectile Motion

    CERN Document Server

    Busic, B

    2005-01-01

    A convenient change of variables in the problem of maximizing the horizontal range of the projectile motion, with an arbitrary initial vertical position of the projectile, provides a simple, straightforward solution.

  6. Saturation Effect of Projectile Excitation in Ion-Atom Collisions

    Science.gov (United States)

    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.

  7. PERFORATION OF PLASTIC SPHERICAL SHELLS UNDER IMPACT BY CYLINDRICAL PROJECTILES

    Institute of Scientific and Technical Information of China (English)

    NING Jian-guo; SONG Wei-dong

    2006-01-01

    The objective is to study the perforation of a plastic spherical shell impacted by a cylindrical projectile. First, the deformation modes of the shell were given by introducing an isometric transformation. Then, the perforation mechanism of the shell was analyzed and an analytical model was advanced. Based on Hamilton principle, the governing equation was obtained and solved using Runge-Kuta method. Finally, some important theoretical predictions were given to describe the perforation mechanism of the shell. The results will play an important role in understanding the perforation mechanism of spherical shells impacted by a projectile.

  8. Dispersion Analysis of the XM881APFSDS Projectile

    Directory of Open Access Journals (Sweden)

    Thomas F. Erline

    2001-01-01

    Full Text Available This study compares the results of a dispersion test with mathematical modeling. A 10-round group of modified 25-mm XM881 Armor Piercing Fin Stabilized Discarding Sabot projectiles was fired from the M242 chain gun into a designated target. The mathematical modeling results come from BALANS, a product of Arrow Tech Associates. BALANS is a finite-element lumped parameter code that has the capability to model a flexible projectile being fired from a flexible gun. It also has the unique feature of an automated statistical evaluation of dispersion. This study represents an effort to evaluate a simulation approach with experiment.

  9. Optimization of Construction of the rocket-assisted projectile

    Directory of Open Access Journals (Sweden)

    Arkhipov Vladimir

    2017-01-01

    Full Text Available New scheme of the rocket motor of rocket-assisted projectile providing the increase in distance of flight due to controlled and optimal delay time of ignition of the solid-propellant charge of the SRM and increase in reliability of initiation of the SRM by means of the autonomous system of ignition excluding the influence of high pressure gases of the propellant charge in the gun barrel has been considered. Results of the analysis of effectiveness of using of the ignition delay device on motion characteristics of the rocket-assisted projectile has been presented.

  10. Perturbation of Initial Stability of an FSAPDS Projectile

    Directory of Open Access Journals (Sweden)

    R. S. Acharya

    2006-11-01

    Full Text Available For a spinning projectile, the initial stability condition is 2 = 1+ (4 K3 / K22 > 0. In the presentstudy, this condition has been modified for the malalignments arising due to pressure gradientand damping moment for an FSAPDS projectile. The equations of motion are established for thefirst phase of motion. A mathematical model for the first phase of motion has been developed.The effect of perturbation on the trajectory and stability of motion are discussed. It is provedthat if 3 K(a parameter appearing due to perturbation(-K22 2 /4 , the initial stability ofmotion will breakdown.

  11. Intermediate Mass Fragment Emission Pattern in Peripheral Heavy-Ion Collisions at Fermi Energies

    Science.gov (United States)

    Piantelli, S.; Bidini, L.; Poggi, G.; Bini, M.; Casini, G.; Maurenzig, P. R.; Olmi, A.; Pasquali, G.; Stefanini, A. A.; Taccetti, N.

    2002-02-01

    The emission pattern in the vperp-vpar plane of intermediate mass fragments with Z = 3-7 (IMF) has been studied in the collision 116Sn+ 93Nb at 29.5A MeV as a function of the total kinetic energy loss of the reaction. This pattern shows that for peripheral reactions most IMF's are emitted at velocities intermediate between those of the projectile- and target-like products. Coulomb trajectory calculations show that these IMF's are produced in the interaction zone in a short time interval at the end of the target-projectile interaction.

  12. Collision induced fragmentation of fast molecular ions in solids and gases. [Review, wake effects, excited states

    Energy Technology Data Exchange (ETDEWEB)

    Gemmell, D S

    1979-01-01

    A brief review is given of recent high resolution measurements on fragments arising from the collision-induced dissociation of fast (MeV) molecular ions. For solid targets, strong wake effects are observed. For gaseous targets, excited electronic states of the projectile ions play an important role. Measurements of this type provide useful information on the charge states of fast ions traversing matter. The experimental techniques show promise as a unique method for determining the geometrical structures of the molecular-ion projectiles. 41 references.

  13. Nuclear energy release from fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Souza, S.R. [Instituto de Física, Universidade Federal do Rio de Janeiro Cidade Universitária, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Tsang, M.B. [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Feng-Shou, E-mail: fszhang@bnu.edu.cn [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000 (China)

    2016-08-15

    It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting {sup 230,232}Th and {sup 235,238}U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for {sup 230,232}Th and {sup 235,238}U are around 0.7–0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

  14. Nuclear energy release from fragmentation

    Science.gov (United States)

    Li, Cheng; Souza, S. R.; Tsang, M. B.; Zhang, Feng-Shou

    2016-08-01

    It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting 230,232Th and 235,238U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for 230,232Th and 235,238U are around 0.7-0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

  15. Element Distribution and Multiplicity of Heavy Fragments

    CERN Multimedia

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  16. BOOM: A Computer-Aided Engineering Tool for Exterior Ballistics of Smart Projectiles

    Science.gov (United States)

    2011-06-01

    run on PC, Unix, or Mac systems. 15. SUBJECT TERMS projectiles, trajectory , aeroballistics, flight mechanics, smart projectiles 16. SECURITY...system model are provided. The procedure for running BOOM is also outlined, with input data files described in the appendices. Example trajectories ...in equation 9, the aerodynamic forces on the projectile are split into standard steady (SA) and Magnus (MA) terms as follows

  17. Fragmentation and Hadronization

    OpenAIRE

    Webber, B. R.

    1999-01-01

    Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation of fragmentation functions, hadronization models, single-particle yields and spectra in Z decay, comparisons between quark and gluon jets, current and target fragmentation in deep inelastic scattering, heavy quark fragmentation, Bose-Einstein correlations and WW fragmentation.

  18. 3D Numerical Simulation of Projectile Penetration into Concrete Target

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Basing on the explicit instantaneous dynamics software MSC-Dytran and the general coupling arithmetic, the process of the projectile penetration into concrete target was simulated with the point-line-surface-body modeling method. Simulation results are in agreement with experimental results. The simulated data could provide design reference for the defense engineering construction and penetrator design.

  19. Apparatus for Teaching Physics: A Versatile Projectile Motion Board.

    Science.gov (United States)

    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)

  20. The Long Decay Model of One-Dimensional Projectile Motion

    Science.gov (United States)

    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…

  1. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    Science.gov (United States)

    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…

  2. Projectile Motion in the "Language" of Orbital Motion

    Science.gov (United States)

    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…

  3. Motion of a projectile in a rotating earth

    Directory of Open Access Journals (Sweden)

    B. K. Banerjee

    1957-10-01

    Full Text Available Semi-theoretical expressions for the corrections to be included in the Range Tables for rotation of the earth have been deduced and numerical values for 25 pd.., streamlined projectile fired with super charge have been calculated. The expressions are in good agreement with similar attempts by other workers.

  4. High performance projectile seal development for non perfect railgun bores

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, T.R.; Vine, F.E. Le; Riedy, P.E.; Panlasigui, A. [Maxwell Labs., Inc., San Diego, CA (United States); Hawke, R.S.; Susoeff, A.R. [Lawrence Livermore National Lab., CA (United States)

    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.

  5. Projectile General Motion in a Vacuum and a Spreadsheet Simulation

    Science.gov (United States)

    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…

  6. Shedding Phenomenon of Ventilated Partial Cavitation around an Underwater Projectile

    Institute of Scientific and Technical Information of China (English)

    WANG Yi-Wei; HUANG Chen-Guang; DU Te-Zhuan; WU Xian-Qian; FANG Xin; LIANG Nai-Gang; WEI Yan-Peng

    2012-01-01

    A new shedding phenomenon of ventilated partial cavitations is observed around an axisymmetric projectile in a horizontal launching experiment. The experiment system is established based on SHPB launching and high speed photography. A numerical simulation is carried out based on the homogeneous mixture approach, and its predicted evolutions of cavities are compared with the experimental results. The cavity breaks off by the interaction between the gas injection and the re-entry jet at the middle location of the projectile, which is obviously different from natural cavitation. The mechanism of cavity breaking and shedding is investigated, and the influences of important factors are also discussed.%A new shedding phenomenon of ventilated partial cavitations is observed around an axisymmetric projectile in a horizontal launching experiment.The experiment system is established based on SHPB launching and high speed photography.A numerical simulation is carried out based on the homogeneous mixture approach,and its predicted evolutions of cavities are compared with the experimental results.The cavity breaks off by the interaction between the gas injection and the re-entry jet at the middle location of the projectile,which is obviously different from natural cavitation.The mechanism of cavity breaking and shedding is investigated,and the influences of important factors are also discussed.

  7. On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts

    Science.gov (United States)

    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…

  8. Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

    Science.gov (United States)

    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…

  9. Flight Performance of a Man Portable Guided Projectile Concept

    Science.gov (United States)

    2014-02-01

    investigating the mechatronics , control, and performance of the maneuver technology (27). 4 3. Aerodynamic Characterization The projectile geometry is...efforts focus on understanding the effects of the transient wing exposure to the airstream on the flight behavior. Additionally, mechatronic design and

  10. Small-angle fragmentation of carbon ions at 0.6 GeV/n: a comparison with models of ion-ion interactions

    Directory of Open Access Journals (Sweden)

    Krutenkova A.P.

    2015-01-01

    Full Text Available 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.

  11. Eigenmodes of decay and discrete fragmentation processes

    CERN Document Server

    Giraud, B G; Giraud, B G; Peschanski, R

    1994-01-01

    Linear rate equations are used to describe the cascading decay of an initial heavy cluster into fragments. This representation is based upon a triangular matrix of transition rates. We expand the state vector of mass multiplicities, which describes the process, into the biorthonormal basis of eigenmodes provided by the triangular matrix. When the transition rates have a scaling property in terms of mass ratios at binary fragmentation vertices, we obtain solvable models with explicit mathematical properties for the eigenmodes. A suitable continuous limit provides an interpolation between the solvable models. It gives a general relationship between the decay products and the elementary transition rates.

  12. Study of Relativistic Nucleus-nucleus Coll.Induced by 16O Projectiles

    CERN Document Server

    2002-01-01

    A double experiment in which two detector systems (Streamer Chamber, Plastic Ball Calorimeter), running concurrently via a beam split (West Area H3, X5), search for quark matter formation in violent collisions of |1|6O or |2|0Ne with target nuclei between |4|0Ca and |2|0|6Pb. The acceleration of |1|6O will be facilitated by a high charge state injector, consisting of an ECR source and an RFQ pre-accelerator, installed by GSI and LBL at the PS Linac 1. Experimental equipment will be a streamer chamber installed in the Vertex Magnet of experiment WA75 together with beam hodoscopes and a downstream trigger calorimeter selecting violent events by the absence of energy flow to the projectile fragmentation region. Observed particles will be p, @p, K|0, @L and @L. In addition there will be the Plastic Ball, 800-fold @DE-E particle identifier system, covering the target fragmentation and backward fireball regions. Together with a multisegmented large solid angle (@+~9|0 of beam) energy calorimeter and a trigger calor...

  13. Experimental Research on Behavior of Composite Material Projectile Penetrating Concrete Target

    Institute of Scientific and Technical Information of China (English)

    ZHONG Weizhou; SONG Shuncheng; ZHANG Fangju; ZHANG Qingping; HUANG Xicheng; LI Sizhong; LU Yonggang

    2008-01-01

    Projectile made of carbon fiber composite material shell and metal warhead penetrates concrete target at speeds of 336 m/s, 447 m/s and 517 m/s.The angles between the perpendicular of target surface and projectile axis are 0° and 30° .The thickness of concrete target is 200 mm and the compression strength is 30 MPa.The experimental results indicate that the strength of composite material structure is high.Composite projectile can go through concrete target without fiber segregation and breakage.The percent fill is 18.5% in the composite material projectile.It is about twice as that of metal projectile, if the density of metal is taken as 7.8 g/cm3.Comparing with metal projectile, low-density, high-strength composite material can lessen projectile weight, improve charge-weight ratio of detonator and enhance destructive powder.

  14. Quantum-mechanical calculation of multiple electron removal and fragmentation cross sections in He+-H2O collisions

    Science.gov (United States)

    Murakami, Mitsuko; Kirchner, Tom; Horbatsch, Marko; Lüdde, Hans Jürgen

    2012-08-01

    Electron removal and fragmentation cross sections are calculated for He+(1s)-H2O collisions at impact energies from 20 keV/amu to several MeV/amu by using the nonperturbative basis generator method for ion-molecule collisions. Previous work for proton impact is extended to deal with the dressed projectile in the present case. The effects from the active projectile electron are taken into account by applying the same single-particle Hamiltonian to all electrons and by using the inclusive-probability formalism in the final-state analysis. Fragment-ion yields are evaluated from the single-, double-, and triple-electron removal cross sections, and the results are compared with the available experimental data. Very reasonable agreement is obtained for fragmentation caused by direct ionization, while some discrepancies remain in the capture and loss data.

  15. Application of pulse shape discrimination in Si detector for fission fragment angular distribution measurements

    Indian Academy of Sciences (India)

    B K Nayak; E T Mirgule; R K Choudhury

    2005-12-01

    Pulse shape discrimination (PSD) with totally depleted transmission type Si surface barrier detector in reverse mount has been investigated to identify fission fragments in the presence of elastic background in heavy ion-induced fission reactions by both numerical simulation and experimental studies. The PSD method is compared with the other conventional methods adopted to identify fission fragments with solid-state detectors such as - telescope and single thin detector and the data for the 10B + 232Th fission reaction are presented. Results demonstrate the usefulness of a single transmission-type surface barrier detector for the identification of fission fragments and projectiles like heavy ions.

  16. New neutron-deficient isotopes from 78Kr fragmentation

    Science.gov (United States)

    Blank, B.; Goigoux, T.; Ascher, P.; Gerbaux, M.; Giovinazzo, J.; Grévy, S.; Kurtukian Nieto, T.; Magron, C.; Agramunt, J.; Algora, A.; Guadilla, V.; Montaner-Piza, A.; Morales, A. I.; Orrigo, S. E. A.; Rubio, B.; Ahn, D. S.; Doornenbal, P.; Fukuda, N.; Inabe, N.; Kiss, G.; Kubo, T.; Kubono, S.; Nishimura, S.; Phong, V. H.; Sakurai, H.; Shimizu, Y.; Söderström, P.-A.; Sumikama, T.; Suzuki, H.; Takeda, H.; Wu, J.; Fujita, Y.; Tanaka, M.; Gelletly, W.; Aguilera, P.; Molina, F.; Diel, F.; Lubos, D.; de Angelis, G.; Napoli, D.; Borcea, C.; Boso, A.; Cakirli, R. B.; Ganioglu, E.; Chiba, J.; Nishimura, D.; Oikawa, H.; Takei, Y.; Yagi, S.; Wimmer, K.; de France, G.; Go, S.

    2016-06-01

    In an experiment with the RIKEN projectile fragment separator called BigRIPS at the RIKEN Nishina Center, the fragmentation of a 78Kr beam allowed the observation of new neutron-deficient isotopes at the proton drip line. Clean identification spectra could be produced and 63Se,67Kr, and 68Kr were identified for the first time. In addition, 59Ge was also observed. Three of these isotopes, 59Ge,63Se, and 67Kr, are potential candidates for ground-state two-proton radioactivity. In addition, the isotopes 58Ge,62Se, and 66Kr were also sought but without success. The present experiment also allowed the determination of production cross sections for some of the most exotic isotopes. These measurements confirm the trend already observed that the empirical parametrization of fragmentation cross sections, EPAX, significantly overestimates experimental cross sections in this mass region.

  17. Size Effects in Heavy Ions Fragmentation

    CERN Document Server

    Barrañon, A; Dorso, C O

    2003-01-01

    Rise-Plateau Caloric curves for different Heavy Ion collisions have been obtained, in the range of experimental observations. Limit temperature decreases when the residual size is increased, in agreement with recent theoretical analysis of experimental results reported by other Collaborations. Besides, promptly emitted particles influence on temperature plateau is shown. LATINO binary interaction semiclassical model is used to reproduce the inter-nucleonic forces via Pandharipande Potential and fragments are detected with an Early Cluster Recognition Algorithm.

  18. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  19. Investigation of Nuclear Fragmentation in Relativistic Heavy Ion Collisions Using Plastic - Nuclear - Track Detectors

    CERN Multimedia

    2002-01-01

    In this experiment CR39 plastic nuclear track detectors will be used which are sensitive to detect relativistic nuclear fragments with charges Z@$>$5. They will be analyzed using an automatic track measuring system which was developed at the University of Siegen.\\\\ \\\\ This allows to measure large quantities of tracks in these passive detectors and to perform high statistics experiments. We intend to measure cross sections for the production of nuclear fragments from heavy ion beams at the SPS. \\\\ \\\\ The energy independence of the cross sections predicted by the idea of limiting fragmentation will be tested at high energies. In exposures with different targets we plan to analyze the factorization of the fragmentation cross sections into a target depending factor and a factor depending on the beam particle and the fragment. The cross sections for one proton remov Coulomb dissociation. \\\\ \\\\ We plan to investigate Coulomb dissociation for different targets and different energies. Fragment and projectile charges ...

  20. Magnetic processes in a collapsing dense core. II. Fragmentation. Is there a fragmentation crisis?

    Science.gov (United States)

    Hennebelle, P.; Teyssier, R.

    2008-01-01

    Context: A large fraction of stars are found in binary systems. It is therefore important for our understanding of the star formation process, to investigate the fragmentation of dense molecular cores. Aims: We study the influence of the magnetic field, ideally coupled to the gas, on the fragmentation in multiple systems of collapsing cores. Methods: We present high resolution numerical simulations performed with the RAMSES MHD code starting with a uniform sphere in solid body rotation and a uniform magnetic field parallel to the rotation axis. We pay particular attention to the strength of the magnetic field and interpret the results using the analysis presented in a companion paper. Results: The results depend much on the amplitude, A, of the perturbations seeded initially. For a low amplitude, A=0.1, we find that for values of the mass-to-flux over critical mass-to-flux ratio, μ, as high as μ = 20, the centrifugally supported disk which fragments in the hydrodynamical case is stabilized and remains axisymmetric. Detailed investigations reveal that this is due to the rapid growth of the toroidal magnetic field induced by the differential motions within the disk. For values of μ smaller than ≃5, corresponding to higher magnetic intensities, there is no centrifugally supported disk because of magnetic braking. When the amplitude of the perturbation is equal to A=0.5, each initial peak develops independently and the core fragments for a large range of μ. Only for values of μ close to 1 is the magnetic field able to prevent the fragmentation. Conclusions: Since a large fraction of stars are binaries, the results of low magnetic intensities preventing the fragmentation in the case of weak perturbations is problematic. We discuss three possible mechanisms which could lead to the formation of binary systems, namely the presence of high amplitude fluctuations in the core initially, ambipolar diffusion and fragmentation during the second collapse.

  1. Developmental changes of misconception and misperception of projectiles.

    Science.gov (United States)

    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.

  2. Electron loss of fast projectiles in the collisions with molecules

    CERN Document Server

    Matveev, V I; Rakhimov, Kh Yu

    2011-01-01

    The single and multiple electron loss of fast highly charged projectiles in the collisions with neutral molecules are studied within the framework of a nonperturbative approach. The cross sections for single, double, and triple electron losses are calculated for the collision system $Fe^{q+}\\to N_2$ ($q$=24, 25, 26) at the collision energies 10, 100, and 1000 MeV/u. The effects caused by the collision multiplicity and the orientation of the axis of target molecule are treated. It is shown that 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 effect is negligible.

  3. Two dimensional fractional projectile motion in a resisting medium

    Science.gov (United States)

    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.

  4. Strategies to protect ram accelerator projectiles from in-tube gasdynamic heating

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanoff, D.W. [Eloret, Sunnyvale, CA (United States)

    2000-11-01

    A serious problem in advancing ram accelerator technology is the very high in-tube heat transfer rate to the projectile. Herein, we examine a number of strategies for protecting the projectile from gasdynamic heating. Radiation cooling of the projectile and flying the projectile through alternating regions of fuel-oxidizer-diluent drive gas and pure hydrogen are found to be totally unworkable. The ablative cooling technique has serious problems with a substantial retreat of the projectile surface. A transpiration cooling technique using liquid ammonia is calculated to provide adequate protection of the projectile for ram accelerator missions from 3 to 7 or 8 km/sec. Techniques for flying the projectile in pure hydrogen are also examined. One may have a vortex arrangement with a pure hydrogen core surrounded by a fuel-oxidizer-diluent mixture. The projectile may also fly in pure hydrogen while the driving energy is supplied by a deflagrating or detonating solid coating on the tube wall or by electrical energy input. The techniques for flying the projectile in pure hydrogen are judged to be extremely complex and expensive to implement. The transpiration technique appears to be the most viable way to protect projectiles flying in the 4 - 7 km/sec range. (orig.)

  5. Multiplicative Quaternion Extended Kalman Filtering for Nonspinning Guided Projectiles

    Science.gov (United States)

    2013-07-01

    micro- electromechanical system ( MEMS ) gyroscopes have been able to measure the spin-rates of fin- stabilized projectiles such as mortars, which...model, the statistics of the gyroscope and accelerometer noise are measureable, and can be easily incorporated into an extended Kalman filtering...tradeoff between affordability, durability, and performance. Automotive-grade MEMS components have been used in the harsh gun-launch environment for

  6. Aerodynamic loads on a ball-obturated tubular projectile

    OpenAIRE

    Bry, William Arthur

    1982-01-01

    Approved for public release, distribution unlimited A tubular projectile is one with a hole bored along its longitudinal axis. The hole presents a problem in getting the round expelled from a gun. Some means of sealing the hole until the round clears the muzzle is required. A ball -obturator offers one practical means of accomplishing this without any accompanying FOD hazard. The ball-obturator, analogous to a common ballvalve, remains closed under the force of the expand...

  7. Measuring the Effects of Lift and Drag on Projectile Motion

    Science.gov (United States)

    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.…

  8. Guiding Supersonic Projectiles Using Optically Generated Air Density Channels

    Science.gov (United States)

    2015-03-24

    ideal case, when ( ) (0)T T  , the collapse point of the laser spot goes off to infinity as the pulse power approaches the critical power, i.e. 0.6...laser pulse . We propose changing the laser pulse energy from shot-to-shot to build longer effective channels. We find that current femtosecond lasers...systems with multi-millijoules laser pulses could provide trajectory correction of several meters on 5 km trajectories for sub-kilogram projectiles

  9. Projectile - Mass asymmetry systematics for low energy incomplete fusion

    Directory of Open Access Journals (Sweden)

    Singh Pushpendra P.

    2015-01-01

    Full Text Available 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.

  10. Numerical simulation of multiphase cavitating flows around an underwater projectile

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The present simulation investigates the multiphase cavitating flow around an underwater projectile.Based on the Homogeneous Equilibrium Flow assumption,a mixture model is applied to simulate the multiphase cavitating flow including ventilated cavitation caused by air injection as well as natural cavitation that forms in a region where the pressure of liquid falls below its vapor pressure. The transport equation cavitating model is applied.The calculations are executed based on a suite of CFD code.The hyd...

  11. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    Science.gov (United States)

    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 Cannon-Caliber Electromagnetic Projectile

    Science.gov (United States)

    1993-09-01

    Plasma Armature Railgun." IEEE Transactions on Magnetics, vol. 25, no. 1, pp. 256-261, January 1989. Mongeau, P. P. " Inductively Commutated Coilguns ...of the Army position, unless so designated by other authorized documents. The use of trade names or manufacturers’ names in this report does not...electromagnetic (EM) projectile design is evaluated by adopting finite element procedures similar to those employed in the analysis of kinetic energy

  13. Magnus Force of Common Projectile Bodies with Turbulent Layers

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun

    2005-01-01

    Calculating formulae of Magnus force on common projectile bodies (cone-shaped and parabola-shaped) with turbulent layers were built based on Magnus theory. The effects of temperature exponential were considered, and curve-fitting approaches were adopted in the research that could give more exact result data. Both flow layer constants and shape constants are presented in Magnus force formulae, which are useful to evaluate Magnus force in different states.

  14. A projectile for a rectangular barreled rail gun

    OpenAIRE

    Juanche, Francisco M.

    1999-01-01

    The Physics Department at the Naval Postgraduate School is developing a concept to overcome the problems that keep present rail guns from being practical weapons. The rails must be replaced often if the rail gun operation is to be continuous. Replacing the rails in present rail gun configurations is time consuming. The Physics Department's design concept uses a rectangular barrel as part of the solution to the problem of replacing the rails. The projectile will require flat surfaces to mainta...

  15. Destabilization and intracranial fragmentation of a full metal jacket bullet.

    Science.gov (United States)

    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.

  16. Recent Precision Experiments with Exotic Nuclei Produced with Uranium Projectiles and Experimental Prospects at Fair

    Directory of Open Access Journals (Sweden)

    Geissel H.

    2014-03-01

    Full Text Available Precision experiments with relativistic fragments separated in-flight require special experimentalmethods to overcome the inherent large emittance from the creation in nuclear reactions and atomic interactions in matter. At GSI relativistic exotic nuclei have been produced via uranium projectile fragmentation and fission and investigated with the inflight separator FRS directly, or in combination with either the storage-cooler ring ESR or the FRS Ion Catcher. 1000 A·MeV 238U ions were used to create 60 new neutron-rich isotopes separated and identified with the FRS to measure their production cross sections. In another experimental campaign the fragments were separated in flight and injected into the storage-cooler ring ESR for accurate mass and lifetime measurements. In these experimentswe have obtained accurate new mass values analyzed via a novel method which has reduced the systematic errors for both Schottky Mass Spectrometry (SMS and for Isochronous Mass Spectrometry (IMS. Pioneering experiments have been carried out with the FRS Ion Catcher consisting of three experimental components, the dispersive magnetic system of the FRS with a monoenergetic and a homogeneous degrader, a cryogenic stopping cell filled with pure helium and a multiple-reflection time-of flight mass separator. The FRS Ion Catcher enables high precision spectroscopy experiments with eV to keV exotic nuclides. Results from these different FRS experiments are presented in this overview together with prospects for the next-generation facility Super-FRS. The novel features of the Super-FRS compared with the present FRS will be discussed in addition.

  17. Binary mask programmable hologram.

    Science.gov (United States)

    Tsang, P W M; Poon, T-C; Zhou, Changhe; Cheung, K W K

    2012-11-19

    We report, for the first time, the concept and generation of a novel Fresnel hologram called the digital binary mask programmable hologram (BMPH). A BMPH is comprised of a static, high resolution binary grating that is overlaid with a lower resolution binary mask. The reconstructed image of the BMPH can be programmed to approximate a target image (including both intensity and depth information) by configuring the pattern of the binary mask with a simple genetic algorithm (SGA). As the low resolution binary mask can be realized with less stringent display technology, our method enables the development of simple and economical holographic video display.

  18. Initiation of Detonation in Explosives by Impact of Projectiles

    Directory of Open Access Journals (Sweden)

    H.S. Yadav

    2006-04-01

    Full Text Available This paper presents a study of initiation of detonation in explosives by the impact ofprojectiles. The shock wave produced by the impact of projectiles has been considered as thestimulus for initiation of detonation. Three types of projectiles, namely (i flyer plate, (ii flatendedrod, and (iii round-ended rod or a shaped charge jet, have been considered to impact andproduce a shock wave in the explosives. Deriving relations for the parameters of impact-generatedshock wave in the explosives and projectiles, and the sound velocity in the compressed explosives,it has been shown that the difference of kinetic energy of the flyer plate before and after theimpact, which is equal to the total energy of the shock wave in the explosives, leads to criticalenergy criterion for shock initiation of explosives. In this study, the critical criterion has beenused to derive the relations for initiation of explosives by a shaped charge jet, Vj2 D = K0 , whereV j and D denote the velocity and diameter of the jet, and K0 is a constant of the explosive.

  19. Fragment Identification and Statistics Method of Hypervelocity Impact SPH Simulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaotian; JIA Guanghui; HUANG Hai

    2011-01-01

    A comprehensive treatment to the fragment identification and statistics for the smoothed particle hydrodynamics (SPH) simulation of hypervelocity impact is presented.Based on SPH method, combined with finite element method (FEM), the computation is performed.The fragments are identified by a new pre- and post-processing algorithm and then converted into a binary graph.The number of fragments and the attached SPH particles are determined by counting the quantity of connected domains on the binary graph.The size, velocity vector and mass of each fragment are calculated by the particles' summation and weighted average.The dependence of this method on finite element edge length and simulation terminal time is discussed.An example of tungsten rods impacting steel plates is given for calibration.The computation results match experiments well and demonstrate the effectiveness of this method.

  20. Binary cluster collision dynamics and minimum energy conformations

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, Francisco [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Germany); Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Rogan, José; Valdivia, J.A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile); Varas, A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Nano-Bio Spectroscopy Group, ETSF Scientific Development Centre, Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Av. Tolosa 72, E-20018 San Sebastián (Spain); Kiwi, Miguel, E-mail: m.kiwi.t@gmail.com [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y Nanotecnología, CEDENNA, Avenida Ecuador 3493, Santiago (Chile)

    2013-10-15

    The collision dynamics of one Ag or Cu atom impinging on a Au{sub 12} cluster is investigated by means of DFT molecular dynamics. Our results show that the experimentally confirmed 2D to 3D transition of Au{sub 12}→Au{sub 13} is mostly preserved by the resulting planar Au{sub 12}Ag and Au{sub 12}Cu minimum energy clusters, which is quite remarkable in view of the excess energy, well larger than the 2D–3D potential barrier height. The process is accompanied by a large s−d hybridization and charge transfer from Au to Ag or Cu. The dynamics of the collision process mainly yields fusion of projectile and target, however scattering and cluster fragmentation also occur for large energies and large impact parameters. While Ag projectiles favor fragmentation, Cu favors scattering due to its smaller mass. The projectile size does not play a major role in favoring the fragmentation or scattering channels. By comparing our collision results with those obtained by an unbiased minimum energy search of 4483 Au{sub 12}Ag and 4483 Au{sub 12}Cu configurations obtained phenomenologically, we find that there is an extra bonus: without increase of computer time collisions yield the planar lower energy structures that are not feasible to obtain using semi-classical potentials. In fact, we conclude that phenomenological potentials do not even provide adequate seeds for the search of global energy minima for planar structures. Since the fabrication of nanoclusters is mainly achieved by synthesis or laser ablation, the set of local minima configurations we provide here, and their distribution as a function of energy, are more relevant than the global minimum to analyze experimental results obtained at finite temperatures, and is consistent with the dynamical coexistence of 2D and 3D liquid Au clusters conformations obtained previously.

  1. Electron Capture in Collisions of Slow Highly Charged Ions with an Atom and a Molecule: Processes and Fragmentation Dynamics

    Directory of Open Access Journals (Sweden)

    Xavier Husson

    2002-03-01

    Full Text Available Abstract : Processes involved in slow collisions between highly charged ions (HCI and neutral targets are presented. First, the mechanisms responsible for double electron capture are discussed. We show that, while the electron-nucleus interaction is expected to be dominant at projectile velocities of about 0.5 a.u., the electron-electron interaction plays a decisive role during the collision and gains importance when the projectile velocity decreases. This interaction has also to be invoked in the capture of core electrons by HCI. Finally, the molecular fragmentation of H2 following the impact of HCI is studied.

  2. Strain Measurement for Hollow Projectiles During Its Penetration of Concrete Targets

    Institute of Scientific and Technical Information of China (English)

    王琳; 王富耻; 王鲁; 李树奎

    2004-01-01

    Gives a new technique to measure the dynic deformation behavior and strain development of a hollow steel projectile during its penetration of concrete targets. Direct strain measurement was performed by applying strain gages attached to the inner walls of the hollow projectile, linked with on-board testing and storage recorder. This on-board test-record system is easy to operate, cost-effective and can provide reasonable, accurate and detailed information. Obverse ballistic experiments were carried out on ogival-nose hollow projectiles normally impacting concrete targets at velocities from 150 m/s to 300 m/s. The deformation process of projectiles was measured, recorded and played back. Profiles of voltage-time relationship were successively obtained and transfered to strain-time relationship with the aid of calibration tables. It was found that projectiles go through a series of compression and tension deformations intermittently. Relationships between strain development and projectile deformation process were discussed.

  3. Study of high-speed interaction processes between fluoropolymer projectiles and aluminum-based targets

    Institute of Scientific and Technical Information of China (English)

    Evgeny A. KHMELNIKOV; Alexey V. STYROV; Konstantin V. SMAGIN; Natalia S. KRAVCHENKO; Valery L. RUDENKO; Vladimir I. FALALEEV; Sergey S. SOKOLOV; Artem V. SVIDINSKY; Natalia F. SVIDINSKAYA

    2015-01-01

    The experimental results and numerical modeling of penetration process of fluoropolymer projectiles in aluminum-based targets are pre-sented. Analysis of mathematical models for interaction of elastoplastic projectile and target without taking additional energy released during interaction of fluoropolymer and aluminum into consideration is carried out. Energy fraction which is spent effectively on the increase in cavity volume is determined. The experimental and calculated results of penetration by combined and inert projectiles are compared.

  4. Chemical modification of projectile residues and target material in a MEMIN cratering experiment

    Science.gov (United States)

    Ebert, Matthias; Hecht, Lutz; Deutsch, Alexander; Kenkmann, Thomas

    2013-01-01

    In the context of the MEMIN project, a hypervelocity cratering experiment has been performed using a sphere of the iron meteorite Campo del Cielo as projectile accelerated to 4.56 km s-1, and a block of Seeberger sandstone as target material. The ejecta, collected in a newly designed catcher, are represented by (1) weakly deformed, (2) highly deformed, and (3) highly shocked material. The latter shows shock-metamorphic features such as planar deformation features (PDF) in quartz, formation of diaplectic quartz glass, partial melting of the sandstone, and partially molten projectile, mixed mechanically and chemically with target melt. During mixing of projectile and target melts, the Fe of the projectile is preferentially partitioned into target melt to a greater degree than Ni and Co yielding a Fe/Ni that is generally higher than Fe/Ni in the projectile. This fractionation results from the differing siderophile properties, specifically from differences in reactivity of Fe, Ni, and Co with oxygen during projectile-target interaction. Projectile matter was also detected in shocked quartz grains. The average Fe/Ni of quartz with PDF (about 20) and of silica glasses (about 24) are in contrast to the average sandstone ratio (about 422), but resembles the Fe/Ni-ratio of the projectile (about 14). We briefly discuss possible reasons of projectile melting and vaporization in the experiment, in which the calculated maximum shock pressure does not exceed 55 GPa.

  5. Dynamics of drag and force distributions for projectile impact in a granular medium

    CERN Document Server

    Ciamarra, M P; Lee, A T; Goldman, D I; Swinney, H L; Ciamarra, Massimo Pica; Lara, Antonio H.; Lee, Andrew T.; Goldman, Daniel I.; Swinney, Harry L.

    2003-01-01

    Our experiments and molecular dynamics simulations on a projectile penetrating a two-dimensional granular medium reveal that the mean deceleration of the projectile is constant and proportional to the impact velocity. Thus, the time taken for a projectile to decelerate to a stop is independent of its impact velocity. The simulations show that the probability distribution function of forces on grains is time-independent during a projectile's penetration of the medium. At all times the force distribution function decreases exponentially for large forces.

  6. Multiple ionization of neon induced by Li3+ and C3+ projectiles: influence of projectile screening in the ionization and electron capture channels

    Science.gov (United States)

    Ihani, J. S.; Luna, H.; Wolff, W.; Montenegro, E. C.

    2013-06-01

    Neq + (q = 1,2,3,4) ionization and charge exchange cross sections (total electron capture, single electron capture and transfer ionization) in the collisions with Li3+, with energies between 100 and 900 keV amu-1, and C3+, with energies between 250 and 500 keV amu-1 are reported. Bare Li3+ projectiles give a key benchmark to study the role of projectile screening in collisions involving dressed projectile ions, and the measurements have shown a strong screening effect for all n-fold recoil ion charge states in the ionization channel which, unexpectedly, does not appear for transfer ionization.

  7. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  8. Molecular depth profiling in ice matrices using C{sub 60} projectiles

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-06-15

    The prospects of molecular sputter depth profiling using C{sub 60}{sup +} 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{sup +} ion source and a newly developed fullerene ion source. The C{sub 60}{sup +} 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{sub 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{sub 60} ions, until at a total ion fluence of about 10{sup 13} cm{sup -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{sup -14} cm{sup 2}, until at total fluences of about 10{sup 14} cm{sup -2} a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga{sup +} ions were used to erode the surface.

  9. Fracture of the humerus caused by a slingshot projectile

    Directory of Open Access Journals (Sweden)

    Dar Tahir Ahmed

    2012-02-01

    Full Text Available 【Abstract】Unconventional and 憂on-lethal?weapons are being used in crowd control regularly nowadays. The use of these arms is not risk-free. The paramilitary forces in 2010 used the old fashioned slingshots for crowd control in Kashmir. A young male suffered from a fracture of the distal humerus due to a marble from a slingshot. He was managed by debridement and plaster splintage. Use of apparently innocuous weapons for crowd control is not without risk, as the projectiles fired from them can achieve high velocities and cause significant damage. Kew words: Humeral fractures; Conducted energy weapon injuries; Firearms

  10. Analysis of vertical projectile penetration in granular soils

    Science.gov (United States)

    Boguslavskii, Yu; Drabkin, S.; Salman, A.

    1996-03-01

    A model of vertical dynamic penetration of projectiles in granular soils was developed based on known experiments and the theory of dimensions. The depth of penetration is derived as a function of initial velocity and material properties. Velocity and acceleration are obtained as functions of time and depth of penetration. Under certain conditions two acceleration peaks are observed, an initial one due to dynamic and a second one due to static characteristics of penetration. Static properties of soils are derived using dynamic measurements. Numerical examples are provided. Theoretical and experimental results coincide reasonably well.

  11. Comment on ‘Wind-influenced projectile motion’

    Science.gov (United States)

    Winther Andersen, Poul

    2015-11-01

    We comment on the article ‘Wind-influenced projectile motion’ by Bernardo et al (2015 Eur. J. Phys. 36 025016) where they examine the trajectory of a particle that is subjected to gravity and a linear air resistance plus the influence from the wind. They find by using the Lambert W function that the particle's trajectory for a special angle, the critical angle {θ }{{C}}, between the initial velocity and the horizontal is part of a straight line. In this comment we will show that this result can be proved without using the Lambert W function which is not that well known to beginning students of physics.

  12. Aerodynamic Jump: A Short Range View for Long Rod Projectiles

    OpenAIRE

    Mark Bundy

    2001-01-01

    It is shown that aerodynamic jump for a nonspinning kinetic energy penetrator is not – as conventional definitions may infer – a discontinuous change in the direction of motion at the origin of free flight, nor is it the converse, a cumulative redirection over a domain of infinite extent. Rather, with the aid of an alternative kinematical definition, it is shown that aerodynamic jump for such a projectile is a localized redirection of the center-of-gravity motion, caused by the force of lift ...

  13. Fracture of the humerus caused by a slingshot projectile

    Institute of Scientific and Technical Information of China (English)

    Tahir Ahmed Dar; Riyaz Ahmed Dar; Mubashir Rashid; Shabir Ahmed Dhar

    2011-01-01

    Unconventional and 'non-lethal' weapons are being used in crowd control regularly nowadays. The use of these arms is not risk-free. The paramilitary forces in 2010 used the old fashioned slingshots for crowd control in Kashmir. A young male suffered from a fracture of the distal humerus due to a marble from a slingshot. He was managed by debridement and plaster splintage. Use of apparently innocuous weapons for crowd control is not without risk, as the projectiles fired from them can achieve high velocities and cause significant damage.

  14. Development of Subcaliber Projectiles for the Hispano-Suiza Gun

    Science.gov (United States)

    1943-11-01

    SUBOALIBER PRO JECTILES FOR THE HISPANO- SUIZA GUN 𔃺TECMEPUC-lT, TJ 0 ABERDEEN P 𔃺i7 CiiTDM. ST~lU-TL A T, 1?7,, by CTa * UG r C. L. Critchfield I P I, 2...FOR THE HISPANO- SUIZA GUN by C. L. Critchfield and J. McG. Millar TECiN•IcAr LITPP.py ABERDE " , :PT’- , Approved on November 12, 1943 for submission...Hispano- Suiza gun ....... 6 2. 20-ram sabot-projectiles of Series B and C ......... ... 12 3. Type C2 at h ft from the muzzle . .......... . 13 h. The 20

  15. Response of composite laminates on impact of high velocity projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Siva Kumar, K.; Balakrishna Bhat, T. [Defence Metallurgical Research Lab., Hyderabad (India)

    1998-05-01

    Past work on damage of composites subjected to low velocity and hypervelocity impact has been briefly reviewed and some new results on the glass fibre reinforced plastic composite laminates impacted with high velocity projectiles are presented. The effect of thickness of the laminates and the angle of attack on the energy absorption by the composite laminates and the area of damage caused by impact are described. A correlation is made between the energy absorption and the area of damage. Also described is a new method called infiltration radiography useful for assessing the damage in laminated composites upon ballistic impact. (orig.) 28 refs.

  16. Secondary lead poisoning a projectile housed in the human body

    Directory of Open Access Journals (Sweden)

    Juan Bernardo Gerstner Garcés

    2012-09-01

    Full Text Available 72 1024x768 Normal 0 21 false false false ES X-NONE X-NONE With the increase of violence and use of firearms in Colombia, we may see more cases of lead poisoning in our environment, and must be prepared to diagnose and treat them. Subtle signs and symptoms as unexplained anemia, gastro-intestinal discomfort and abdominal cramps, and severe as changes in behavior and neurological status, nephropathy, and unexplained death, may be associated with a history of gunshot wounds and projectiles in the human body, and must offer the patient knowledge and management strategies of pathology.

  17. Increasing Student Engagement and Enthusiasm: A Projectile Motion Crime Scene

    Science.gov (United States)

    Bonner, David

    2010-05-01

    Connecting physics concepts with real-world events allows students to establish a strong conceptual foundation. When such events are particularly interesting to students, it can greatly impact their engagement and enthusiasm in an activity. Activities that involve studying real-world events of high interest can provide students a long-lasting understanding and positive memorable experiences, both of which heighten the learning experiences of those students. One such activity, described in depth in this paper, utilizes a murder mystery and crime scene investigation as an application of basic projectile motion.

  18. Coulomb effects in low-energy nuclear fragmentation

    Science.gov (United States)

    Wilson, John W.; Chun, Sang Y.; Badavi, Francis F.; John, Sarah

    1993-01-01

    Early versions of the Langley nuclear fragmentation code NUCFRAG (and a publicly released version called HZEFRG1) assumed straight-line trajectories throughout the interaction. As a consequence, NUCFRAG and HZEFRG1 give unrealistic cross sections for large mass removal from the projectile and target at low energies. A correction for the distortion of the trajectory by the nuclear Coulomb fields is used to derive fragmentation cross sections. A simple energy-loss term is applied to estimate the energy downshifts that greatly alter the Coulomb trajectory at low energy. The results, which are far more realistic than prior versions of the code, should provide the data base for future transport calculations. The systematic behavior of charge-removal cross sections compares favorably with results from low-energy experiments.

  19. First experimental results of a cryogenic stopping cell with short-lived, heavy uranium fragments produced at 1000 MeV/u

    NARCIS (Netherlands)

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

    2013-01-01

    A cryogenic stopping cell (CSC) has been commissioned with U-238 projectile fragments produced at 1000 MeV/u. The spatial isotopic separation in flight was performed with the FRS applying a monoenergetic degrader. For the first time, a stopping cell was operated with exotic nuclei at cryogenic tempe

  20. Tracing a phase transition with fluctuations of the largest fragment size: Statistical multifragmentation models and the ALADIN S254 data

    CERN Document Server

    Pietrzak, T; Aumann, T; Bacri, C O; Barczyk, T; Bassini, R; Bianchin, S; Boiano, C; Botvina, A S; Boudard, A; Brzychczyk, J; Chbihi, A; Cibor, J; Czech, B; De Napoli, M; Ducret, J -E; Emling, H; Frankland, J D; Hellstrom, M; Henzlova, D; Imme, G; Iori, I; Johansson, H; Kezzar, K; Lafriakh, A; Le Fèvre, A; Gentil, E Le; Leifels, Y; Luhning, J; Lukasik, J; Lynch, W G; Lynen, U; Majka, Z; Mocko, M; Muller, W F J; Mykulyak, A; Orth, H; Otte, A N; Palit, R; Pawlowski, P; Pullia, A; Raciti, G; Rapisarda, E; Sann, H; Schwarz, C; Sfienti, C; Simon, H; Summerer, K; Trautmann, W; Tsang, M B; Verde, G; Volant, C; Wallace, M; Weick, H; Wiechula, J; Wieloch, A; Zwieglinski, B

    2010-01-01

    A phase transition signature associated with cumulants of the largest fragment size distribution has been identified in statistical multifragmentation models and examined in analysis of the ALADIN S254 data on fragmentation of neutron-poor and neutron-rich projectiles. Characteristics of the transition point indicated by this signature are weakly dependent on the A/Z ratio of the fragmenting spectator source. In particular, chemical freeze-out temperatures are estimated within the range 5.9 to 6.5 MeV. The experimental results are well reproduced by the SMM model.

  1. Isomeric states in neutron-deficient A~80-90 nuclei populated in the fragmentation of Ag107

    OpenAIRE

    Garnsworthy, A.B.; Cáceres, Lucía; Estévez Aguado, María Esther; Jungclaus, Andrea; Kurtukian Nieto, Teresa; Wieland, O.

    2009-01-01

    The relativistic projectile fragmentation of a 750 MeV per nucleon beam of Ag107 was used to populate isomeric states in neutron-deficient nuclei around A=80-90. Reaction products were separated and unambiguously identified using the GSI FRagment Separator (FRS) and its ancillary detectors. At the final focal plane, the fragments were slowed from relativistic energies by means of an aluminium degrader and implanted in a passive stopper in the center of the high-efficiency, high-granularity St...

  2. Binary colloidal crystals

    NARCIS (Netherlands)

    Christova-Zdravkova, C.G.

    2005-01-01

    Binary crystals are crystals composed of two types of particles having different properties like size, mass density, charge etc. In this thesis several new approaches to make binary crystals of colloidal particles that differ in size, material and charge are reported We found a variety of crystal st

  3. New projectiles: multicharged metal clusters and biopolymers; De nouveaux projectiles, les agregats metalliques et les biopolymeres multicharges

    Energy Technology Data Exchange (ETDEWEB)

    Della-Negra, S.; Gardes, D.; Le Beyec, Y.; Waast, B.

    1991-12-31

    Metal clusters and molecules are the one mean to realize simultaneous impacts of several atoms on a reduced surface({approx}100A). The interaction characteristics is the non-linearity of energy deposition; the perturbation that the cluster produces, is above than the sum of the perturbation induced by its components, taken separately. The purpose of ORION project is to accelerate these new projectiles at ORSAY Tandem. The considered mass range is from 100 Daltons to 100 000 Daltons and energy range from MeV to GeV.

  4. Comment on "The motion of an arbitrarily rotating spherical projectile and its application to ball games"

    DEFF Research Database (Denmark)

    Jensen, Jens Højgaard

    2014-01-01

    are independent of the Reynolds number and proportional to the square of the projectile's velocity. In this paper, by dimensional analysis, the latter assumption is shown to be incorrect for forces dependent on the angular velocity of the projectile, e.g. the lift force....

  5. Semi-theoretical analyses of the concrete plate perforated by a rigid projectile

    Institute of Scientific and Technical Information of China (English)

    Hao Wu; Qin Fang; Ya-Dong Zhang; Zi-Ming Gong

    2012-01-01

    Based on the three-stage perforation model,a semi-theoretical analysis is conducted for the ballistic performances of a rigid kinetic projectile impacting on concrete plates.By introducing the projectile resistance coefficients,dimensionless formulae are proposed for depth of penetration (DOP),perforation limit thickness,ballistic limit velocity,residual velocity and perforation ratio,with the projectile nosed geometries and projectile-target interfacial friction taken into account.Based on the proposed formula for DOP and lots of penetration tests data of normal and high strength concrete targets,a new expression is obtained for target strength parameter.By comparisons between the results of the proposed formulae and existing empirical formulae and large amount of projectile penetration or perforation tests data for monolithic and segmented concrete targets,the validations of the proposed formulae are verified.It is found that the projectile-target interfacial friction can be neglected in the predictions of characteristic ballistic parameters.The dimensionless DOP for low-to-mid speed impacts of non-flat nosed projectiles increases almost linearly with the impact factor by a coefficient of 2/(πS).The anti-perforation ability of the multilayered concrete plates is dependent on both the target plate thickness and the projectile impact velocity.The variation range of the perforation ratio is 1-3.5 for concrete targets.

  6. An Analytic Approach to Projectile Motion in a Linear Resisting Medium

    Science.gov (United States)

    Stewart, Sean M.

    2006-01-01

    The time of flight, range and the angle which maximizes the range of a projectile in a linear resisting medium are expressed in analytic form in terms of the recently defined Lambert W function. From the closed-form solutions a number of results characteristic to the motion of the projectile in a linear resisting medium are analytically confirmed,…

  7. Projectile Motion on an Inclined Misty Surface: I. Capturing and Analysing the Trajectory

    Science.gov (United States)

    Ho, S. Y.; Foong, S. K.; Lim, C. H.; Lim, C. C.; Lin, K.; Kuppan, L.

    2009-01-01

    Projectile motion is usually the first non-uniform two-dimensional motion that students will encounter in a pre-university physics course. In this article, we introduce a novel technique for capturing the trajectory of projectile motion on an inclined Perspex plane. This is achieved by coating the Perspex with a thin layer of fine water droplets…

  8. Solution to Projectile Motion with Quadratic Drag and Graphing the Trajectory in Spreadsheets

    Science.gov (United States)

    Benacka, Jan

    2010-01-01

    This note gives the analytical solution to projectile motion with quadratic drag by decomposing the velocity vector to "x," "y" coordinate directions. The solution is given by definite integrals. First, the impact angle is estimated from above, then the projectile coordinates are computed, and the trajectory is graphed at various launch angles and…

  9. Spreadsheet Application Showing the Proper Elevation Angle, Points of Shot and Impact of a Projectile

    Science.gov (United States)

    Benacka, Jan

    2015-01-01

    This paper provides the formula for the elevation angle at which a projectile has to be fired in a vacuum from a general position to hit a target at a given distance. A spreadsheet application that models the trajectory is presented, and the problem of finding the points of shot and impact of a projectile moving in a vacuum if three points of the…

  10. Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition

    Science.gov (United States)

    2015-09-01

    ARL-TR-7479 ● SEP 2015 US Army Research Laboratory Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition...Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition by John J Ritter and Richard A Beyer Weapons and Materials Research...

  11. Reaction dynamics of {sup 34-38}Mg projectile with carbon target using Glauber model

    Energy Technology Data Exchange (ETDEWEB)

    Shama, Mahesh K., E-mail: maheshphy82@gmail.com [School of Physics and Material Sciences, Thapar University Patiala-147004 (India); Department of Applied Sciences, Chandigarh Engineering College, Landran Mohali-140307 (India); Panda, R. N. [Department of Physics, ITER, Shiksha O Anusandhan University, Bhubaneswar-751030 (India); Sharma, Manoj K. [School of Physics and Material Sciences, Thapar University Patiala-147004 (India); Patra, S. K. [Institute of Physics, Sachivalaya marg Bhubneswar-751005 (India)

    2015-08-28

    We have studied nuclear reaction cross-sections for {sup 34-38}Mg isotopes as projectile with {sup 12}C target at projectile energy 240AMeV using Glauber model with the conjunction of densities from relativistic mean filed formalism. We found good agreement with the available experimental data. The halo status of {sup 37}Mg is also investigated.

  12. Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction

    Science.gov (United States)

    Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.

    2009-01-01

    We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…

  13. Projectile Nose Mass Abrasion of High-Speed Penetration into Concrete

    Directory of Open Access Journals (Sweden)

    Haijun Wu

    2012-01-01

    Full Text Available Based on the dynamic spherical cavity expansion theory of concrete and the analysis of experimental data, a mass abrasion model of projectile considering the hardness of aggregates, the relative strength of target and projectile, and the initial impact velocity is constructed in this paper. Furthermore, the effect of mass abrasion on the penetration depth of projectile and the influence of hardness of aggregates and strength of projectile on penetration depth and mass loss are also analyzed. The results show that, for the ogive-nose projectile with the CRH of 3 and aspect ratio of 7 penetrating the concrete of 35 MPa, the “rigid-body penetration” model is available when the initial impact velocity is lower than 800 m/s. However, when the initial impact velocity is higher than 800 m/s, the “deforming/eroding body penetration” model should be adopted. Through theoretical analysis and numerical calculation, the results indicate that the initial impact velocity is the most important factor of mass abrasion. The hardness of aggregates and the strength of projectile are also significant factors. But relatively speaking, the sensitivity of strength of projectile to mass abrasion is higher, which indicates that the effect of projectile material on mass abrasion is more dramatic than the hardness of aggregates.

  14. Real-time estimation of projectile roll angle using magnetometers: in-lab experimental validation

    Science.gov (United States)

    Changey, S.; Pecheur, E.; Wey, P.; Sommer, E.

    2013-12-01

    The knowledge of the roll angle of a projectile is decisive to apply guidance and control law. For example, the goal of ISL's project GSP (Guided Supersonic Projectile) is to change the flight path of an airdefence projectile in order to correct the aim error due to the target manoeuvres. The originality of the concept is based on pyrotechnical actuators and onboard sensors which control the angular motion of the projectile. First of all, the control of the actuators requires the precise control of the roll angle of the projectile. To estimate the roll angle of the projectile, two magnetometers are embedded in the projectile to measure the projection of the Earth magnetic field along radial axes of the projectiles. Then, an extended Kalman filter (EKF) is used to compute the roll angle estimation. As the rolling frequency of the GSP is about 22 Hz, it was easy to test the navigation algorithm in laboratory. In a previous paper [1], the In-Lab demonstration of this concept showed that the roll angle estimation was possible with an accuracy of about 1◦ . In this paper, the demonstration is extended to high-speed roll rate, up to 1000 Hz. Thus, two magnetometers, a DSP (Digital Signal Processor) and a LED (Light Eminent Diode), are rotated using a pneumatic motor; the DSP runs an EKF and a guidance algorithm to compute the trigger times of the LED. By using a high-speed camera, the accuracy of the method can be observed and improved.

  15. Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction

    Science.gov (United States)

    Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.

    2009-01-01

    We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…

  16. Impact perforation of polymer–metal laminates: Projectile nose shape sensitivity

    National Research Council Canada - National Science Library

    Mohagheghian, I; McShane, G.J; Stronge, W.J

    2016-01-01

    ... into the influence of a polymer coating on the resistance to projectile perforation of a target plate remain relatively limited. It has been shown by Mohagheghian et al., in press that a polymer layer can significantly enhance the impact perforation resistance of a thin metallic plate struck by a blunt-nosed projectile. When placed on the impacted (proximal) fa...

  17. Projectile charge state dependent sputtering of solid surfaces

    CERN Document Server

    Hayderer, G

    2000-01-01

    dependence on the ion kinetic energy. This new type of potential sputtering not only requires electronic excitation of the target material, but also the formation of a collision cascade within the target in order to initiate the sputtering process and has therefore been termed kinetically assisted potential sputtering. In order to study defects induced by potential sputtering on the atomic scale we performed measurements of multiply charged Ar ion irradiated HOPG (highly oriented pyrolitic graphite) samples with scanning tunneling microscopy (STM). The only surface defects found in the STM images are protrusions. The mean diameter of the defects increases with projectile charge state while the height of the protrusions stays roughly the same indicating a possible pre-equilibrium effect of the stopping of slow multiply charged projectiles in HOPG. Total sputter yields for impact of slow singly and multiply charged ions on metal- (Au), oxide- (Al2O3, MgO) and alkali-halide surfaces (LiF) have been measured as a...

  18. Fiber-interferometric detection of gun-launched projectiles

    Science.gov (United States)

    Goodwin, Peter M.; Marshall, Bruce R.; Gustavsen, Richard L.; Lang, John M.; Pacheco, Adam H.; Loomis, Eric N.; Dattelbaum, Dana M.

    2017-01-01

    We are developing a new diagnostic useful for the non-invasive detection of projectile passage in the launch tube of a gas gun. The sensing element consists of one or more turns of single-mode optical fiber that is epoxy-bonded around the external circumference of the launch tube. The hoop strain induced in the launch tube by the passage of the projectile causes a momentary expansion of the fiber loop. This transient change in path length is detected with high sensitivity using a fiber optic-based interferometer developed by the NSTec Special Technologies Laboratory. We have fielded this new diagnostic, along with fiber optic Bragg grating (FBG) strain gauges we previously used for this purpose, on a variety of gas guns used for shock compression studies at Los Alamos and Sandia National Laboratories. We anticipate that, when coupled with a broad-range analog demodulator circuit, the fiber optic interferometer will have improved dynamic range over that of the FBG strain gauge approach. Moreover, in contrast to the FBG strain gauge which is somewhat temperature sensitive, the interferometric approach requires no alignment immediately prior to the experiment and is therefore easier to implement. Both approaches provide early, pre-event signals useful for triggering high-latency diagnostics.

  19. Study on Overall Concept Planning of Terminal Correction Mortar Projectiles

    Institute of Scientific and Technical Information of China (English)

    XU Jin-xiang

    2008-01-01

    The system composition, the operational principle of terminal correction mortar projectiles (TCMP) and the concept planning design of TCMP are researched in this paper. An overall design and aerodynamic configuration layout for TCMP are made in this paper, and its aerodynamic coefficients are calculated by using computational fluid dynamics (CFD) software. Test results of TCMP simulated ballistic projectiles indicate the designed TCMP can satisfy the interior ballistic demand and has a fine flight stability. The drag coefficients identified from the radar velocity-time data are in accord with the CFD computed results. According to the exposure frequency of the ground laser designator, a four-quadrant impulse correction scheme and a high exposure frequency impulse correction scheme are brought. The latter can calculate the target azimuth angle by counting the times of the facula passing through one quadrant. Simulation results also show that the guidance precision of the velocity pursuit is higher than that of the body pursuit, and the detector axis is less circuitous. Researches on the typical trajectory indicate that the terminal impulse correction can improve the hit precision of TCMP remarkably.

  20. A new calibration algorithms of spinning projectile aerodynamic parameters

    Institute of Scientific and Technical Information of China (English)

    CONG Ming-yu; ZHANG Wei; WANG Li-ping

    2005-01-01

    This paperdemonstrates that the application of calibration algorithms of aerodynamic parameters for the trajectory of spinning projectile is successful. First, from the point of view of the trajectory simulation, a general summary of well-known trajectory models is given. A five degrees of freedom (5 DOF) model is developed that can match the projectile motion essentially in the vertex region, and the results obtained by 5 DOF model are in close agreement with those of a more sophisticated 6 DOF model for elevation angles above 45 degrees. Secondly, the calibration algorithms have been developed and are summarized. The methods of calibrating the flight trajectory models are compared, and these methods are shown to be effective in the representative cases. In addition, the method of Mach number calibration (MNC) is presented; some possible areas in MNC for further investigation are indicated together with benefits to be gained. The utilization of MNC schemes not only allow a worthwhile reduction of calibration rounds firing in range and accuracy (R&A) trial and production of firing tables (PFT) test, but also make PFT and fire control data (FCD) more cost effective.

  1. Evidence for a large radius of the 11Be projectile

    Science.gov (United States)

    So, W. Y.; Choi, K. S.; Cheoun, Myung-Ki; Kim, K. S.

    2016-05-01

    We investigate ratios of the elastic scattering cross section to Rutherford cross section, PE, and angular distributions of breakup cross section by using an optical model which exploits various long-range dynamic polarization potentials as well as short-range nuclear bare potentials for the 11Be projectile. From these simultaneous analyses, we extract a large radius of a halo projectile from the experimental data for PE and the angular distribution of the breakup cross section of the 11Be + 64Zn and 11 + 120Sn systems. It results from the fact that a large radius for the long-range nuclear potential is more reasonable for properly explaining these data simultaneously. The extracted reduced interaction radius turns out to be r0=3.18 ˜3.61 fm for 11Be nucleus, which is larger than the conventional value of r0=1.1 ˜1.5 fm used in the standard radius form R =r0A1 /3 . Furthermore, the larger radius as well as the normalization constant N is shown to be important for understanding Coulomb dipole strength distribution.

  2. A projectile-oriented, design study for a cannon-caliber electromagnetic launcher

    Science.gov (United States)

    Zielinski, Alexander E.

    1993-01-01

    In the design of an efficient gun system the terminal performance must be considered in conjunction with the required input energy. Power conversion for EM acceleration can involve an arduous assessment of numerous, complex components. Results for integrating a finned-rod with a solid armature are here presented. An evaluation is conducted for a rod-projectile launched from a 23 mm, round-bore augmented railgun. We evaluate the projectile design by considering launch, flight, and terminal effects. Four capacitor-based pulsed power supply systems are considered for the launcher. The host vehicle weight limit and largest number of projectiles stowed provide guidance in selecting the optimum configuration. System weight is estimated. Simple scaling for power components is provided to further appraise launcher feasibility. Projectile effectiveness is evaluated at the target using a weapons simulation code and a similar-caliber, conventionally launched projectile.

  3. Design and performance of Sandia`s contactless coilgun for 50 mm projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, R.J.; Cnare, E.C.; Cowan, M.; Duggin, B.W.; Lipinski, R.J.; Marder, B.M. [Sandia National Labs., Albuquerque, NM (United States); Douglas, G.M. [Rockwell Power Systems Co., Albuquerque, NM (United States); Shimp, K.J. [EG and G, Inc., Albuquerque, NM (United States)

    1991-12-31

    A multi-stage, contactless coilgun is being designed to demonstrate the applicability of this technology to accelerate nominal 50 mm (2 inch) diameter projectiles to velocities of 3 km/s. Forty stages of this design (Phase 1 coilgun) will provide a testbed for coil designs and system components while accelerating 200 to 400 gram projectiles to 1 km/s. We have successfully qualified the Phase 1 gun by operating 40 stages at half energy (10 kJ stored/stage) accelerating 340 gram, room-temperature, aluminum-armature projectiles to 406 m/s. We expect to accelerate 200 gram projectiles cooled to {minus}196{degrees}C to three times this velocity when operating at full energy. This paper describes the design and performance of the Phase 1 coilgun and includes discussion of coil development, projectile design, capacitor banks, firing system, and integration. 10 refs.

  4. Design and performance of Sandia's contactless coilgun for 50 mm projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, R.J.; Cnare, E.C.; Cowan, M.; Duggin, B.W.; Lipinski, R.J.; Marder, B.M. (Sandia National Labs., Albuquerque, NM (United States)); Douglas, G.M. (Rockwell Power Systems Co., Albuquerque, NM (United States)); Shimp, K.J. (EG and G, Inc., Albuquerque, NM (United States))

    1991-01-01

    A multi-stage, contactless coilgun is being designed to demonstrate the applicability of this technology to accelerate nominal 50 mm (2 inch) diameter projectiles to velocities of 3 km/s. Forty stages of this design (Phase 1 coilgun) will provide a testbed for coil designs and system components while accelerating 200 to 400 gram projectiles to 1 km/s. We have successfully qualified the Phase 1 gun by operating 40 stages at half energy (10 kJ stored/stage) accelerating 340 gram, room-temperature, aluminum-armature projectiles to 406 m/s. We expect to accelerate 200 gram projectiles cooled to {minus}196{degrees}C to three times this velocity when operating at full energy. This paper describes the design and performance of the Phase 1 coilgun and includes discussion of coil development, projectile design, capacitor banks, firing system, and integration. 10 refs.

  5. Instantaneous charge state of Uranium projectiles in fully ionized plasmas from energy loss experiments

    CERN Document Server

    Morales, Roberto; Casas, David

    2016-01-01

    The instantaneous charge state of uranium ions traveling through a fully ionized hydrogen plasma has been theoretically studied and compared with one of the first energy loss experiments in plasmas, carried out at GSI-Darmstadt by Hoffmann \\textit{et al.} in the 90's. For this purpose, two different methods to estimate the instantaneous charge state of the projectile have been employed: (1) rate equations using ionization and recombination cross sections, and (2) equilibrium charge state formulas for plasmas. Also, the equilibrium charge state has been obtained using these ionization and recombination cross sections, and compared with the former equilibrium formulas. The equilibrium charge state of projectiles in plasmas is not always reached, it depends mainly on the projectile velocity and the plasma density. Therefore, a non-equilibrium or an instantaneous description of the projectile charge is necessary. The charge state of projectile ions cannot be measured, except after exiting the target, and experime...

  6. Mathematical Model to Simulate the Trajectory Elements ofan Artillery Projectile Proof Shot

    Directory of Open Access Journals (Sweden)

    K.K. Chand

    2007-01-01

    Full Text Available In external ballistics of a conventional spin-stabilised artillery projectile, there are a numberof trajectory models developed for computing trajectory elements having varying degrees ofcomplexity. The present study attempts to propose a single mathematical model, viz., simplifiedpoint-mass/simple particle trajectory model to simulate the trajectory elements of a typical spin-stabilised flat-head artillery projectile proof shot. Due to difficulties in the projectile shape andsize, and the complicated nature of air resistance, an accurate mathematical prediction of thetrajectory is difficult. To simplify the computations, the governing equations of motion of theprojectile have been simplified and assumed that the projectile is a particle and the only forcesacting on the projectile are drag and gravity. With this model, trajectory elements have beengenerated and compared with experimental results obtained in the field test. The measuringinstrument used in this case is a Doppler radar.

  7. Earliest stone-tipped projectiles from the Ethiopian rift date to >279,000 years ago.

    Science.gov (United States)

    Sahle, Yonatan; Hutchings, W Karl; Braun, David R; Sealy, Judith C; Morgan, Leah E; Negash, Agazi; Atnafu, Balemwal

    2013-01-01

    Projectile weapons (i.e. those delivered from a distance) enhanced prehistoric hunting efficiency by enabling higher impact delivery and hunting of a broader range of animals while reducing confrontations with dangerous prey species. Projectiles therefore provided a significant advantage over thrusting spears. Composite projectile technologies are considered indicative of complex behavior and pivotal to the successful spread of Homo sapiens. Direct evidence for such projectiles is thus far unknown from >80,000 years ago. Data from velocity-dependent microfracture features, diagnostic damage patterns, and artifact shape reported here indicate that pointed stone artifacts from Ethiopia were used as projectile weapons (in the form of hafted javelin tips) as early as >279,000 years ago. In combination with the existing archaeological, fossil and genetic evidence, these data isolate eastern Africa as a source of modern cultures and biology.

  8. Design and performance of Sandia's contactless coilgun for 50 mm projectiles

    Science.gov (United States)

    Kaye, Ronald J.; Cnare, Eugene C.; Cowan, M.; Duggin, Billy W.; Lipinski, Ronald J.; Marder, Barry M.; Douglas, Gary M.; Shimp, Kenneth J.

    1991-10-01

    A multi-stage, contactless coilgun is being designed to demonstrate the applicability of this technology to accelerate nominal 50 mm (2 inch) diameter projectiles to velocities of 3 km/s. Forty stages of this design (Phase 1 coilgun) will provide a testbed for coil designs and system components while accelerating 200 to 400 gram projectiles to 1 km/s. We have successfully qualified the Phase 1 gun by operating 40 stages at half energy (10 kJ stored/stage) accelerating 340 gram, room-temperature, aluminum-armature projectiles to 406 m/s. We expect to accelerate 200 gram projectiles cooled to -196 C to three times this velocity when operating at full energy. This paper describes the design and performance of the Phase 1 coilgun and includes discussion of coil development, projectile design, capacitor banks, firing system, and integration.

  9. Mechanisms in Impact Fragmentation

    OpenAIRE

    Wittel, Falk K.; Carmona, Humberto A.; Kun, Ferenc; Herrmann, Hans J.

    2015-01-01

    The brittle fragmentation of spheres is studied numerically by a 3D Discrete Element Model. Large scale computer simulations are performed with models that consist of agglomerates of many spherical particles, interconnected by beam-truss elements. We focus on a detailed description of the fragmentation process and study several fragmentation mechanisms involved. The evolution of meridional cracks is studied in detail. These cracks are found to initiate in the inside of the specimen with quasi...

  10. DNA fragmentation in apoptosis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cleavage of chromosomal DNA into oligonucleosomal size fragments is an integral part of apoptosis. Elegant biochemical work identified the DNA fragmentation factor (DFF) as a major apoptotic endonuclease for DNA fragmentation in vitro. Genetic studies in mice support the importance of DFF in DNA fragmentation and possibly in apoptosis in vivo. Recent work also suggests the existence of additional endonucleases for DNA degradation. Understanding the roles of individual endonucleases in apoptosis, and how they might coordinate to degrade DNA in different tissues during normal development and homeostasis, as well as in various diseased states, will be a major research focus in the near future.

  11. Finite Element Modeling of Transient Temperatures in a Small-Caliber Projectile

    Directory of Open Access Journals (Sweden)

    M. B. Thomas

    2010-01-01

    Full Text Available Problem statement: Future generations of intelligent munitions will use Microelectromechanical Systems (MEMS for guidance, fuzing logic and assessment of the battlefield environment. The temperatures fund in a gun system, however, are sufficient to damage some materials used in the fabrication of MEMS. The motivation of this study is to model the dynamic temperature distribution in a typical small-caliber projectile. Approach: An axisymmetric finite-element model of a projectile is developed to simulate temperatures through internal ballistics (the projectile is in the gun barrel and external ballistics (the projectile travels in a free trajectory towards the target. Accuracy of the simulation is confirmed through comparison to analytical models and to payloads attached to experimental projectiles. In the simulation, the exact values for some boundary conditions are unknown and/or unknowable. A sensitivity analysis determines the effect of these uncertain parameters. Results: The simulation shows that friction at the projectile-gun barrel interface is primarily responsible for elevated temperatures in a gun system. Other factors have much smaller effects. The short duration of the internal ballistics prevents the frictional heat from diffusing into the bulk of the projectile. As a result, the projectile has a shallow, high-temperature zone at its bearing surface as it leaves the gun barrel. During external ballistics, this heat will diffuse through the projectile, but most of the projectile experiences temperatures of 56°C or lower. Simulation shows that the polymer package around a MEMS device will further attenuate heat flow, limiting temperatures in the device to less than 30°C. Conclusion: The finite element model demonstrates that a MEMS device may be engineered to survive temperatures expected in the ballistic environment.

  12. A Method for Guiding a Salvo of guided Projectiles to a Target, a System and a Computer Program Product

    NARCIS (Netherlands)

    Ruizenaar, M.G.A.

    2011-01-01

    The invention relates to a method of guiding a salvo of guided projectiles to a target. The method comprises the steps of generating a beam defining a common reference coordinate system, determining the position of each projectile relative to the beam, and providing to each projectile: position

  13. Decay analysis of compound nuclei with mass A$\\sim 30-200$ formed in the reactions involving loosely bound projectiles

    CERN Document Server

    Kaur, Mandeep; Sharma, Manoj K; Gupta, Raj K

    2015-01-01

    The dynamics of the reactions forming compound nuclei using loosely bound projectiles is analysed within the framework of dynamical cluster decay model (DCM) of Gupta and Collaborators. We have analysed different reactions with $^{7}Li$, $^{9}Be$ and $^{7}Be$ as neutron rich and neutron deficient projectiles, respectively, on different targets at the three $E_{lab}$ values, forming compound nuclei within the mass region A$\\sim 30-200$. The contributions of light particles LPs ($A\\le4$) cross sections $\\sigma_{LP}$, energetically favoured intermediate mass fragments IMFs ($5 \\le A_2 \\le 20$) cross sections $\\sigma_{IMF}$ as well as fusion-fission $\\it{ff}$ cross sections $\\sigma_{ff}$ constitute the $\\sigma_{fus}$ (=$\\sigma_{LP}$+$\\sigma_{IMF}$+$\\sigma_{ff}$) for these reactions. The contribution of the emitted LPs, IMFs and ff fragments is added for all the angular momentum upto the $\\ell_{max}$ value, for the resepctive reactions. Interestingly, we find that the $\\Delta R^{emp}$, the only parameter of model ...

  14. Binary Formation in Star-Forming Clouds with Various Metallicities

    CERN Document Server

    Machida, Masahiro N

    2008-01-01

    Cloud evolution for various metallicities is investigated by three-dimensional nested grid simulations, in which the initial ratio of rotational to gravitational energy of the host cloud \\beta_0 (=10^-1 - 10^-6) and cloud metallicity Z (=0 - Z_\\odot) are parameters. Starting from a central number density of n = 10^4 cm^-3, cloud evolution for 48 models is calculated until the protostar is formed (n \\simeq 10^23 cm^-3) or fragmentation occurs. The fragmentation condition depends both on the initial rotational energy and cloud metallicity. Cloud rotation promotes fragmentation, while fragmentation tends to be suppressed in clouds with higher metallicity. Fragmentation occurs when \\beta_0 > 10^-3 in clouds with solar metallicity, while fragmentation occurs when \\beta_0 > 10^-5 in the primordial gas cloud. Clouds with lower metallicity have larger probability of fragmentation, which indicates that the binary frequency is a decreasing function of cloud metallicity. Thus, the binary frequency at the early universe ...

  15. The Coincident Fission Fragment Detector (CFFD)

    Science.gov (United States)

    Wakhle, A.; Hammerton, K.; Kohley, Z.; Yurkon, J.; Stiefel, K.

    2017-08-01

    A Parallel Plate Avalanche Counter (PPAC) based fission detector system, called the Coincident Fission Fragment Detector (CFFD), has been developed for the ReA3 re-accelerator facility of the National Superconducting Cyclotron Laboratory (NSCL). Binary reaction kinematics are reconstructed based on position and time-of-flight measurements of fission fragments. Large area PPACs provide 1 ns level time resolution and mm level position resolution. The detectors allow measurements of fission product angular and mass distributions of heavy-ion induced fusion reactions. The 30 cm by 40 cm active area of each PPAC provides large solid angle coverage well suited for measurements of low intensity rare-isotope beams (RIBs).

  16. The role of pebble fragmentation in planetesimal formation I. Experimental study

    CERN Document Server

    Syed, M Bukhari; Jansson, K Wahlberg; Johansen, A

    2016-01-01

    Previous work on protoplanetary dust growth shows halt at centimeter sizes owing to the occurrence of bouncing at velocities of $\\geq$ 0.1 $ms^{-1}$ and fragmentation at velocities $\\geq$ 1 $ms^{-1}$. To overcome these barriers, spatial concentration of cm-sized dust pebbles and subsequent gravitational collapse have been proposed. However, numerical investigations have shown that dust aggregates may undergo fragmentation during the gravitational collapse phase. This fragmentation in turn changes the size distribution of the solids and thus must be taken into account in order to understand the properties of the planetesimals that form. To explore the fate of dust pebbles undergoing fragmenting collisions, we conducted laboratory experiments on dust-aggregate collisions with a focus on establishing a collision model for this stage of planetesimal formation. In our experiments, we analysed collisions of dust aggregates with masses between 1.4 g and 180 g, mass ratios between target and projectile from 125 to 1 ...

  17. Rotation Periods of Binary Asteroids with Large Separations - Confronting the Escaping Ejecta Binaries Model with Observations

    CERN Document Server

    Polishook, D; Prialnik, D

    2010-01-01

    Durda et al. (2004), using numerical models, suggested that binary asteroids with large separation, called Escaping Ejecta Binaries (EEBs), can be created by fragments ejected from a disruptive impact event. It is thought that six binary asteroids recently discovered might be EEBs because of the high separation between their components (~100 > a/Rp > ~20). However, the rotation periods of four out of the six objects measured by our group and others and presented here show that these suspected EEBs have fast rotation rates of 2.5 to 4 hours. Because of the small size of the components of these binary asteroids, linked with this fast spinning, we conclude that the rotational-fission mechanism, which is a result of the thermal YORP effect, is the most likely formation scenario. Moreover, scaling the YORP effect for these objects shows that its timescale is shorter than the estimated ages of the three relevant Hirayama families hosting these binary asteroids. Therefore, only the largest (D~19 km) suspected astero...

  18. Scaling of C{sub 60} ionization and fragmentation with the energy deposited in collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions (2-130 keV)

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, D. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)]. E-mail: dbm@yosemite.ups-tlse.fr; Moretto-Capelle, P.; Bordenave-Montesquieu, A.; Rentenier, A. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)

    2001-03-14

    Fragmentation, ionization and C{sub 2} fragment evaporation of the C{sub 60} molecule induced by collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} monocharged ions have been measured in coincidence with the electron emission in the 2-130 keV projectile energy range. The time-of-flight mass spectra were found to vary strongly with the collision energy or velocity and the projectile. On the other hand, they scale rather nicely with the energy deposited in the molecule. Relative weights of the total multi-fragmentation into small C{sub n}{sup +} fragments (n=1-14), individual multi-fragmentation (n=1,7 and 11), double ionization of the intact molecule and evaporation of C{sub 2} molecules associated with the doubly charged fullerene ion, are used to illustrate our finding quantitatively. (author). Letter-to-the-editor.

  19. Enhancing Binary Images of Non-Binary LDPC Codes

    CERN Document Server

    Bhatia, Aman; Siegel, Paul H

    2011-01-01

    We investigate the reasons behind the superior performance of belief propagation decoding of non-binary LDPC codes over their binary images when the transmission occurs over the binary erasure channel. We show that although decoding over the binary image has lower complexity, it has worse performance owing to its larger number of stopping sets relative to the original non-binary code. We propose a method to find redundant parity-checks of the binary image that eliminate these additional stopping sets, so that we achieve performance comparable to that of the original non-binary LDPC code with lower decoding complexity.

  20. Projectile Two-dimensional Coordinate Measurement Method Based on Optical Fiber Coding Fire and its Coordinate Distribution Probability

    Science.gov (United States)

    Li, Hanshan; Lei, Zhiyong

    2013-01-01

    To improve projectile coordinate measurement precision in fire measurement system, this paper introduces the optical fiber coding fire measurement method and principle, sets up their measurement model, and analyzes coordinate errors by using the differential method. To study the projectile coordinate position distribution, using the mathematical statistics hypothesis method to analyze their distributing law, firing dispersion and probability of projectile shooting the object center were put under study. The results show that exponential distribution testing is relatively reasonable to ensure projectile position distribution on the given significance level. Through experimentation and calculation, the optical fiber coding fire measurement method is scientific and feasible, which can gain accurate projectile coordinate position.

  1. Expert Systems Aimed at General Design of Projectiles

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhi-hua; HOU Ni-na; HU Yu-hui

    2007-01-01

    Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.

  2. Adolescents' cognition of projectile motion: a pilot study.

    Science.gov (United States)

    Zhao, Jun-Yan; Yu, Guoliang

    2009-04-01

    Previous work on the development of intuitive knowledge about projectile motion has shown a dissociation between action knowledge expressed on an action task and conceptual knowledge expressed on a judgment task for young children. The research investigated the generality of dissociation for adolescents. On the action task, participants were asked to swing Ball A of a bifilar pendulum to some height then release it to collide with Ball B, which was projected to hit a target. On the judgment task, participants indicated orally the desired swing angle at which Ball A should be released so that Ball B would strike a target. Unlike previous findings with adults, the adolescents showed conceptual difficulties on the judgment task and well-developed action knowledge on the action task, which suggests dissociation between the two knowledge systems is also present among adolescents. The result further supports the hypothesis that the two knowledge systems follow different developmental trajectories and at different speeds.

  3. Aerodynamic Jump: A Short Range View for Long Rod Projectiles

    Directory of Open Access Journals (Sweden)

    Mark Bundy

    2001-01-01

    Full Text Available It is shown that aerodynamic jump for a nonspinning kinetic energy penetrator is not – as conventional definitions may infer – a discontinuous change in the direction of motion at the origin of free flight, nor is it the converse, a cumulative redirection over a domain of infinite extent. Rather, with the aid of an alternative kinematical definition, it is shown that aerodynamic jump for such a projectile is a localized redirection of the center-of-gravity motion, caused by the force of lift due to yaw over the relatively short region from entry into free flight until the yaw reaches its first maximum. A rigorous proof of this statement is provided, but the primary objective of this paper is to provide answers to the questions: what is aerodynamic jump, what does it mean, and what aspects of the flight trajectory does it refer to, or account for.

  4. Mandibular fracture wounded by a projectile of a firearm

    Directory of Open Access Journals (Sweden)

    Juan Carlos Quintana Díaz

    2015-08-01

    Full Text Available A case of a male Yemenite 20 year-old-patient from Ibb city that was attended by a team of interdisciplinary Cuban professors at the Hospital of Al Waheda belonging to Thamar University, who received a maxillofacial wounded by a projectile of a firearm, which caused him great destruction of the tissues of the jawbone region is presented. A reduction and fixing of the fracture was performed with excellent esthetical and functional results. In this work, it is set out how the life of this patient was saved and the maxillofacial wound was reconstructed, thanks to the arduous work of the Cuban professors that gave the patient back to the society alive, with an excellent esthetical and functional rehabilitation, demonstrating one more time the humanitarian work of the Cuban medicine in other countries. 

  5. Polymer Recovery from Auto Shredder Residue by Projectile Separation Method

    Directory of Open Access Journals (Sweden)

    Dong Yang Wu

    2012-04-01

    Full Text Available The number of vehicles on the road has been increasing at an enormous rate over the last decade. By 2015, the number of vehicles that reach the end of their life will be close to a million per year in Australia. Most metallic parts of the vehicle can be recycled but the plastic components and components of other materials are normally shredded and disposed in landfills. As more vehicles are using composite materials, the percentage of materials sent to landfill is alarming. This paper reviews existing polymer recycling techniques for End-of-Life Vehicles (ELVs and proposes a more efficient electrostatic based projectile separation method. The test rig is at the preliminary stage of development and initial outcomes are promising.

  6. Reaction of Projectiles with Targets during Hypervelocity Impact

    Science.gov (United States)

    Russell, Rod; Bless, Stephan; Persad, Chadee; Manthiram, Karthish

    2009-06-01

    Hollow tungsten projectiles were filled with bismuth oxide or copper and shot into aluminum blocks at 2200 m/s. The blocks were cut open, and the contents and morphology of the penetration channels were examined. In the case of copper fill, the channel was found to be filled with a black foam containing closed-cell bubbles. X-ray diffraction revealed the presence of CuAl2, indicating reaction with the aluminum target. In the case of bismuth oxide, there was little foam, but the penetration channel walls had many craters, which contained nodules of bismuth metal, again indicating reaction with the target. There were variations in crater diameter apparently corresponding to the onset and termination of the reactions. The exothermic nature of the reactions produced cracks in the target blocks.

  7. Kuiper Binary Object Formation

    CERN Document Server

    Nazzario, R C; Covington, C; Kagan, D; Hyde, T W

    2005-01-01

    It has been observed that binary Kuiper Belt Objects (KBOs) exist contrary to theoretical expectations. Their creation presents problems to most current models. However, the inclusion of a third body (for example, one of the outer planets) may provide the conditions necessary for the formation of these objects. The presence of a third massive body not only helps to clear the primordial Kuiper Belt but can also result in long lived binary Kuiper belt objects. The gravitational interaction between the KBOs and the third body causes one of four effects; scattering into the Oort cloud, collisions with the growing protoplanets, formation of binary pairs, or creation of a single Kuiper belt object. Additionally, the initial location of the progenitors of the Kuiper belt objects also has a significant effect on binary formation.

  8. Non-invasive timing of gas gun projectiles with light detection and ranging

    Science.gov (United States)

    Goodwin, P. M.; Bartram, B. D.; Gibson, L. L.; Wu, M.; Dattelbaum, D. M.

    2014-05-01

    We have developed a Light Detection and Ranging (LIDAR) diagnostic to track the position of a projectile inside of a gas gun launch tube in real-time. This capability permits the generation of precisely timed trigger pulses useful for triggering high-latency diagnostics such as a flash lamp-pumped laser. An initial feasibility test was performed using a 72 mm bore diameter single-stage gas gun routinely used for dynamic research at Los Alamos. A 655 nm pulsed diode laser operating at a pulse repetition rate of 100 kHz was used to interrogate the position of the moving projectile in real-time. The position of the projectile in the gun barrel was tracked over a distance of ~ 3 meters prior to impact. The position record showed that the projectile moved at a velocity of 489 m/s prior to impacting the target. This velocity was in good agreement with independent measurements of the projectile velocity by photon Doppler velocimetry and timing of the passage of the projectile through optical marker beams positioned at the muzzle of the gun. The time-to-amplitude conversion electronics used enable the LIDAR data to be processed in real-time to generate trigger pulses at preset separations between the projectile and target.

  9. Study of the projectile impact on aluminum targets divided by water

    Science.gov (United States)

    Saburi, Tei; Kubota, Shiro; Ogata, Yuji; Wada, Yuji; Nakanishi, Toshikazu

    2007-06-01

    The impact behavior of a projectile into aluminum alloy targets divided by water was experimentally observed using high-speed video camera, and a numerical simulation was conducted using LS-DYNA. The target size was 5mm in thick, 200mm in height and width. Two target plates were positioned parallel at a distance of 120-180mm, and the space between targets was filled up with water. A SNCM steel projectile was 10mm in height, and 10mm in diameter. The projectile was accelerated by a compact accelerator using an explosive, and impacted on the first target. Impact experiments without water in the gap space were also conducted. In case without water, the projectile penetrated both two targets. On the other hand, in case that water fills up in the gap, The projectile did not penetrate the second target plate, and the both target plates were entirely and largely deformed compared with the case that water is absent. Numerical simulation of the projectile impact was conducted using a finite element code of LS-DYNA. ALE(Arbitrary Lagrangian Eulerian) method was adopted to simulate fluid-structure interaction problem. The deformation behavior of targets was confirmed by the simulation, and the importance of water effect on the deformation of the targets and the de-acceleration of the projectile velocity was shown.

  10. Techniques for Transition and Surface Temperature Measurements on Projectiles at Hypersonic Velocities- A Status Report

    Science.gov (United States)

    Wilder, M. C.; Bogdanoff, D. W.

    2005-01-01

    A research effort to advance techniques for determining transition location and measuring surface temperatures on graphite-tipped projectiles in hypersonic flight in a ballistic range is described. Projectiles were launched at muzzle velocities of approx. 4.7 km/sec into air at pressures of 190-570 Torr. Most launches had maximum pitch and yaw angles of 2.5-5 degrees at pressures of 380 Torr and above and 3-6 degrees at pressures of 190-380 Torr. Arcjet-ablated and machined, bead-blasted projectiles were launched; special cleaning techniques had to be developed for the latter class of projectiles. Improved methods of using helium to remove the radiating gas cap around the projectiles at the locations where ICCD (intensified charge coupled device) camera images were taken are described. Two ICCD cameras with a wavelength sensitivity range of 480-870 nm have been used in this program for several years to obtain images. In the last year, a third camera, with a wavelength sensitivity range of 1.5-5 microns [in the infrared (IR)], has been added. ICCD and IR camera images of hemisphere nose and 70 degree sphere-cone nose projectiles at velocities of 4.0-4.7 km/sec are presented. The ICCD images clearly show a region of steep temperature rise indicative of transition from laminar to turbulent flow. Preliminary temperature data for the graphite projectile noses are presented.

  11. Evolution of binary seeds in collapsing protostellar gas clouds

    Science.gov (United States)

    Satsuka, Tatsuya; Tsuribe, Toru; Tanaka, Suguru; Nagamine, Kentaro

    2017-02-01

    We perform 3D smoothed particle hydrodynamics (SPH) simulations of gas accretion on to the seeds of binary stars to investigate their short-term evolution. Taking into account the dynamically evolving envelope with non-uniform distribution of gas density and angular momentum of accreting flow, our initial condition includes a seed binary and a surrounding gas envelope, modelling the phase of core collapse of gas cloud when the fragmentation has already occurred. We run multiple simulations with different values of initial mass ratio q0 (the ratio of secondary over primary mass) and gas temperature. For our simulation setup, we find a critical value of qc = 0.25 which distinguishes the later evolution of mass ratio q as a function of time. If q0 ≳ qc, the secondary seed grows faster and q increases monotonically towards unity. If q0 ≲ qc, on the other hand, the primary seed grows faster and q is lower than q0 at the end of the simulation. Based on our numerical results, we analytically calculate the long-term evolution of the seed binary including the growth of binary by gas accretion. We find that the seed binary with q0 ≳ qc evolves towards an equal-mass binary star and that with q0 ≲ qc evolves to a binary with an extreme value of q. Binary separation is a monotonically increasing function of time for any q0, suggesting that the binary growth by accretion does not lead to the formation of close binaries.

  12. Kuiper Binary Object Formation

    OpenAIRE

    Nazzario, R. C.; Orr, K.; Covington, C.; Kagan, D.; Hyde, T. W.

    2005-01-01

    It has been observed that binary Kuiper Belt Objects (KBOs) exist contrary to theoretical expectations. Their creation presents problems to most current models. However, the inclusion of a third body (for example, one of the outer planets) may provide the conditions necessary for the formation of these objects. The presence of a third massive body not only helps to clear the primordial Kuiper Belt but can also result in long lived binary Kuiper belt objects. The gravitational interaction betw...

  13. Binary Masking & Speech Intelligibility

    DEFF Research Database (Denmark)

    Boldt, Jesper

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experime...... mask using a directional system and a method for correcting errors in the target binary mask. The last part of the thesis, proposes a new method for objective evaluation of speech intelligibility....

  14. Eclipsing Binary Pulsars

    CERN Document Server

    Freire, P C C

    2004-01-01

    The first eclipsing binary pulsar, PSR B1957+20, was discovered in 1987. Since then, 13 other eclipsing low-mass binary pulsars have been found, 12 of these are in globular clusters. In this paper we list the known eclipsing binary pulsars and their properties, with special attention to the eclipsing systems in 47 Tuc. We find that there are two fundamentally different groups of eclipsing binary pulsars; separated by their companion masses. The less massive systems (M_c ~ 0.02 M_sun) are a product of predictable stellar evolution in binary pulsars. The systems with more massive companions (M_c ~ 0.2 M_sun) were formed by exchange encounters in globular clusters, and for that reason are exclusive to those environments. This class of systems can be used to learn about the neutron star recycling fraction in the globular clusters actively forming pulsars. We suggest that most of these binary systems are undetectable at radio wavelengths.

  15. String fragmentation; La fragmentation des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Laboratoire de Physique Subatomique et des Technologies Associees - SUBATECH, Centre National de la Recherche Scientifique, 44 - Nantes (France)

    1997-10-01

    The classical string model is used in VENUS as a fragmentation model. For the soft domain simple 2-parton strings were sufficient, whereas for higher energies up to LHC, the perturbative regime of the QCD gives additional soft gluons, which are mapped on the string as so called kinks, energy singularities between the leading partons. The kinky string model is chosen to handle fragmentation of these strings by application of the Lorentz invariant area law. The `kinky strings` model, corresponding to the perturbative gluons coming from pQCD, takes into consideration this effect by treating the partons and gluons on the same footing. The decay law is always the Artru-Menessier area law which is the most realistic since it is invariant to the Lorentz and gauge transformations. For low mass strings a manipulation of the rupture point is necessary if the string corresponds already to an elementary particle determined by the mass and the flavor content. By means of the fragmentation model it will be possible to simulate the data from future experiments at LHC and RHIC 3 refs.

  16. Fragmentation trees reloaded.

    Science.gov (United States)

    Böcker, Sebastian; Dührkop, Kai

    2016-01-01

    Untargeted metabolomics commonly uses liquid chromatography mass spectrometry to measure abundances of metabolites; subsequent tandem mass spectrometry is used to derive information about individual compounds. One of the bottlenecks in this experimental setup is the interpretation of fragmentation spectra to accurately and efficiently identify compounds. Fragmentation trees have become a powerful tool for the interpretation of tandem mass spectrometry data of small molecules. These trees are determined from the data using combinatorial optimization, and aim at explaining the experimental data via fragmentation cascades. Fragmentation tree computation does not require spectral or structural databases. To obtain biochemically meaningful trees, one needs an elaborate optimization function (scoring). We present a new scoring for computing fragmentation trees, transforming the combinatorial optimization into a Maximum A Posteriori estimator. We demonstrate the superiority of the new scoring for two tasks: both for the de novo identification of molecular formulas of unknown compounds, and for searching a database for structurally similar compounds, our method SIRIUS 3, performs significantly better than the previous version of our method, as well as other methods for this task. SIRIUS 3 can be a part of an untargeted metabolomics workflow, allowing researchers to investigate unknowns using automated computational methods.Graphical abstractWe present a new scoring for computing fragmentation trees from tandem mass spectrometry data based on Bayesian statistics. The best scoring fragmentation tree most likely explains the molecular formula of the measured parent ion.

  17. Fragmentation of monoclonal antibodies

    Science.gov (United States)

    Vlasak, Josef

    2011-01-01

    Fragmentation is a degradation pathway ubiquitously observed in proteins despite the remarkable stability of peptide bond; proteins differ only by how much and where cleavage occurs. The goal of this review is to summarize reports regarding the non-enzymatic fragmentation of the peptide backbone of monoclonal antibodies (mAbs). The sites in the polypeptide chain susceptible to fragmentation are determined by a multitude of factors. Insights are provided on the intimate chemical mechanisms that can make some bonds prone to cleavage due to the presence of specific side-chains. In addition to primary structure, the secondary, tertiary and quaternary structures have a significant impact in modulating the distribution of cleavage sites by altering local flexibility, accessibility to solvent or bringing in close proximity side chains that are remote in sequence. This review focuses on cleavage sites observed in the constant regions of mAbs, with special emphasis on hinge fragmentation. The mechanisms responsible for backbone cleavage are strongly dependent on pH and can be catalyzed by metals or radicals. The distribution of cleavage sites are different under acidic compared to basic conditions, with fragmentation rates exhibiting a minimum in the pH range 5–6; therefore, the overall fragmentation pattern observed for a mAb is a complex result of structural and solvent conditions. A critical review of the techniques used to monitor fragmentation is also presented; usually a compromise has to be made between a highly sensitive method with good fragment separation and the capability to identify the cleavage site. The effect of fragmentation on the function of a mAb must be evaluated on a case-by-case basis depending on whether cleavage sites are observed in the variable or constant regions, and on the mechanism of action of the molecule. PMID:21487244

  18. The Paradigm of Projectile Motion and its Consequences for Special Relativity. Making Sense of Physics

    CERN Document Server

    Klevgard, Paul A

    2015-01-01

    The classical (Newtonian) concept of projectile motion underwent a series of seemingly minor changes and adjustments between the discovery of the quantum (Planck, 1900) and the early codification of quantum theory (Dirac, 1928). The goal of physicists in this period was to keep change to a minimum and preserve as much as possible of the traditional projectile paradigm (TPP). These adjustments were successful in masking an all-out projectile paradigm crisis, but they have left us with a conceptual muddle. This has been especially deleterious for special relativity and our understanding of space contraction and time dilation.

  19. Projectile motion in real-life situation: Kinematics of basketball shooting

    Science.gov (United States)

    Changjan, A.; Mueanploy, W.

    2015-06-01

    Basketball shooting is a basic practice for players. The path of the ball from the players to the hoop is projectile motion. For undergraduate introductory physics courses student must be taught about projectile motion. Basketball shooting can be used as a case study for learning projectile motion from real-life situation. In this research, we discuss the relationship between optimal angle, minimum initial velocity and the height of the ball before the player shoots the ball for basketball shooting problem analytically. We found that the value of optimal angle and minimum initial velocity decreases with increasing the height of the ball before the player shoots the ball.

  20. A Micro-Doppler Modulation of Spin Projectile on CW Radar

    Directory of Open Access Journals (Sweden)

    Liu Zhi-Xue

    2017-01-01

    Full Text Available To obtain the spin speed of projectile effectively, a micro-Doppler modulation model of rotating projectile measured by continuous-wave radar (CW radar is introduced. High spin speed of projectile brings micro-Doppler modulation on echoes of CW radar, and there are many micro-Doppler modulation harmonic waves in the zero intermediate frequency (ZIF echoes. The frequency interval of the adjacent harmonic waves is several times of rotational frequency, but the integral multiple is unknown. The simulation results prove correctness of the proposed mathematic model.

  1. Isospin Against Size Effects In Projectile Dynamical Fission For 112,124Sn+58,64Ni and 124Xe+64Zn Reactions At 35 A.MeV

    Science.gov (United States)

    Russotto, P.; De Filippo, E.; Pagano, A.; Piasecki, E.; Acosta, L.; Amorini, F.; Anzalone, A.; Auditore, L.; Baran, V.; Berceanu, I.; Boiano, C.; Borderie, B.; Bruno, M.; Cap, T.; Cardella, G.; Castoldi, A.; Cavallaro, S.; Chatterjee, M. B.; Chbihi, A.; Colonna, M.; D'Agostino, M.; D'Andrea, M.; Di Toro, M.; Fichera, F.; Francalanza, L.; Geraci, E.; Gianì, R.; Gnoffo, B.; Grimaldi, A.; Grzeszczuk, A.; Guazzoni, C.; Guazzoni, P.; Giudice, N.; Kowalski, S.; La Guidara, E.; Lanzalone, G.; Lanzanò, G.; Lombardo, I.; Maiolino, C.; Marquínez-Durán, G.; Minniti, T.; Papa, M.; Pagano, E. V.; Passaro, G.; Pirrone, S.; Płaneta, R.; Politi, G.; Porto, F.; Quattrocchi, L.; Rivet, M. F.; Rosato, E.; Riccio, F.; Rizzo, F.; Saccà, G.; Schmidt, K.; Siwek-Wilczyńska, K.; Skwira-Chalot, I.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.; Wieleczko, J. P.; Wilczyński, J.; Zambon, P.; Zetta, L.; Zipper, W.

    2014-05-01

    In past experiments, mass asymmetric projectile-target combinations124Sn+64Ni and 112Sn+58Ni were investigated at ELab(112'124Sn)=35 A.MeVbeam energybyusing the 4n multi-detector CHIMERA. From a quantitative comparison of cross sections associated to Statistical and Dynamical Fission of the Projectile-Like Fragments, it resulted that Dynamical Fission process is about two times more probable in the neutron rich 124Sn+64Ni system than in the 112 Sn +58 Ni neutron poor one. In contrast, no sizable difference was found for Statistical Fission mechanism. The observed difference in the strength of the Dynamical effects could arise from the difference in entrance channel Isospin (N/Z) content. In order to disentangle Isospin effects from effects due to the different masses of the two systems, a new experiment 124Xe+64Zn at 35 A.MeV beam energy has been recently carried out.

  2. New insight on the high radiation resistance of UO2 against fission fragments

    Science.gov (United States)

    Szenes, G.

    2016-12-01

    Track radii are derived for semiconductors from a temperature distribution Θ(r) in which the width of the distribution is the only materials parameter. Analysis of track data for GeS, InP, GaAs and GaN show that the projectile velocity has no effect on track radii in semiconductors. Due to the missing velocity effect, the threshold for track formation, Set = 20 keV/nm is high in semiconducting UO2 in the whole range of projectile velocities. This is the origin of the high radiation resistance for fission fragments. Consequences for the simulation experiments with insulating CeO2 are discussed. It is verified that sputtering is described accurately by the Arrhenius equation for various materials including UO2. The ion-induced surface potential has a strong effect on the activation energy.

  3. Fractal Fragmentation triggered by meteor impact: The Ries Crater (Germany)

    Science.gov (United States)

    Paredes Marino, Joali; Perugini, Diego; Rossi, Stefano; Kueppers, Ulrich

    2015-04-01

    FRACTAL FRAGMENTATION TRIGGERED BY METEOR IMPACT: THE RIES CRATER (GERMANY) Joali Paredes (1), Stefano Rossi (1), Diego Perugini (1), Ulrich Kueppers (2) 1. Department of Physics and Geology, University of Perugia, Italy 2. Department of Earth and Environmental Sciences, University of Munich, Germany The Nördlinger Ries is a large circular depression in western Bavaria, Germany. The depression was caused by a meteor impact, which occurred about 14.3 million-14.5 million years ago. The original crater rim had an estimated diameter of 24 kilometers. Computer modeling of the impact event indicates that the impact or probably had diameters of about 1.5 kilometers and impacted the target area at an angle around 30 to 50 degrees from the surface in a west- southwest to east-northeast direction. The impact velocity is thought to have been about 20 km/s. The meteor impact generated extensive fragmentation of preexisting rocks. In addition, melting of these rocks also occurred. The impact melt was ejected at high speed provoking its extensive fragmentation. Quenched melt fragments are ubiquitous in the outcrops. Here we study melt fragment size distributions with the aim of understanding the style of melt fragmentation during ejection and to constrain the rheological properties of such melts. Digital images of suevite (i.e. the rock generated after deposition and diagenesis of ash and fragments produced by the meteor impact) were obtained using a high-resolution optical scanner. Successively, melt fragments were traced by image analysis and the images segmented in order to obtain binary images on which impact melt fragments are in black color, embedded on a white background. Hence, the size of fragments was determined by image analysis. Fractal fragmentation theory has been applied to fragment size distributions of melt fragments in the Ries crater. Results indicate that melt fragments follow fractal distributions indicating that fragmentation of melt generated by the

  4. Using a ballistic-caprock model for developing a volcanic projectiles hazard map at Santorini caldera

    Science.gov (United States)

    Konstantinou, Konstantinos

    2015-04-01

    Volcanic Ballistic Projectiles (VBPs) are rock/magma fragments of variable size that are ejected from active vents during explosive eruptions. VBPs follow almost parabolic trajectories that are influenced by gravity and drag forces before they reach their impact point on the Earth's surface. Owing to their high temperature and kinetic energies, VBPs can potentially cause human casualties, severe damage to buildings as well as trigger fires. Since the Minoan eruption the Santorini caldera has produced several smaller (VEI = 2-3) vulcanian eruptions, the last of which occurred in 1950, while in 2011 it also experienced significant deformation/seismicity even though no eruption eventually occurred. In this work, an eruptive model appropriate for vulcanian eruptions is used to estimate initial conditions (ejection height, velocity) for VBPs assuming a broad range of gas concentration/overpressure in the vent. These initial conditions are then inserted into a ballistic model for the purpose of calculating the maximum range of VBPs for different VBP sizes (0.35-3 m), varying drag coefficient as a function of VBP speed and varying air density as a function of altitude. In agreement with previous studies a zone of reduced drag is also included in the ballistic calculations that is determined based on the size of vents that were active in the Kameni islands during previous eruptions (< 1 km). Results show that the horizontal range of VBPs varies between 0.9-3 km and greatly depends on gas concentration, the extent of the reduced drag zone and the size of VBP. Hazard maps are then constructed by taking into account the maximum horizontal range values as well as potential locations of eruptive vents along a NE-SW direction around the Kameni islands (the so-called "Kameni line").

  5. Maximum horizontal range of volcanic ballistic projectiles ejected during explosive eruptions at Santorini caldera

    Science.gov (United States)

    Konstantinou, K. I.

    2015-08-01

    This study investigates the hazard posed by Volcanic Ballistic Projectiles (VBPs) to the Santorini islands considering eruption scenarios that include low (VEI = 2-3) and higher energy (VEI > 3) eruptions. A model that describes rapid decompression of pressurized magma below a caprock along with its fragmentation and acceleration of particles is utilized for estimating initial velocities during vulcanian-style eruptions. These initial velocities are inserted into the ballistic equations assuming that VBPs have a cube-like shape, are subjected to gravity/drag forces and are launched into a zone of reduced drag. Four different diameters of VBPs are considered (0.35 m, 1.0 m, 2.0 m, 3.0 m) and also different values of gas fractions and extent of the reduced drag zone are investigated. The results of these calculations show that an area of 1-2 km width along the western coast of Thera will be within the maximum range of VBPs, provided that the eruptive vent will develop either on Nea Kameni or between Nea Kameni and Thera. Initial velocities for higher energy eruptions are estimated by considering the conversion efficiency of thermal to kinetic energy. For the case of an eruption with VEI = 4 and a number of vents centered between Nea and Palea Kameni, calculations show that the coastal areas of Thera and Therasia are within the maximum horizontal range of VBPs with diameter larger than 0.35 m. As the exact position of the eruptive vent seems to be of crucial importance for determining the areas at risk, continuous seismic and geodetic monitoring of the caldera is needed in order to decipher its likely location.

  6. Embedded Fragments Registry (EFR)

    Data.gov (United States)

    Department of Veterans Affairs — In 2009, the Department of Defense estimated that approximately 40,000 service members who served in OEF/OIF may have embedded fragment wounds as the result of small...

  7. Fragmentation in Biaxial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, G H; Archbold, G C; Hurricane, O A; Miller, P L

    2006-06-13

    We have carried out an experiment that places a ductile stainless steel in a state of biaxial tension at a high rate of strain. The loading of the ductile metal spherical cap is performed by the detonation of a high explosive layer with a conforming geometry to expand the metal radially outwards. Simulations of the loading and expansion of the metal predict strain rates that compare well with experimental observations. A high percentage of the HE loaded material was recovered through a soft capture process and characterization of the recovered fragments provided high quality data, including uniform strain prior to failure and fragment size. These data were used with a modified fragmentation model to determine a fragmentation energy.

  8. DNA fragmentation in spermatozoa

    DEFF Research Database (Denmark)

    Rex, A S; Aagaard, J.; Fedder, J

    2017-01-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

  9. Fragmentation Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The fragmentation model combines patch size and patch continuity with diversity of vegetation types per patch and rarity of vegetation types per patch. A patch was...

  10. Thermodynamics of fragment binding.

    Science.gov (United States)

    Ferenczy, György G; Keserű, György M

    2012-04-23

    The ligand binding pockets of proteins have preponderance of hydrophobic amino acids and are typically within the apolar interior of the protein; nevertheless, they are able to bind low complexity, polar, water-soluble fragments. In order to understand this phenomenon, we analyzed high resolution X-ray data of protein-ligand complexes from the Protein Data Bank and found that fragments bind to proteins with two near optimal geometry H-bonds on average. The linear extent of the fragment binding site was found not to be larger than 10 Å, and the H-bonding region was found to be restricted to about 5 Å on average. The number of conserved H-bonds in proteins cocrystallized with multiple different fragments is also near to 2. These fragment binding sites that are able to form limited number of strong H-bonds in a hydrophobic environment are identified as hot spots. An estimate of the free-energy gain of H-bond formation versus apolar desolvation supports that fragment sized compounds need H-bonds to achieve detectable binding. This suggests that fragment binding is mostly enthalpic that is in line with their observed binding thermodynamics documented in Isothermal Titration Calorimetry (ITC) data sets and gives a thermodynamic rationale for fragment based approaches. The binding of larger compounds tends to more rely on apolar desolvation with a corresponding increase of the entropy content of their binding free-energy. These findings explain the reported size-dependence of maximal available affinity and ligand efficiency both behaving differently in the small molecule region featured by strong H-bond formation and in the larger molecule region featured by apolar desolvation.

  11. Carbon Fragmentation Cross Sections for Hadrontherapy and Space Radiation Protection

    Science.gov (United States)

    De Napoli, M.; Agodi, C.; Cirrone, G. A. P.; Cuttone, G.; Nicolosi, D.; Pandola, L.; Raciti, G.; Romano, F.; Sardina, D.; Scuderi, V.; Tropea, S.; Bondì, M.; Cappuzzello, F.; Carbone, D.; Cavallaro, M.

    2014-05-01

    Fragmentation reactions represent a serious complication in hadrontherapy and space radiation protection. In order to predict their effects, both reliable Monte Carlo codes and experimental data are needed. The shortage of precise measurements, especially of double differential cross sections, has triggered many dedicated experiments at relativistic energies. Aiming to explore the Fermi energy regime, as well, where different reaction mechanisms are involved, we measured the 12C fragmentation at 62 AMeV on a 12C and a 197Au target. A high granularity Si-CsI hodoscope allowed to identify the charge and the mass of detected fragments and measure their energy and emission angle. In this work we report the double differential cross sections for the production of different fragments as a function of the emission angle. Experimental results are compared with the GEANT-4 Monte Carlo predictions performed using two reaction models, the Quantum Molecular Dynamic and the Binary Light Ion Cascade.

  12. AN EXPERIMENTAL TECHNIQUE TO MEASURE PROJECTILE DECELERATION HISTORY DURING NORMAL PENETRATION

    Institute of Scientific and Technical Information of China (English)

    INTO PLAIN; Liu Xiaohu; Liu Ji; Wang Cheng

    2000-01-01

    The present paper presents a new experimental method to measure the deceleration time his tory of projectiles penetrating into concrete in full-size test. The experiment can be carried out by using an onboard accelerometer to measure the projectile deceleration history and the data are transmitted to a ground recording system. With this experimental method, a series of tests on hemisphere-nose steel projectiles pene trating normally into plain concrete at the velocity region 150 - 400 m/s have been executed and the deceler ation histories obtained. The high frequency portion in the deceleration data has been investigated and proved to be the structure response of projectile. The characteristics of deceleration history have also been analyzed and discussed.

  13. Time of flight and range of the motion of a projectile in a constant gravitational field

    Directory of Open Access Journals (Sweden)

    P. A. Karkantzakos

    2009-01-01

    Full Text Available In this paper we study the classical problem of the motion of a projectile in a constant gravitational field under the influenceof a retarding force proportional to the velocity. Specifically, we express the time of flight, the time of fall and the range ofthe motion as a function of the constant of resistance per unit mass of the projectile. We also prove that the time of fall isgreater than the time of rise with the exception of the case of zero constant of resistance where we have equality. Finally weprove a formula from which we can compute the constant of resistance per unit mass of the projectile from time of flight andrange of the motion when the acceleration due to gravity and the initial velocity of the projectile are known.

  14. A Web-Based Video Digitizing System for the Study of Projectile Motion.

    Science.gov (United States)

    Chow, John W.; Carlton, Les G.; Ekkekakis, Panteleimon; Hay, James G.

    2000-01-01

    Discusses advantages of a video-based, digitized image system for the study and analysis of projectile motion in the physics laboratory. Describes the implementation of a web-based digitized video system. (WRM)

  15. 'The Monkey and the Hunter' and Other Projectile Motion Experiments with Logo.

    Science.gov (United States)

    Kolodiy, George Oleh

    1988-01-01

    Presents the LOGO computer language as a source to experience and investigate scientific laws. Discusses aspects and uses of LOGO. Lists two LOGO programs, one to simulate a gravitational field and the other projectile motion. (MVL)

  16. A New Simple Model for the Mushrooming Deformation of Projectile Impacting on A Deformable Target

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaoqing; Yang Guitong

    2004-01-01

    Based on Taylor's model and Hawkyard's model, a new simple model for the mushrooming deformation of projectile impacting on a deformable target is installed considering the penetration of the projectile to the deformable target. In the model, the following time-dependent variables are involved in: the extent and the particle velocity in the rigid zone; the extent, the cross-section area and the particle velocity in plastic zone; the velocity and depth of the penetrating of projectile to the target. Solving the set of equations, analytic solution is given. The profiles of deformed projectile and shape parameters for different initial impact velocities are shown. The duration time of deformation increases with increasing the impact velocity. The analytical results by using this model are coincident with experimental result.

  17. Shape Distribution of Fragments from Microsatellite Impact Tests

    Science.gov (United States)

    Liou, J.C.; Hanada, T.

    2009-01-01

    Fragment shape is an important factor for conducting reliable orbital debris damage assessments for critical space assets, such as the International Space Station. To date, seven microsatellite impact tests have been completed as part of an ongoing collaboration between Kyushu University and the NASA Orbital Debris Program Office. The target satellites ranged in size from 15 cm 15 cm 15 cm to 20 cm 20 cm 20 cm. Each target satellite was equipped with fully functional electronics, including circuits, battery, and transmitter. Solar panels and multi-layer insulation (MLI) were added to the target satellites of the last two tests. The impact tests were carried out with projectiles of different sizes and impact speeds. All fragments down to about 2 mm in size were collected and analyzed based on their three orthogonal dimensions, x, y, and z, where x is the longest dimension, y is the longest dimension in the plane perpendicular to x, and z is the longest dimension perpendicular to both x and y. Each fragment was also photographed and classified by shape and material composition. This data set serves as the basis of our effort to develop a fragment shape distribution. Two distinct groups can be observed in the x/y versus y/z distribution of the fragments. Objects in the first group typically have large x/y values. Many of them are needle-like objects originating from the fragmentation of carbon fiber reinforced plastic materials used to construct the satellites. Objects in the second group tend to have small x/y values, and many of them are box-like or plate-like objects, depending on their y/z values. Each group forms the corresponding peak in the x/y distribution. However, only one peak can be observed in the y/z distribution. These distributions and how they vary with size, material type, and impact parameters will be described in detail within the paper.

  18. Binary Neutron Star Mergers

    Directory of Open Access Journals (Sweden)

    Joshua A. Faber

    2012-07-01

    Full Text Available We review the current status of studies of the coalescence of binary neutron star systems. We begin with a discussion of the formation channels of merging binaries and we discuss the most recent theoretical predictions for merger rates. Next, we turn to the quasi-equilibrium formalisms that are used to study binaries prior to the merger phase and to generate initial data for fully dynamical simulations. The quasi-equilibrium approximation has played a key role in developing our understanding of the physics of binary coalescence and, in particular, of the orbital instability processes that can drive binaries to merger at the end of their lifetimes. We then turn to the numerical techniques used in dynamical simulations, including relativistic formalisms, (magneto-hydrodynamics, gravitational-wave extraction techniques, and nuclear microphysics treatments. This is followed by a summary of the simulations performed across the field to date, including the most recent results from both fully relativistic and microphysically detailed simulations. Finally, we discuss the likely directions for the field as we transition from the first to the second generation of gravitational-wave interferometers and while supercomputers reach the petascale frontier.

  19. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  20. Contribution to the modeling, design, and experimental study of an augmentel railgun and its projectile

    OpenAIRE

    2011-01-01

    This thesis was supervised by Professor Jean-Marie Kauffmann of the University of Franche-Comté. The co-director at the Royal Military Academy was Dr. Johan Gallant and the experiments at Franch-German Research Institute ISL were directed by Dr. Markus Schneider. A conventional electromagnetic railgun is composed of two conducting rails connected by a projectile. The magnetic field generated by the current in the rails interacts in the projectile resulting in an electromagnetic force accelera...

  1. [A sign of the rotational impact of the gunshot projectile on the flat bone].

    Science.gov (United States)

    Leonov, S V

    2014-01-01

    The objective of the present work was to study the mechanisms of formation of the gunshot fracture of the flat bones with special reference to the translational and rotational motion of the projectile. A total of 120 real and experimental injuries of this type were available for the investigation with the use of simulation by the finite-elemental analysis. A set of morphological features has been identified that make it possible to determine the direction of rotation of the gunshot projectile.

  2. Comment on "The motion of an arbitrarily rotating spherical projectile and its application to ball games"

    OpenAIRE

    Jensen, Jens Højgaard

    2014-01-01

    In a recent paper (Robinson G and Robinson I 2013 Phys. Scr. 88 018101) the authors developed the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary wind, assuming that both the drag force and the lift force are independent of the Reynolds number and proportional to the square of the projectile's velocity. In this paper, by dimensional analysis, the latter assumption is shown to be incorrect for forces depe...

  3. Numeric Computation of the Radar Cross Section of In flight Projectiles

    Science.gov (United States)

    2016-11-01

    the motion of a spinning ballistic projectile in the mobile i-j-k frame and that of a spinning top in the fixed x-y-z ground frame. The pitch and yaw...right). When no spin , pitch, and yaw motions are accounted for, these pictures describe the radar-projectile relative orientation in the AFDTD radar... top of one another. ....................................................................41 Fig. 19 Dynamic RCS vs. time curves obtained for the

  4. Aerodynamic Optimization of a Supersonic Bending Body Projectile by a Vector-Evaluated Genetic Algorithm

    Science.gov (United States)

    2016-12-01

    ARL-CR-0810 ● DEC 2016 US Army Research Laboratory Aerodynamic Optimization of a Supersonic Bending Body Projectile by a Vector...not return it to the originator. ARL-CR-0810 ● DEC 2016 US Army Research Laboratory Aerodynamic Optimization of a ...Supersonic Bending Body Projectile by a Vector-Evaluated Genetic Algorithm prepared by Justin L Paul Academy of Applied Science 24 Warren Street

  5. Binary Popldation Synthcsis Study

    Institute of Scientific and Technical Information of China (English)

    HAN Zhanwen

    2011-01-01

    Binary population synthesis (BPS), an approach to evolving millions of stars (including binaries) simultaneously, plays a crucial role in our understanding of stellar physics, the structure and evolution of galaxies, and cosmology. We proposed and developed a BPS approach, and used it to investigate the formation of many peculiar stars such as hot subdwarf stars, progenitors of type la supernovae, barium stars, CH stars, planetary nebulae, double white dwarfs, blue stragglers, contact binaries, etc. We also established an evolution population synthesis (EPS) model, the Yunnan Model, which takes into account binary interactions for the first time. We applied our model for the origin of hot subdwarf stars in the study of elliptical galaxies and explained their far-UV radiation.

  6. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  7. Ablation and deceleration of mass-driver launched projectiles for space disposal of nuclear wastes

    Science.gov (United States)

    Park, C.; Bowen, S. W.

    1981-01-01

    The energy cost of launching a projectile containing nuclear waste is two orders of magnitude lower with a mass driver than with a typical rocket system. A mass driver scheme will be feasible, however, only if ablation and deceleration are within certain tolerable limits. It is shown that if a hemisphere-cylinder-shaped projectile protected thermally with a graphite nose is launched vertically to attain a velocity of 17 km/sec at an altitude of 40 km, the mass loss from ablation during atmospheric flight will be less than 0.1 ton, provided the radius of the projectile is under 20 cm and the projectile's mass is of the order of 1 ton. The velocity loss from drag will vary from 0.4 to 30 km/sec, depending on the mass and radius of the projectile, the smaller velocity loss corresponding to large mass and small radius. Ablation is always within a tolerable range for schemes using a mass driver launcher to dispose of nuclear wastes outside the solar system. Deceleration can also be held in the tolerable range if the mass and diameter of the projectile are properly chosen.

  8. NUMERICAL SIMULATION OF THREE DIMENSIONAL INTERACTING TURBULENCE FLOW FIELD OVER PROJECTILE WITH LATERAL JETS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to study complicated interacting flow field over projectile with lateral jets. External interacting turbulence flow over projectile with lateral jets was numerically simulated firstly in supersonic speed and zero attack angle. The three dimensional Reynolds-averaged NavierStokes equations and implicit finite volume TVD scheme grid of single zone including projectile base was produced by algebraic arithmetic. Body-fitted grid was generated for the lateral nozzle exit successfully so that the nozzle exit can be simulated more accurately. The high Reynolds number two-equation κ-ε turbulence models were used.The main features of the complex flow are captured. The two kinds of flow field over projectile with and without lateral jets are compared from shock structure, pressure of body and base, etc. It shows that lateral jets not only can provide push force, but also change aerodynamics characteristic of projectile significantly. The results are very important for the study of projectile with lateral rocket boosters.``

  9. Fairly direct hit. Advances in imaging of shotgun projectiles in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Eggert, Sebastian [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); University of Zurich, Institute of Forensic Medicine, Zurich (Switzerland); Kubik-Huch, Rahel A.; Peters, Alexander [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Klarhoefer, Markus [Siemens Healthcare, Zurich (Switzerland); Bolliger, Stephan A.; Thali, Michael J. [University of Zurich, Institute of Forensic Medicine, Zurich (Switzerland); Anderson, Suzanne [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); University of Notre Dame Australia, Radiology, Sydney School of Medicine, Sydney, NSW (Australia); Froehlich, Johannes M. [Federal Institute of Technology, Pharmaceutical Sciences, Zurich (Switzerland)

    2015-09-15

    To investigate the magnetic properties of different types of projectiles and qualify the metal artefact reduction technique for diagnostic and/or forensic MRI. Ten different projectiles embedded in ordnance gelatine blocks underwent an in vitro 1.5-T MR study with seven sequences including a recently developed metal artefact reduction sequence (Advanced WARP) combining VAT (view-angle-tilting) and SEMAC (slice-encoding metal-artefact-correction). Resulting image quality (five-point scale: 1=best; 5=worst) was scored. Quantifiable magnetic characteristics were correlated with qualitative rating of the MR sequences and torque dislodgment. Metal artefact reduction sequence (median: 2.5) significantly (p < 0.001) improves depiction of projectiles in comparison to all other MR pulse sequences (median: 4.75). Images from diamagnetic composed bullets (median: 2) are much less disturbed compared to magnetic attracted ones (median: 5). Correlation (0.623) between deflection angle measurement (ferromagnetic mean 84.2 ; paramagnetic 62 ; diamagnetic mean 0 ) and median qualitative image quality was highly significant (p = 0.027). Torque dislodgement was distinct for elongated magnetic attracted projectiles. Significant improvement of MR imaging of projectiles using metal artefact reduction techniques has important implications for diagnostic/forensic work-up. The correlations between magnetic attraction force, deflection-angle results and image properties demonstrate that the MR safety of projectiles can be estimated with one of these methods. (orig.)

  10. Experimental investigation on underwater trajectory deviation of high-speed projectile with different nose shape

    Science.gov (United States)

    Zhang, Wei; Qi, Yafei; Huang, Wei; Gao, Yubo

    2017-01-01

    The investigation on free-surface impact of projectiles has last for more than one hundred years due to its noticeable significance on improving defensive weapon technology. Laboratory-scaled water entry experiments for trajectory stability had been performed with four kinds of projectiles at a speed range of 20˜200 m/s. The nose shapes of the cylindrical projectiles were designed into flat, ogive, hemi-sphere and cone to make comparisons on the trajectory deviation when they were launched into water at a certain angle of 0˜20°. Two high-speed cameras positioned orthogonal to each other and normal to the water tank were employed to capture the entire process of projectiles' penetration. From the experimental results, the consecutive images in two planes were presented to display the general process of the trajectory deviation. Compared with the effect of impact velocities and nose shape on trajectory deviation, it merited conclude that flat projectiles had a better trajectory stability, while ogival projectiles experienced the largest attitude change. The characteristics of pressure waves were also investigated.

  11. Study of Hypervelocity Projectile Impact on Thick Metal Plates

    Directory of Open Access Journals (Sweden)

    Shawoon K. Roy

    2016-01-01

    Full Text Available Hypervelocity impacts generate extreme pressure and shock waves in impacted targets that undergo severe localized deformation within a few microseconds. These impact experiments pose unique challenges in terms of obtaining accurate measurements. Similarly, simulating these experiments is not straightforward. This study proposed an approach to experimentally measure the velocity of the back surface of an A36 steel plate impacted by a projectile. All experiments used a combination of a two-stage light-gas gun and the photonic Doppler velocimetry (PDV technique. The experimental data were used to benchmark and verify computational studies. Two different finite-element methods were used to simulate the experiments: Lagrangian-based smooth particle hydrodynamics (SPH and Eulerian-based hydrocode. Both codes used the Johnson-Cook material model and the Mie-Grüneisen equation of state. Experiments and simulations were compared based on the physical damage area and the back surface velocity. The results of this study showed that the proposed simulation approaches could be used to reduce the need for expensive experiments.

  12. Spectroscopy of exotic 123,125Ag produced in fragmentation reactions

    Science.gov (United States)

    Stefanescu, I.; Walters, W. B.; Hoteling, N.; Tomlin, B.; Mantica, P. F.; Pereira, J.; Becerril, A.; Fleckenstein, T.; Hecht, A. A.; Lorusso, G.; Quinn, M.; Pinter, J. S.; Stoker, J. B.

    2008-04-01

    We extended the experimental knowledge in the mass-region around 132Sn by identifying the decay of high-spin isomers in the exotic odd-mass 123,125Ag. The two isotopes were produced at the NSCL laboratory by projectile fragmentation of a 136Xe beam at 120MeV/u directed onto a thick Be target. The NSCL Beta Counting System, was used identify secondary beam fragments. Prompt and delayed gamma-rays following the deexcitation of the fragments were detected with the SEGA array. Partial level schemes for 123,125Ag are proposed for the first time. The observed states show single-particle characteristics, indicating strong Z=50 and N=82 shell gaps and also support the proposed weakened nucleon-nucleon interaction in this mass-region.

  13. Fluctuations of fragment observables

    CERN Document Server

    Gulminelli, F

    2006-01-01

    This contribution presents a review of our present theoretical as well as experimental knowledge of different fluctuation observables relevant to nuclear multifragmentation. The possible connection between the presence of a fluctuation peak and the occurrence of a phase transition or a critical phenomenon is critically analyzed. Many different phenomena can lead both to the creation and to the suppression of a fluctuation peak. In particular, the role of constraints due to conservation laws and to data sorting is shown to be essential. From the experimental point of view, a comparison of the available fragmentation data reveals that there is a good agreement between different data sets of basic fluctuation observables, if the fragmenting source is of comparable size. This compatibility suggests that the fragmentation process is largely independent of the reaction mechanism (central versus peripheral collisions, symmetric versus asymmetric systems, light ions versus heavy ion induced reactions). Configurationa...

  14. Eclipsing Binary Update, No. 2.

    Science.gov (United States)

    Williams, D. B.

    1996-01-01

    Contents: 1. Wrong again! The elusive period of DHK 41. 2. Stars observed and not observed. 3. Eclipsing binary chart information. 4. Eclipsing binary news and notes. 5. A note on SS Arietis. 6. Featured star: TX Ursae Majoris.

  15. N-Bit Binary Resistor

    Science.gov (United States)

    Tcheng, Ping

    1989-01-01

    Binary resistors in series tailored to precise value of resistance. Desired value of resistance obtained by cutting appropriate traces across resistors. Multibit, binary-based, adjustable resistor with high resolution used in many applications where precise resistance required.

  16. Characterization of fragment emission in $^{20}$Ne (7 - 10 MeV/nucleon) + $^{12}$C reactions

    CERN Document Server

    Dey, Aparajita; Bhattacharya, S; Kundu, S; Banerjee, K; Mukhopadhyay, S; Gupta, D; Bhattacharjee, T; Banerjee, S R; Bhattacharya, S; Rana, T K; Basu, S K; Saha, R; Krishan, K; Mukherjee, A; Bandyopadhyay, D; Beck, C

    2007-01-01

    The inclusive energy distributions of the complex fragments (3 $\\leq$ Z $\\leq$ 7) emitted from the bombardment of $^{12}$C by $^{20}$Ne beams with incident energies between 145 and 200 MeV have been measured in the angular range 10$^{o} \\leq \\theta_{lab} \\leq$ 50$^{o}$. Damped fragment yields in all the cases have been found to be the characteristic of emission from fully energy equilibrated composites. The binary fragment yields are compared with the standard statistical model predictions. Enhanced yields of entrance channel fragments (5 $\\leq$ Z $\\leq$ 7) indicate the survival of orbiting-like process in $^{20}$Ne + $^{12}$C system at these energies.

  17. Sand Behavior Induced by High-Speed Penetration of Projectile. Phenomenological studies of the response of granular and geological media to high-speed (Mach 1-5) projectiles

    Science.gov (United States)

    2011-02-07

    are summarized as follows: Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato starch . Circumferential...Distribution Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato starch as shown in Fig.11. It was found that...The major results are summarized as follows: 1. Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato

  18. Fragments of Time

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    Time travel films necessarily fragment linear narratives, as scenes are revisited with differences from the first time we saw it. Popular films such as Back to the Future mine comedy from these visitations, but there are many different approaches. One extreme is Chris Marker's La Jetée - a film...... made almost completely of still images, recounting the end of the world. These stills can be viewed as fragments that have survived the end of the world and now provide the only access to the events that occured. Shane Carruth's Primer has a different approach to time travel, the narrative diegesis...

  19. The Serendipity of Fragmentation

    DEFF Research Database (Denmark)

    Leixnering, Stephan; Meyer, Renate E.

    , it was the central government’s task to coordinate, steer and control the newly emerged decentralized organizations. This raises questions about the overall design of the public sector at present. Our paper engages with the prevalent public governance phenomenon of fragmentation from a design perspective in order...... form of organizing between networks and formal organization: lacking a single center and featuring multiplex and multifaceted relations within the politico-administrative apparatus and between government and PSOs, high fragmentation, local and robust action, but latent structures of significant formal...

  20. IMPACT fragmentation model developments

    Science.gov (United States)

    Sorge, Marlon E.; Mains, Deanna L.

    2016-09-01

    The IMPACT fragmentation model has been used by The Aerospace Corporation for more than 25 years to analyze orbital altitude explosions and hypervelocity collisions. The model is semi-empirical, combining mass, energy and momentum conservation laws with empirically derived relationships for fragment characteristics such as number, mass, area-to-mass ratio, and spreading velocity as well as event energy distribution. Model results are used for several types of analysis including assessment of short-term risks to satellites from orbital altitude fragmentations, prediction of the long-term evolution of the orbital debris environment and forensic assessments of breakup events. A new version of IMPACT, version 6, has been completed and incorporates a number of advancements enabled by a multi-year long effort to characterize more than 11,000 debris fragments from more than three dozen historical on-orbit breakup events. These events involved a wide range of causes, energies, and fragmenting objects. Special focus was placed on the explosion model, as the majority of events examined were explosions. Revisions were made to the mass distribution used for explosion events, increasing the number of smaller fragments generated. The algorithm for modeling upper stage large fragment generation was updated. A momentum conserving asymmetric spreading velocity distribution algorithm was implemented to better represent sub-catastrophic events. An approach was developed for modeling sub-catastrophic explosions, those where the majority of the parent object remains intact, based on estimated event energy. Finally, significant modifications were made to the area-to-mass ratio distribution to incorporate the tendencies of different materials to fragment into different shapes. This ability enabled better matches between the observed area-to-mass ratios and those generated by the model. It also opened up additional possibilities for post-event analysis of breakups. The paper will discuss

  1. Orbits for sixteen binaries

    Directory of Open Access Journals (Sweden)

    Cvetković Z.

    2006-01-01

    Full Text Available In this paper orbits for 13 binaries are recalculated and presented. The reason is that recent observations show higher residuals than the corresponding ephemerides calculated by using the orbital elements given in the Sixth Catalog of Orbits of Visual Binary Stars. The binaries studied were: WDS 00182+7257 = A 803, WDS 00335+4006 = HO 3, WDS 00583+2124 = BU 302, WDS 01011+6022 = A 926, WDS 01014+1155 = BU 867, WDS 01112+4113 = A 655, WDS 01361−2954 + HJ 3447, WDS 02333+5219 = STT 42 AB,WDS 04362+0814 = A 1840 AB,WDS 08017−0836 = A 1580, WDS 08277−0425 = A 550, WDS 17471+1742 = STF 2215 and WDS 18025+4414 = BU 1127 Aa-B. In addition, for three binaries - WDS 01532+1526 = BU 260, WDS 02563+7253 = STF 312 AB and WDS 05003+3924 = STT 92 AB - the orbital elements are calculated for the first time. In this paper the authors present not only the orbital elements, but the masses dynamical parallaxes, absolute magnitudes and ephemerides for the next five years, as well.

  2. Equational binary decision diagrams

    NARCIS (Netherlands)

    Groote, J.F.; Pol, J.C. van de

    2000-01-01

    We incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tautology checkin

  3. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and

  4. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  5. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Rune Hansen, Esben; Srinivasa Rao, S.; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  6. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  7. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tauto

  8. Isotopic yield in cold binary fission of even-even $^{244-258}$Cf isotopes

    CERN Document Server

    Santhosh, K P; Krishnan, Sreejith

    2016-01-01

    The cold binary fission of even-even 244-258Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. The favorable fragment combinations are obtained from the cold valley plot (plot of driving potential vs. mass number of fragments) and by calculating the yield for charge minimized fragments. It is found that highest yield for 244,246,248Cf isotopes are for the fragments with isotope of Pb (Z=82) as one fragment, whereas for 250Cf and 252Cf isotopes the highest yield is for the fragments with isotope of Hg (Z=80) as one fragment. In the case of 254,256,258Cf isotopes the highest yield is for the fragments with Sn (Z=50) as one fragment. Thus, the fragment combinations with maximum yield reveal the role of doubly magic and near doubly magic nuclei in binary fission. It is found that asymmetric splitting is favoured for Cf isotopes with mass number A 252. In the case of Cf isotope with A=252, there is an equal probability for asymmetric and symmetric splitti...

  9. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  10. Binary scission configurations in fission of light actinides

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, Tsutomu [Tohoku Univ., Sendai (Japan). Lab. of Nuclear Science; Nagame, Y.; Nishinaka, I.; Tsukada, K.; Ikezoe, H.; Tanikawa, M.; Zhao, Y.L.; Sueki, K.; Nakahara, H.

    1997-07-01

    Mass and kinetic energy distributions of fission fragments have been accurately measured by a double velocity time-of-flight technique in the 13 MeV proton-induced fissions of {sup 232}Th and {sup 238}U. A binary structure is observed in total kinetic energy distributions in the fragments with mass number around A=130 for both the fissions, indicating that there are at least two kinds of scission configurations. A correlation between the scission configurations and mass yield distributions reveals that elongated scission configurations are associated with the symmetric mass distribution and compact scission configurations with the asymmetric mass distribution. (author)

  11. Measuring the Velocity and Orientation of Mortar Shaped Projectiles by Using the Automated Computer Vision Analysis Method

    Science.gov (United States)

    2014-06-01

    position cameras and the mortars follow a ballistic path, the motion of the projectile should follow a straight line in the undistorted field of view...angle of attack estimates that ranged from 0.72 to 12.03 deg. Spin-stabilized projectiles exhibit epicyclic motion behavior at high frequencies...UNCLASSIFIED AD-E403 531 Technical Report ARMET-TR-13042 MEASURING THE VELOCITY AND ORIENTATION OF MORTAR SHAPED PROJECTILES

  12. Freeze out temperature on light projectile induced reaction

    Energy Technology Data Exchange (ETDEWEB)

    Murata, J. [Kyoto Univ. (Japan); Haga, M.; Haseno, M. [and others

    1997-05-01

    Nuclear temperature was deduced for 12GeV proton induced target multi-fragmentation reactions on Au, Tm, Sm, Ag targets. Using isotope yield ratios, clear target mass dependence was obtained for high-multiplicity events. Deduced temperatures for light targets have higher value than those for heavy targets. (author)

  13. Ionization and fragmentation of cold clusters of PAH molecules - collisions with keV ions

    Science.gov (United States)

    Holm, A. I. S.; Zettergren, H.; Gatchell, M.; Johansson, H. A. B.; Seitz, F.; Schmidt, H. T.; Rousseau, P.; Ławicki, A.; Capron, M.; Domaracka, A.; Lattouf, E.; Maclot, S.; Maisonny, R.; Chesnel, J.-Y.; Manil, B.; Adoui, L.; Huber, B. A.; Cederquist, H.

    2012-11-01

    We discuss the ionization and fragmentation of isolated monomers and cold clusters of polycyclic aromatic hydrocarbon (PAH) molecules in collisions with keV ions in low or high charge states. With low charge state projectile ions, PAH cluster or monomer targets are thermally excited through electronic stopping processes directly in close peripheral or penetrating collisions while only single or few electrons are removed. With high charge state projectiles, electrons are very effectively removed from both the cluster and the monomer target already at very large distances with very little direct target heating. Singly charged and internally very hot PAH monomers are dominant fragmentation products following collisions between Xe20+ ions and PAH clusters. We suggest that this due to an unusually strong dominance of multiple-ionization over single ionization for PAH clusters interacting with highly charged ions. Here, charge and excitation energy is very rapidly redistributed within the clusters before they Coulomb explode and we suggest that these Coulomb explosions induce strong internal heating in the individual PAH molecules. We thus conclude that PAH cluster fragmentation always dominates strongly for all ionization processes regardless if these are due to interactions with ions in high or low charge states. These findings are discussed in view of simple models for cluster evaporation or single and multiple ionizations of PAH clusters.

  14. Angular momenta of fission fragments in the α-accompanied fission of 252Cf

    Science.gov (United States)

    Jandel, M.; Kliman, J.; Krupa, L.; Morháč, M.; Hamilton, J. H.; Kormicki, J.; Ramayya, A. V.; Hwang, J. K.; Luo, Y. X.; Fong, D.; Gore, P.; Ter-Akopian, G. M.; Oganessian, Yu. Ts.; Rodin, A. M.; Fomichev, A. S.; Popeko, G. S.; Daniel, A. V.; Rasmussen, J. O.; Macchiavelli, A. O.; Stoyer, M. A.; Donangelo, R.; Cole, J. D.

    2005-06-01

    For the first time, average angular momenta of the ternary fission fragments 100, 102Zr, 106Mo, 144, 146Ba and 138, 140, 142Xe from the α-accompanied fission of 252Cf were obtained from relative intensities of prompt γ-ray transitions with the use of the statistical model calculation. Average values of the angular momenta were compared with the corresponding values for the same fission fragments from the binary fission of 252Cf. Results indicate the presence of a decreasing trend in the average values of angular momenta induced in ternary fission fragments compared to the same binary fission fragments. On the average, the total angular momentum extracted for ternary fission fragments is ˜1.4 ℏ lower than in binary fission. Consequently, results indicate that the mechanism of the ternary α-particles emission may directly effect an induction of angular momenta of fission fragments, and possible scenarios of such mechanisms are discussed. Further, the dependence of the angular momenta of 106Mo and 140Xe on the number of emitted neutrons from correlated pairs of primary fragments was obtained also showing a decreasing dependence of average angular momenta with increasing number of emitted neutrons. Consequences are briefly discussed.

  15. Learning to assign binary weights to binary descriptor

    Science.gov (United States)

    Huang, Zhoudi; Wei, Zhenzhong; Zhang, Guangjun

    2016-10-01

    Constructing robust binary local feature descriptors are receiving increasing interest due to their binary nature, which can enable fast processing while requiring significantly less memory than their floating-point competitors. To bridge the performance gap between the binary and floating-point descriptors without increasing the computational cost of computing and matching, optimal binary weights are learning to assign to binary descriptor for considering each bit might contribute differently to the distinctiveness and robustness. Technically, a large-scale regularized optimization method is applied to learn float weights for each bit of the binary descriptor. Furthermore, binary approximation for the float weights is performed by utilizing an efficient alternatively greedy strategy, which can significantly improve the discriminative power while preserve fast matching advantage. Extensive experimental results on two challenging datasets (Brown dataset and Oxford dataset) demonstrate the effectiveness and efficiency of the proposed method.

  16. Fragmented Work Stories

    DEFF Research Database (Denmark)

    Humle, Didde Maria; Reff Pedersen, Anne

    2015-01-01

    by exploring how different types of fragmentation create meanings. This is done by studying the work stories of job and personnel consultants and by drawing on the results of a narrative, ethnographic study of a consultancy. The analysis demonstrates how work stories are social practices negotiated, retold...

  17. Picking Up (On) Fragments

    NARCIS (Netherlands)

    Ellis, Phil

    2015-01-01

    abstractThis article discusses the implications for archival and media archaeological research and reenactment artwork relating to a recent arts practice project: reenacttv: 30 lines / 60 seconds. It proposes that archival material is unstable but has traces and fragments that are full of creative p

  18. Fragments of the Past

    Directory of Open Access Journals (Sweden)

    Peter Szende

    2016-10-01

    Full Text Available With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  19. Cryobiology of coral fragments.

    Science.gov (United States)

    Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

    2013-02-01

    Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (Pcoral tissue, but not in the zooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (Pcoral tissue (∼75% loss) and zooxanthellae numbers declined in response to chilling alone (Pcoral against tissue loss after 45min of cryoprotectant exposure (P>0.05, ANOVA), but it did not protect against the loss of zooxanthellae (Pcoral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Picking Up (On) Fragments

    NARCIS (Netherlands)

    Ellis, Phil

    2015-01-01

    abstractThis article discusses the implications for archival and media archaeological research and reenactment artwork relating to a recent arts practice project: reenacttv: 30 lines / 60 seconds. It proposes that archival material is unstable but has traces and fragments that are full of creative p

  1. Wildlife habitat fragmentation.

    Science.gov (United States)

    John. Lehmkuhl

    2005-01-01

    A primary issue in forest wildlife management is habitat fragmentation and its effects on viability, which is the "bottom line" for plant and animal species of conservation concern. Population viability is the likelihood that a population will be able to maintain itself (remain viable) over a long period of time-usually 100 years or more. Though it is true...

  2. The influence of aerodynamic coefficients on the elements of classic projectile paths

    Directory of Open Access Journals (Sweden)

    Damir D. Jerković

    2011-04-01

    Full Text Available The article deals with the results of the research on the influence of aerodynamic coefficient values on the trajectory elements and the stability parameters of classic axisymmetric projectiles. It presents the characteristic functions of aerodynamic coefficients with regard to aerodynamic parameters and the projectile body shape. The trajectory elements of the model of classic axisymmetric projectiles and the analyses of their changes were presented with respect to the aerodynamic coefficient values. Introduction Classic axisymmetric projectiles fly through atmosphere using muzzle velocity as initial energy resource, so the aerodynamic force and moment have the most significant influence on the motion of projectiles. The aerodynamic force and moment components represented as aerodynamic coefficients depend on motion velocity i. e. flow velocity, the flow features produced by projectile shape and position in the flow, and angular velocity (rate of the body. The functional dependence of aerodynamic coefficients on certain influential parameters, such as angle of attack and angular velocity components is expressed by the derivative of aerodynamic coefficients. The determination of aerodynamic coefficients and derivatives enables complete definition of the aerodynamic force and moment acting on the classic projectile. The projectile motion problem is considered in relation to defining the projectile stability parameters and the conditions under which the stability occurs. The comparative analyses of aerodynamic coefficient values obtained by numerical methods, semi empirical calculations and experimental research give preliminary evaluation of the quality of the determined values. The flight simulation of the motion of a classic axisymetric projectile, which has the shape defined by the aerodynamic coefficient values, enables the comparative analyses of the trajectory elements and stability characteristics. The model of the classic projectile

  3. Cryogenic micro-calorimeters for mass spectrometric identification of neutral molecules and molecular fragments

    CERN Document Server

    Novotný, O; Enss, C; Fleischmann, A; Gamer, L; Hengstler, D; Kempf, S; Krantz, C; Pabinger, A; Pies, C; Savin, D W; Schwalm, D; Wolf, A

    2015-01-01

    We have systematically investigated the energy resolution of a magnetic micro-calorimeter (MMC) for atomic and molecular projectiles at impact energies ranging from $E\\approx13$ to 150~keV. For atoms we obtained absolute energy resolutions down to $\\Delta E \\approx 120$~eV and relative energy resolutions down to $\\Delta E/E\\approx10^{-3}$. We also studied in detail the MMC energy-response function to molecular projectiles of up to mass 56~u. We have demonstrated the capability of identifying neutral fragmentation products of these molecules by calorimetric mass spectrometry. We have modeled the MMC energy-response function for molecular projectiles and conclude that backscattering is the dominant source of the energy spread at the impact energies investigated. We have successfully demonstrated the use of a detector absorber coating to suppress such spreads. We briefly outline the use of MMC detectors in experiments on gas-phase collision reactions with neutral products. Our findings are of general interest fo...

  4. Charge-to-mass dispersion methods for abrasion-ablation fragmentation models

    Science.gov (United States)

    Townsend, L. W.; Norbury, J. W.

    1985-01-01

    Methods to describe the charge-to-mass dispersion distributions of projectile prefragments are presented and used to determine individual isotope cross-sections or various elements produced in the fragmentation of relativistic argon nuclei by carbon targets. Although slight improvements in predicted cross-sections are obtained for the quantum mechanical giant dipole resonance (GDR) distribution when compared qith the predictions of the geometric GDR model, the closest agreement between theory and experiment continues to be obtained with the simple hypergeometric distribution, which treats the nucleons in the nucleus as completely uncorrelated.

  5. Nuclear fragmentation energy and momentum transfer distributions in relativistic heavy-ion collisions

    Science.gov (United States)

    Khandelwal, Govind S.; Khan, Ferdous

    1989-01-01

    An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.

  6. Rotation periods of binary asteroids with large separations - Confronting the Escaping Ejecta Binaries model with observations

    Science.gov (United States)

    Polishook, D.; Brosch, N.; Prialnik, D.

    2011-03-01

    Durda et al. (Durda, D.D., Bottke, W.F., Enke, B.L., Merline, W.J., Asphaug, E., Richardson, D.C., Leinhardt, Z.M. [2004]. Icarus 170, 243-257), using numerical models, suggested that binary asteroids with large separation, called Escaping Ejecta Binaries (EEBs), can be created by fragments ejected from a disruptive impact event. It is thought that six binary asteroids recently discovered might be EEBs because of the high separation between their components (∼100 > a/Rp > ∼20). However, the rotation periods of four out of the six objects measured by our group and others and presented here show that these suspected EEBs have fast rotation rates of 2.5-4 h. Because of the small size of the components of these binary asteroids, linked with this fast spinning, we conclude that the rotational-fission mechanism, which is a result of the thermal YORP effect, is the most likely formation scenario. Moreover, scaling the YORP effect for these objects shows that its timescale is shorter than the estimated ages of the three relevant Hirayama families hosting these binary asteroids. Therefore, only the largest (D ∼ 19 km) suspected asteroid, (317) Roxane, could be, in fact, the only known EEB. In addition, our results confirm the triple nature of (3749) Balam by measuring mutual events on its lightcurve that match the orbital period of a nearby satellite in addition to its distant companion. Measurements of (1509) Esclangona at different apparitions show a unique shape of the lightcurve that might be explained by color variations.

  7. Chemical projectile-target interaction during hypervelocity cratering experiments (MEMIN project).

    Science.gov (United States)

    Ebert, M.; Hecht, L.; Deutsch, A.; Kenkmann, T.

    2012-04-01

    The detection and identification of meteoritic components in impact-derived rocks are of great value for confirming an impact origin and reconstructing the type of extraterrestrial material that repeatedly stroke the Earth during geologic evolution [1]. However, little is known about processes that control the projectile distribution into the various impactites that originate during the cratering and excavation process, and inter-element fractionation between siderophile elements during impact cratering. In the context of the MEMIN project, cratering experiments have been performed using spheres of Cr-V-Co-Mo-W-rich steel and of the iron meteorite Campo del Cielo (IAB) as projectiles accelerated to about 5 km/s, and blocks of Seeberger sandstone as target. The experiments were carried out at the two-stage acceleration facilities of the Fraunhofer Ernst-Mach-Institute (Freiburg). Our results are based on geochemical analyses of highly shocked ejecta material. The ejecta show various shock features including multiple sets of planar deformations features (PDF) in quartz, diaplectic quartz, and partial melting of the sandstone. Melting is concentrated in the phyllosilicate-bearing sandstone matrix but involves quartz, too. Droplets of molten projectile have entered the low-viscosity sandstone melt but not quartz glass. Silica-rich sandstone melts are enriched in the elements that are used to trace the projectile, like Fe, Ni, Cr, Co, and V (but no or little W and Mo). Inter-element ratios of these "projectile" tracer elements within the contaminated sandstone melt may be strongly modified from the original ratios in the projectiles. This fractionation most likely result from variation in the lithophile or siderophile character and/or from differences in reactivity of these tracer elements with oxygen [2] during interaction of metal melt with silicate melt. The shocked quartz with PDF is also enriched in Fe and Ni (experiment with a meteorite iron projectile) and in Fe

  8. Accuracy Improvement Capability of Advanced Projectile Based on Course Correction Fuze Concept

    Directory of Open Access Journals (Sweden)

    Ahmed Elsaadany

    2014-01-01

    Full Text Available Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake and the second is devoted to drift correction (canard based-correction fuze. The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.

  9. Accuracy improvement capability of advanced projectile based on course correction fuze concept.

    Science.gov (United States)

    Elsaadany, Ahmed; Wen-jun, Yi

    2014-01-01

    Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake) and the second is devoted to drift correction (canard based-correction fuze). The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.

  10. Experimental investigation on ballistic stability of high-speed projectile in sand

    Science.gov (United States)

    Zhang, Wei; Huang, Xianglin; Qi, Yafei; Li, Dacheng; Tao, Jialiang; Huang, Wei

    2017-01-01

    The investigation on ballistic stability of high-speed projectile in granular materials is important to study the EPW (earth-penetrating weapon). Laboratory-scaled sand entry experiments for the trajectory in the sand have been performed at a range of velocities from 30 m/s to 150 m/s. In addition, pressure sensor was embedded in the sand to record the sand stress which reflects the penetration performance of projectile during the impact. The slender projectiles were designed into flat nose shape with three kinds of L/D (length-diameter ratio) to make comparisons on the trajectory when those projectiles were launched at normal and oblique impact angles (0˜25deg) along a view window. A high-speed camera beside window was employed to capture the entire process of projectiles' penetration. Basing on the comparison of different tests, theoretical analysis is carried out on the relationship between ballistic stability and associated conditions. By utilizing DIC technique, the vector field of sand velocity was acquired, and the spreading direction of the impacting energy was observed. It can be concluded that the sand stress is the function of penetrating velocity, L/D and the shot angle. It increases with the growing of penetrating velocity and L/D, decreases with the shot angle. To a certain extent, the biggest initial velocity leads to the highest stress.

  11. A Six Degree of Freedom Trajectory Analysis of Spin-Stabilized Projectiles

    Science.gov (United States)

    Gkritzapis, Dimitrios N.; Panagiotopoulos, Elias E.; Margaris, Dionissios P.; Papanikas, Dimitrios G.

    2007-12-01

    A full six degrees of freedom (6-DOF) flight dynamics model is proposed for the accurate prediction of short and long-range trajectories of high and low spin-stabilized projectiles via atmospheric flight to final impact point. The projectile is assumed to be both rigid (non-flexible), and rotationally symmetric about its spin axis launched at low and high pitch angles. The projectile maneuvering motion depends on the most significant force and moment variations in addition to gravity and Magnus Effect. The computational flight analysis takes into consideration the Mach number and total angle of attack effects by means of the variable aerodynamic coefficients. For the purposes of the present work, linear interpolation has been applied from the tabulated database of McCoy's book. The aforementioned variable flight model is compared with a trajectory atmospheric motion based on appropriate constant mean values of the aerodynamic projectile coefficients. Static stability, also called gyroscopic stability, is examined as a necessary condition for stable flight motion in order to locate the initial spinning projectile rotation. Static stability examination takes into account the overturning moment variations with Mach number flight motion. The developed method gives satisfactory results compared with published data of verified experiments and computational codes on atmospheric dynamics model analysis.

  12. Numerical Investigation of Bending-Body Projectile Aerodynamics for Maneuver Control

    Science.gov (United States)

    Youn, Eric; Silton, Sidra

    2015-11-01

    Precision munitions are an active area of research for the U.S. Army. Canard-control actuators have historically been the primary mechanism used to maneuver fin-stabilized, gun-launched munitions. Canards are small, fin-like control surfaces mounted at the forward section of the munition to provide the pitching moment necessary to rotate the body in the freestream flow. The additional lift force due to the rotated body and the canards then alters the flight path toward the intended target. As velocity and maneuverability requirements continue to increase, investigation of other maneuver mechanisms becomes necessary. One option for a projectile with a large length-to-diameter ratio (L/D) is a bending-body design, which imparts a curvature to the projectile body along its axis. This investigation uses full Navier-Stokes computational fluid dynamics simulations to evaluate the effectiveness of an 8-degree bent nose tip on an 8-degree bent forward section of an L/D =10 projectile. The aerodynamic control effectiveness of the bending-body concept is compared to that of a standard L/D =10 straight-body projectile as well as that of the same projectile with traditional canards. All simulations were performed at supersonic velocities between Mach 2-4.

  13. Hydrocode Simulation with Modified Johnson-Cook Model and Experimental Analysis of Explosively Formed Projectiles

    Science.gov (United States)

    Hussain, G.; Hameed, A.; Hetherington, J. G.; Barton, P. C.; Malik, A. Q.

    2013-04-01

    The formation of mild steel (MS) and copper (Cu) explosively formed projectiles (EFPs) was simulated in AUTODYN using both the Johnson-Cook (JC) and modified Johnson-Cook (JCM) constitutive models. The JC model was modified by increasing the hardening constant by 10%. The previously established semi-empirical equations for diameter, length, velocity, and depth of penetration were used to verify the design of the EFP. The length-to-diameter (L/D) ratio of the warhead used in the simulation varied between 1 projectile distortion or breakup for large standoff applications, the design of the EFP warhead was modified to obtain a lower L/D ratio. Simulations from the JC model underestimated the EFP diameter, resulting in an unrealistically elongated projectile. This shortcoming was resolved by employing the JCM model, giving good agreement with the experimental results. The projectile velocity and hole characteristics in 10-mm-thick aluminum target plates were studied for both models. The semi-empirical equations and the JC model overestimated the projectile velocity, whereas the JCM model underestimated the velocity slightly when compared to the experimental results. The depths of penetration calculated by the semi-empirical equations in the aluminum (Al) target plate were 55 and 52 mm for Cu and MS EFPs, respectively.

  14. Magnetic-Moment Fragmentation and Monopole Crystallization

    Directory of Open Access Journals (Sweden)

    M. E. Brooks-Bartlett

    2014-01-01

    Full Text Available The Coulomb phase, with its dipolar correlations and pinch-point–scattering patterns, is central to discussions of geometrically frustrated systems, from water ice to binary and mixed-valence alloys, as well as numerous examples of frustrated magnets. The emergent Coulomb phase of lattice-based systems has been associated with divergence-free fields and the absence of long-range order. Here, we go beyond this paradigm, demonstrating that a Coulomb phase can emerge naturally as a persistent fluctuating background in an otherwise ordered system. To explain this behavior, we introduce the concept of the fragmentation of the field of magnetic moments into two parts, one giving rise to a magnetic monopole crystal, the other a magnetic fluid with all the characteristics of an emergent Coulomb phase. Our theory is backed up by numerical simulations, and we discuss its importance with regard to the interpretation of a number of experimental results.

  15. Binary Tetrahedral Flavor Symmetry

    CERN Document Server

    Eby, David A

    2013-01-01

    A study of the T' Model and its variants utilizing Binary Tetrahedral Flavor Symmetry. We begin with a description of the historical context and motivations for this theory, together with some conceptual background for added clarity, and an account of our theory's inception in previous works. Our model endeavors to bridge two categories of particles, leptons and quarks, a unification made possible by the inclusion of additional Higgs particles, shared between the two fermion sectors and creating a single coherent system. This is achieved through the use of the Binary Tetrahedral symmetry group and an investigation of the Tribimaximal symmetry evidenced by neutrinos. Our work details perturbations and extensions of this T' Model as we apply our framework to neutrino mixing, quark mixing, unification, and dark matter. Where possible, we evaluate model predictions against experimental results and find excellent matching with the atmospheric and reactor neutrino mixing angles, an accurate prediction of the Cabibb...

  16. The Binary Garrote

    CERN Document Server

    Kappen, H J

    2011-01-01

    In this paper, I present a new model and solution method for sparse regression. The model introduces binary selector variables $s_i$ for the features $i$ in a way that is similar to Breiman's Garrote model. I refer to this method as the binary Garrote (BG). The posterior probability for $s_i$ is computed in the variational approximation. The BG is compared numerically with the Lasso method and with ridge regression. Numerical results on synthetic data show that the BG yields more accurate predictions and more accurately reconstructs the true model than the other methods. The naive implementation of the BG requires the inversion of a modified covariance matrix which scales cubic in the number of features. We indicate how for sparse problem the solution can be computed linear in the number of features.

  17. Binary Love Relations

    CERN Document Server

    Yagi, Kent

    2015-01-01

    When in a tight binary, the mutual tidal deformations of neutron stars imprint onto observables, encoding information about their internal structure at supranuclear densities and gravity in the extreme-gravity regime. Gravitational wave observations of their late binary inspiral may serve as a tool to extract the individual tidal deformabilities, but this is made difficult by degeneracies between them in the gravitational wave model. We here resolve this problem by discovering approximately universal relations between dimensionless combinations of the individual tidal deformabilities. We show that these relations break degeneracies in the gravitational wave model, allowing for the accurate extraction of both deformabilities. Such measurements can be used to better differentiate between equation-of-state models, and improve tests of General Relativity and cosmology.

  18. Binary Love relations

    Science.gov (United States)

    Yagi, Kent; Yunes, Nicolás

    2016-07-01

    When in a tight binary, the mutual tidal deformations of neutron stars get imprinted onto observables, encoding information about their internal structure at supranuclear densities and gravity in the extreme-gravity regime. Gravitational wave (GW) observations of their late binary inspiral may serve as a tool to extract the individual tidal deformabilities, but this is made difficult by degeneracies between them in the GW model. We here resolve this problem by discovering approximately equation-of-state (EoS)-insensitive relations between dimensionless combinations of the individual tidal deformabilities. We show that these relations break degeneracies in the GW model, allowing for the accurate extraction of both deformabilities. Such measurements can be used to better differentiate between EoS models, and improve tests of general relativity and cosmology.

  19. Electroeluting DNA fragments.

    Science.gov (United States)

    Zarzosa-Alvarez, Ana L; Sandoval-Cabrera, Antonio; Torres-Huerta, Ana L; Bermudez-Cruz, Rosa M

    2010-09-05

    Purified DNA fragments are used for different purposes in Molecular Biology and they can be prepared by several procedures. Most of them require a previous electrophoresis of the DNA fragments in order to separate the band of interest. Then, this band is excised out from an agarose or acrylamide gel and purified by using either: binding and elution from glass or silica particles, DEAE-cellulose membranes, "crush and soak method", electroelution or very often expensive commercial purification kits. Thus, selecting a method will depend mostly of what is available in the laboratory. The electroelution procedure allows one to purify very clean DNA to be used in a large number of applications (sequencing, radiolabeling, enzymatic restriction, enzymatic modification, cloning etc). This procedure consists in placing DNA band-containing agarose or acrylamide slices into sample wells of the electroeluter, then applying current will make the DNA fragment to leave the agarose and thus be trapped in a cushion salt to be recovered later by ethanol precipitation.

  20. Binary-Signal Recovery

    Science.gov (United States)

    Griebeler, Elmer L.

    2011-01-01

    Binary communication through long cables, opto-isolators, isolating transformers, or repeaters can become distorted in characteristic ways. The usual solution is to slow the communication rate, change to a different method, or improve the communication media. It would help if the characteristic distortions could be accommodated at the receiving end to ease the communication problem. The distortions come from loss of the high-frequency content, which adds slopes to the transitions from ones to zeroes and zeroes to ones. This weakens the definition of the ones and zeroes in the time domain. The other major distortion is the reduction of low frequency, which causes the voltage that defines the ones or zeroes to drift out of recognizable range. This development describes a method for recovering a binary data stream from a signal that has been subjected to a loss of both higher-frequency content and low-frequency content that is essential to define the difference between ones and zeroes. The method makes use of the frequency structure of the waveform created by the data stream, and then enhances the characteristics related to the data to reconstruct the binary switching pattern. A major issue is simplicity. The approach taken here is to take the first derivative of the signal and then feed it to a hysteresis switch. This is equivalent in practice to using a non-resonant band pass filter feeding a Schmitt trigger. Obviously, the derivative signal needs to be offset to halfway between the thresholds of the hysteresis switch, and amplified so that the derivatives reliably exceed the thresholds. A transition from a zero to a one is the most substantial, fastest plus movement of voltage, and therefore will create the largest plus first derivative pulse. Since the quiet state of the derivative is sitting between the hysteresis thresholds, the plus pulse exceeds the plus threshold, switching the hysteresis switch plus, which re-establishes the data zero to one transition

  1. Water fragmentation by bare and dressed light ions with MeV energies: Fragment-ion-energy and time-of-flight distributions

    Science.gov (United States)

    Wolff, W.; Luna, H.; Schuch, R.; Cariatore, N. D.; Otranto, S.; Turco, F.; Fregenal, D.; Bernardi, G.; Suárez, S.

    2016-08-01

    The energy and time-of-flight distributions of water ionic fragments produced by impact of fast atoms and bare and dressed ions; namely, H+, Li0 -3 +, C1 +, and C2 + are reported in this work. Fragment species as a function of emission energy and time-of-flight were recorded by using an electrostatic spectrometer and a time-of-flight mass spectrometer, respectively. An improved Coulomb explosion model coupled to a classical trajectory Monte Carlo (CTMC) simulation gave the energy centroids of the fragments for the dissociation channels resulting from the removal of two to five electrons from the water molecule. For the energy distribution ranging up to 50 eV, both the experiment and model reveal an isotropic production of multiple charged oxygen ions, as well as hydrogen ions. From the ion energy distribution, relative yields of the dissociation resulting from multiple ionization were obtained as a function of the charge state, as well as for several projectile energies. Multiple-ionization yields with charge state up to 4+, were extracted from the measurements of the time-of-flight spectra, focused on the production of single and multiple charged oxygen ions. The measurements were compared to ion-water collision experiments investigated at the keV energy range available in the literature, revealing differences and similarities in the fragment-ion energy distribution.

  2. Multiplicity of secondary electrons emitted by carbon thin targets by impact of H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles at MeV energies; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l`impact de projectiles H{sup 0}, H{sub 2}{sup +} et H{sub 3}{sup +} d`energie de l`ordre du MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vidovic, Zvonimir [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

    1997-06-24

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25 - 2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. Phenomenological and theoretical descriptions as well as a summary of the main theoretical models are the subjects of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of the thin carbon foils crossed by an energetic projectile is described in the chapter two. In this chapter there are also presented the method and the algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H{sup 0} atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of the ions with solids. The role of the proximity of the protons, molecular ions fragments, upon the amplitude of these collected effects is evidenced from the study of the statistics of forward emission. The experiments allowed us to shed light on various aspects of atom and polyatomic ion interactions with solid surfaces. (author) 136 refs., 41 figs., 3 tabs.

  3. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  4. A study of the perforation of stiffened plates by rigid projectiles

    Institute of Scientific and Technical Information of China (English)

    Jianguo Ning; Weidong Song; Jing Wang

    2005-01-01

    In the present paper, a four-stage perforation model that accurately predicts the residual velocity is developed by adopting an energy method. The four stages are plug formation, dishing formation, petal formation and projectile exit. In addition, some important experimental results are presented and analyzed to validate the present perforation model. In the experiments, high speed camera system is used to record the perforation process. Observations on target damage and measurements of initial velocities and residual velocities with the aid of the system are presented. Numerical simulations are carried out for projectiles against single and layered plates adopted in the experiments. The perforation process is studied and the deformation and failure modes are obtained. The predictions of numerical simulations and analytical model are found in reasonably good agreement with those of experiments, and can be used to predict the ballistic limit and residual velocity of stiffened plates perforated by rigid projectiles.

  5. Projectile motion of a once rotating object: physical quantities at the point of return

    Science.gov (United States)

    Arabasi, Sameer

    2016-09-01

    Vertical circular motion is a widely used example to explain non-uniform circular motion in most undergraduate general physics textbooks. However, most of these textbooks do not elaborate on the case when this motion turns into projectile motion under certain conditions. In this paper, we describe thoroughly when a mass attached to a cord, moving in a vertical circular motion, turns into a projectile and its location and velocity when it rejoins the circular orbit. This paper provides an intuitive understanding, supported by basic kinematic equations, to give an interesting elegant connection between circular motion and projectile motion—something lacking in most physics textbooks—and will be very useful to present to an undergraduate class to deepen their understanding of both models of motion.

  6. On the non-equilibrium dynamics of cavitation around the underwater projectile in variable motion

    Science.gov (United States)

    Chen, Y.; Lu, C. J.; Li, J.; Chen, X.; Gong, Z. X.

    2015-12-01

    In this work, the dynamic behavior of the non-equilibrium cavitation occurring around the underwater projectiles navigating with variable speed was numerically and theoretically investigated. The cavity collapse induced by the decelerating motion of the projectiles can be classified into two types: periodic oscillation and damped oscillation. In each type the evolution of the total mass of vapor in cavity are found to have strict correlation with the pressure oscillation in far field. By defining the equivalent radius of cavity, we introduce the specific kinetic energy of collapse and demonstrate that its change-rate is in good agreement with the pressure disturbance. We numerically investigated the influence of angle of attack on the collapse effect. The result shows that when the projectile decelerates, an asymmetric-focusing effect of the pressure induced by collapse occurs on its pressure side. We analytically explained such asymmetric-focusing effect.

  7. Numerical Computations of Transonic Critical AerodynamicBehavior of a Realistic Artillery Projectile

    Directory of Open Access Journals (Sweden)

    Ahmed F. M. Kridi

    2009-01-01

    Full Text Available The determination of aerodynamic coefficients by shell designers is a critical step in the development of any projectile design. Of particular interest is the determination of the aerodynamic coefficients at transonic speeds. It is in this speed regime that the critical aerodynamic behavior occurs and a rapid change in the aerodynamic coefficients is observed. Two-dimensional, transonic, flow field computations over projectiles have been made using Euler equations which were used for solution with no special treatment required. In this work a solution algorithm is based on finite difference MacCormack’s technique for solving mixed subsonic-supersonic flow problem. Details of the asymmetrically located shock waves on the projectiles have been determined. Computed surface pressures have been compared with experimental data and are found to be in good agreement. The pitching moment coefficient, determined from the computed flow fields, shows the critical aerodynamic behavior observed in free flights.

  8. Probable projectile-target combinations for the synthesis of super heavy nucleus $^{286}$112

    CERN Document Server

    Santhosh, K P

    2014-01-01

    The fusion cross sections for the reactions of all the projectile-target combinations found in the cold valleys of $^{286}$112 have been studied using scattering potential as the sum of Coulomb and proximity potential, so as to predict the most probable projectile-target combinations in heavy ion fusion reactions for the synthesis of super heavy nucleus $^{286}$112. While considering the nature of potential pockets and half lives of the colliding nuclei, the systems $^{82}$Ge + $^{204}$Hg, $^{80}$Ge + $^{206}$Hg and $^{78}$Zn + $^{208}$Pb found in the deep cold valley region and the systems $^{48}$Ca+$^{238}$U, $^{38}$S+$^{248}$Cm and $^{44}$Ar+$^{242}$Pu in the cold valleys are predicted to be the better optimal projectile-target combinations for the synthesis of super heavy nucleus $^{286}$112.

  9. Treatment of ion-atom collisions using a partial-wave expansion of the projectile wavefunction

    Energy Technology Data Exchange (ETDEWEB)

    Foster, M [Los Alamos National Laboratory; Colgan, J [Los Alamos National Laboratory; Wong, T G [SANTA CLARA U; Madison, D H [MISSOURI U

    2008-01-01

    We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge scattering quantities. Here we show that such calculations are possible using modern high-performance computing. We demonstrate the utility of our method by examining elastic scattering of protons by hydrogen and helium atoms, problems familiar to undergraduate students of atomic scattering. Application to ionization of helium using partial-wave expansions of the projectile wavefunction, which has long been desirable in heavy-ion collision physics, is thus quite feasible.

  10. Extended Range of a Gun Launched Smart Projectile Using Controllable Canards

    Directory of Open Access Journals (Sweden)

    Mark Costello

    2001-01-01

    Full Text Available This effort investigates the extent to which moveable canards can extend the range of indirect fire munitions using both projectile body and canard lift. Implications on terminal velocity and time of flight using this mechanism to extend range are examined for various canard configurations. Performance predictions are conducted using a six-degree-of-freedom simulation model that has previously been validated against range data. The projectile dynamic equations are formed in the body frame and aerodynamic loads from the body and canards are Mach number and angle of attack dependent. The projectile body aerodynamic moments include unsteady aerodynamic damping. The focus of the study is directed toward low cost competent munitions that extend range and as such a simple flight control system is considered which utilizes only timer, roll rate, and roll attitude inputs.

  11. Probable Projectile-Target Combinations for the Synthesis of Super Heavy Nucleus 286112

    Directory of Open Access Journals (Sweden)

    K. P. Santhosh

    2014-02-01

    Full Text Available The fusion cross sections for the reactions of all the projectile-target combinations found in the cold valleys of 286112 have been studied using scattering potential as the sum of Coulomb and proximity potential, so as to predict the most probable projectile-target combinations in heavy ion fusion reactions for the synthesis of super heavy nucleus 286112. While considering the nature of potential pockets and half lives of the colliding nuclei, the systems 82Ge + 204Hg, 80Ge + 206Hg and 78Zn + 208Pb found in the deep cold valley region and the systems 48Ca+238U, 38S+248Cm and 44Ar+242Pu in the cold valleys are predicted to be the better optimal projectile-target combinations for the synthesis of super heavy nucleus 286112.

  12. Ground target localization algorithm for semi-active laser terminal correction projectile

    Directory of Open Access Journals (Sweden)

    Xing-long Li

    2016-06-01

    Full Text Available A target localization algorithm, which uses the measurement information from onboard GPS and onboard laser detector to acquire the target position, is proposed to obtain the accurate position of ground target in real time in the trajectory correction process of semi-active laser terminal correction projectile. A target localization model is established according to projectile position, attitude and line-of-sight angle. The effects of measurement errors of projectile position, attitude and line-of-sight angle on localization accuracy at different quadrant elevation angles are analyzed through Monte-Carlo simulation. The simulation results show that the measurement error of line-of-sight angle has the largest influence on the localization accuracy. The localization accuracy decreases with the increase in quadrant elevation angle. However, the maximum localization accuracy is less than 7 m. The proposed algorithm meets the accuracy and real-time requirements of target localization.

  13. Hypervelocity impact on brittle materials of semi-infinite thickness: fracture morphology related to projectile diameter

    Science.gov (United States)

    Taylor, Emma A.; Kay, Laurie; Shrine, Nick R. G.

    Hypervelocity impact on brittle materials produces features not observed on ductile targets. Low fracture toughness and high yield strength produce a range of fracture morphologies including cracking, spallation and shatter. For sub-mm diameter projectiles, impact features are characterised by petaloid spallation separated by radial cracks. The conchoidal or spallation diameter is a parameter in current cratering equations. An alternative method for interpreting hypervelocity impacts on glass targets of semi-infinite thickness is tested against impact data produced using the Light Gas Gun (LGG) facility at the University of Kent at Canterbury (UKC), U.K. Spherical projectiles of glass and other materials with diameters 30-300 μm were fired at ~5 km s^-1 at a glass target of semi-infinite thickness. The data is used to test a power law relationship between projectile diameter and crack length. The results of this work are compared with published cratering/spallation equations for brittle materials.

  14. Orbital deflection of fragments produced through peripheral reactions of heavy nuclei at 290 MeV/nucleon

    Science.gov (United States)

    Momota, S.; Kanazawa, M.; Kitagawa, A.; Sato, S.

    2017-02-01

    The orbital deflection phenomenon of reaction products formed through peripheral reactions of heavy nuclei at intermediate energy is studied to examine the contributions of the Coulomb potential and nuclear potential that act between the projectile and target nuclei. The angular distributions of fragments produced in 1-nucleon removal and exchange reactions of 40Ar and 84Kr beams with C, Al, Nb, Tb, and Au targets at 290 MeV/nucleon were observed. A significant deflection effect was successfully identified in observed angular distributions at energies as low as Ei = 100 MeV/nucleon. The deflection effect increases with the atomic number of the target nuclei. The observed deflection effect is consistently explainable using the classical deflection angle, which is obtained with respect to a simple framework of the Coulomb potential and the real part of the energy-dependent nuclear potential, and the characteristic impact parameter between the projectile and target nuclei.

  15. Study on measurement method for projectile location based on light screen

    Science.gov (United States)

    Han, Feng; Liu, QunHua; Sun, GuoBin

    2008-09-01

    In weapon-ammunition system, firing accuracy of projectile is major characteristic parameter weighing fire effect and capability of weapon-ammunition system for target. At present, firing accuracy of projectile is obtained by measuring the two-dimensional coordinates of projectile for target. In order to measure the parameters of two-dimensional coordinates of projectile for target, a new type of measurement system is proposed. The measurement system is composed of four high sensitivity light screens (known as target) with special geometrical frame. Light source of the screens is formed by special infrared LED array. The PIN infrared photodiodes array is used as the sensors. The longest effective distance between light source and sensors is 4m. It is impossible to achieve using traditional methods. Four light screens and high-precision timers are combined in order to acquire the value of time when the projectile flies across the position of four light screens. The real-time data acquirement and processing and display of two-dimensional coordinates and the projectile velocity can be realized. The principle of measurement system and the design of high sensitivity light screen are introduced emphatically. The measurement system was verified by using five kinds of small caliber pellets. As compared with the paper target sheet, the measurement system designed can meet the demand of check-up test of gun, bullet and ammunition. The firing testing in the target field has proved that the measurement system has the advantages of simple construction, easy operation and high precision and high sensitivity.

  16. Systematic study of probable projectile-target combinations for the synthesis of the superheavy nucleus 302120

    Science.gov (United States)

    Santhosh, K. P.; Safoora, V.

    2016-08-01

    Probable projectile-target combinations for the synthesis of the superheavy element 302120 have been studied taking the Coulomb and proximity potential as the interaction barrier. The probabilities of the compound nucleus formation PCN for the projectile-target combinations found in the cold reaction valley of 302120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion, and evaporation residue cross sections for the reactions of all probable projectile-target combinations so as to predict the most promising projectile-target combinations for the synthesis of the superheavy element 302120 in heavy-ion fusion reactions. The calculated fusion and evaporation cross sections for the more asymmetric ("hotter") projectile-target combination is found to be higher than the less asymmetric ("colder") combination. It can be seen from the nature of the quasifission barrier height, mass asymmetry, the probability of compound nucleus formation, survival probability, and excitation energy, the systems 44Ar+258No , 46Ar+256No , 48Ca+254Fm , 50Ca+252Fm , 54Ti+248Cf , and 58Cr+244Cm in deep region I of the cold reaction valley and the systems 62Fe+240Pu , 64Fe+238Pu , 68Ni+234U , 70Ni+232U , 72Ni+230U , and 74Zn+228Th in the other cold valleys are identified as the better projectile-target combinations for the synthesis of 302120. Our predictions on the synthesis of 302120 superheavy nuclei using the combinations 54Cr+248Cm , 58Fe+244Pu , 64Ni+238U , and 50Ti+249Cf are compared with available experimental data and other theoretical predictions.

  17. Visual binary stars: data to investigate formation of binaries

    Science.gov (United States)

    Kovaleva,, D.; Malkov,, O.; Yungelson, L.; Chulkov, D.

    Statistics of orbital parameters of binary stars as well as statistics of their physical characteristics bear traces of star formation history. However, statistical investigations of binaries are complicated by incomplete or missing observational data and by a number of observational selection effects. Visual binaries are the most common type of observed binary stars, with the number of pairs exceeding 130 000. The most complete list of presently known visual binary stars was compiled by cross-matching objects and combining data of the three largest catalogues of visual binaries. This list was supplemented by the data on parallaxes, multicolor photometry, and spectral characteristics taken from other catalogues. This allowed us to compensate partly for the lack of observational data for these objects. The combined data allowed us to check the validity of observational values and to investigate statistics of the orbital and physical parameters of visual binaries. Corrections for incompleteness of observational data are discussed. The datasets obtained, together with modern distributions of binary parameters, will be used to reconstruct the initial distributions and parameters of the function of star formation for binary systems.

  18. Physics Learning Achievement Study: Projectile, Using Mathematica Program of Faculty of Science and Technology Phetchabun Rajabhat University Students

    Science.gov (United States)

    Hutem, Artit; Kerdmee, Supoj

    2013-01-01

    The propose of this study is to study Physics Learning Achievement, projectile motion, using the Mathematica program of Faculty of Science and Technology Phetchabun Rajabhat University students, comparing with Faculty of Science and Technology Phetchabun Rajabhat University students who study the projectile motion experiment set. The samples are…

  19. Experimental Study and Numerical Simulation of Hypervelocity Projectile Impact on Double-Wall Structure

    Institute of Scientific and Technical Information of China (English)

    陈沿海; 张庆明; 黄风雷

    2004-01-01

    Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-DYNA was employed for the simulation of hypervelocity impact on the double-wall structure. By using elementary shock wave theory, the experimental results above are analyzed. The analysis can provide an explanation for the penetration mechanism of hypervelocity projectile impact on double-wall structure about the effect of front wall thickness and impact velocity.

  20. On the geometrical place formed by the maximum heights of projectile motion with air resistance

    CERN Document Server

    Hernández-Saldaña, H

    2010-01-01

    We present an analysis on the geometrical place formed by the set of maxima of the orbits of a projectile launched in a media with linear drag. Such a place is written in term of the Lambert W function in polar coordinates, confirming the special role played by this function in the problem. In order to characterize it, a study of the curvature is presented in two parameterizations, in terms of the launching angle and in the polar one. The angles of maximum curvature are compared with other important angles in the projectile problem.

  1. Estimating 3D positions and velocities of projectiles from monocular views.

    Science.gov (United States)

    Ribnick, Evan; Atev, Stefan; Papanikolopoulos, Nikolaos P

    2009-05-01

    In this paper, we consider the problem of localizing a projectile in 3D based on its apparent motion in a stationary monocular view. A thorough theoretical analysis is developed, from which we establish the minimum conditions for the existence of a unique solution. The theoretical results obtained have important implications for applications involving projectile motion. A robust, nonlinear optimization-based formulation is proposed, and the use of a local optimization method is justified by detailed examination of the local convexity structure of the cost function. The potential of this approach is validated by experimental results.

  2. Double excitation of Ar{sup 16+} projectiles in the intermediate velocity regime

    Energy Technology Data Exchange (ETDEWEB)

    Adoui, L.; Chetioui, A.; Despiney, I.; L`hoir, A.; Rozet, J.P.; Schmaus, D.; Touati, A.; Vernhet, D.; Wohrer, K. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides; Cassimi, A.; Grandin, J.P.; Ramillon, J.M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Stephan, C. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    1993-12-31

    The double excitation of Ar{sup 16+} projectiles is observed at GANIL with Ar{sup 16+} projectiles of 13.6 MeV/u (v=23 a.u.) by looking at the radiative decay of the double excited states, thus avoiding the interference effect. Moreover, double excitation together with single excitation in very similar systems (Ar{sup 16+} {yields} He, N{sub 2}, Ne, Ar, Kr, Xe) have been studied, thus allowing to a real test of the two-electron mechanism. 1 fig., 4 refs.

  3. Experimental and Analytical Study on the Penetration of Corundum-Rubble Concrete Subjected to Projectile Impact

    Directory of Open Access Journals (Sweden)

    Y. L. Xue

    2017-01-01

    Full Text Available A new type of composite concrete which can be called corundum-rubble concrete (CRC was presented to improve the resistance of protective structure to the projectile impact. Comparative experiments were conducted between CRC and reinforced concrete, and a modified Taylor model was proposed to predict the penetration depth of CRC targets. Experimental results show that CRC is much higher than reinforced concrete in both strength and hardness and shows excellent resistance to the 0.125 m-diameter projectile impact. Theoretical analyses demonstrated that the modified Taylor model’s predicted results were in good agreement with the measured values.

  4. Acceleration Measurement of Projectile High Velocity Penetrating Concrete Target and Acceleration Signal Analysis

    Institute of Scientific and Technical Information of China (English)

    Peng XU; Jing ZU; Jing-biao FAN

    2010-01-01

    A kind of novel on-boand memory acceleratian measure equipment, self-developed, had been employed in recent field test to obtain the acceleration of projectile penetrating many kinds of concrete target. At the same time, the aluminum foam with different density and pore-diameters had been utilized to protect cirruit modules. Fur-thermore, with the theoretical analysis, computer simulation and field test, the high frequency's impact on the tested acceleration of the projectile had been discussed; At last, the analysis on output signal tested the validity of test data.

  5. Effectiveness of projectile screening in single and multiple ionization of Ne by B{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, W.; Luna, H.; Santos, A. C. F.; Montenegro, E. C. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, 21945-970 RJ (Brazil); DuBois, R. D. [Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States); Montanari, C. C.; Miraglia, J. E. [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, C1428EGA, Buenos Aires (Argentina)

    2011-10-15

    Pure multiple ionization cross sections of Ne by B{sup 2+} projectiles have been measured in the energy range of 0.75 to 4.0 MeV and calculated using the continuum distorted wave-eikonal initial state approximation. The experiment and calculations show that the ionization cross sections by B{sup 2+}, principally for the production of highly charged recoils, is strongly enhanced when compared to the bare projectile with the same charge state, He{sup 2+}, at the same velocities.

  6. Quantitative functional analysis of Late Glacial projectile points from northern Europe

    DEFF Research Database (Denmark)

    Dev, Satya; Riede, Felix

    2012-01-01

    This paper discusses the function of Late Glacial arch-backed and tanged projectile points from northern Europe in general and southern Scandinavia in particular. Ballistic requirements place clear and fairly well understood constraints on the design of projectile points. We outline the argument...... surely fully serviceable, diverged considerably from the functional optimum predicated by ballistic theory. These observations relate directly to southern Scandinavian Late Glacial culture-history which is marked by a sequence of co-occurrence of arch-backed and large tanged points in the earlier part...

  7. Heavy meson fragmentation at LHC

    Directory of Open Access Journals (Sweden)

    M. A. Gomshi Nobary

    2003-06-01

    Full Text Available   Large Hadron Collider (LHC at CERN will provide excellent opportunity to study the production and decay of heavy mesons and baryons with high statistics. We aim at the heavy mesons in this work and calculate their fragmentation functions consistent with this machine and present their total fragmentation probabilities and average fragmentation parameters.

  8. SCALING AND 4-QUARK FRAGMENTATION

    NARCIS (Netherlands)

    SCHOLTEN, O; BOSVELD, GD

    1991-01-01

    The conditions for a scaling behaviour from the fragmentation process leading to slow protons are discussed- The scaling referred to implies that the fragmentation functions depend on the light-cone momentum fraction only. It is shown that differences in the fragmentation functions for valence- and

  9. The Physics of Protoplanetesimal Dust Agglomerates. V. Multiple Impacts of Dusty Agglomerates at Velocities Above the Fragmentation Threshold

    Science.gov (United States)

    Kothe, Stefan; Güttler, Carsten; Blum, Jürgen

    2010-12-01

    In recent years, a number of new experiments have advanced our knowledge on the early growth phases of protoplanetary dust aggregates. Some of these experiments have shown that collisions between porous and compacted agglomerates at velocities above the fragmentation threshold velocity can lead to growth of the compact body, when the porous collision partner fragments upon impact and transfers mass to the compact agglomerate. To obtain a deeper understanding of this potentially important growth process, we performed laboratory and drop tower experiments to study multiple impacts of small, highly porous dust-aggregate projectiles onto sintered dust targets. The projectile and target consisted of 1.5 μm monodisperse, spherical SiO2 monomers with volume filling factors of 0.15 ± 0.01 and 0.45 ± 0.05, respectively. The fragile projectiles were accelerated by a solenoid magnet and combined with a projectile magazine with which 25 impacts onto the same spot on the target could be performed in vacuum. We measured the mass-accretion efficiency and the volume filling factor for different impact velocities between 1.5 and 6.0 m s^{-1}. The experiments at the lowest impact speeds were performed in the Bremen drop tower under microgravity conditions to allow partial mass transfer also for the lowest adhesion case. Within this velocity range, we found a linear increase of the accretion efficiency with increasing velocity. In the laboratory experiments, the accretion efficiency increases from 0.12 to 0.21 in units of the projectile mass. The recorded images of the impacts showed that the mass transfer from the projectile to the target leads to the growth of a conical structure on the target after less than 100 impacts. From the images, we also measured the volume filling factors of the grown structures, which ranged from 0.15 (uncompacted) to 0.40 (significantly compacted) with increasing impact speed. The velocity dependency of the mass-transfer efficiency and the packing

  10. Evaluation of interatomic potentials for noble gas atoms from rainbow scattering under axial channeling at Ag(1 1 1) surface by computer simulations based on binary collision approximation

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Wataru, E-mail: take@sp.ous.ac.jp

    2016-01-01

    The rainbow angles corresponding to pronounced peaks in the angular distributions of scattered projectiles with small angle, attributed to rainbow scattering (RS), under axial surface channeling conditions are strongly dependent on the interatomic potentials between projectiles and target atoms. The dependence of rainbow angles on normal energy of projectile energy to the target surface that has been experimentally obtained by Schüller and Winter (SW) (2007) for RS of He, Ne and Ar atoms from a Ag(1 1 1) surface with projectile energies of 3–60 keV was evaluated by the three-dimensional computer simulations using the ACOCT code based on the binary collision approximation with interatomic pair potentials. Consequently, the ACOCT results employing the Moliere pair potential with screening length correction close to adjustable one of O’Connor and Biersack (OB) formula are almost in agreement with the experimental ones, being self-consistent with the SW’s ones analyzed by computer simulations of classical trajectory calculations as RS from corrugated equipotential planes based on continuum potentials including the Moliere pair potential with screening length correction of the OB formula.

  11. The african origin of complex projectile technology: an analysis using tip cross-sectional area and perimeter.

    Science.gov (United States)

    Sisk, Matthew L; Shea, John J

    2011-01-01

    Despite a body of literature focusing on the functionality of modern and stylistically distinct projectile points, comparatively little attention has been paid to quantifying the functionality of the early stages of projectile use. Previous work identified a simple ballistics measure, the Tip Cross-Sectional Area, as a way of determining if a given class of stone points could have served as effective projectile armatures. Here we use this in combination with an alternate measure, the Tip Cross-Sectional Perimeter, a more accurate proxy of the force needed to penetrate a target to a lethal depth. The current study discusses this measure and uses it to analyze a collection of measurements from African Middle Stone Age pointed stone artifacts. Several point types that were rejected in previous studies are statistically indistinguishable from ethnographic projectile points using this new measure. The ramifications of this finding for a Middle Stone Age origin of complex projectile technology is discussed.

  12. The African Origin of Complex Projectile Technology: An Analysis Using Tip Cross-Sectional Area and Perimeter

    Directory of Open Access Journals (Sweden)

    Matthew L. Sisk

    2011-01-01

    Full Text Available Despite a body of literature focusing on the functionality of modern and stylistically distinct projectile points, comparatively little attention has been paid to quantifying the functionality of the early stages of projectile use. Previous work identified a simple ballistics measure, the Tip Cross-Sectional Area, as a way of determining if a given class of stone points could have served as effective projectile armatures. Here we use this in combination with an alternate measure, the Tip Cross-Sectional Perimeter, a more accurate proxy of the force needed to penetrate a target to a lethal depth. The current study discusses this measure and uses it to analyze a collection of measurements from African Middle Stone Age pointed stone artifacts. Several point types that were rejected in previous studies are statistically indistinguishable from ethnographic projectile points using this new measure. The ramifications of this finding for a Middle Stone Age origin of complex projectile technology is discussed.

  13. Systematic study on probable projectile-target combinations for the synthesis of the $^{302}$120 superheavy nucleus

    CERN Document Server

    Santhosh, K P

    2016-01-01

    Probable projectile-target combinations for the synthesis of superheavy element $^{302}$120 have been studied taking Coulomb and proximity potential as the interaction barrier. The probabilities of compound nucleus formation, PCN for the projectile-target combinations found in the cold reaction valley of $^{302}$120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion and evaporation residue cross sections for the reactions of all the probable projectile-target combinations so as to predict the most promising projectile-target combinations for the synthesis of SHE $^{302}$120 in heavy ion fusion reactions. The calculated fusion and evaporation cross section for the more asymmetric (hotter) projectile-target combination is found to be higher than the less asymmetric (colder) combination. It can be seen from the nature of quasi-fission barrier height, mass asymmetry, probability of compound nucleus formation, survival probability and excitation energy, the system...

  14. Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?

    CERN Document Server

    Hennebelle, P

    2007-01-01

    Abridged. A large fraction of stars are found in binary systems. It is therefore important for our understanding of the star formation process, to investigate the fragmentation of dense molecular cores. We study the influence of the magnetic field, ideally coupled to the gas, on the fragmentation in multiple systems of collapsing cores. We present high resolution numerical simulations performed with the RAMSES MHD code starting with a uniform sphere in solid body rotation and a uniform magnetic field parallel to the rotation axis. We pay particular attention to the strength of the magnetic field and interpret the results using the analysis presented in a companion paper. The results depend much on the amplitude, $A$, of the perturbations seeded initially. For a low amplitude, $A=0.1$, we find that for values of the mass-to-flux over critical mass-to-flux ratio, $\\mu$, as high as $\\mu = 20$, the centrifugally supported disk which fragments in the hydrodynamical case, is stabilized and remains axisymmetric. Det...

  15. Picking Up (On Fragments

    Directory of Open Access Journals (Sweden)

    Phil Ellis

    2015-09-01

    Full Text Available This article discusses the implications for archival and media archaeological research and reenactment artwork relating to a recent arts practice project: reenacttv: 30 lines / 60 seconds. It proposes that archival material is unstable but has traces and fragments that are full of creative potential to re-think and re-examine past media historical events through a media archaeological approach to reenactment. The article contains images and links to videos from the final reenactment artworks as well as from rehearsals in Vienna and Bradford.

  16. An Archeology of Fragments

    Directory of Open Access Journals (Sweden)

    Gerald L. Bruns

    2014-10-01

    Full Text Available This is a short (fragmentary history of fragmentary writing from the German Romantics (F. W. Schlegel, Friedrich Hölderlin to modern and contemporary concrete or visual poetry. Such writing is (often deliberately a critique of the logic of subsumption that tries to assimilate whatever is singular and irreducible into totalities of various categorical or systematic sorts. Arguably, the fragment (parataxis is the distinctive feature of literary Modernism, which is a rejection, not of what precedes it, but of what Max Weber called “the rationalization of the world” (or Modernity whose aim is to keep everything, including all that is written, under surveillance and control.

  17. Chaos in Binary Category Computation

    CERN Document Server

    Gonçalves, Carlos Pedro

    2010-01-01

    Category computation theory deals with a web-based systemic processing that underlies the morphic webs, which constitute the basis of categorial logical calculus. It is proven that, for these structures, algorithmically incompressible binary patterns can be morphically compressed, with respect to the local connectivities, in a binary morphic program. From the local connectivites, there emerges a global morphic connection that can be characterized by a low length binary string, leading to the identification of chaotic categorial dynamics, underlying the algorithmically random pattern. The work focuses on infinite binary chains of C2, which is a category that implements an X-OR-based categorial logical calculus.

  18. Rotational mixing in close binaries

    CERN Document Server

    de Mink, S E; Langer, N; Yoon, S -Ch; Brott, I; Glebbeek, E; Verkoulen, M; Pols, O R

    2008-01-01

    Rotational mixing is a very important but uncertain process in the evolution of massive stars. We propose to use close binaries to test its efficiency. Based on rotating single stellar models we predict nitrogen surface enhancements for tidally locked binaries. Furthermore we demonstrate the possibility of a new evolutionary scenario for very massive (M > 40 solar mass) close (P < 3 days) binaries: Case M, in which mixing is so efficient that the stars evolve quasi-chemically homogeneously, stay compact and avoid any Roche-lobe overflow, leading to very close (double) WR binaries.

  19. Evolution of Close Binary Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, K; Eggleton, P

    2005-01-24

    We collected data on the masses, radii, etc. of three classes of close binary stars: low-temperature contact binaries (LTCBs), near-contact binaries (NCBs), and detached close binaries (DCBs). They restrict themselves to systems where (1) both components are, at least arguably, near the Main Sequence, (2) the periods are less than a day, and (3) there is both spectroscopic and photometric analysis leading to reasonably reliable data. They discuss the possible evolutionary connections between these three classes, emphasizing the roles played by mass loss and angular momentum loss in rapidly-rotating cool stars.

  20. Low autocorrelation binary sequences

    Science.gov (United States)

    Packebusch, Tom; Mertens, Stephan

    2016-04-01

    Binary sequences with minimal autocorrelations have applications in communication engineering, mathematics and computer science. In statistical physics they appear as groundstates of the Bernasconi model. Finding these sequences is a notoriously hard problem, that so far can be solved only by exhaustive search. We review recent algorithms and present a new algorithm that finds optimal sequences of length N in time O(N {1.73}N). We computed all optimal sequences for N≤slant 66 and all optimal skewsymmetric sequences for N≤slant 119.