Correlated electron capture in the impact parameter and final projectile charge-state dependence of ECC cusp production in 0.53 MeV u-1 F8+ + Ne

International Nuclear Information System (INIS)

Skutlartz, A.; Hagmann, S.; Schmidt-Boecking, H.

1988-01-01

The impact parameter dependence of ECC cusp electron production in collisions of fast, highly charged ions with atoms is investigated by measuring the scattered projectiles in coincidence with cusp electrons emitted at 0 0 with respect to the beam axis. The absolute probabilities for ECC cusp production show a maximum at b ≅ 0.10 au, decrease strongly for smaller impact parameters and more gently toward larger impact parameters. In addition the final charge state of the scattered projectile is also determined simultaneously for each collision event. The probabilities, as a function of the projectile final charge state, are large for the case where at least one or more electrons are simultaneously captured into bound states of the projectile, but are surprisingly small for collisions in which a projectile did not capture an electron into a bound state. (author)

Recent results on fusion and direct reactions with weakly bound stable nuclei

International Nuclear Information System (INIS)

Shrivastava, A.

2011-01-01

Recent measurements of fusion and direct reactions in case of weakly bound stable nuclei at extreme sub-barrier energies using a sensitive off beam technique are presented. First section deals with deep sub-barrier fusion cross-section measurement for 67 Li + 198 Pt followed by the study of fragment capture reaction of 7 Li + 198 Pt. Deviation in the slope of the fusion excitation function, as observed in case of medium heavy systems, is absent in the present asymmetric systems at these low energies. This study shows the absence of fusion hindrance, suggesting modifications in models that explain deep sub-barrier fusion data to incorporate weakly bound asymmetric systems

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.

Subcaliber discarding sabot airgun projectiles.

Science.gov (United States)

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

2014-03-01

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

Universality of projectile fragmentation model

International Nuclear Information System (INIS)

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

2012-01-01

Presently projectile fragmentation reaction is an important area of research as it is used for the production of radioactive ion beams. In this work, the recently developed projectile fragmentation model with an universal temperature profile is used for studying the charge distributions of different projectile fragmentation reactions with different projectile target combinations at different incident energies. The model for projectile fragmentation consists of three stages: (i) abrasion, (ii) multifragmentation and (iii) evaporation

Prevention of breakdown behind railgun projectiles

International Nuclear Information System (INIS)

Hawke, R.S.

1992-01-01

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

Backward ejected electrons produced by 1-MeV/u Oq+ (q=3--8) projectile ions colliding with argon gas

International Nuclear Information System (INIS)

Breinig, M.; Berryman, J.W.; Segner, F.; Desai, D.D.

1994-01-01

The cross sections for ejecting electrons into a cone of half-angle ∼2 degree centered on the backward direction have been measured as a function of electron energy for 1-MeV/u O q+ (q=3--8) projectiles colliding with Ar. For O 3+ and O 4+ projectiles, the cross sections have also been measured in coincidence with exit charge states (q+1) and (q+2) of the projectile. A prominent feature in all spectra is a target LMM Auger peak. The cross sections for producing Ar LMM Auger electrons are nearly independent of projectile incident charge states. A projectile electron-loss peak is produced when the projectile brings loosely bound L-shell electrons into the collision. The shape of this peak is independent of the projectile exit charge state within experimental error. The measured electron-loss production cross sections at 180 degree are compared with the predictions of various on-shell approximations to the impulse approximation. Peak height and position are sensitive functions of the on-shell approximation used. The predictions of the elastic scattering model agree well with the data

Mercury as the Unaccreted Projectile: Thermal Consequences

Science.gov (United States)

Asphaug, Erik; Gabriel, Travis; Jackson, Alan; Perera, Viranga

2017-10-01

Mercury retained substantial volatiles during its formation, in far greater proportion than the Moon, despite losing ~2/3 of its rocky mantle. Its volatile-rich geochemistry would contraindicate a giant impact because it would drive away the volatiles, as in the hypothesis for the Moon. However, the thermal consequences of Mercury formation vary considerably between the two giant impact scenarios, ‘direct hit’ (DH; Benz et al. 1989) and ‘hit and run’ (HR; Asphaug and Reufer 2014). Each begins with a differentiated chondritic proto-Mercury (PM) a bit larger than Mars. In DH, PM gets eroded by a very energetic impactor half its mass, at ~6-7 times the escape velocity. To remove half of PM’s mantle, the post-impact target gets completely shock-vaporized and is sheared apart into space. The bound remnant in DH would experience a comparable deposition of shock enthalpy, as in Moon formation, and would expand into a much larger volume of heliocentric space, leading to a dry planet. The bound remnant will go on to re-accrete much of the silicate mantle that it just lost, another challenge for DH. In HR, PM is the projectile that slams into a terrestrial planet twice its size (proto-Venus or proto-Earth). For typical impact angle and speed, a typical outcome is to ‘bounce”. But for HR to explain Mercury, PM must avoid accretion every time it encounters the target, until it is scattered or migrates away (or is accreted, in which case there is no Mercury), leading to multi-HR scenarios. Tides are intense in HR because the projectile grazes the target core; gravity does most of the work of mantle stripping. Shocks play a secondary role. Whereas in DH the impactor blasts the target inside-out, in HR the runner emerges relatively unshocked, and undispersed except for losing the gravitationally-unbound material. HR is a mechanism for collecting low-shocked remnants, because the intensely shocked material ends up bound to the target or escaping to heliocentric space

EMGWS, D1 projectile tests

International Nuclear Information System (INIS)

Creighton, W.J.

1991-01-01

This paper reports on the 90 mm EMGWS D1 Projectile which is an unguided projectile that is designed for launch from an Electromagnetic gun to achieve significant armor penetration. It is being developed under the broader program called Electromagnetic Gun Weapon System (EMGWS) which is sponsored by DARPA, DNA, and the U.S. Army. The 90 mm D1 Type II 'workhorse' Projectile is used to prove out material strength, fabrication techniques, and projectile structural integrity. The type II flight projectile is designed to allow maximum stress levels of 100-ksi when launched at 100-kilogees peak acceleration. The total weight of the projectile is 2.0 kg to attain a muzzle velocity of 3.0 km/s from a 9-Megajoule EM Gun. The Type II projectile configuration employs a tungsten nosetip plus 12 segmented tungsten penetrators, a two-piece aluminum discarding sabot, an aluminum pusher plate, and a nylon obturator. The pusher plate can incorporate either a solid or plasma armature

Electron-hydrogen collisions with dressed target and Volkov projectile states in a laser field

International Nuclear Information System (INIS)

Smith, P.H.G.; Flannery, M.R.

1992-01-01

Cross sections for the 1S-2S and 1S-2P O transitions in laser-assisted e - -H(1S) collisions are calculated in both the multi-channel eikonal treatment and the Born wave approximation, as a function of impact energy and laser field intensity. The laser considered is a monotonic, plane-polarized CO 2 laser (photon energy = 0.117 eV) with the polarization direction parallel to the initial projectile velocity. The first part of this paper confines the laser perturbation to the bound electrons of the atom. The second part extends the laser perturbation to the projectile electron, and the familiar Volkov dressed states are used. (author)

Robust stabilization of nonlinear systems via stable kernel representations with L2-gain bounded uncertainty

NARCIS (Netherlands)

van der Schaft, Arjan

1995-01-01

The approach to robust stabilization of linear systems using normalized left coprime factorizations with H∞ bounded uncertainty is generalized to nonlinear systems. A nonlinear perturbation model is derived, based on the concept of a stable kernel representation of nonlinear systems. The robust

In-flight dynamics of volcanic ballistic projectiles

Science.gov (United States)

Taddeucci, J.; Alatorre-Ibargüengoitia, M. A.; Cruz-Vázquez, O.; Del Bello, E.; Scarlato, P.; Ricci, T.

2017-09-01

Centimeter to meter-sized volcanic ballistic projectiles from explosive eruptions jeopardize people and properties kilometers from the volcano, but they also provide information about the past eruptions. Traditionally, projectile trajectory is modeled using simplified ballistic theory, accounting for gravity and drag forces only and assuming simply shaped projectiles free moving through air. Recently, collisions between projectiles and interactions with plumes are starting to be considered. Besides theory, experimental studies and field mapping have so far dominated volcanic projectile research, with only limited observations. High-speed, high-definition imaging now offers a new spatial and temporal scale of observation that we use to illuminate projectile dynamics. In-flight collisions commonly affect the size, shape, trajectory, and rotation of projectiles according to both projectile nature (ductile bomb versus brittle block) and the location and timing of collisions. These, in turn, are controlled by ejection pulses occurring at the vent. In-flight tearing and fragmentation characterize large bombs, which often break on landing, both factors concurring to decrease the average grain size of the resulting deposits. Complex rotation and spinning are ubiquitous features of projectiles, and the related Magnus effect may deviate projectile trajectory by tens of degrees. A new relationship is derived, linking projectile velocity and size with the size of the resulting impact crater. Finally, apparent drag coefficient values, obtained for selected projectiles, mostly range from 1 to 7, higher than expected, reflecting complex projectile dynamics. These new perspectives will impact projectile hazard mitigation and the interpretation of projectile deposits from past eruptions, both on Earth and on other planets.

Fired missile projectiles

International Nuclear Information System (INIS)

Williams, K.D.; Gieszl, R.; Keller, P.J.; Drayer, B.P.

1989-01-01

This paper reports ferromagnetic properties of fired missile projectiles (bullets, BBs, etc) investigated. Projectile samples were obtained from manufactures, police, and commercial sources. Deflection measurements at the portal of a 1.5-T magnetic field were performed for 47 projectiles. Sixteen bullets were examined in gelatin phantoms for rotation-translation movements as well. Ferromagnetic bullets displayed considerable deflection forces in the presence of the magnetic field and could be rotated to 80 degrees from their previous alignments when introduced perpendicular to the magnetic field in our gelatin phantom experiments. Military bullet calibers appear to pose the greatest ferromagnetic risk. Commercial sporting ammunition is generally nonferromagnetic

Projectile Motion Hoop Challenge

Science.gov (United States)

Jordan, Connor; Dunn, Amy; Armstrong, Zachary; Adams, Wendy K.

2018-04-01

Projectile motion is a common phenomenon that is used in introductory physics courses to help students understand motion in two dimensions. Authors have shared a range of ideas for teaching this concept and the associated kinematics in The Physics Teacher; however, the "Hoop Challenge" is a new setup not before described in TPT. In this article an experiment is illustrated to explore projectile motion in a fun and challenging manner that has been used with both high school and university students. With a few simple materials, students have a vested interest in being able to calculate the height of the projectile at a given distance from its launch site. They also have an exciting visual demonstration of projectile motion when the lab is over.

Batch Computed Tomography Analysis of Projectiles

Science.gov (United States)

2016-05-01

ARL-TR-7681 ● MAY 2016 US Army Research Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt, Chris M...Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt and Matthew S Bratcher Weapons and Materials Research...values to account for projectile variability in the ballistic evaluation of armor. 15. SUBJECT TERMS computed tomography , CT, BS41, projectiles

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.

Small caliber guided projectile

Science.gov (United States)

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

2010-08-24

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

Embolism of high energy firearm projectile

Directory of Open Access Journals (Sweden)

Jaime Álvarez Soler

2016-12-01

Full Text Available The embolism of a projectile is very rare and out of the normal context, so the cor-oner in front of a wound projectile firearm must make a very judicious and careful analysis to recover the projectile and/or its fragments. This case presents evidence how modern military high-velocity weapons have a high kinetic energy which is transferred to body tissues, so including their fragments and parts of the projectile can cause serious injury and embolism, requiring a great effort scientific and in-terdisciplinary to give technical support to justice.

Projectile penetration into ballistic gelatin.

Science.gov (United States)

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

2014-01-01

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

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.

Prediction of projectile ricochet behavior after water impact.

Science.gov (United States)

Baillargeon, Yves; Bergeron, Guy

2012-11-01

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

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

Science.gov (United States)

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

2017-02-01

We present here the study of the individual hypervelocity massive projectiles (440-540 keV, 33-36 km/s Au4004+ cluster) impact on 1-layer free-standing graphene. The secondary ions were detected and recorded separately from each individual impact in the transmission direction using a time-of-flight mass spectrometer. We observed C1-10± ions emitted from graphene, the projectiles which penetrated the graphene, and the Au1-3± fragment ions in mass spectra. During the projectile-graphene interaction, the projectile loses ˜15% of its initial kinetic energy (˜0.18 keV/atom, 72 keV/projectile). The Au projectiles are neutralized when approaching the graphene and then partially ionized again via electron tunneling from the hot rims of the holes on graphene, obtaining positive and negative charges. The projectile reaches an internal energy of ˜450-500 eV (˜4400-4900 K) after the impact and then undergoes a ˜90-100 step fragmentation with the ejection of Au1 atoms in the experimental time range of ˜0.1 μs.

Passive control of cavitating flow around an axisymmetric projectile by using a trip bar

Directory of Open Access Journals (Sweden)

Jian Huang

2017-07-01

Full Text Available Quasi-periodical evolutions such as shedding and collapsing of unsteady cloud cavitating flow, induce strong pressure fluctuations, what may deteriorate maneuvering stability and corrode surfaces of underwater vehicles. This paper analyzed effects on cavitation stability of a trip bar arranged on high-speed underwater projectile. Small scale water tank experiment and large eddy simulation using the open source software OpenFOAM were used, and the results agree well with each other. Results also indicate that trip bar can obstruct downstream re-entrant jet and pressure wave propagation caused by collapse, resulting in a relatively stable sheet cavity between trip bar and shoulder of projectiles. Keywords: Unsteady cavitating flow, Trip bar, Re-entrant jet, Passive flow control

Reactions with weakly bound nuclei at near barrier energies

International Nuclear Information System (INIS)

Nanal, Vandana

2014-01-01

In reactions with weakly bound nuclei, the effect of breakup on fusion process has attracted much attention in recent years. The experimental study shows that breakup channel leads to suppression of complete fusion at above barrier energies due to loss of flux. The fusion barrier distribution can provide a further insight into understanding the influence of coupling to the breakup channels. Similar information could be obtained from the elastic and quasielastic (QEL) scattering because of the conservation of the reaction flux (i.e. R+T= 1), where R is the reflection probability and T is the transmission probability. Thus, quasi-elastic scattering at backward angles is the counterpart of the fusion process and it is expected that the barrier distributions extracted from two processes, namely, QEL and fusion should be similar. While this is true for tightly bound reaction systems, in reactions involving weakly bound projectiles significant differences have been observed for QEL barrier distributions with and without inclusion of breakup processes. This talk will present the recent results for fusion and quasi-elastic scattering in "6","7Li + "1"9"7Au system. Developmental efforts towards a momentum achromatic separator, MARIE, to extract projectile-like secondary ion beams following the reactions of heavy-ion beams from superconducting LINAC booster at Mumbai will also be presented. (author)

Elastic scattering and total reaction cross section for the 6He + 27Al system

International Nuclear Information System (INIS)

Benjamim, E.A.; Lepine-Szily, A.; Mendes Junior, D.R.; Lichtenthaeler, R.; Guimaraes, V.; Gomes, P.R.S.; Chamon, L.C.; Hussein, M.S.; Moro, A.M.; Arazi, A.; Padron, I.; Alcantara Nunez, J.; Assuncao, M.; Barioni, A.; Camargo, O.; Denke, R.Z.; Faria, P.N. de; Pires, K.C.C.

2007-01-01

The elastic scattering of the radioactive halo nucleus 6 He on 27 Al target was measured at four energies close to the Coulomb barrier using the RIBRAS (Radioactive Ion Beams in Brazil) facility. The Sao Paulo Potential (SPP) was used and its diffuseness and imaginary strength were adjusted to fit the elastic scattering angular distributions. Reaction cross-sections were extracted from the optical model fits. The reduced reaction cross-sections of 6 He on 27 Al are similar to those for stable, weakly bound projectiles as 6,7 Li, 9 Be and larger than stable, tightly bound projectile as 16 O on 27 Al

Continuous measurements of in-bore projectile velocity

International Nuclear Information System (INIS)

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

1989-01-01

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

Dynamic effects of interaction of composite projectiles with targets

Energy Technology Data Exchange (ETDEWEB)

Zakharov, V. M. [Scientific Research Institute of Applied Mathematics and Mechanics of Tomsk State University, 36, Lenin Avenue, Tomsk, 634050 (Russian Federation)

2016-01-15

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

Photon emission from massive projectile impacts on solids.

Science.gov (United States)

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

2011-01-01

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

Charge-exchange products of BEVALAC projectiles

International Nuclear Information System (INIS)

Rasmussen, J.

1982-11-01

There is a substantial production of fragments of all masses lighter than the projectile, such fragments being centered in a narrow region of velocity space around the beam velocity. The exciting studies about anomalons deal with the curious enhanced reactivity of some of these secondary fragments. I direct attention here to the rather rare fragments of the same mass number as the projectile but differing in charge by one unit. We also keep track, as a frame of reference, of the products that have lost one neutron from the projectile

Passage of stable isotope-labeled grass silage fiber and fiber-bound protein through the gastroinstestinal tract of dairy cows

NARCIS (Netherlands)

Warner, D.; Dijkstra, J.; Hendriks, W.H.; Pellikaan, W.F.

2013-01-01

Fractional passage rates are required to predict nutrient absorption in ruminants but data on nutrient-specific passage kinetics are largely lacking. With the use of the stable isotope ratio (d) as an internal marker, we assessed passage kinetics of fiber and fiber-bound nitrogen (N) of

Predicting the Accuracy of Unguided Artillery Projectiles

Science.gov (United States)

2016-09-01

ability to penetrate a target. If the impact angle is small, the projectile may more likely ricochet, and any penetration will not be as deep as a...projectile experiences less drag and thus increased impact velocity and penetration . However, a blunt nose projectile has more strength at the tip and...fire 15. NUMBER OF PAGES 139 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE

Breakup of the projectile at 35 MeV/nucleon

International Nuclear Information System (INIS)

Gonthier, P.L.; Harper, P.; Bouma, B.; Ramaker, R.; Cebra, D.A.; Koenig, Z.M.; Fox, D.; Westfall, G.D.

1990-01-01

Projectile breakup processes are probed by studying the emission of α particles in coincidence with projectile-like fragments as a function of the dissipated energy in the collisions of 35 MeV/nucleon 16 O with 58 Ni. Energy correlations between α particles and projectile-like fragments at small-angle geometries allow the separation of the sources of α emission from projectile-like and target-like fragments. We find that the slope parameters of the decay energy distributions, the average excitation energies, and the α particle multiplicities of the projectile-like fragments increase with increasing dissipation of energy. If the linear dependence, exhibited by the data, of the slope parameter with the dissipated energy is included in model calculations, the majority of the coincidence yield in the forward hemisphere can be explained. However, an excess yield of the data on the opposite side of the beam from the observed projectile-like fragment still remains. Such analysis of the data suggests that the breakup of the projectile is the dominant source of light particles at forward angles. Processes resulting in the breakup of the projectile must be better understood in order to study other processes leading to similar phenomena

Stopping power. Projectile and target modeled as oscillators

International Nuclear Information System (INIS)

Stevanovic, N.; Nikezic, D.

2005-01-01

In this Letter the collision of two quantum harmonic oscillators was considered. The oscillators interact through the Coulomb interaction. Stopping power of projectile was calculated assuming that both, target and projectile may be excited. It has been shown that the frequency of the projectile oscillation, ω p influences on stopping power, particularly in the region of Bragg peak. If, ω p ->0 is substitute in the expression for stopping power derived in this Letter, then it comes to the form when the projectile has been treated as point like charged particle

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,…

Orientation estimation algorithm applied to high-spin projectiles

International Nuclear Information System (INIS)

Long, D F; Lin, J; Zhang, X M; Li, J

2014-01-01

High-spin projectiles are low cost military weapons. Accurate orientation information is critical to the performance of the high-spin projectiles control system. However, orientation estimators have not been well translated from flight vehicles since they are too expensive, lack launch robustness, do not fit within the allotted space, or are too application specific. This paper presents an orientation estimation algorithm specific for these projectiles. The orientation estimator uses an integrated filter to combine feedback from a three-axis magnetometer, two single-axis gyros and a GPS receiver. As a new feature of this algorithm, the magnetometer feedback estimates roll angular rate of projectile. The algorithm also incorporates online sensor error parameter estimation performed simultaneously with the projectile attitude estimation. The second part of the paper deals with the verification of the proposed orientation algorithm through numerical simulation and experimental tests. Simulations and experiments demonstrate that the orientation estimator can effectively estimate the attitude of high-spin projectiles. Moreover, online sensor calibration significantly enhances the estimation performance of the algorithm. (paper)

Orientation estimation algorithm applied to high-spin projectiles

Science.gov (United States)

Long, D. F.; Lin, J.; Zhang, X. M.; Li, J.

2014-06-01

High-spin projectiles are low cost military weapons. Accurate orientation information is critical to the performance of the high-spin projectiles control system. However, orientation estimators have not been well translated from flight vehicles since they are too expensive, lack launch robustness, do not fit within the allotted space, or are too application specific. This paper presents an orientation estimation algorithm specific for these projectiles. The orientation estimator uses an integrated filter to combine feedback from a three-axis magnetometer, two single-axis gyros and a GPS receiver. As a new feature of this algorithm, the magnetometer feedback estimates roll angular rate of projectile. The algorithm also incorporates online sensor error parameter estimation performed simultaneously with the projectile attitude estimation. The second part of the paper deals with the verification of the proposed orientation algorithm through numerical simulation and experimental tests. Simulations and experiments demonstrate that the orientation estimator can effectively estimate the attitude of high-spin projectiles. Moreover, online sensor calibration significantly enhances the estimation performance of the algorithm.

Supercavitating flow around high-speed underwater projectile near free surface induced by air entrainment

Directory of Open Access Journals (Sweden)

Chang Xu

2018-03-01

Full Text Available Cavitating flow near free surface is a complicated issue and may provide new inspiration on high-speed surface cruising. This study observes stable supercavitating flow as a new phenomenon in a launch experiment of axisymmetric projectile when the upper side of the projectile coincides with the free surface. A numerical approach is established using large eddy-simulation and volume-of-fluid methods, and good agreements are achieved between numerical and experimental results. Supercavity formation mechanism is revealed by analyzing the experiment photographs and the iso-surface of 90% water volume fraction in numerical results. The entrainment of a large amount of air into the cavity can cause the pressure inside the cavity to similarly increase with the pressure outside the cavity, which makes the actual cavitation number close to zero and is similar to supercavitation. Cases with various headforms of the projectile and cavitation numbers on the cavitating flow, as well as the drag reduction effects are further examined. Results indicate that the present strategy near the free surface could possibly be a new effective approach for high-speed cruising after vigorous design optimization in the future.

Stability Criterion for a Finned Spinning Projectile

OpenAIRE

S. D. Naik

2000-01-01

The state-of-the-art in gun projectile technology has been used for the aerodynamic stabilisation.This approach is acceptable for guided and controlled rockets but the free-flight rockets suffer fromunacceptable dispersion. Sabot projectiles with both spin and fms developed during the last decadeneed careful analysis. In this study, the second method of Liapunov has been used to develop stability criterion for a projectile to be designed with small fins and is made to spin in the flight. This...

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...

Study of the threshold anomaly in systems involving weakly bound nuclei

International Nuclear Information System (INIS)

Figueira, J.M.; Niello, J.O. Fernandez; Abelof, G.A.; Arazi, A.; Barmak, D.H.; Capurro, O.A.; Carnelli, P.; Fimiani, L.; Marti, G.V.; Heimann, D. Martinez; Negri, A.E.; Pacheco, A.J.; Gomes, P.R.S.; Lubian, J.; Monteiro, D.S.

2009-01-01

Full text: One of the dominant mechanisms in systems involving weakly bound nuclei is the break-up channel; however, the dynamics of this process remains poorly understood. In elastic scattering of strongly bound nuclei it is clearly established that there is always a threshold anomaly (TA) in the optical potential. The TA is characterized by a localized peak in the real part of the potential and by a decrease of the imaginary part of the potential as the bombarding energy decreases towards the Coulomb barrier. But when at least one of the nuclei is weakly bound the results are different for different systems. Three kinds of situations have been reported: the usual TA is observed; the usual TA is not observed because the potentials are almost constant even close to the Coulomb barrier; the so-called Break up Threshold Anomaly (BTA), where the imaginary potential increases as the bombarding energy decreases towards the Coulomb barrier. The BTA is attributed to a strong coupling of the elastic channel with the breakup process, which might have a much larger cross section than fusion at sub-barrier energies. In order to understand how those differences are affected by the system properties it is important to have data of new systems available. In this work we contribute original elastic scattering data of the weakly bound 6,7 Li projectiles on 144 Sm at near coulomb barrier energies. The measurements have been performed at the TANDAR Laboratory using 6 Li and 7 Li beams and a 100 μg/cm 2 thick 144 Sm target. Eleven different bombarding energies between 21 and 42.3 MeV were used for each projectile. The results are analyzed using phenomenological optical potentials and compared with results from other systems involving weakly bound nuclei. (author)

Finite element investigation of explosively formed projectiles (EFP)

International Nuclear Information System (INIS)

Ahmad, I.

1999-01-01

This thesis report represents the numerical simulation of explosively formed projectiles (EFP), a type of linear self-forging fragment device. The simulation is performed using a finite element code DYNA2D. It also explicates that how the shape, velocity and kinetic energy of an explosively formed projectile is effected by various parameters. Different parameters investigated are mesh density, material, thickness, contour and types of liner. Effect of shape of casing and material model is also analyzed. The shapes of projectiles at different times after detonation are shown. The maximum velocity and kinetic energy of the projectile have been used to ascertain the effect of above mentioned parameters. (author)

Visualization of Projectile Flying at High Speed in Dusty Atmosphere

Science.gov (United States)

Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro

2017-10-01

Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

Projectile rapidity dependence in target fragmentation

International Nuclear Information System (INIS)

Haustein, P.E.; Cumming, J.B.; Hseuh, H.C.

1979-01-01

The thick-target, thick-catcher technique was used to determine mean kinetic properties of selected products of the fragmentation of Cu by 1 H, 4 He, and 12 C ions (180 to 28,000 MeV/amu). Momentum transfer, as inferred from F/B ratios, is ovserved to occur most efficiently for the lower velocity projectiles. Recoil properties of target fragments vary strongly with product mass, but show only a weak dependence on projectile type. The projectile's rapidity is shown to be a useful variable for quantitative intercomparison of different reactions. These results indicate that E/sub proj//A/sub proj/ is the dominant parameter which governs the mean recoil behavior of target fragments. 20 references

Computed tomography of projectile injuries

International Nuclear Information System (INIS)

Jeffery, A.J.; Rutty, G.N.; Robinson, C.; Morgan, B.

2008-01-01

Computed tomography (CT) is a gold standard in clinical imaging but forensic professions have been slow to embrace radiological advances. Forensic applications of CT are now exponentially expanding, replacing other imaging methods. As post-mortem cross-sectional imaging increases, radiologists will fall under increasing pressure to interpret complex forensic cases involving both living and deceased patients. This review presents a wide variety of weapon and projectile types aiding interpretation of projectile injuries both in forensic and clinical practice

A design of inverse Taylor projectiles using material simulation

International Nuclear Information System (INIS)

Tonks, Michael; Harstad, Eric; Maudlin, Paul; Trujillo, Carl

2008-01-01

The classic Taylor cylinder test, in which a right circular cylinder is projected at a rigid anvil, exploits the inertia of the projectile to access strain rates that are difficult to achieve with more traditional uniaxial testing methods. In this work we present our efforts to design inverse Taylor projectiles, in which a tapered projectile becomes a right circular cylinder after impact, from annealed copper and show that the self-correcting geometry leads to a uniform compressive strain in the radial direction. We design projectiles using finite element simulation and optimization that deform as desired in tests with minor deviations in the deformed geometry due to manufacturing error and uncertainty in the initial velocity. The inverse Taylor projectiles designed in this manner provide a simple means of validating constitutive models. This work is a step towards developing a general method of designing Taylor projectiles that provide stress–strain behavior relevant to particular engineering problems

Femoral vessel injury by a nonlethal weapon projectile

Directory of Open Access Journals (Sweden)

Rodrigo Bruno Biagioni, MD

2018-06-01

Full Text Available Rubber projectiles are used as an alternative to metal bullets owing to their lower morbidity and mortality rate. There are few reports of vascular lesions of extremities caused by rubber projectiles in the literature. The authors report the case of a 37-year-old man who was the victim of a penetrating injury to the left thigh with a rubber projectile. He reported only pain at the site of the injury; pulses were decreased in the affected limb. After arteriography confirmed an injury to the superficial femoral artery, he underwent an arterial and venous femorofemoral bypass using a reversed contralateral saphenous vein. Keywords: Vascular trauma, Nonlethal projectile, Penetrating trauma

Projectile ionization in fast heavy-ion--atom collisions

International Nuclear Information System (INIS)

Schneider, D.; Prost, M.; Stolterfoht, N.; Nolte, G.; Du Bois, R.

1983-01-01

Electron emission following the ionization of projectile ions has been investigated systematically in collisions with Ne/sup q/+ and Ar/sup q/+ ions at several hundred MeV incident on different target gases. The projectile electrons are concentrated within one maximum, the electron-loss peak (ELP). The variation of the shape and intensity of the ELP with the projectile energy, its charge state, the observation angle, and the target gas has been measured. Theoretical predictions which are based on the binary-encounter approximation show, in general, good agreement with the experimental data. The contributions of the different subshells to the ELP are deduced. It is shown that electronic screening of the target nucleus plays an important role in the ionization process of the projectile ions

Secondary electron emission with molecular projectiles

International Nuclear Information System (INIS)

Kroneberger, K.; Rothard, H.; Koschar, P.; Lorenzen, P.; Kemmler, J.; Keller, N.; Maier, R.; Groeneveld, K.O.; Clouvas, A.; Veje, E.

1990-01-01

The authors present results for the secondary electron emission (SEE) from thin foil targets, induced by both molecular ions and their atomic constituents as projectiles. The Sternglass theory for kinetic SEE states a proportionality between γ and the electronic stopping power, S e , which has been verified in various experiments. With comparing secondary electron (SE) yields induced by molecular projectiles to those induced by monoatomic projectiles, it is therefore possible to test models for the energy loss of molecular or cluster projectiles. Since the atomic constituents of the molecule are repelled from each other due to Coulomb explosion (superimposed by multiple scattering) while traversing the solid, it is interesting to measure the residual mutual influence on SEE and S e with increasing internuclear separation. This can only be achieved with thin foils, where (as in the present case) the SE-yields from the exit surface can be measured separately. The authors measured the SE-yields from the entrance (γ B ) and exit (γ F ) surfaces of thin C- and Al-foils (150 to 1,000 angstrom) with CO + , C + and O + (15 to 85 keV/u) and H 2 + and H + (0.3 to 1.2 MeV/u). The molecular effect defined as the ratio R(γ) between the yields induced by molecular projectiles and the sum of those induced by their atomic constituents was calculated. The energy dependence of R(γ) can be well represented by the calculated energy loss ratio of di-proton-clusters by Brandt. This supports Brandt's model for the energy loss of clusters

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.

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.

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.

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.

Study of projectile break-up process at intermediate energies

International Nuclear Information System (INIS)

Kumar, Harish; Parashari, Siddharth; Tali, Suhail A.

2016-01-01

The projectile break-up reactions are explained in terms of incomplete fusion or massive transfer reactions leading to the formation of composite system with less mass, charge and excitation energy, as compared to the complete fusion (CF) process. Since, the existing theoretical models are not applicable to reproduce the experimentally measured ICF, data satisfactory below 10 MeV/nucleon energies; thereby the study of the role of the entrance channel parameters in the fusion reactions is still a relevant problem in establishing the explicit inference regarding the influence of ICF on CF at 4-7 MeV/nucleon energies. Recently reported some studies have also shown that alpha Q-value is also an important parameter which affects the onset of ICF and conflict with the suggestion of Morgenstern et al. Keeping in view the recent aspects, to provide more strength to the aspect of projectile-target mass-asymmetry effect, role of non α-cluster projectile over α-cluster projectile, the present work has been carried out which will be useful to understand a clearer picture about the conflict between mass-asymmetry and projectile structure effect on break-up fusion process. As such, excitation function measurement of residues produced in 13 C + 175 Lu system has been carried out in a series of experiments of comparative study using α-cluster as well as non α-cluster projectiles with deformed heavier target nuclei at lower projectile energies ≈ 4-7 MeV/nucleon

Transient processes induced by heavy projectiles in silicon

International Nuclear Information System (INIS)

Lazanu, Ionel; Lazanu, Sorina

2010-01-01

The thermal spike model developed for the electronic stopping power regime is extended to consider both ionization and nuclear energy loss processes of the projectile as electronic and atomic heat distinct sources. The time and space dependencies of the lattice and electron temperatures near the projectile trajectory are calculated and discussed for different ions in silicon, at room and cryogenic temperatures, taking into account the peculiarities of electron-phonon interaction in both domains. The model developed contributes to the understanding of transient microscopic processes immediately after the projectile interaction in the target.

X-ray yields from high-energy heavy ions channeled through a crystal: their crystal thickness and projectile dependences

International Nuclear Information System (INIS)

Kondo, C.; Takabayashi, Y.; Muranaka, T.; Masugi, S.; Azuma, T.; Komaki, K.; Hatakeyama, A.; Yamazaki, Y.; Takada, E.; Murakami, T.

2005-01-01

X-rays emitted from Ar 17+ , Fe 24+ and Kr 35+ ions of about 400 MeV/u transmitting through a thin Si crystal of about 20 μm thickness have been measured in a planar channeling condition and compared with those in a random incident condition. We have found that the X-ray yield from Ar 17+ ions is larger for the channeling condition than for the random incidence, while those from Fe 24+ and Kr 35+ ions are rather smaller. Such tendencies are explained by considering the projectile dependences of excitation and ionization probabilities together with X-ray emission rates. A crude simulation has qualitatively reproduced these experimental results. When the crystal thickness is small, the X-ray yield is smaller in the channeling condition than in the random incident condition, because excitation is depressed. However, for thicker crystals, the X-ray yield is larger, since the survived population of projectile-bound electrons is larger due to small ionization probabilities under the channeling condition. This inversion occurs at a specific crystal thickness depending on projectile species. Whether the thickness of the used crystal is smaller or larger than the inversion thickness determines enhancement or depression of the X-ray yield in the channeling condition

Electromagnetic launcher for heavy projectiles

Science.gov (United States)

Kozlov, A. V.; Kotov, A. V.; Polistchook, V. P.; Shurupov, A. V.; Shurupov, M. A.

2017-11-01

In this paper, we present the electromagnetic launcher with capacitive power source of 4.8 MJ. Our installation allows studying of the projectile acceleration in railgun in two regimes: with a solid armature and with a plasma piston. The experiments with plasma piston were performed in the railgun with the length of barrel of 0.7-1.0 m and its inner diameter of 17-24 mm. The velocities of lexan projectiles with weight of 5-15 g were in a range of 2.5-3.5 km/s. The physical mechanisms that limit speed of throwing in railgun are discussed.

Local behavior of reinforced concrete slabs to aircraft engine projectile impact

International Nuclear Information System (INIS)

Yoo, Hyeon Kyeong; Choi, Hyun; Chung, Chul Hun; Lee, Jung Whee; Kim, Sang Yun

2011-01-01

Structural safety evaluation of nuclear power plant considers two distinct types of structural failure, local failure and global failure. In the local failure evaluation, considered projectiles can be divided as internal and external projectile according to the impact location, and they also can be divided as rigid and soft projectile according to the deformation level after impact. Frequently considered projectiles are aircraft engine, tornado, and turbine projectile. When the speed and weight of the projectiles are considered, the most influential projectile is aircraft engine, which is one of the soft projectiles. Sugano et al. performed impact test using an engine model projectile, which is derived from GE-J79 engine and concentrated mass-spring model idealization. Kojima and Sugano et al. demonstrated from their experiments that steel liner on the rear side of the concrete wall reduces impact induced damage and suppresses debris scattering. Chung et al. performed comparison study of various formulae suggested for local damage evaluation using previously performed numerous local impact test results. Also, they validated a methodology of numerical analysis for impact simulation using LS-DYNA. Previously suggested formulae and research results do not consider the effect of liner plate or curved shape of the containment building walls on the local damage. In this research, flat wall and curved wall are individually modeled using the same curvature of nuclear power plants, and the effects of curvature and liner plates on the local damage are analytically investigated

Femoral vessel injury by a nonlethal weapon projectile.

Science.gov (United States)

Biagioni, Rodrigo Bruno; Miranda, Gustavo Cunha; Mota de Moraes, Leonardo; Nasser, Felipe; Burihan, Marcelo Calil; Ingrund, José Carlos

2018-06-01

Rubber projectiles are used as an alternative to metal bullets owing to their lower morbidity and mortality rate. There are few reports of vascular lesions of extremities caused by rubber projectiles in the literature. The authors report the case of a 37-year-old man who was the victim of a penetrating injury to the left thigh with a rubber projectile. He reported only pain at the site of the injury; pulses were decreased in the affected limb. After arteriography confirmed an injury to the superficial femoral artery, he underwent an arterial and venous femorofemoral bypass using a reversed contralateral saphenous vein.

Study of breakup and transfer of weakly bound nucleus 6Li to explore the low energy reaction dynamics

Science.gov (United States)

Zhang, G. L.; Zhang, G. X.; Hu, S. P.; Zhang, H. Q.; Gomes, P. R. S.; Lubian, J.; Guo, C. L.; Wu, X. G.; Yang, J. C.; Zheng, Y.; Li, C. B.; He, C. Y.; Zhong, J.; Li, G. S.; Yao, Y. J.; Guo, M. F.; Sun, H. B.; Valiente-Dobòn, J. J.; Goasduff, A.; Siciliano, M.; Galtarosa, F.; Francesco, R.; Testov, D.; Mengoni, D.; Bazzacco, D.; John, P. R.; Qu, W. W.; Wang, F.; Zheng, L.; Yu, L.; Chen, Q. M.; Luo, P. W.; Li, H. W.; Wu, Y. H.; Zhou, W. K.; Zhu, B. J.; Li, E. T.; Hao, X.

2017-11-01

Investigation of the breakup and transfer effect of weakly bound nuclei on the fusion process has been an interesting research topic in the past several years. However, owing to the low intensities of the presently available radioactive ion beam (RIB), it is difficult to clearly explore the reaction mechanisms of nuclear systems with unstable nuclei. In comparison with RIB, the beam intensities of stable weakly bound nuclei such as 6,7Li and 9Be, which have significant breakup probability, are orders of magnitude higher. Precise fusion measurements have already been performed with those stable weakly bound nuclei, and the effect of breakup of those nuclei on the fusion process has been extensively studied. Those nuclei indicated large production cross sections for particles other than the α + x breakup. The particles are originated from non-capture breakup (NCBU), incomplete fusion (ICF) and transfer processes. However, the conclusion of reaction dynamics was not clear and has the contradiction. In our previous experiments we have performed 6Li+96Zr and 154Sm at HI-13 Tandem accelerator of China Institute of Atomic Energy (CIAE) by using HPGe array. It is shown that there is a small complete fusion (CF) suppression on medium-mass target nucleus 96Zr different from about 35% suppression on heavier target nucleus 154Sm at near-barrier energies. It seems that the CF suppression factor depends on the charge of target nuclei. We also observed one neutron transfer process. However, the experimental data are scarce for medium-mass target nuclei. In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, we performed the 6Li+89Y experiment with incident energies of 22 MeV and 34 MeV on Galileo array in cooperation with Si-ball EUCLIDES at Legnaro National Laboratory (LNL) in Italy. Using particle-particle and particle-γ coincidences, the different reaction mechanisms can be clearly explored.

Design and testing of high-pressure railguns and projectiles

International Nuclear Information System (INIS)

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

1984-01-01

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

Stable rotating dipole solitons in nonlocal media

DEFF Research Database (Denmark)

Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

2006-01-01

We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

Cambodian students’ prior knowledge of projectile motion

Science.gov (United States)

Piten, S.; Rakkapao, S.; Prasitpong, S.

2017-09-01

Students always bring intuitive ideas about physics into classes, which can impact what they learn and how successful they are. To examine what Cambodian students think about projectile motion, we have developed seven open-ended questions and applied into grade 11 students before (N=124) and after (N=131) conventional classes. Results revealed several consistent misconceptions, for instance, many students believed that the direction of a velocity vector of a projectile follows the curved path at every position. They also thought the direction of an acceleration (or a force) follows the direction of motion. Observed by a pilot sitting on the plane, the falling object, dropped from a plane moving at a constant initial horizontal speed, would travel backward and land after the point of its release. The greater angle of the launched projectile creates the greater horizontal range. The hand force imparted with the ball leads the ball goes straight to hit the target. The acceleration direction points from the higher position to lower position. The misconceptions will be used as primary resources to develop instructional instruments to promote Cambodian students’ understanding of projectile motion in the following work.

Electronic emission produced by light projectiles at intermediate energies

International Nuclear Information System (INIS)

Bernardi, G.C.

1989-01-01

Two aspects of the electronic emission produced by light projectiles of intermediate energies have been studied experimentally. In the first place, measurements of angular distributions in the range from θ = 0 deg -50 deg induced by collisions of 50-200 keV H + incident on He have been realized. It was found that the double differential cross section of electron emission presents a structure focussed in the forward direction and which extends up to relatively large angles. Secondly, the dependence of the double differential cross section on the projectile charge was studied using H + and He 3 2+ projectiles of 50 and 100 keV/amu incident on He. Strong deviations from a constant scaling factor were found for increasing projectile charge. The double differential cross sections and the single differential cross sections as a function of the emission angle, and the ratios of the emissions induced by He 3 2+ and H + at equal incident projectile velocities are compared with the 'Continuum Distorted Wave-Eikonal Initial State' (CDW-EIS) approximation and the 'Classical Trajectory Monte Carlo' (CTMC) method. Both approximations, in which the potential of the projectile exercises a relevant role, reproduce the general aspects of the experimental results. An electron analyzer and the corresponding projectile beam line has been designed and installed; it is characterized by a series of properties which are particularly appropriate for the study of double differential electronic emission in gaseous as well as solid targets. The design permits to assure the conditions to obtain a well localized gaseous target and avoid instrumental distortions of the measured distributions. (Author) [es

Design and Analysis of A Spin-Stabilized Projectile Experimental Apparatus

Science.gov (United States)

Siegel, Noah; Rodebaugh, Gregory; Elkins, Christopher; van Poppel, Bret; Benson, Michael; Cremins, Michael; Lachance, Austin; Ortega, Raymond; Vanderyacht, Douglas

2017-11-01

Spinning objects experience an effect termed `The Magnus Moment' due to an uneven pressure distribution based on rotation within a crossflow. Unlike the Magnus force, which is often small for spin-stabilized projectiles, the Magnus moment can have a strong detrimental effect on aerodynamic flight stability. Simulations often fail to accurately predict the Magnus moment in the subsonic flight regime. In an effort to characterize the conditions that cause the Magnus moment, researchers in this work employed Magnetic Resonance Velocimetry (MRV) techniques to measure three dimensional, three component, sub-millimeter resolution fluid velocity fields around a scaled model of a spinning projectile in flight. The team designed, built, and tested using a novel water channel apparatus that was fully MRI-compliant - water-tight and non-ferrous - and capable of spinning a projectile at a constant rotational speed. A supporting numerical simulation effort informed the design process of the scaled projectile to thicken the hydrodynamic boundary layer near the outer surface of the projectile. Preliminary testing produced two-dimensional and three-dimensional velocity data and revealed an asymmetric boundary layer around the projectile, which is indicative of the Magnus effect.

Ionization of one-electron oxygen and fluorine projectiles by molecular hydrogen

International Nuclear Information System (INIS)

Tipping, T.N.; Sanders, J.M.; Hall, J.; Shinpaugh, J.L.; Lee, D.H.; McGuire, J.H.; Richard, P.

1988-01-01

Cross sections for projectile ionization have been measured for hydrogenlike oxygen and fluorine ions incident on a molecular-hydrogen target over a projectile energy range of 0.5--2.5 MeV/amu. The experimental cross sections are compared to the plane-wave Born approximation (PWBA) and to the Glauber-approximation cross sections all of which were calculated for atomic hydrogen and multiplied by 2. The PWBA calculations have a projectile energy dependence similar to the measured cross sections but slightly underestimate them. The Glauber approximation also underestimates the measured projectile-ionization cross sections when the hydrogen target electrons are neglected, while it overestimates the measured cross sections when the effects of the hydrogen target electrons are included. The measured projectile-ionization cross sections for hydrogenlike ions incident on molecular hydrogen are approximately a factor of 2 smaller than previously reported projectile-ionization cross sections for hydrogenlike ions incident on helium. No cross sections are available for atomic hydrogen in this velocity and ion-charge regime

Analysis on the resistive force in penetration of a rigid projectile

Directory of Open Access Journals (Sweden)

Xiao-wei Chen

2014-09-01

Full Text Available According to the dimensionless formulae of DOP (depth of penetration of a rigid projectile into different targets, the resistive force which a target exerts on the projectile during the penetration of rigid projectile is theoretically analyzed. In particular, the threshold Vc of impact velocity applicable for the assumption of constant resistive force is formulated through impulse analysis. The various values of Vc corresponding to different pairs of projectile-target are calculated, and the consistency of the relative test data and numerical results is observed.

Development of odd-Z-projectile reactions for transactinide element synthesis

International Nuclear Information System (INIS)

Folden III, Charles Marvin

2004-01-01

The development of new odd-Z-projectile reactions leading to the production of transactinide elements is described. The cross section of the even-Z-projectile 208Pb(64Ni, n)271Ds reaction was measured at two new energies using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. In total, seven decay chains attributable to 271Ds were observed. These data, combined with previous results, establish an excitation function for the production of 271Ds. The maximum cross section was 20 +15 -11 pb at a center-of-target energy of 311.5 MeV in the laboratory frame.The data from the 271Ds experiments were used to estimate the optimum beam energy for the new odd-Z-projectile 208Pb(65Cu, n)272-111 reaction using the Fusion by Diffusion theory proposed by Swiatecki, Siwek-Wilczynska, and Wilczynski. A cross section for this reaction was measured for the first time, at a center-of-target energy of 321.1 MeV in the laboratory frame. The excitation energy f or compound nuclei formed at the target center was 13.2 MeV. One decay chain was observed, resulting in a measured cross section of 1.7 +3.9 -1.4 pb. This decay chain is in good agreement with previously published data on the decay of 272-111.The new odd-Z-projectile 208Pb(55Mn, n)262Bh reaction was studied at three different projectile energies, and 33 decay chains of 262Bh were observed. The existence of a previously reported alpha-decaying isomeric state in this nuclide was confirmed. Production of the ground state was preferred at all three beam energies. The maximum cross section was 540 +180 -150 pb at a projectile center-of-target energy of 264.0 MeV. This cross section is much larger than that previously reported for the even-Z-projectile 209Bi(54Cr, n)262Bh reaction, which may be because the 54Cr projectile energies in the latter reaction were too high for optimum production of the 1n product. At the highest projectile energy of 268.0 MeV in the target center, two decay

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…

On the Inertia Term of Projectile's Penetration Resistance

Directory of Open Access Journals (Sweden)

Yu Shan

2013-01-01

Full Text Available The effect of the target inertia term of rigid kinetic energy projectiles (KEP’s penetration resistance is investigated using nonlinear dynamic code LS-DYNA and four constitutive models. It is found that the damage number of target can be used to measure the influence of the inertia term. The smaller the damage number is, the less influence the inertia term has. The less dependent the resistance has on projectile velocity, the more accurate it is to treat the resistance as a constant. For the ogive-nose projectile with CRH of 3, when the target is aluminum, steel, or other metals, the threshold velocity for the constant resistance is at least 1258 m/s; when the target is concrete, rock, or other brittle materials, if the velocity of the projectile is greater than 400 m/s or so, the damage number would be very large, and the penetration resistance would clearly depend on the projectile’s velocity. The higher the elastic wave velocity is, the more penetration process is affected by the impact face.

Fatal lawn mower related projectile injury.

Science.gov (United States)

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

2014-06-01

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

Ion collision-induced chemistry in pure and mixed loosely bound clusters of coronene and C60 molecules.

Science.gov (United States)

Domaracka, Alicja; Delaunay, Rudy; Mika, Arkadiusz; Gatchell, Michael; Zettergren, Henning; Cederquist, Henrik; Rousseau, Patrick; Huber, Bernd A

2018-05-23

Ionization, fragmentation and molecular growth have been studied in collisions of 22.5 keV He2+- or 3 keV Ar+-projectiles with pure loosely bound clusters of coronene (C24H12) molecules or with loosely bound mixed C60-C24H12 clusters by using mass spectrometry. The heavier and slower Ar+ projectiles induce prompt knockout-fragmentation - C- and/or H-losses - from individual molecules and highly efficient secondary molecular growth reactions before the clusters disintegrate on picosecond timescales. The lighter and faster He2+ projectiles have a higher charge and the main reactions are then ionization by ions that are not penetrating the clusters. This leads mostly to cluster fragmentation without molecular growth. However, here penetrating collisions may also lead to molecular growth but to a much smaller extent than with 3 keV Ar+. Here we present fragmentation and molecular growth mass distributions with 1 mass unit resolution, which reveals that the same numbers of C- and H-atoms often participate in the formation and breaking of covalent bonds inside the clusters. We find that masses close to those with integer numbers of intact coronene molecules, or with integer numbers of both intact coronene and C60 molecules, are formed where often one or several H-atoms are missing or have been added on. We also find that super-hydrogenated coronene is formed inside the clusters.

Physics of projectile fragments

International Nuclear Information System (INIS)

Minamisono, Tadanori

1982-01-01

This is a study report on the polarization phenomena of the projectile fragments produced by heavy ion reactions, and the beta decay of fragments. The experimental project by using heavy ions with the energy from 50 MeV/amu to 250 MeV/amu was designed. Construction of an angle-dispersion spectrograph for projectile fragments was proposed. This is a two-stage spectrograph. The first stage is a QQDQQ type separator, and the second stage is QDQD type. Estimation shows that Co-66 may be separated from the nuclei with mass of 65 and 67. The orientation of fragments can be measured by detecting beta-ray. The apparatus consists of a uniform field magnet, an energy absorber, a stopper, a RF coil and a beta-ray hodoscope. This system can be used for not only this purpose but also for the measurement of hyperfine structure. (Kato, T.)

Projectile-power-compressed magnetic-field pulse generator

International Nuclear Information System (INIS)

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

1983-01-01

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

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...

Hidrodinamički model podvodnog projektila / Hidrodinamical model of an underwater projectile

Directory of Open Access Journals (Sweden)

Miroslav Radosavljević

2008-07-01

Full Text Available Radi dobijanja kvalitetnog matematičkog modela podvodnog projektila u radu su definisane ulazne i izlazne veličine, brzine i ubrzanje projektila. Uz zadate uslove mogućeg kretanja projektila definisan je model podvodnog projektila sa šest jednačina. / The paper analyzes an underwater projectile. The input and output values, the projectile speed and acceleration are defined for a quality definition of the projectile mathematical model. With the conditions of the projectile potential movement previously set out, the torpedo model is defined by six equations.

High-velocity Penetration of Concrete Targets with Three Types of Projectiles: Experiments and Analysis

Directory of Open Access Journals (Sweden)

Shuang Zhang

Full Text Available Abstract This study conducted high-velocity penetration experiments using conventional ogive-nose, double-ogive-nose, and grooved-tapered projectiles of approximately 2.5 kg and initial velocities between 1000 and 1360 m/s to penetrate or perforate concrete targets with unconfined compressive strengths of nominally 40MPa. The penetration performance data of these three types of projectiles with two different types of materials (i.e., AerMet100 and DT300 were obtained. The crater depth model considering both the projectile mass and the initial velocity was proposed based on the test results and a theoretical analysis. The penetration ability and the trajectory stability of these three projectile types were compared and analyzed accordingly. The results showed that, under these experimental conditions, the effects of these two different kinds of projectile materials on the penetration depth and mass erosion rate of projectile were not obvious. The existing models could not reflect the crater depths for projectiles of greater weights or higher velocities, whereas the new model established in this study was reliable. The double-ogive-nose has a certain effect of drag reduction. Thus, the double-ogive-nose projectile has a higher penetration ability than the conventional ogive-nose projectile. Meanwhile, the grooved-tapered projectile has a better trajectory stability, because the convex parts of tapered shank generated the restoring moment to stabilize the trajectory.

The dynamics of target ionization by fast higly charged projectiles

International Nuclear Information System (INIS)

Moshammer, R.; Ullrich, J.; Unverzagt, M.; Olsen, R.E.; Doerner, R.; Mergel, V.; Schmidt-Boecking, H.

1995-12-01

We report on the first kinematically complete investigation of single target ionization by fast heavy ions, on the measurement of all low energy electrons down to zero emission velocities and on the determination of the projectile energy loss on the level of ΔE p /E p ∼10 -7 . This has been achieved by combining a high-resolution recoil-ion momentum spectrometer with a novel 4π electron analyzer. The complete momentum balance between electron, recoil-ion and projectile for single ionization of helium by 3.6 MeV/u Ni 24+ was explored. Low energy electrons are found to be ejected mainly into the forward direction with a most likely longitudinal energy of only 2 eV. The electron momentum is not balanced, as might be expected, by the projectile momentum but is nearly completely compensated by the recoil ion. Surprisingly, the momenta of the helium-atom ''fragments'', the electron and the He 1+ recoil ion, are considerably larger than the total momentum loss of the projectile: the target atom seems to dissociate in the strong, longranging projectile potential. The collision has to be considered as a real three body interaction. (orig.)

A Flexible Online Apparatus for Projectile Launch Experiments

Directory of Open Access Journals (Sweden)

Carlos Manuel Paiva

2013-01-01

Full Text Available In order to provide a more flexible learning environment in physics, the developed projectile launch apparatus enables students to determine the acceleration of gravity and the dependence of a set of parameters in the projectile movement. This apparatus is remotely operated and accessed via web, by first scheduling an access time slot. This machine has a number of configuration parameters that support different learning scenarios with different complexities.

Projectile Motion Hoop Challenge

Science.gov (United States)

Jordan, Connor; Dunn, Amy; Armstrong, Zachary; Adams, Wendy K.

2018-01-01

Projectile motion is a common phenomenon that is used in introductory physics courses to help students understand motion in two dimensions. Authors have shared a range of ideas for teaching this concept and the associated kinematics in "The Physics Teacher" ("TPT"); however, the "Hoop Challenge" is a new setup not…

Coincidence measurements of slow recoil ions with projectile ions in 42-MeV Arq+-Ar collisions

International Nuclear Information System (INIS)

Tonuma, T.; Kumagai, H.; Matsuo, T.; Tawara, H.

1989-01-01

Slow Ar recoil-ion production cross sections by projectiles of 1.05-MeV/amu Ar q+ (q=4,6,8,10,12,14) were measured using a projectile-ion--recoil-ion coincidence technique. The present results indicate that the average recoil ion charges left-angle i right-angle increase with increasing the incident projectile charge q and the number of the lost and captured electrons from and/or into projectiles, whereas the projectile charge-changing cross sections for loss ionization decrease steeply with increasing q for low-charge-state projectiles, and those for transfer ionization increase rapidly with increasing q for high-charge-state projectiles. For Ar projectiles with q=10, which corresponds to the equilibrium charge state of Ar projectiles at the present collision energy, the average recoil-ion charges are nearly the same in both loss and transfer ionization, and a pure ionization process plays a much more important role in producing highly charged recoil ions, in contrast to projectile electron loss or transfer processes, which play a role in other projectile charge states

Multifragmentation of gold nuclei interacting with photoemulsion nuclei at an energy of 10.7 GeV per projectile nucleon

International Nuclear Information System (INIS)

Gulamov, K.G.; Navotny, V.Sh.; Uzhinskii, V.V.

1999-01-01

Experimental data on the distributions of fragments with respect to the bound charge (Z bound , Z b3 ) and with respect to the multiplicities and on their correlations are presented. These data are compared with analogous data at 600 MeV per projectile nucleon that were obtained at the ALADIN facility. It has been shown that the processes of gold-nucleus multifragmentation at intermediate and high energies have some common features. At the same time, the multiplicity of medium-mass fragments becomes somewhat less at high energies. Data presented in this study are analyzed within the framework combining the statistical model of nuclear multifragmentation with the Regge model of the breakup of nuclei. This combined model has been shown to reproduce qualitatively the experimental results under discussion. The most pronounced discrepancies have been observed for the yields of doubly charged fragments. The transverse momenta of fragments have been analyzed as functions of the bound charge Z bound . It has been demonstrated that the model underestimates considerably the transverse momenta of fragments. This is interpreted as evidence for a strong radial flow of spectator fragments

Spinning projectile's attitude measurement with LW infrared radiation under sea-sky background

Science.gov (United States)

Xu, Miaomiao; Bu, Xiongzhu; Yu, Jing; He, Zilu

2018-05-01

With the further development of infrared radiation research in sea-sky background and the requirement of spinning projectile's attitude measurement, the sea-sky infrared radiation field is used to carry out spinning projectile's attitude angle instead of inertial sensors. Firstly, the generation mechanism of sea-sky infrared radiation is analysed. The mathematical model of sea-sky infrared radiation is deduced in LW (long wave) infrared 8 ∼ 14 μm band by calculating the sea surface and sky infrared radiation. Secondly, according to the movement characteristics of spinning projectile, the attitude measurement model of infrared sensors on projectile's three axis is established. And the feasibility of the model is analysed by simulation. Finally, the projectile's attitude calculation algorithm is designed to improve the attitude angle estimation accuracy. The results of semi-physical experiments show that the segmented interactive algorithm estimation error of pitch and roll angle is within ±1.5°. The attitude measurement method is effective and feasible, and provides accurate measurement basis for the guidance of spinning projectile.

Study of incomplete fusion sensitivity to projectile structure from forward recoil range distribution measurement

International Nuclear Information System (INIS)

Kumar, Harish; Tali, Suhail A.; Afzal Ansari, M.

2017-01-01

Recently, the projectile structure is found to affect the incomplete fusion (ICF) process by using α- and non-α-cluster structured projectiles which is explored in terms of projectile α-Q-value and is still limited only for a very few systems. Keeping in view the recent aspects especially the projectile structure effect on ICF, the present work is carried out in the series of experiment by using α- and non-α-cluster structured projectiles. Presently, the FRRDs of evaporation residues (ERs) produced in 13 C + 175 Lu system have been measured at ≈ 88 MeV energy. In this work, an attempt has been made to have a better knowledge of projectile α-Q-value effect on ICF

Initiation of Gaseous Detonation by Conical Projectiles

Science.gov (United States)

Verreault, Jimmy

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

Energy dependence of the optical potential of weakly and tightly bound nuclei as projectiles on a medium-mass target

International Nuclear Information System (INIS)

Figueira, J. M.; Arazi, A.; Carnelli, P.; Heimann, D. Martinez; Negri, A. E.; Pacheco, A. J.; Niello, J. O. Fernandez; Capurro, O. A.; Fimiani, L.; Marti, G. V.; Lubian, J.; Monteiro, D. S.; Gomes, P. R. S.

2010-01-01

Angular distributions for the elastic scattering of the weakly bound 6,7 Li+ 144 Sm systems were measured with high accuracy at bombarding energies from 85% up to 170% of the Coulomb barrier. An optical model analysis was performed, and the relevant parameters of the real and imaginary parts of the optical potential were extracted. The results are compared with those previously published for the tightly bound 12 C+ 144 Sm and 16 O+ 144 Sm systems. The usual threshold anomaly observed in the behavior of the potential of tightly bound systems was not observed for either weakly bound system. This absence is attributed to the repulsion due to breakup coupling which cancels the attraction arising from couplings with bound channels.

Double ionization of H2 caused by two sequential projectile-electron collisions

International Nuclear Information System (INIS)

Edwards, A.K.; Wood, R.M.; Ezell, R.L.

1985-01-01

The impact-parameter calculations of Hansteen et al. [J. Phys. B 17, 3545 (1984)] for K-shell ionization are used to predict the cross sections for the double ionization of H 2 and He by H + and D + projectiles as a function of projectile velocity. The calculated values in the case of the H 2 target are typically a factor of 12 lower than the measured values, but the calculations and measurements show similar velocity dependencies. The results indicate that for projectile energies less than 1 MeV/amu, the double-ionization process of H 2 occurs mainly by two independent interactions between the electrons and projectile. For the He target, the calculated and measured values for the double-ionization cross section are much closer in magnitude, but the calculations predict a more rapid falloff with projectile velocity than is observed

Electron loss and capture from low-charge-state oxygen projectiles in methane

International Nuclear Information System (INIS)

Santos, A C F; Wolff, W; Sant’Anna, M M; Sigaud, G M; DuBois, R D

2013-01-01

Absolute cross sections for single- and double-electron loss and single- and multiple-electron capture of 15–1000 keV oxygen projectiles (q = −1, 0, 1, 2) colliding with the methane molecule are presented. The experimental data are used to examine cross-section scaling characteristics for the electron loss of various projectiles. In addition, a modified version of the free-collision model was employed for the calculation of the single- and total-electron-loss cross sections of oxygen projectiles presented in this work. The comparison of the calculated cross sections with the present experimental data shows very good agreement for projectile velocities above 1.0 au. The comparison of the present single-electron-capture cross sections with other projectiles having the same charge shows good agreement, and a common curve can be drawn through the different data sets. (paper)

Mechanisms of Li-projectile breakup-up

International Nuclear Information System (INIS)

Rebel, H.; Srivastava, D.K.

1990-08-01

Various experimental and theoretical features observed in recent studies of break-up of 6 Li and 7 Li projectiles in the field of atomic nuclei are discussed, in particular for the transitional energy regime of 10-30 MeV/amu. The discussion is organized as three independent lectures presented at the International School on Nuclear Physics, Kiev (UkSSR), 28 May - 8 June, 1990. After a survey on the main experimental facts and on the basic reaction mechanisms, current theoretical approaches are illustrated by an application to the analysis of elastic break-up of 156 MeV 6 Li projectiles. Finally Coulomb break-up is discussed as a novel tool of laboratory nuclear astrophysics. (orig.) [de

A Simple General Solution for Maximal Horizontal Range of Projectile Motion

OpenAIRE

Busic, Boris

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.

Variation of the binary encounter peak energy as a function of projectile atomic number

International Nuclear Information System (INIS)

Sanders, J.M.

1994-01-01

The energy of the binary encounter peak, in spectra of electrons emitted at 0 degrees with respect to the projectile beam direction, has been studied to investigate its dependence on the atomic number of the projectile ion. The projectiles all had the same squared velocity of 0.6 MeV/u, and all had the same charge q=7. The Z of the projectiles ranged from 8 to 35, and the target was H 2 . The Energy E BEP of the binary encounter peak and also the energy t of the cusp formed by electron loss or electron capture to the projectile continuum (ELC or ECC) were obtained from fits to the spectra. Considerable care was required in fitting the cusp in order to properly ascertain the cusp energy. The energy shift ΔE, defined as the difference between 4t and E BEP , was obtained for each projectile. It is found that the energy shift decreases as the projectile Z increases. This trend is the opposite of that seen for projectile charge where the shift increases as q increases. Such a trend is not well described by the simple elastic scattering model of binary encounter electron production

On ballistic parameters of less lethal projectiles influencing the severity of thoracic blunt impacts.

Science.gov (United States)

Pavier, Julien; Langlet, André; Eches, Nicolas; Jacquet, Jean-François

2015-01-01

The development and safety certification of less lethal projectiles require an understanding of the influence of projectile parameters on projectile-chest interaction and on the resulting terminal effect. Several energy-based criteria have been developed for chest injury assessment. Many studies consider kinetic energy (KE) or energy density as the only projectile parameter influencing terminal effect. In a common KE range (100-160 J), analysis of the firing tests of two 40 mm projectiles of different masses on animal surrogates has been made in order to investigate the severity of the injuries in the thoracic region. Experimental results have shown that KE and calibre are not sufficient to discriminate between the two projectiles as regards their injury potential. Parameters, such as momentum, shape and impedance, influence the projectile-chest interaction and terminal effect. A simplified finite element model of projectile-structure interaction confirms the experimental tendencies. Within the range of ballistic parameters used, it has been demonstrated that maximum thoracic deflection is a useful parameter to predict the skeletal level of injury, and it largely depends on the projectile pre-impact momentum. However, numerical simulations show that these results are merely valid for the experimental conditions used and cannot be generalised. Nevertheless, the transmitted impulse seems to be a more general factor governing the thorax deflection.

Strain Behavior of Concrete Panels Subjected to Different Nose Shapes of Projectile Impact.

Science.gov (United States)

Lee, Sangkyu; Kim, Gyuyong; Kim, Hongseop; Son, Minjae; Choe, Gyeongcheol; Nam, Jeongsoo

2018-03-09

This study evaluates the fracture properties and rear-face strain distribution of nonreinforced and hooked steel fiber-reinforced concrete panels penetrated by projectiles of three different nose shapes: sharp, hemispherical, and flat. The sharp projectile nose resulted in a deeper penetration because of the concentration of the impact force. Conversely, the flat projectile nose resulted in shallower penetrations. The penetration based on different projectile nose shapes is directly related to the impact force transmitted to the rear face. Scabbing can be more accurately predicted by the tensile strain on the rear face of concrete due to the projectile nose shape. The tensile strain on the rear face of the concrete was reduced by the hooked steel fiber reinforcement because the hooked steel fiber absorbed some of the impact stress transmitted to the rear face of the concrete. Consequently, the strain behavior on the rear face of concrete according to the projectile nose shape was confirmed.

Strain Behavior of Concrete Panels Subjected to Different Nose Shapes of Projectile Impact

Directory of Open Access Journals (Sweden)

Sangkyu Lee

2018-03-01

Full Text Available This study evaluates the fracture properties and rear-face strain distribution of nonreinforced and hooked steel fiber-reinforced concrete panels penetrated by projectiles of three different nose shapes: sharp, hemispherical, and flat. The sharp projectile nose resulted in a deeper penetration because of the concentration of the impact force. Conversely, the flat projectile nose resulted in shallower penetrations. The penetration based on different projectile nose shapes is directly related to the impact force transmitted to the rear face. Scabbing can be more accurately predicted by the tensile strain on the rear face of concrete due to the projectile nose shape. The tensile strain on the rear face of the concrete was reduced by the hooked steel fiber reinforcement because the hooked steel fiber absorbed some of the impact stress transmitted to the rear face of the concrete. Consequently, the strain behavior on the rear face of concrete according to the projectile nose shape was confirmed.

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.)

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

International Nuclear Information System (INIS)

Eggert, Sebastian; Kubik-Huch, Rahel A.; Peters, Alexander; Klarhoefer, Markus; Bolliger, Stephan A.; Thali, Michael J.; Anderson, Suzanne; Froehlich, Johannes M.

2015-01-01

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.)

An experimental study on the deformation and fracture modes of steel projectiles during impact

International Nuclear Information System (INIS)

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

2013-01-01

Highlights: • The fracture process is ductile for the unhardened projectiles. • A combined ductile–brittle fracture process is obtained for the HRC 40 projectiles. • The fragmentation of HRC 52 projectiles has cleavage as the main mechanism. • The fracture modes were confirmed in a metallurgical study. • The hardened materials have a stochastic variation of the mechanical properties. - Abstract: Previous investigations of the penetration and perforation of high-strength steel plates struck by hardened steel projectiles have shown that under certain test conditions the projectile may fracture or even fragment upon impact. Simulations without an accurate failure description for the projectile material will then predict perforation of the target instead of fragmentation of the projectile, and thus underestimate the ballistic limit velocity of the target plate. This paper presents an experimental investigation of the various deformation and fracture modes that may occur in steel projectiles during impact. This is studied by conducting Taylor bar impact tests using 20 mm diameter, 80 mm long, tool steel projectiles with three different hardness values (HRC 19, 40 and 52). A gas gun was used to fire the projectiles into a rigid wall at impact velocities ranging from 100 to 350 m/s, and the deformation and fracture processes were captured by a high-speed video camera. From the tests, several different deformation and fracture modes were registered for each hardness value. To investigate the influence of material on the deformation and fracture modes, several series of tensile tests on smooth axisymmetric specimens were carried out to characterise the mechanical properties of the three materials. To gain a deeper understanding of the various processes causing fracture and fragmentation during impact, a metallurgical investigation was conducted. The fracture surfaces of the failed projectiles of different hardness were investigated, and the microstructure was

Positivity bounds on double parton distributions

International Nuclear Information System (INIS)

Diehl, Markus; Kasemets, Tomas

2013-03-01

Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions that follow from their interpretation as probability densities, taking into account all possible spin correlations between two partons in an unpolarized proton. These bounds constrain the size of the polarized distributions and can for instance be used to set upper limits on the effects of spin correlations in double hard scattering. We show that the bounds are stable under leading-order DGLAP evolution to higher scales.

Electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with many-electron atomic targets

International Nuclear Information System (INIS)

Mueller, C.; Gruen, N.; Voitkiv, A.B.

2002-01-01

We study single- and double-electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with neutral many-electron target atoms. The simultaneous interaction of the target with two projectile electrons is found to be the dominant process in the double-electron loss provided the atomic number of the projectile, Z p , that of the target, Z t , and the collision velocity, v, satisfy the condition Z p Z t /v>0.4. It is shown that for a wide range of projectile and target atomic numbers the asymptotic double-to-single loss ratio strongly depends on the target atomic number but is nearly independent of the nuclear charge of the projectile. It is also demonstrated that many-photon exchange between the target and each of the projectile electrons considerably influences the double loss in collisions with very heavy targets

Features of projectile motion in the special theory of relativity

International Nuclear Information System (INIS)

Shahin, Ghassan Y

2006-01-01

A relativistic projectile motion in a vacuum is examined by means of elementary consequences of special relativity. Exact analytical expressions were found for the kinematics variables using basic mathematical tools. The trajectory equation was established and the area under the trajectory traversed by the relativistic projectile was determined. It was found that, unlike non-relativistic projectile motion, the launching angles that maximize both the horizontal range as well as the area under the trajectory are functions of the initial speed. It is anticipated that this paper will be consistent with the intuition of students and serve as a resource for further problems usually encountered in the special theory of relativity

Ultrahigh-speed X-ray imaging of hypervelocity projectiles

Science.gov (United States)

Miller, Stuart; Singh, Bipin; Cool, Steven; Entine, Gerald; Campbell, Larry; Bishel, Ron; Rushing, Rick; Nagarkar, Vivek V.

2011-08-01

High-speed X-ray imaging is an extremely important modality for healthcare, industrial, military and research applications such as medical computed tomography, non-destructive testing, imaging in-flight projectiles, characterizing exploding ordnance, and analyzing ballistic impacts. We report on the development of a modular, ultrahigh-speed, high-resolution digital X-ray imaging system with large active imaging area and microsecond time resolution, capable of acquiring at a rate of up to 150,000 frames per second. The system is based on a high-resolution, high-efficiency, and fast-decay scintillator screen optically coupled to an ultra-fast image-intensified CCD camera designed for ballistic impact studies and hypervelocity projectile imaging. A specially designed multi-anode, high-fluence X-ray source with 50 ns pulse duration provides a sequence of blur-free images of hypervelocity projectiles traveling at speeds exceeding 8 km/s (18,000 miles/h). This paper will discuss the design, performance, and high frame rate imaging capability of the system.

Characteristics and measurement of supersonic projectile shock waves by a 32-microphone ring array

Science.gov (United States)

Chang, Ho; Wu, Yan-Chyuan; Tsung, Tsing-Tshih

2011-08-01

This paper discusses about the characteristics of supersonic projectile shock wave in muzzle region during firing of high explosive anti-tank (HEAT) and high explosive (HE) projectiles. HEAT projectiles are fired horizontally at a muzzle velocity of Mach 3.5 from a medium caliber tank gun equipped with a newly designed multi-perforated muzzle brake, whereas HE projectiles are fired at elevation angles at a muzzle velocity of Mach 2 from a large caliber howitzer equipped with a newly designed double-baffle muzzle brake. In the near field, pressure signatures of the N-wave generated from projectiles are measured by 32-microphone ring array wrapped by cotton sheath. Records measured by the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements made in this study can be a significant reference for developing guns, tanks, or the chassis of fighting vehicles.

Non-contact and contact measurement system for detecting projectile position in electromagnetic launch bore

Science.gov (United States)

Xu, Weidong; Yuan, Weiqun; Xu, Rong; Zhao, Hui; Cheng, Wenping; Zhang, Dongdong; Zhao, Ying; Yan, Ping

2017-12-01

This paper introduces a new measurement system for measuring the position of a projectile within a rapid fire electromagnetic launching system. The measurement system contains both non-contact laser shading and metal fiber contact measurement devices. Two projectiles are placed in the rapid fire electromagnetic launch bore, one in the main accelerating segment and the other in the pre-loading segment. The projectile placed in the main accelerating segment should be shot first, and then the other is loaded into the main segment from the pre-loading segment. The main driving current (I-main) can only be discharged again when the second projectile has arrived at the key position (the projectile position corresponds to the discharging time) in the main accelerating segment. So, it is important to be able to detect when the second projectile arrives at the key position in the main accelerating segment. The B-dot probe is the most widely used system for detecting the position of the projectile in the electromagnetic launch bore. However, the B-dot signal is affected by the driving current amplitude and the projectile velocity. There is no current in the main accelerating segment when the second projectile moves into this segment in rapid fire mode, so the B-dot signal for detecting the key position is invalid. Due to the presence of a high-intensity magnetic field, a high current, a high-temperature aluminum attachment, smoke and strong vibrations, it is very difficult to detect the projectile position in the bore accurately. So, other measurements need to be researched and developed in order to achieve high reliability. A measurement system based on a laser (non-contact) and metal fibers (contact) has been designed, and the integrated output signal based on this detector is described in the following paper.

Optimisation of design parameters for modular range enhanced projectile

OpenAIRE

Jelic, Z

2016-01-01

There is an underpinning requirement for artillery systems to achieve longer range, better precision, and an adequate lethal effect. The main objective of this research is to investigate various methods of range increase and propose optimal solution for range extension of existing artillery systems. The proposed solution is novel, modular projectile design. Several methodologies for projectile range increment (such as improved aerodynamics and ballistic profile) were combined to achieve the "...

Systematics of new isotopic production cross sections from neon projectiles

International Nuclear Information System (INIS)

Chen, C.X.; Guzik, T.G.; McMahon, M.; Wefel, J.P.; Flores, I.; Lindstrom, P.J.; Tull, C.E.; Mitchell, J.W.; Cronqvist, M.; Crawford, H.J.

1996-02-01

New isotopic production cross sections from 22 Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.)

Roll Attitude Determination of Spin Projectile Based on GPS and Magnetoresistive Sensor

Directory of Open Access Journals (Sweden)

Dandan Yuan

2017-01-01

Full Text Available Improvement in attack accuracy of the spin projectiles is a very significant objective, which increases the overall combat efficiency of projectiles. The accurate determination of the projectile roll attitude is the recent objective of the efficient guidance and control. The roll measurement system for the spin projectile is commonly based on the magnetoresistive sensor. It is well known that the magnetoresistive sensor produces a sinusoidally oscillating signal whose frequency slowly decays with time, besides the possibility of blind spot. On the other hand, absolute sensors such as GPS have fixed errors even though the update rates are generally low. To earn the benefit while eliminating weaknesses from both types of sensors, a mathematical model using filtering technique can be designed to integrate the magnetoresistive sensor and GPS measurements. In this paper, a mathematical model is developed to integrate the magnetoresistive sensor and GPS measurements in order to get an accurate prediction of projectile roll attitude in a real flight time. The proposed model is verified using numerical simulations, which illustrated that the accuracy of the roll attitude measurement is improved.

Determination of extra trajectory parameters of projectile layout motion

Science.gov (United States)

Ishchenko, A.; Burkin, V.; Faraponov, V.; Korolkov, L.; Maslov, E.; Diachkovskiy, A.; Chupashev, A.; Zykova, A.

2017-11-01

The paper presents a brief description of the experimental track developed and implemented on the base of the RIAMM TSU for external trajectory investigations on determining the main aeroballistic parameters of various shapes projectiles, in the wide velocity range. There is comparison between the experimentally obtained dependence of the fin-stabilized projectile mock-up aerodynamic drag coefficient on the Mach number with the 1958 aerodynamic drag law and aerodynamic tests of the same mock-up

The role of the spectator assumption in models for projectile fragmentation

International Nuclear Information System (INIS)

Mc Voy, K.W.

1984-01-01

This review is restricted to direct-reaction models for the production of projectile fragments in nuclear collisions, at beam energies of 10 or more MeV/nucleon. Projectile fragments are normally identified as those which have near-beam velocities, and there seem to be two principal mechanisms for the production of these fast particles: 1. Direct breakup, 2. Sequential breakup. Of the two, the authors exclude from their discussion the ''sequential breakup'' process, in which the projectile is excited by the initial collision (either via inelastic scattering or transfer to unbound states) and then subsequently decays, outside the range of interaction

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

Systematics of new isotopic production cross sections from neon projectiles

Energy Technology Data Exchange (ETDEWEB)

Chen, C X; Guzik, T G; McMahon, M; Wefel, J P [Louisiana State Univ., Baton Rouge, LA (United States); Flores, I; Lindstrom, P J; Tull, C E [Lawrence Berkeley Lab., CA (United States); Mitchell, J W [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Cronqvist, M; Crawford, H J [California Univ., Berkeley, CA (United States). Space Sciences Lab.; and others

1996-02-01

New isotopic production cross sections from {sup 22}Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.). 9 refs.

Can the Σ-nn system be bound?

International Nuclear Information System (INIS)

Stadler, A.; Gibson, B.F.

1994-01-01

Motivated by the Σ-hypernuclear states reported in (K - ,π ± ) experiments, we have explored the possibility that there exists a particle-stable Σ - nn bound state. For the Juelich A hyperon-nucleon, realistic-force model, our calculations yield little reason to expect a positive-parity bound state or resonance in either the J=1/2 or the J=3/2 channels

Calculation of forces arising from impacting projectiles upon yielding structures

International Nuclear Information System (INIS)

Drittler, K.; Gruner, P.; Krivy, J.

1977-01-01

Calculations concerning the impact of airplanes upon nuclear power plant buildings usually imply that the building [QUOTE]acts' as a rigid target. This assumption is justified for considerations concerning the structural integrity of the building being hit. However, for investigating induced vibrations of components within the structure, this approach might-in general-be too conservative. It is expected, that yielding of the structure during impact reduces the peak values of the loads and changes the temporal behaviour of the load function which is obtained for a rigid target. To calculate the changes of the load function which are due to deformations of the structure, Riera's method is extended for the case of a yielding target. The calculations are performed with a one-dimensional model for the projectile. The presented model calculations seem to verify that the motion of the target does not have much influence on the impact force for projectiles similar to the model projectile, provided the displacement of the yielding target is small in comparison with the path covered by the free-flying projectile during a time which is equivalent to the total time of impact. (Auth.)

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.

Projectile Aerodynamic Jump Due to Lateral Impulsives

National Research Council Canada - National Science Library

Cooper, Gene

2003-01-01

.... The formulation shows for sufficiently long-range target interception; lateral impulse trajectory response for a guided projectile is independent of when the impulse is activated during the yaw cycle...

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.

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

Directory of Open Access Journals (Sweden)

Yonatan Sahle

Full Text Available 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.

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

Directory of Open Access Journals (Sweden)

NianSong Zhang

2015-01-01

Full Text Available 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.

Antiscreening mode of projectile-electron loss

International Nuclear Information System (INIS)

Montanari, C.C.; Miraglia, J.E.; Arista, N.R.

2003-01-01

The inelastic contribution of target electrons to different electronic processes in the projectile is obtained by employing the local-density approximation as usually applied in the dielectric formalism. Projectile-electron-loss cross sections due to the electron-electron interaction are calculated and compared with those obtained by using atomic antiscreening theories. We also calculate ionization cross sections and stopping power for bare ions impinging on different gases. The good agreement with the experimental data and the simplicity of the local-density approximation make it an efficient method for describing inelastic processes of gaseous target electrons. It is expected to be useful for targets with large atomic number. In this case, the number of possible final states to be considered by the traditional atomic methods makes it a tough task to be tackled. On the contrary, the more electrons the target has, the better the local plasma approximation is expected to be

Evaluating the risk of eye injuries: intraocular pressure during high speed projectile impacts.

Science.gov (United States)

Duma, Stefan M; Bisplinghoff, Jill A; Senge, Danielle M; McNally, Craig; Alphonse, Vanessa D

2012-01-01

To evaluate the risk of eye injuries by determining intraocular pressure during high speed projectile impacts. A pneumatic cannon was used to impact eyes with a variety of projectiles at multiple velocities. Intraocular pressure was measured with a small pressure sensor inserted through the optic nerve. A total of 36 tests were performed on 12 porcine eyes with a range of velocities between 6.2 m/s and 66.5 m/s. Projectiles selected for the test series included a 6.35  mm diameter metal ball, a 9.25  mm diameter aluminum rod, and an 11.16  mm diameter aluminum rod. Experiments were designed with velocities in the range of projectile consumer products such as toy guns. A range of intraocular pressures ranged between 2017 mmHg to 26,426 mmHg (39 psi-511 psi). Four of the 36 impacts resulted in globe rupture. Intraocular pressures dramatically above normal physiological pressure were observed for high speed projectile impacts. These pressure data provide critical insight to chronic ocular injuries and long-term complications such as glaucoma and cataracts.

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

International Nuclear Information System (INIS)

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

Multiplicity of secondary electrons emitted by carbon thin targets by impact of H0, H2+ and H3+ projectiles at MeV energies

International Nuclear Information System (INIS)

Vidovic, Zvonimir

1997-01-01

This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + 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 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 2 + and H 3 + 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)

Classical gluon production amplitude for nucleus-nucleus collisions:First saturation correction in the projectile

International Nuclear Information System (INIS)

Chirilli, Giovanni A.; Kovchegov, Yuri V.; Wertepny, Douglas E.

2015-01-01

We calculate the classical single-gluon production amplitude in nucleus-nucleus collisions including the first saturation correction in one of the nuclei (the projectile) while keeping multiple-rescattering (saturation) corrections to all orders in the other nucleus (the target). In our approximation only two nucleons interact in the projectile nucleus: the single-gluon production amplitude we calculate is order-g"3 and is leading-order in the atomic number of the projectile, while resumming all order-one saturation corrections in the target nucleus. Our result is the first step towards obtaining an analytic expression for the first projectile saturation correction to the gluon production cross section in nucleus-nucleus collisions.

Study of breakup and transfer of weakly bound nucleus 6Li to explore the low energy reaction dynamics

Directory of Open Access Journals (Sweden)

Zhang G. L.

2017-01-01

In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, we performed the 6Li+89Y experiment with incident energies of 22 MeV and 34 MeV on Galileo array in cooperation with Si-ball EUCLIDES at Legnaro National Laboratory (LNL in Italy. Using particle-particle and particle-γ coincidences, the different reaction mechanisms can be clearly explored.

Scattering of mass-3 projectiles from heavy nuclei

International Nuclear Information System (INIS)

Mukhopadyay, S.; Srivastava, D.K.; Ganguly, N.K.

1976-01-01

The interaction between heavy ions is a subject of great interest. It is well known that α-particle scattering shows most of the features which are observed in heavy ion scattering. In as much as mass-3 system is intermediate between heavy and light particles it will be interesting to investigate the scattering of mass-3 projectiles to see if it is possible to extend it to study the heavy ion scattering. Indeed; it has been seen that the 'molecular type' potentials, with a soft repulsive core and a shallow attractive well used for heavy ion collisions can be used to fit the elastic scattering data of mass-3 projectiles also. In the first part of this paper, a description is given of how this potential is generated with a special emphasis on saturation and second order effect through a density dependent interaction between nucleon and mass-3 projectiles. In the second part it is shown that the asymmetry dependence observed in the potential describing the scattering of mass-3 particles from heavier nuclei actually originates from the isospin interaction, when triton and helion are treated as two members of an isospin doublet. (Auth.)

Improvements to a model of projectile fragmentation

International Nuclear Information System (INIS)

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

2011-01-01

In a recent paper [Phys. Rev. C 83, 044612 (2011)] we proposed a model for calculating cross sections of various reaction products which arise from disintegration of projectile-like fragments resulting from heavy-ion collisions at intermediate or higher energy. The model has three parts: (1) abrasion, (2) disintegration of the hot abraded projectile-like fragment (PLF) into nucleons and primary composites using a model of equilibrium statistical mechanics, and (3) possible evaporation of hot primary composites. It was assumed that the PLF resulting from abrasion has one temperature T. Data suggested that, while just one value of T seemed adequate for most cross-section calculations, a single value failed when dealing with very peripheral collisions. We have now introduced a variable T=T(b) where b is the impact parameter of the collision. We argue that there are data which not only show that T must be a function of b but, in addition, also point to an approximate value of T for a given b. We propose a very simple formula: T(b)=D 0 +D 1 [A s (b)/A 0 ] where A s (b) is the mass of the abraded PLF and A 0 is the mass of the projectile; D 0 and D 1 are constants. Using this model we compute cross sections for several collisions and compare with data.

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.

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)

Fatal lawn mower related projectile injury

DEFF Research Database (Denmark)

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

2014-01-01

was initially overlooked, later interpreted as a possible gunshot homicide, and finally identified as a lawn mower related projectile injury when autopsy revealed a piece of metal thread in the main bronchus to the right middle lobe, hemopericardium, and right-sided hemothorax. To our knowledge, this injury...

Effect of Projectile Materials on Foreign Object Damage of a Gas-Turbine Grade Silicon Nitride

Science.gov (United States)

Choi, Sung R.; Racz, Zsolt; Bhatt, Ramakrishna T.; Brewer, David N.; Gyekenyesi, John P.

2005-01-01

Foreign object damage (FOD) behavior of AS800 silicon nitride was determined using four different projectile materials at ambient temperature. The target test specimens rigidly supported were impacted at their centers by spherical projectiles with a diameter of 1.59 mm. Four different types of projectiles were used including hardened steel balls, annealed steel balls, silicon nitride balls, and brass balls. Post-impact strength of each target specimen impacted was determined as a function of impact velocity to better understand the severity of local impact damage. The critical impact velocity where target specimens fail upon impact was highest with brass balls, lowest with ceramic ball, and intermediate with annealed and hardened steel balls. Degree of strength degradation upon impact followed the same order as in the critical impact velocity with respect to projectile materials. For steel balls, hardened projectiles yielded more significant impact damage than annealed counterparts. The most important material parameter affecting FOD was identified as hardness of projectiles and was correlated in terms of critical impact velocity, impact deformation, and impact load.

Remarks on Bousso's covariant entropy bound

CERN Document Server

Mayo, A E

2002-01-01

Bousso's covariant entropy bound is put to the test in the context of a non-singular cosmological solution of general relativity found by Bekenstein. Although the model complies with every assumption made in Bousso's original conjecture, the entropy bound is violated due to the occurrence of negative energy density associated with the interaction of some the matter components in the model. We demonstrate how this property allows for the test model to 'elude' a proof of Bousso's conjecture which was given recently by Flanagan, Marolf and Wald. This corroborates the view that the covariant entropy bound should be applied only to stable systems for which every matter component carries positive energy density.

Effect of Nonsmooth Nose Surface of the Projectile on Penetration Using DEM Simulation

Directory of Open Access Journals (Sweden)

Jing Han

2017-01-01

Full Text Available The nonsmooth body surface of the reptile in nature plays an important role in reduction of resistance and friction when it lives in a soil environment. To consider whether it was feasible for improving the performance of penetrating projectile we investigated the influence of the convex as one of nonsmooth surfaces for the nose of projectile. A numerical simulation study of the projectile against the concrete target was developed based on the discrete element method (DEM. The results show that the convex nose surface of the projectile is beneficial for reducing the penetration resistance greatly, which is also validated by the experiments. Compared to the traditional smooth nose structure, the main reason of difference is due to the local contact normal pressure, which increases dramatically due to the abrupt change of curvature caused by the convex at the same condition. Accordingly, the broken particles of the concrete target obtain more kinetic energy and their average radial flow velocities will drastically increase simultaneously, which is in favor of decreasing the interface friction and the compaction density of concrete target around the nose of projectile.

Charge dependence of one and two electron processes in collisions between hydrogen molecules and fast projectiles

International Nuclear Information System (INIS)

Wells, E.; Ben-Itzhak, I.; Carnes, K.D.; Krishnamurthi, V.

1996-01-01

The ratio of double- to single-ionization (DI/SI) as well as the ratio of ionization-excitation to single-ionization (IE/SI) in hydrogen molecules was studied by examining the effect of the projectile charge on these processes. The DI/SI and IE/SI ratios were measured using the coincidence time of flight technique at a fixed velocity (1 MeV/amu) over a range of projectile charge states (q = 1-9,14,20). Preliminary results indicate that for a highly charged F 9+ projectile the DI/SI and IE/SI ratios are 6.8% and 24.7%, respectively, a large increase from the ratios of 0.13% and 1.95%, respectively, for H + projectiles. For low charge states, the DI/SI is negligible relative to the IE/SI ratio, while for more highly charged projectiles the DI/SI ratio becomes comparable to the IE/SI ratio. This indicates that double-ionization increases much more rapidly with projectile charge than ionization-excitation

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.

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.

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.

Computational Simulation of High-Speed Projectiles in Air, Water, and Sand

Science.gov (United States)

2007-12-03

Supercavitating projectiles can be used for underwater mine neutralization, beach and surf zone mine clearance, littoral ASW, and neutralizing combat...swimmer systems. The water entry phase of flight is interesting and challenging due to projectile transitioning from flight in air to supercavitating ...is formed. Neaves and Edwards [1] simulated this case using a supercavitation code developed at NSWC-PC. The results presented are in good agreement

Energy-dependent expansion of .177 caliber hollow-point air gun projectiles.

Science.gov (United States)

Werner, Ronald; Schultz, Benno; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

2017-05-01

Amongst hundreds of different projectiles for air guns available on the market, hollow-point air gun pellets are of special interest. These pellets are characterized by a tip or a hollowed-out shape in their tip which, when fired, makes the projectiles expand to an increased diameter upon entering the target medium. This results in an increase in release of energy which, in turn, has the potential to cause more serious injuries than non-hollow-point projectiles. To the best of the authors' knowledge, reliable data on the terminal ballistic features of hollow-point air gun projectiles compared to standard diabolo pellets have not yet been published in the forensic literature. The terminal ballistic performance (energy-dependent expansion and penetration) of four different types of .177 caliber hollow-point pellets discharged at kinetic energy levels from approximately 3 J up to 30 J into water, ordnance gelatin, and ordnance gelatin covered with natural chamois as a skin simulant was the subject of this investigation. Energy-dependent expansion of the tested hollow-point pellets was observed after being shot into all investigated target media. While some hollow-point pellets require a minimum kinetic energy of approximately 10 J for sufficient expansion, there are also hollow-point pellets which expand at kinetic energy levels of less than 5 J. The ratio of expansion (RE, calculated by the cross-sectional area (A) after impact divided by the cross-sectional area (A 0 ) of the undeformed pellet) of hollow-point air gun pellets reached values up of to 2.2. The extent of expansion relates to the kinetic energy of the projectile with a peak for pellet expansion at the 15 to 20 J range. To conclude, this work demonstrates that the hollow-point principle, i.e., the design-related enlargement of the projectiles' frontal area upon impact into a medium, does work in air guns as claimed by the manufacturers.

Simulation of the flow past a long-range artillery projectile

OpenAIRE

Kaurinkoski, Petri

2000-01-01

In this work, an eddy breakup model for chemical reactions is implemented to an existing multi-block Navier-Stokes solver, which is then used to solve the flow past a supersonic long-range base-bleed projectile. The new scheme is validated by simulating an axisymmetric bluff-body stabilized flame, which has been measured in a wind tunnel and simulated numerically by other work groups. Comparison of the numerical results for the projectile shows the importance of the chemistry modelling fo...

Measurements of recoil and projectile momentum distributions for 19-MeV F9+ + Ne collisions

International Nuclear Information System (INIS)

Frohne, V.; Cheng, S.; Ali, R.M.; Raphaelian, M.L.; Cocke, C.L.; Olson, R.

1996-01-01

The collision system of 19-MeV F 9+ on Ne has been studied using recoil and projectile momentum spectroscopy. For each event, identified by final recoil and projectile charge state, the three-dimensional momentum vector of the recoil ion and the transverse momentum vector of the projectile ion were measured. The transverse momenta of the recoil and projectile ions were found to be equal in magnitude and opposite in direction, indicating that the transverse momentum exchange is dominated by interactions between the two ion cores. The transverse momentum distributions are well described by nCTMC calculations. The longitudinal momentum distributions of the recoil ions show that a large fraction of the momentum transferred to the projectile is carried off by continuum electrons. The recoil ions are scattered slightly backward, in partial agreement with predictions of nCTMC calculations. copyright 1996 The American Physical Society

Projectile fragmentation processes in 35-MeV/amu (α,xy) reactions

International Nuclear Information System (INIS)

Koontz, R.W.; Chang, C.C.; Holmgren, H.D.; Wu, J.R.

1979-01-01

Coincidence measurements with 35-MeV/amu α particles show that at least three projectile-fragmentation processes occur. The dominant process is ''absorptive'' breakup, where one component of the projectile interacts strongly with the target resulting in the emission of evaporation or nonstatistical particles while the other component behaves as a spectator. The other fragmentation processes which are observed account for only a few percent of the breakup cross section

Experimental study of the penetrating of plates by projectile at low initial speeds

Science.gov (United States)

Orlov, M. Yu; Orlova, Yu N.; Smakotin, Ig L.; Glazyrin, V. P.; Orlov, Yu N.

2017-11-01

The research of the penetration process of lightweight plates by a projectile in the range of initial velocities up to 325 m/s was attempted. The projectile was a shell bullet and the barriers were of ice, MDF-panels and plexiglas barriers. The response of barriers to impact loading is studied. High-speed shooting of each experiment is obtained, including photos of the front and rear sides of the barriers. An attempt was made to reproduce the scenario of the destruction of barriers. The results of experiments can be interpreted only as qualitative tests. Projectile was not destroyed.

Ballistics considerations for small-caliber, low-density projectiles

International Nuclear Information System (INIS)

Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Milora, S.L.; Qualls, A.L.

1993-01-01

One major application for single- and two-stage light gas guns is for fueling magnetic fusion confinement devices. Powder guns are not a feasible alternative due to possible plasma contamination by residual powder gases and the eventual requirement of steady-state operation at ∼ 1 Hz, which will dictate a closed gas handling system where propellant gases are recovered, processed and recompressed. Interior ballistic calculations for single-stage light gas guns, both analytical and numerical, are compared to an extensive data base for low density hydrogenic projectiles (pellets). Some innovative range diagnostics are described for determining the size and velocity of these small (several mm) size projectiles. A conceptual design of a closed cycle propellant gas system is presented including tradeoffs between different light propellant gases

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.

Extended Range of a Gun Launched Smart Projectile Using Controllable Canards

OpenAIRE

Mark Costello

2001-01-01

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...

Microadaptive Flow Control Applied to a Spinning Projectile

National Research Council Canada - National Science Library

McMichael, J; Lovas, A; Plostins, P; Sahu, J; Brown, G; Glezer, A

2005-01-01

... technology developed, the flight control technology required to enable the MAFC on spinning projectiles, the design of the flight test and validation hardware, and the results of the open-loop flight test...

Electromagnetic projectile acceleration utilizing distributed energy sources

International Nuclear Information System (INIS)

Parker, J.V.

1982-01-01

Circuit equations are derived for an electromagnetic projectile accelerator (railgun) powered by a large number of capacitive discharge circuits distributed along its length. The circuit equations are put into dimensionless form and the parameters governing the solutions derived. After specializing the equations to constant spacing between circuits, the case of lossless rails and negligible drag is analyzed to show that the electrical to kinetic energy transfer efficiency is equal to sigma/2, where sigma = 2mS/Lq 2 0 and m is the projectile mass, S the distance between discharge circuit, Lthe rail inductance per unit length, and q 0 the charge on the first stage capacitor. For sigma = 2 complete transfer of electrical to kinetic energy is predicted while for sigma>2 the projective-discharge circuit system is unstable. Numerical solutions are presented for both lossless rails and for finite rail resistance. When rail resistance is included, >70% transfer is calculated for accelerators of arbitrary length. The problem of projectile startup is considered and a simple modification of the first two stages is described which provides proper startup. Finally, the results of the numerical solutions are applied to a practical railgun design. A research railgun designed for repeated operation at 50 km/sec is described. It would have an overall length of 77 m, an electrical efficiency of 81%, a stored energy per stage of 105 kJ, and a charge transfer of <50 C per stage. A railgun of this design appears to be practicable with current pulsed power technology

STABLE SILICA-GRAFTED POLYMER-BOUND BULKY-PHOSPHITE MODIFIED RHODIUM HYDROFORMYLATION CATALYSTS

NARCIS (Netherlands)

JONGSMA, T; VANAERT, H; FOSSEN, M; CHALLA, G; VANLEEUWEN, PWNM

1993-01-01

The present study demonstrates that silica-grafted polymer-bound phosphite modified rhodium complexes can be used in continuous flow reactors. The hydroformylation of styrene was carried out at moderate pressure (p(CO/H-2) = 30 bar) and temperature (T = 100-degrees-C), yielding constant conversions

Electromagnetic interference analysis of magnetic resistance sensors inside a projectile under complex electromagnetic environments

International Nuclear Information System (INIS)

Guo, Qingwei; Gao, Min; Lu, Zhicai; Yang, Peijie

2013-01-01

Accurate measurement of angular motion has long been recognized as a daunting task. In recent years the measurement of projectiles utilizing magnetic resistance sensors has become a hot research field. Electromagnetic interference on attitude measurement cannot be ignored in complex electromagnetic environments such as battlefield conditions. In this paper, the influence and function pattern of electromagnetic interference on the measuring performance are theoretically analyzed, and the shielding effectiveness (SE) simulation of projectile is conducted via software Computer Simulation Technology (CST). Considering the specific tests, the intensity of the influence is judged. The simulation indicates that the battlefield's complex electromagnetic environment influences the environment inside the projectile, especially its electronic components and capability. The research results can provide important theoretical support on the errors compensation and precision improvement of the projectile attitude measurement with Magnetic Resistance sensor.

The scaling and dynamics of a projectile obliquely impacting a granular medium.

Science.gov (United States)

Wang, Dengming; Ye, Xiaoyan; Zheng, Xiaojing

2012-01-01

In this paper, the dynamics of a spherical projectile obliquely impacting into a two-dimensional granular bed is numerically investigated using the discrete element method. The influences of projectile's initial velocities and impacting angles are mainly considered. Numerical results show that the relationship between the final penetration depth and the initial impact velocity is very similar to that in the vertical-impact case. However, the dependence of the stopping time on the impact velocity of the projectile exhibits critical characteristics at different impact angles: the stopping time approximately increases linearly with the impact velocity for small impact angles but decreases in an exponential form for larger impact angles, which demonstrates the existence of two different regimes at low and high impact angles. When the impact angle is regarded as a parametric variable, a phenomenological force model at large impact angles is eventually proposed based on the simulation results, which can accurately describe the nature of the resistance force exerted on the projectile by the granular medium at different impact angels during the whole oblique-impact process. The degenerate model agrees well with the existing experimental results in the vertical-impact cases.

The Locus of the apices of projectile trajectories under constant drag

OpenAIRE

Hernández-Saldaña, H.

2017-01-01

We present an analytical solution for the projectile coplanar motion under constant drag parametrised by the velocity angle. We found the locus formed by the apices of the projectile trajectories. The range and time of flight are obtained numerically and we find that the optimal launching angle is smaller than in the free drag case. This is a good example of problems with constant dissipation of energy that includes curvature, and it is proper for intermediate courses of mechanics.

Nuclear reactions with radioactive and stable beams (Part II)

International Nuclear Information System (INIS)

Aguilera R, E.F.; Martinez Q, E.; Gomez C, A.; Lizcano, D.

2005-12-01

At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: 6 He + 209 Bi, 8 Li + 208 Pb, 10 Be + 208 Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system 12 C + 4 He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like 18 O + 4 He, 12 C + 12 C, 12 C + 16 O, 16 O + 16 O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during the second stage of this project, considered for 2005 are described. Also in that year, our group carries out a research stay in the University of Notre Dame, during this stay, the angular distribution of the projectiles of 8 B dispersed in an enriched target of 58 Ni was measured. The same as in the previous experiments, in this occasion it was also possible to measure those angular distributions of the projectiles of 7 Be and 6 Li dispersed in this same target. In this same one our stay group participates in other three experiments proposed by collaborators of other institutions (University of Notre Dame, University of Sao Paulo), where the products of the

Emission of projectile helium fragments in 14N interactions at 2.1 GeV/nucleon

International Nuclear Information System (INIS)

Bhanja, R.; Devi, N.A.L.; Joseph, R.R.; Ojha, I.D.; Shyam, M.; Tuli, S.K.

1983-01-01

An analysis of projectile helium fragments has been performed from the point of view of testing the factorization and limiting fragmentation hypothesis. An event-by-event examination of 923 interactions of 14 N in emulsion at 2.1 GeV per nucleon has been made for target identification. Events with projectile fragments have been divided into various reaction channels according to the multiplicity of He nuclei. The multiplicity distribution, angular structure and other properties of the projectile He fragments have been investigated to see the dependence on different targets and target excitation. The properties of He fragments emitted from the projectile have been found to remain independent of target in peripheral collision processes. The target and projectile breakup properties have been analysed in terms of the collision geometry. Gaussian distributions have been fitted to the projected angular distribution data for He fragments at various intervals of impact parameter and in different reaction channels. The properties of emitted He nuclei exhibit characteristic features of factorization and limiting fragmentation. (orig.)

Inclusive projectile fragmentation in the spectator model

International Nuclear Information System (INIS)

Hussein, M.S.; McVoy, K.W.

1985-01-01

Crazing-angle single spectra for projectile fragments from nuclear collisions exhibit a broad peak centered near the beam velocity, suggesting that these observed fragments play only a 'spectator' role in the reaction. Using only this spectator assumption (but not DWBA), it is found that a 'prior form' formulation of the reaction leads, via closure, to a -type estimate of the inclusive spectator spectrum, thus relating it to the reaction cross section for the 'participant' with the target. It is shown explicitly that this expression includes an improved multi-channel version of the Udagawa-Tamura formula for the 'breakup-fusion' or incomplete fusion cross section, and identifies it as the fluctuation part of the participant-target reaction cross section. A Glauber-type estimate of the distorted wave functions which enter clearly shows how the width of the peak in the spectator spectrum arises from the 'Fermi motion' within the projectile, as in the simple Serber model, but is modified by the 'overlap geometry' of the collision. (Author) [pt

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)

Experimental investigation of magnetoplasma acceleration of dielectric projectiles in a rail gun

International Nuclear Information System (INIS)

Kondratenko, M.M.; Lebedev, E.F.; Ostashev, V.E.; Safonov, V.I.; Fortov, V.E.; Ul'yanov, A.V.

1988-01-01

The authors present results of experimental investigations of the process of a nondestructive electrodynamic acceleration of dielectric projectiles in a magnetoplasma accelerator of rail gun type upon discharge of the electrical energy of the capacitor bank. They describe the phenomenon of decay of the plasma driving piston. They describe the causes of this phenomenon and the practical steps to avoid it. In a specific facility regimes have been achieved with electrodynamic acceleration of projectiles without plasma piston decay at working currents of up to 0.7 MA. In acceleration of projectiles of mass ∼ 1 g a speed of 6 km/sec has been attained and reproduced. The facility constructed can be used efficiently in experiments to investigate the thermophysical properties of substances using dynamic methods as a means of creating intense kinetic energy pulses

Experimental study on the penetration effect of ceramics composite projectile on ceramic / A3 steel compound targets

Directory of Open Access Journals (Sweden)

Di-qi Hu

2017-08-01

Full Text Available In order to improve the penetration of projectiles into ceramic composite armors, the nose of 30 mm standard projectile was replaced by a toughened ceramic nose, and the performance of ceramic-nose projectiles penetrating into ceramic/A3 steel composite targets has been experimentally researched. According to impact dynamics theory,, the performances of 30 mm ceramic-nose projectile and 30 mm standard projectile penetrating into the ceramic/A3 steel composite targets were analyzed and compared using DOP method, especially focusing on the effects made by different nose structures and materials. The aperture and depth of perforation of projectile into the armor plates as well as the residual mass of bullet core under the same conditions were comparatively analyzed. A numerical simulation was built and computed by ANSYS/LS-DYNA. Based on the simulated results, the penetration performance was further analyzed in terms of the residual mass of bullet core. The results show that the ceramic nose has a great effect on the protection of bullet core.

First spatial isotopic separation of relativistic uranium projectile fragments

International Nuclear Information System (INIS)

Magel, A.; Voss, B.; Armbruster, P.; Aumann, T.; Clerc, H.G.; Czajkowski, S.; Folger, H.; Grewe, A.; Hanelt, E.; Heinz, A.; Irnich, H.; Jong, M. de; Junghans, A.; Nickel, F.; Pfuetzner, M.; Roehl, C.; Scheidenberger, C.; Schmidt, K.H.; Schwab, W.; Steinhaeuser, S.; Suemmerer, K.; Trinder, W.; Wollnik, H.

1994-07-01

Spatial isotopic separation of relativistic uranium projectile fragments has been achieved for the first time. The fragments were produced in peripheral nuclear collisions and spatially separated in-flight with the fragment separator FRS at GSI. A two-fold magnetic-rigidity analysis was applied exploiting the atomic energy loss in specially shaped matter placed in the dispersive central focal plane. Systematic investigations with relativistic projectiles ranging from oxygen up to uranium demonstrate that the FRS is a universal and powerful facility for the production and in-flight separation of monoisotopic, exotic secondary beams of all elements up to Z=92. This achievement has opened a new area in heavy-ion research and applications. (orig.)

In-pipe aerodynamic characteristics of a projectile in comparison with free flight for transonic Mach numbers

Science.gov (United States)

Hruschka, R.; Klatt, D.

2018-03-01

The transient shock dynamics and drag characteristics of a projectile flying through a pipe 3.55 times larger than its diameter at transonic speed are analyzed by means of time-of-flight and pipe wall pressure measurements as well as computational fluid dynamics (CFD). In addition, free-flight drag of the 4.5-mm-pellet-type projectile was also measured in a Mach number range between 0.5 and 1.5, providing a means for comparison against in-pipe data and CFD. The flow is categorized into five typical regimes the in-pipe projectile experiences. When projectile speed and hence compressibility effects are low, the presence of the pipe has little influence on the drag. Between Mach 0.5 and 0.8, there is a strong drag increase due to the presence of the pipe, however, up to a value of about two times the free-flight drag. This is exactly where the nose-to-base pressure ratio of the projectile becomes critical for locally sonic speed, allowing the drag to be estimated by equations describing choked flow through a converging-diverging nozzle. For even higher projectile Mach numbers, the drag coefficient decreases again, to a value slightly below the free-flight drag at Mach 1.5. This behavior is explained by a velocity-independent base pressure coefficient in the pipe, as opposed to base pressure decreasing with velocity in free flight. The drag calculated by CFD simulations agreed largely with the measurements within their experimental uncertainty, with some discrepancies remaining for free-flying projectiles at supersonic speed. Wall pressure measurements as well as measured speeds of both leading and trailing shocks caused by the projectile in the pipe also agreed well with CFD.

Locus of the apices of projectile trajectories under constant drag

Science.gov (United States)

Hernández-Saldaña, H.

2017-11-01

Using the hodograph method, we present an analytical solution for projectile coplanar motion under constant drag, parametrised by the velocity angle. We find the locus formed by the apices of the projectile trajectories, and discuss its implementation for the motion of a particle on an inclined plane in presence of Coulomb friction. The range and time of flight are obtained numerically, and we find that the optimal launching angle is smaller than in the drag-free case. This is a good example of a problem with constant dissipation of energy that includes curvature; it is appropriate for intermediate courses of mechanics.

Studies of projectile-like fragments in the 16O + 238U reaction at 20 MeV/u

International Nuclear Information System (INIS)

Dyer, P.; Awes, T.C.; Gelbke, C.K.; Back, B.B.; Mignerey, A.C.; Wolf, K.L.; Breuer, H.; Viola, V.E.; Meyer, W.G.

1979-01-01

Projectile residues were studied in coincidence with angle-correlated fission fragments resulting from reactions of 20-MeV/u 16 O ions on 238 U. Distributions of the missing parallel momentum are shown for different projectile residues, and the dependence of the average parallel recoil momentum on the average parallel momentum of the projectile residue is plotted. 2 figures

Inelastic scattering of quasifree electrons on O7+ projectiles

International Nuclear Information System (INIS)

Toth, G.; Grabbe, S.; Richard, P.; Bhalla, C.P.

1996-01-01

Absolute doubly differential cross sections (DDCS close-quote s) for the resonant inelastic scattering of quasifree target electrons on H-like projectiles have been measured. Electron spectra for 20.25-MeV O 7+ projectiles on an H 2 target were measured. The spectra contain a resonant contribution from the 3l3l ' doubly excited states of O 6+ , which decay predominantly to the 2l states of the O 7+ via autoionization, and a nonresonant contribution from the direct excitation of the projectiles to the O 7+ (2l) state by the quasifree target electrons. Close-coupling R-matrix calculations for the inelastic scattering of free electrons on O 7+ ions were performed. The relation between the electron-ion inelastic scattering calculation and the electron DDCS close-quote s for the ion-atom collision was established by using the inelastic scattering model (ISM). We found excellent agreement between the theoretical and measured resonant peak positions and relative peak heights. The calculated absolute double differential cross sections for the resonance processes are also in good agreement with the measured data. The implication is that collisions of highly charged ions on hydrogen can be used to obtain high-resolution, angle- resolved differential inelastic electron-scattering cross section. copyright 1996 The American Physical Society

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

OpenAIRE

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 corr...

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. © 2015 American Academy of Forensic Sciences.

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.

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…

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...

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

Experimental impact-parameter--dependent probabilities for K-shell vacancy production by fast heavy-ion projectiles

International Nuclear Information System (INIS)

Randall, R.R.; Bednar, J.A.; Curnutte, B.; Cocke, C.L.

1976-01-01

The impact-parameter dependence of the probability for production of target K x rays has been measured for oxygen projectiles on copper and for carbon and fluorine projectiles on argon at scaled velocities near 0.5. The O-on-Cu data were taken for 1.56-, 1.88-, and 2.69-MeV/amu O beams incident upon thin Cu foils. A thin Ar-gas target was used for 1.56-MeV/amu C and F beams, permitting measurements to be made for charge-pure C +4 , C +6 , F +9 and F +5 projectiles. Ar and Cu K x rays were observed with a Si(Li) detector and scattered projectiles with a collimated surface-barrier detector. Comparison of the shapes of the measured K-vacancy--production probability curves with predictions of the semiclassical Coulomb approximation (SCA) shows adequate agreement for the O-on-Cu system. For the higher ratio of projectile-to-target nuclear charge (Z 1 /Z 2 ) characterizing the C-on-Ar and F-on-Ar systems, the SCA predictions are entirely inadequate in describing the observed impact-parameter dependence. In particular, they cannot account for large probabilities found at large impact parameters. Furthermore, the dependence of the shapes on the projectile charge state is found to become pronounced at larger Z 1 /Z 2 . Attempts to account for this behavior in terms of alternative vacancy-production processes are discussed

Supercavitating Projectile Tracking System and Method

Science.gov (United States)

2009-12-30

Distribution is unlimited 20100104106 Attorney Docket No. 96681 SUPERCAVITATING PROJECTILE TRACKING SYSTEM AND METHOD STATEMENT OF GOVERNMENT...underwater track or path 14 of a supercavitating vehicle under surface 16 of a body of water. In this embodiment, passive acoustic or pressure...transducers 12 are utilized to measure a pressure field produced by a moving supercavitating vehicle. The present invention provides a low-cost, reusable

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…

Unusual behavior of projectile fragments formed in the bombardment of copper with relativistic Ar ions

International Nuclear Information System (INIS)

Dersch, G.; Beckmann, R.; Feige, G.

1985-01-01

The interaction properties of projectile fragments from the fragmentation of 0.9 GeV/nucleon and 1.8 GeV/nucleon 40 Ar with Cu have been studied using radioactivation techniques. In this experiment, two identical copper blocks, 1 cm thick and 8 cm in diameter, are irradiated by relativistic projectiles in different configurations. In configuration 0, the blocks are touching while in configuration 10 or 20, the blocks are separated by 10 or 20 cm of air, respectively. It is assumed that when the relativistic projectiles interact with the first block of each pair, projectile fragments are created which interact with other nuclei in the first and second blocks. What is measured is the ratio of some target fragment activity, such as 24 Na or 28 Mg, produced in the second block relative to the first block, R

Deformations on Hole and Projectile Surfaces Caused By High Velocity Friction During Ballistic Impact

Science.gov (United States)

Karamış, M. B.

2018-01-01

In this study, the deformations caused by the ballistic impact on the MM composites and on projectile surfaces are examined. The hole section and grain deformation of unreinforced targets are also examined after impact. The relatively high complexity of impact problems is caused by the large number of intervening parameters like relative velocity of projectile and target, shape of colliding objects, relative stiffness and masses, time-dependent surface of contact, geometry and boundary conditions and material characteristics. The material used in this investigation are 2024 and 7075 aluminum alloys as matrix reinforced with SiC and Al2O3 particles. The matrix materials are extensively used in defense applications due to its favorable ballistic properties, moderate strength, high corrosion resistance and super plastic potential. Two different composites were produced; one by casting and the other by lamination. The ballistic tests of the composite targets were carried out according to NIJ Standard-0101.04, Temperature 21 °C, RH=65% with 7.62 mm projectiles. The bullet weight was 9.6 g and their muzzle velocities were in the range of 770-800 m/s. The projectiles consisted of a steel core, copper jacket and lead material. The composite targets were positioned 15 m from the rifle. The interaction between projectiles and the target hole created after impact were examined by light microscopy and photography. Different damage and failure mechanisms such as petalling, cracking, spalling, dishing, etc., were observed on the target body. On the other hand, dramatic wear and damages on the projectile surface were also observed. The targets were supported with Al-5083 backing blocks having 40 mm thickness.

Projectile like fragment production in Ar induced reactions around the Fermi energy

International Nuclear Information System (INIS)

Borrel, V.; Gatty, B.; Jacquet, D.; Galin, J.

1986-01-01

The production of projectile like fragments (PLF) has been studied in Ar induced reactions on various targets. It shows very clearly, that besides the predominance of fragmentation for most of the products, the transfer process is still a very strong component for products nearby the projectile. The influence of the target neutron excess on the PLF production is investigated as well as the evolution with incident energy of the characteristics of the different competing processes

Experimental characterisation of sprays resulting from impacts of liquid-containing projectiles

Energy Technology Data Exchange (ETDEWEB)

Hostikka, Simo, E-mail: simo.hostikka@aalto.fi [Aalto University, Espoo (Finland); Silde, Ari; Sikanen, Topi; Vepsä, Ari; Paajanen, Antti [VTT Technical Research Centre of Finland Ltd, Espoo (Finland); Honkanen, Markus [Pixact Oy, Tampere (Finland)

2015-12-15

Highlights: • Detailed characterisation of sprays resulting from the impacts of water-filled metal projectiles on a hard wall. • Experimental measurements of spray speed, direction and droplet size. • Detailed analysis of overall spray evolution. • The spray characterisation information can be used in CFD analyses of aircraft impact fires. - Abstract: Modelling and analysing fires following aircraft impacts requires information about the behaviour of liquid fuel. In this study, we investigated sprays resulting from the impacts of water-filled metal projectiles on a hard wall. The weights of the projectiles were in the range of 38–110 kg, with 8.6–68 kg water, and the impact speeds varied between 96 and 169 m/s. The overall spray behaviour was observed with high-speed video cameras. Ultra-high-speed cameras were used in backlight configuration for measuring the droplet size and velocity distributions. The results indicate that the liquid leaves the impact position as a thin sheet of spray in a direction perpendicular to the projectile velocity. The initial spray speeds were 1.5–2.5 times the impact speed, and the Sauter mean diameters were in the 147–344 μm range. This data can be used as boundary conditions in CFD fire analyses, considering the two-phase fuel flow. The overall spray observations, including the spray deceleration rate, can be used for validating the model.

Enhanced RAMAC performance in subdetonative propulsion mode with semi-combustible projectile

Energy Technology Data Exchange (ETDEWEB)

Legendre, J.F.; Giraud, M. [French-German Res. Inst., Saint-Louis (France)

2000-11-01

Investigations are carried out at ISL to determine the experimental conditions required to accelerate a projectile in the mass range from 1.5 to 2 kg up to a muzzle velocity of 3 km/s while keeping the maximum acceleration below 40,000 g. Therefore, two smooth-bore ram-accelerators denoted RAMAC 30-II and RAMAC 90, in caliber 30 and 90 mm respectively, are being operated in the thermally choked propulsion mode. Different material configurations for the projectile afterbody have been investigated, while keeping an aluminum nose cone. Besides afterbodies made of aluminum or magnesium alloy only, a third configuration is presented relying on a short magnesium part fitted to the base of an aluminum afterbody. This configuration denoted as ''semi-combustible'' is designed so that magnesium particles are steadily injected and burnt-out within the combustion zone at the base, therefore providing an additional heat release and consequently a significantly greater forward thrust. Experimental results achieved in both 30 and 90 mm along a 300-caliber-long ram-section and using up to three different gaseous mixtures are presented. To date, for a given semi-combustible projectile and an injection velocity into the ram-section of 1380 m/s, a maximum muzzle velocity of 2380 m/s has been achieved in RAMAC 30-II and 2180 m/s in RAMAC 90, the initial projectile mass being 69 g and 1608 g respectively. (orig.)

Spectrum of gluino bound states

International Nuclear Information System (INIS)

Chanowitz, M.; Sharpe, S.; California Univ., Berkeley

1983-01-01

Using the bag model to first order in αsub(s) we find that if light gluinos exist they will appear as constituents of electrically charged bound states which are stable against strong interaction decay. We review the present experimental constraints and conclude that light, long-lived charged hadrons containing gluinos might exist with lifetimes between 2x10 - 8 and 10 - 14 s. (orig.)

Projectile metallic foreign bodies in the orbit: a retrospective study of epidemiologic factors, management, and outcomes.

Science.gov (United States)

Finkelstein, M; Legmann, A; Rubin, P A

1997-01-01

Intraorbital projectile metallic foreign bodies are associated with significant ocular and orbital injuries. The authors sought to evaluate epidemiologic factors, the incidence of associated ocular and orbital injury, and the nature and necessity of surgical intervention in these cases. Charts of all patients with projectile intraorbital metallic foreign bodies seen at our institution (27) over the preceding 7 years were evaluated with respect to age, sex, type of injury, associated ocular and orbital injuries, location of the projectile (anterior, epibulbar, or posterior), postinjury visual acuity, and surgical intervention. The majority of patients were male, between the ages of 11 and 30, and had BB pellet injuries. Thirteen projectiles were lodged anteriorly, 4 were in an epibulbar position, and the remaining 10 were posterior to the equator. Twelve of 13 anterior, and 4 of 4 epibulbar foreign bodies were removed surgically, whereas only 2 of 10 posterior foreign bodies required surgery. No case of surgical intervention resulted in a decrease of visual acuity. Associated ocular injuries were both more common and severe in patients with posteriorly located foreign bodies. Final visual acuity was better at presentation and at discharge in patients with anteriorly located foreign bodies. Intraorbital projectile metallic foreign bodies can be a source of significant ocular morbidity. Management of these cases is dependent on the location of the projectile. Ancillary radiographic studies can be helpful. Surgery to remove the projectile should be considered in each case, but foreign bodies that are not readily accessible often may be left safely in place. Closer regulation of the pellet gun industry, with an emphasis on education and protective eyewear use, would be helpful in reducing these injuries.

Commissioning the A1900 projectile fragment separator

CERN Document Server

Morrissey, D J; Steiner, M; Stolz, A; Wiedenhöver, I

2003-01-01

An important part of the recent upgrade of the NSCL facility is the replacement of the A1200 fragment separator with a new high acceptance device called the A1900. The design of the A1900 device represents a third generation projectile fragment separator (relative to the early work at LBL) as it is situated immediately after the primary accelerator, has a very large acceptance, a bending power significantly larger than that of the cyclotron and is constructed from large superconducting magnets (quadrupoles with 20 and 40 cm diameter warm bores). The A1900 can accept over 90% of a large range of projectile fragmentation products produced at the NSCL, leading to large gains in the intensity of the secondary beams. The results of initial tests of the system with a restricted momentum acceptance (+-0.5%) indicate that the A1900 is performing up to specifications. Further large gains in the intensities of primary beams, typically two or three orders of magnitude, will be possible as the many facets of high current...

Optical potentials derived from microscopic separable interactions including binding and recoil effects

International Nuclear Information System (INIS)

Siciliano, E.R.; Walker, G.E.

1976-01-01

We first consider a projectile scattering from a nucleon bound in a fixed potential. A separable Galilean invariant projectile-nucleon interaction is adopted. Without using the fixed scatterer approximation or using closure on the intermediate target nucleon states we obtain various forms for the projectile-bound nucleon t matrix. Effects due to intermediate target excitation and nucleon recoil are discussed. By making the further approximations of closure and fixed scatterers we make connection with the work of previous authors. By generalizing to projectile interaction with several bound nucleons and examining the appropriate multiple scattering series we identify the optical potential for projectile elastic scattering from the many-body system. Different optical potentials are obtained for different projectile-bound nucleon t matrices, and we study the differences predicted by these dissimilar optical potentials for elastic scattering. In a model problem, we study pion-nucleus elastic scattering and compare the predictions obtained by adopting procedures used by (1) Landau, Phatak, and Tabakin and (2) Piepho-Walker to the predictions obtained in a less restrictive, but computationally difficult treatment

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.

Numerical Study on the Projectile Impact Resistance of Multi-Layer Sandwich Panels with Cellular Cores

Directory of Open Access Journals (Sweden)

Liming Chen

Full Text Available Abstract The projectile impact resistance of sandwich panels with cellular cores with different layer numbers has been numerically investigated by perpendicular impact of rigid blunt projectile in ABAQUS/Explicit. These panels with corrugation, hexagonal honeycomb and pyramidal truss cores are impacted at velocities between 50 m/s and 202 m/s while the relative density ranges from 0.001 to 0.15 The effects of core configuration and layer number on projectile impact resistance of sandwich panels with cellular cores are studied. At low impact velocity, sandwich panels with cellular cores outperform the corresponding solid ones and non-montonicity between relative density and projectile resistance of sandwich panels is found and analyzed. Multiplying layer can reduce the maximum central deflection of back face sheet of the above three sandwich panels except pyramidal truss ones in high relative density. Hexagonal honeycomb sandwich panel is beneficial to increasing layer numbers in lowering the contact force and prolonging the interaction time. At high impact velocity, though corrugation and honeycomb sandwich panels are inferior to the equal-weighted solid panels, pyramidal truss ones with high relative density outperform the corresponding solid panels. Multiplying layer is not the desirable way to improve high-velocity projectile resistance.

The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin

International Nuclear Information System (INIS)

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)

A High-Spin Rate Measurement Method for Projectiles Using a Magnetoresistive Sensor Based on Time-Frequency Domain Analysis.

Science.gov (United States)

Shang, Jianyu; Deng, Zhihong; Fu, Mengyin; Wang, Shunting

2016-06-16

Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin rate, which has long been regarded as a daunting task, is the basis of precise guidance and control. Magnetoresistive (MR) sensors can be applied to spin rate measurement, especially in the high-spin and high-g projectile launch environment. In this paper, based on the theory of a MR sensor measuring spin rate, the mathematical relationship model between the frequency of MR sensor output and projectile spin rate was established through a fundamental derivation. By analyzing the characteristics of MR sensor output whose frequency varies with time, this paper proposed the Chirp z-Transform (CZT) time-frequency (TF) domain analysis method based on the rolling window of a Blackman window function (BCZT) which can accurately extract the projectile spin rate. To put it into practice, BCZT was applied to measure the spin rate of 155 mm artillery projectile. After extracting the spin rate, the impact that launch rotational angular velocity and aspect angle have on the extraction accuracy of the spin rate was analyzed. Simulation results show that the BCZT TF domain analysis method can effectively and accurately measure the projectile spin rate, especially in a high-spin and high-g projectile launch environment.

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.

Refractive effects in the scattering of loosely bound nuclei

International Nuclear Information System (INIS)

Carstoiu, F.; Trache, L.; Tribble, R.E.; Gagliardi, C.A.; Carstoiu, F.

2004-07-01

A study of the interaction of the loosely bound nuclei 6,7 Li at 9 and 19 MeV/nucleon with light targets has been undertaken. With the determination of unambiguous optical potentials in mind, elastic data for four projectile-target combinations and one neutron transfer reaction 13 C( 7 Li, 8 Li) 12 C have been measured over a large angular range. The kinematical regime encompasses a region where the mean field (optical potential) has a marked variation with mass and energy, but turns out to be sufficiently surface transparent to allow strong refractive effects to be manifested in elastic scattering data at intermediate angles. The identified exotic feature, a 'plateau' in the angular distributions at intermediate angles, is fully confirmed in four reaction channels and is interpreted as a pre-rainbow oscillation resulting from the interference of the barrier and internal barrier far-side scattering sub-amplitudes. (authors)

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 $^{197}$Au targets by 60 and 200 GeV/nucleon $^{16}$O and $^{32}$S 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 $\\gamma$ ray activities in Ames, Iowa, USA. Preliminary results indicate an ED one-neutron removal cross section for 200 GeV/nucleon $^{16}$O projectiles on $^{197}$Au of approximately 0.45~barns. The result i...

Study of the effect of hard projectiles impacting reinforced concrete walls

International Nuclear Information System (INIS)

Berriaud, C.; Sokolovsky, A.

1977-01-01

Among the risks examined in the framework of nuclear safety in France, quite unlikely events are examined as constituting a safety cover. This type of event includes the possible impact of aircrafts, or rotor splinters. Research on the limit strength of a wall under the impact of a hard projectile presently gives incentive results. First, a good agreement appears between works performed in parallel directions by EDF and CEA. Secondly, the special field of aerial projectiles is much better known as it was with previous formulations. Third, such research highly contributes to the knowledge of the mechanical strength of reinforced concrete structures [fr

Multiple electromagnetic excitations of relativistic projectiles

International Nuclear Information System (INIS)

Llope, W.J.; Braun-Munzinger, P.

1992-01-01

Conditions optimum for the first experimental verification of the multiplication electromagnetic excitations of nuclei in relativistic nucleus-nucleus collisions are described. The relative magnitudes of three important physical processes that might interfere with such a measurement are compared to the predicted strengths for the single and multiple electromagnetic excitations for various choices of the projectile mass and beam energy. Strategies are presented for making inferences concerning the presence of multiple excitation strength in experimental data

Reaction Mechanism and Structure Interplay for Proton Elastic Scattering from Halo Nuclei

International Nuclear Information System (INIS)

Crespo, R.; Johnson, R.C.

1999-01-01

The aim of this work is to clarify what properties of the projectile w.f. are relevant to describe elastic scattering of halo nuclei from stable nuclei. In particular, we examine how far elastic scattering observables probe correlation effects among projectile nucleons. Our treatment is based on a multiple scattering expansion of the proton-projectile transition amplitude in a form which is well adapted to the weakly bound cluster picture of halo nuclei. In the specific case of 11 Li scattering from protons at 800 MeV/u we show that because core recoil effects are significant, scattering cross sections can not, in general, be deduced from knowledge of the total matter density alone. We advocate that the optical potential concept for the scattering of halo nuclei on protons should be avoided and that the multiple scattering series for the full transition amplitude should be used instead

Reaction mechanism and structure interplay for proton elastic scattering from halo nuclei

International Nuclear Information System (INIS)

Crespo, R.; Johnson, R. C.

1999-01-01

The aim of this work is to clarify what properties of the projectile w.f. are relevant to describe elastic scattering of halo nuclei from stable nuclei. In particular, we examine how far elastic scattering observables probe correlation effects among projectile nucleons. Our treatment is based on a multiple scattering expansion of the proton-projectile transition amplitude in a form which is well adapted to the weakly bound cluster picture of halo nuclei. In the specific case of 11 Li scattering from protons at 800 MeV/u we show that because core recoil effects are significant, scattering crosssections cannot, in general, be deduced from knowledge of the total matter density alone. We advocate that the optical potential concept for the scattering of halo nuclei on protons should be avoided and that the multiple scattering series for the full transition amplitude should be used instead

Penetration Experiments with 6061-T6511 Aluminum Targets and Spherical-Nose Steel Projectiles at Striking Velocities Between 0.5 and 3.0 km/s

Energy Technology Data Exchange (ETDEWEB)

Forrestal, M.J.; Piekutowski, A.J.

1999-02-04

We conducted depth of penetration experiments with 7.11-mm-diameter, 74.7-mm-long, spherical-nose, 4340 steel projectiles launched into 250-mm-diameter, 6061-T6511 aluminum targets. To show the effect of projectile strength, we used projectiles that had average Rockwell harnesses of R{sub c} = 36.6, 39.5, and 46.2. A powder gun and two-stage, light-gas guns launched the 0.023 kg projectiles at striking velocities between 0.5 and 3.0 km/s. Post-test radiographs of the targets showed three response regions as striking velocities increased: (1) the projectiles remained visibly undeformed, (2) the projectiles permanently deformed without erosion, and (3) the projectiles eroded and lost mass. To show the effect of projectile strength, we compared depth-of-penetration data as a function of striking velocity for spherical-nose rods with three Rockwell harnesses at striking velocities ranging from 0.5 to 3.0 km/s. To show the effect of nose shape, we compared penetration data for the spherical-nose projectiles with previously published data for ogive-nose projectiles.

Fusion with projectiles form carbon to argon at energies between 20A and 60A MeV

International Nuclear Information System (INIS)

Galin, J.

1986-03-01

A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MEV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behaviour. Finally, the decay of highly excited (E* approximately 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

Ionization of hydrogen by a relativistic heavy projectile

International Nuclear Information System (INIS)

Hofstetter, S.; Hofmann, C.; Soff, G.

1991-10-01

Using a relativistic analogue of the classical trajectory Monte-Carlo method we investigate the influence of the magnetic field of a relativistic heavy projectile on the ionization cross section of hydrogen. In particular we focus our attention on the angular and energy distribution of the emitted delta electrons. (orig.)

Search for relativistic projectile fragments with charges 4/3, 5/3, 7/3, and 8/3

International Nuclear Information System (INIS)

Bloomer, M.A.; Friedlander, E.M.; Heckman, H.H.; Karant, Y.J.

1984-01-01

Recent speculation on the cause of the anomalously short reaction mean free paths of projectile fragmentation products (PF's) produced from relativistic heavy-ion (RHI) collisions with emulsion nuclei has led to the suggestion that nuclei with bound third-integral charges might be present among the PF's. The authors were thus motivated to search for such fractional charges among the 1 less than or equal to Z less than or equal to 3 PF's produced by the interactions of 1.88 GeV/nucleon 56 Fe nuclei in G-5 nuclear emulsion. Results show that all charge measurements for each PF are narrowly distributed around their integer means, and, with the possible exception of the set of measurements scattered around Z = 2.33, there is no indication that PF's of third-integral charge are produced with the same relative abundance as reported for anomalons to date, i.e., 2-6% for 3 less than or equal to Z less than or equal to 26

Evidence for a bound on the lifetime of de Sitter space

International Nuclear Information System (INIS)

Freivogel, Ben; Lippert, Matthew

2008-01-01

Recent work has suggested a surprising new upper bound on the lifetime of de Sitter vacua in string theory. The bound is parametrically longer than the Hubble time but parametrically shorter than the recurrence time. We investigate whether the bound is satisfied in a particular class of de Sitter solutions, the KKLT vacua. Despite the freedom to make the supersymmetry breaking scale exponentially small, which naively would lead to extremely stable vacua, we find that the lifetime is always less than about exp(10 22 ) Hubble times, in agreement with the proposed bound. This result, however, is contingent on several estimates and assumptions; in particular, we rely on a conjectural upper bound on the Euler number of the Calabi-Yau fourfolds used in KKLT compactifications.

Effect of a Bore Evacuator on Projectile In-Bore Dynamics

National Research Council Canada - National Science Library

Carlucci, Donald

2004-01-01

Projectile base pressure measurements were taken in a 155-mm M284 gun tube using an Armament Research, Development and Engineering Center-designed instrumentation package incorporated into a modified...

Study of momentum distributions for projectile fragments of 22Ne and 28Si nuclei in collisions with emulsion

International Nuclear Information System (INIS)

Abou-Steit, S.A.H.

2000-01-01

The charge and mass yield curves and the momentum distributions of the projectile fragments produced in the interactions of 4.1 A GeV/c 22 Ne and 4.5 A GeV/c 28 Si with emulsion have been studied. The overall charge distributions of the projectile fragments resulting from these interactions are presented. The dependence of the mass yield distributions of the projectile fragments on the impact parameter has been tested. The momentum distributions for the considered reactions have been investigated by two methods. First, the projected momentum distributions in the plane of the microscope have been achieved by fitting the projected angular distributions to gaussian ones. It has been found that the width of the distribution changes with the charge of the projectile fragment and it decreases with the increase of the projectile fragment charge. Secondly, the transverse momentum distributions have been compared with previous studies. The momentum distribution, in the forward cone, is a typically narrow gaussian one

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.

A study of the penetration of projectiles into marine sediments

International Nuclear Information System (INIS)

Boisson, J.Y.

1985-01-01

The work described in this document consists of three main parts: - Application, after having reviewed calculation methods and known codes, of a dynamic plasticity model based on the upper bound-method (with dissipated energy calculations by plastic deformations). The soil model used for this calculation is the Cambridge Clay Model. - Carrying out a programme of tests with instrumented small scale penetrators in centrifuge on a consolidated clay-target. The trials are done under 50 g, with projectiles, fired with an airgun at high impact velocity (50 m/s). The penetrators' instrumentation consists of either measuring acceleration, or tip force with strain gauges. - The mounting of a small instrumented penetrator for shallow water depth experimentations, with an accelerometer, and a local cell for tip resistance. A rapid electronic data acquisition system has been developed for these experimentations. The preliminary tests are done in a large tank filled with clay. The geotechnical characteristics of the clay are perfectly controlled. The tests performed under these conditions have shown the following observations: the rapid electronic data acquisition system works perfectly and could be used as a basic component for a deep water instrumentated penetrator; the results, obtained in these particular test conditions, are in a perfect agreement with the predictions of the model developed in the frame of this contract

Explanation of the observed trend in the mean excitation energy of a target as determined using several projectiles

International Nuclear Information System (INIS)

Cabrera-Trujillo, R.; Sabin, J.R.; Oddershede, J.

2003-01-01

Recently, Porter observed [L.E. Porter, Int. J. Quantum Chem. 90, 684 (2002)] that the mean excitation energy and stopping cross section of a target, obtained from fitting experimental data at given projectile charge to a modified Bethe-Block theory, gives projectile dependent results. The main result of his work is that there is a trend for the inferred target mean excitation energy, to decrease as the projectile atomic number increases. However, this result is inconsistent with the usual definition of the mean excitation energy as a function of target excitation properties only. Here we present an explanation of Porter's results based on the Bethe theory extended to take projectile electronic structure explicitly into account

Electromagnetic compression gun for hypervelocity projectile acceleration

International Nuclear Information System (INIS)

Woo, J.T.

1987-01-01

The rapid acceleration of projectiles to very high velocities has applications in many areas. The general requirements for an effective system is simplicity, reliability, compactness and good efficiency. The authors developed a concept by using electromagnetic forces to compressionally heat a plasma to high temperature and pressure to serve as the propellant for the acceleration of projectiles. The concept shares the simplicity of the light gas gun, but because of the high temperature of the propellant, is capable of significantly higher performance. Unlike the electrothermal gun approach to raise the propellant temperature by resistive heating, the electromagnetic concept is more efficient at higher temperatures. Operationally, the concept resembles a railgun in requiring a large pulsed current to drive the system. However, the current flow in this case is entirely external to the gun barrel and is axisymmetric. Therefore, many of the problems associated with railgun operations are avoided. Furthermore, because the current channel is external, there is also greater flexibility in the choice of load impedance to match to the power supply. The concept can also be generalized to a multi-stage regenerative system driven by a pulse forming network to resemble a coaxial accelerator

Morphology and chemistry of projectile residue in small experimental impact craters

Science.gov (United States)

Horz, F.; Fechtig, H.; Janicke, J.; Schneider, E.

1983-01-01

Small-scale impact craters (5-7 mm in diameter) were produced with a light gas gun in high purity Au and Cu targets using soda lime glass (SL) and man-made basalt glass (BG) as projectiles. Maximum impact velocity was 6.4 km/s resulting in peak pressures of approximately 120-150 GPa. Copious amounts of projectile melts are preserved as thin glass liners draping the entire crater cavity; some of this liner may be lost by spallation, however. SEM investigations reveal complex surface textures including multistage flow phenomena and distinct temporal deposition sequences of small droplets. Inasmuch as some of the melts were generated at peak pressures greater than 120 GPa, these glasses represent the most severely shocked silicates recovered from laboratory experiments to date. Major element analyses reveal partial loss of alkalis; Na2O loss of 10-15 percent is observed, while K2O loss may be as high as 30-50 percent. Although the observed volatile loss in these projectile melts is significant, it still remains uncertain whether target melts produced on planetary surfaces are severely fractionated by selective volatilization processes.

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.

Reactions with Weakly Bound Nuclei, at near Barrier Energies, and the Breakup and Transfer Influences on the Fusion and Elastic Scattering

International Nuclear Information System (INIS)

Gomes, P. R. S.; Lubian, J.; Mendes-Junior, D. R.; Faria, P. N. de; Linares, R.; Sigaud, L.; Rangel, J.; Ferreira, J. L.; Paes, B.; Cardozo, E. N.; Cortes, M. R.; Canto, L. F.; Ermamatov, M. J.; Otomar, D. R.; Ferioli, E.; Lotti, P.; Hussein, M. S.

2016-01-01

We present a brief review of the reaction mechanisms involved in collisions of weakly bound projectiles with tightly bound targets, at near-barrier energies. We discuss systematic behaviors of the data, with emphasis in fusion, breakup, nucleon transfer and elastic scattering. The dependence of the breakup cross section on the charge and mass of the target is discussed, and the influence of the breakup channel on complete fusion is investigated. For this purpose, we compare reduced fusion cross sections with a benchmark universal curve. The behaviors observed in the comparisons are explained in terms of polarization potentials and of nucleon transfer followed by breakup. The influence of the breakup process on elastic scattering is also discussed. Some apparent contradictions between results of different authors are explained and some perspectives of the field are presented. (author)

Migration spontanee de projectile intracranien: presentation clinique ...

African Journals Online (AJOL)

Les traumatismes crâniens par arme à feu sont graves. Les manifestations cliniques sont variables et peuvent présenter quelques particularités. Les auteurs rapportent un cas de migration spontané de projectile intracérébral survenue après un traumatisme crânien par arme à feu au cours d'une partie de chasse. Elle a été ...

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…

Investigation of large α production in reactions involving weakly bound 7Li

Science.gov (United States)

Pandit, S. K.; Shrivastava, A.; Mahata, K.; Parkar, V. V.; Palit, R.; Keeley, N.; Rout, P. C.; Kumar, A.; Ramachandran, K.; Bhattacharyya, S.; Nanal, V.; Palshetkar, C. S.; Nag, T. N.; Gupta, Shilpi; Biswas, S.; Saha, S.; Sethi, J.; Singh, P.; Chatterjee, A.; Kailas, S.

2017-10-01

The origin of the large α -particle production cross sections in systems involving weakly bound 7Li projectiles has been investigated by measuring the cross sections of all possible fragment-capture as well as complete fusion using the particle-γ coincidence, in-beam, and off-beam γ -ray counting techniques for the 7Li+93Nb system at near Coulomb barrier energies. Almost all of the inclusive α -particle yield has been accounted for. While the t -capture mechanism is found to be dominant (˜70 % ), compound nuclear evaporation and breakup processes contribute ˜15 % each to the inclusive α -particle production in the measured energy range. Systematic behavior of the t capture and inclusive α cross sections for reactions involving 7Li over a wide mass range is also reported.

Ionization of heavy targets by impact of relativistic projectiles

International Nuclear Information System (INIS)

Deco, G.R.; Fainstein, P.D.; Comision Nacional de Energia Atomica, San Carlos de Bariloche; Rivarola, R.D.

1988-01-01

Electron ejection from atomic targets by impact of bare heavy projectiles at relativistic collision energies is studied theoretically. First-order Born calculations are presented by using initial Darwin and final Sommerfeld-Maue wavefunctions. Comparisons with other calculations and experimental data are given. (orig.)

Calculation of projectile velocity in an electromagnetic mass driver

International Nuclear Information System (INIS)

Ikuta, K.

1986-08-01

The formula for the velocity increase of a projectile accelerated by the single z-pinch between the cylindrical electrodes is established. This formula enables one to consider the necessary stages in the cylindrical electrode array of the accelerator for a required velocity. (author)

Excitation and multiple dissociation of 12C, 14N, and 16O projectiles in peripheral collisions at 32.5 MeV/nucleon

International Nuclear Information System (INIS)

Pouliot, J.; Chan, Y.; DiGregorio, D.E.; Harmon, B.A.; Knop, R.; Moisan, C.; Roy, R.; Stokstad, R.G.; Laboratoire de physique nucleaire, Universite Laval, Quebec, P.Q., Canada G1K7P4)

1991-01-01

Cross sections for the multiple breakup of 16 O, 14 N, and 12 C projectiles scattered by an Au target were measured with an array of 34 phoswich detectors. The dissociation of the projectiles into as many as five charged particles has been observed. The yields of different exit channels correlate approximately with the threshold energy for separation of the projectile into the observed fragments. The excitation spectrum of the primary projectile-like nucleus was reconstructed from the measured positions and kinetic energies of the individual fragments. The energy sharing between projectile and target is consistent with a fast excitation mechanism in which differential increases in projectile excitation energy appear to be accompanied by comparable increases in target excitation. Calculations of the yields based on a sequence of binary decays are presented

Refractive effects in the scattering of loosely bound nuclei

Energy Technology Data Exchange (ETDEWEB)

Carstoiu, F.; Trache, L.; Tribble, R.E.; Gagliardi, C.A. [Texas A and M Univ., College Station, TX (United States). Cyclotron Inst; Carstoiu, F. [Laboratoire de Physique Corpusculaire, IN2P3-CNRS, ISMRA, Universite de Caen, 14 - Caen (France); Carstoiu, F. [National Institute for Physics and Nuclear Engineering, Horia Hulubei, Bucharest-Magurele (Romania)

2004-07-01

A study of the interaction of the loosely bound nuclei {sup 6,7}Li at 9 and 19 MeV/nucleon with light targets has been undertaken. With the determination of unambiguous optical potentials in mind, elastic data for four projectile-target combinations and one neutron transfer reaction {sup 13}C({sup 7}Li,{sup 8}Li){sup 12}C have been measured over a large angular range. The kinematical regime encompasses a region where the mean field (optical potential) has a marked variation with mass and energy, but turns out to be sufficiently surface transparent to allow strong refractive effects to be manifested in elastic scattering data at intermediate angles. The identified exotic feature, a 'plateau' in the angular distributions at intermediate angles, is fully confirmed in four reaction channels and is interpreted as a pre-rainbow oscillation resulting from the interference of the barrier and internal barrier far-side scattering sub-amplitudes. (authors)

Source tracing of natural organic matter bound mercury in boreal forest runoff with mercury stable isotopes.

Science.gov (United States)

Jiskra, Martin; Wiederhold, Jan G; Skyllberg, Ulf; Kronberg, Rose-Marie; Kretzschmar, Ruben

2017-10-18

Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion. We report that Hg associated with high molecular weight NOM in the boreal forest runoff has very similar Hg isotope signatures as compared to the organic soil horizons of the catchment area. The mass-independent fractionation (MIF) signatures (Δ 199 Hg and Δ 200 Hg) measured in soils and runoff were in agreement with typical values reported for atmospheric gaseous elemental mercury (Hg 0 ) and distinctly different from reported Hg isotope signatures in precipitation. We therefore suggest that most Hg in the boreal terrestrial ecosystem originated from the deposition of Hg 0 through foliar uptake rather than precipitation. Using a mixing model we calculated the contribution of soil horizons to the Hg in the runoff. At moderate to high flow runoff conditions, that prevailed during sampling, the uppermost part of the organic horizon (Oe/He) contributed 50-70% of the Hg in the runoff, while the underlying more humified organic Oa/Ha and the mineral soil horizons displayed a lower mobility of Hg. The good agreement of the Hg isotope results with other source tracing approaches using radiocarbon signatures and Hg : C ratios provides additional support for the strong coupling between Hg and NOM. The exploratory results from this study illustrate the potential of Hg stable isotopes to trace the source of Hg from atmospheric deposition through the terrestrial ecosystem to soil runoff, and provide a basis for more in-depth studies investigating the

High speed photography of the plasma flow and the projectiles in the T.U.M. hypervelocity accelerator

International Nuclear Information System (INIS)

Igenbergs, E.; Kuczera, H.; Schroeder, B.

1979-01-01

The hypervelocity accelerator at the Technische Universitaet Muenchen, FRG, accelerates small projectiles (0.1 to 1.0 mm diameter) to velocities around 20 km/s. The photographic equipment consists of two Cordin single-frame image converter cameras and one TRW image converter camera with streak units and multiple-frame units. They are used for plasma flow diagnostics and the measurement of the position and the velocity of the projectiles. The single-frame cameras are triggered with a Laser light bar and the photographic measurement of the projectile velocity will be compared with Doppler-Radar. (author)

Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration.

Energy Technology Data Exchange (ETDEWEB)

Taylor, Paul A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-11-01

Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is nonexistent but necessary to protect the heart and lungs. In tests against ballistic projectiles, protective apparel is placed over ballistic clay and the projectiles are fired into the armor/clay target. The clay represents the human torso and its behind-armor, permanent deflection is the principal metric used to assess armor protection. Although this approach provides relative merit assessment of protection, it does not examine the behind-armor blunt trauma to crucial torso organs. We propose a modeling and simulation (M&S) capability for wound injury scenarios to the head, neck, and torso of the warfighter. We will use this toolset to investigate the consequences of, and mitigation against, blast exposure, blunt force impact, and ballistic projectile penetration leading to damage of critical organs comprising the central nervous, cardiovascular, and respiratory systems. We will leverage Sandia codes and our M&S expertise on traumatic brain injury to develop virtual anatomical models of the head, neck, and torso and the simulation methodology to capture the physics of wound mechanics. Specifically, we will investigate virtual wound injuries to the head, neck, and torso without and with protective armor to demonstrate the advantages of performing injury simulations for the development of body armor. The proposed toolset constitutes a significant advance over current methods by providing a virtual simulation capability to investigate wound injury and optimize armor design without the need for extensive field testing.

Optimization of $^{178m2}$/Hf isomer production in spallation reactions at projectile energies up to 100 MeV using STAPRE and ALICE code simulations

CERN Document Server

Kirischuk, V I; Khomenkov, V P; Strilchuk, N V; Zheltonozhskij, V A

2004-01-01

/sup 178m2/Hf isomer production in different spallation reactions with protons, alpha particles and neutrons at projectile energies up to 100 MeV has been analyzed using both STAPRE and ALICE code simulations. The STAPRE code was used to calculate the isomeric ratios, while the ALICE code was used to simulate the excitation functions of the respective ground states. A number of spallation reactions have been compared taking into account not only /sup 178m2 /Hf isomer productivity but also, first, the isomeric ratios calculated by the STAPRE code; second, the accumulation of the most undesirable Hf isotopes and isomers, such as /sup 172/Hf, /sup 175 /Hf, and /sup 179m/Hf; and, third, the production of other admixtures and by-products that could degrade the quality of the produced /sup 178m2/Hf isomer sources, including all stable Hf isotopes as well. Possibilities and ways of optimizing /sup 178m2/Hf isomer production in spallation reactions at projectile energies up to 100 MeV are discussed. This can be consi...

Heavy-ion stopping powers and the low-velocity-projectile z3 effect

International Nuclear Information System (INIS)

Porter, L.E.

1977-01-01

Recent heavy-ion stopping-power measurements with elemental solid targets have been analyzed in order to ascertain the influence on effective ion charge of incorporating the low-velocity-projectile z 3 effect in Bethe-Bloch calculations. Shell corrections and the mean excitation energy of a given target were held fixed while searching for the best-fit value of a single charge-state parameter. In general, excellent fits to the stopping powers at projectile energies above 0.3 MeV/amu were achieved. Results of the present study compare very favorably with those from other extant methods of analysis

Eikonal calculation of electron-capture cross sections in collisions of H atoms with fast projectiles

International Nuclear Information System (INIS)

Ho, T.S.; Lieber, M.; Chan, F.T.

1981-01-01

We have employed the eikonal method to calculate the cross section for the capture of an electron into an arbitrary nl subshell in collisions between hydrogen atoms and fast projectiles. the projectiles were protons, C 6+ , O 8+ , and Fe 24+ . The energy ranges considered were 20--100 keV in the proton case, and 40--200 keV per nucleon in the other cases. These projectiles were selected because of their importance in fusion plasmas. For the highly charged case of Fe 24+ we found that our formulas, while exact, involved a high degree of cancellation and produced unreliable numerical results, so that a numerical integration of the penultimate formula was substituted. In the proton case agreement with recent experimental data is excellent

Fusion with projectiles from carbon to argon at energies between 20A MeV and 60A MeV

International Nuclear Information System (INIS)

Galin, J.

1986-01-01

Fusion reactions are known to be the dominant reaction channel at low bombarding energies and can now be investigated with a large variety of projectiles at several tens of MeV per nucleon. The gross characteristics of the fusion process can be studied by measuring global quantities, such as the linear momentum transferred from projectile to target and the dissipated energy of the reaction. The strong correlation between these two quantities is demonstrated at moderate bombarding energies, with a Ne projectile on a U target. It is expected that light particle (charged or neutron) multiplicity measurements can be extended to this higher energy domain and be used to selectively filter these collisions, according to their degree of violence. A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MeV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behavior. Finally, the decay of highly excited (E* similarly ordered 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

Some physical magnitudes of interest for nuclear reactions and their dependence on the projectile-target system

International Nuclear Information System (INIS)

Fernandez Niello, J.O.; Pacheco, A.J.

1984-01-01

The design and analysis of experiences with heavy ions requires the knwoledge of several characteristic parameters of the collision and their dependence on the reactant system. In the case of an electrostatic accelerator as the TANDAR, the bombarding energy (function of the projectile) is a direct consequence of the evolution of the charged state distribution for the projectile at the exit of the last stripper, as a function of the atomic number. The complexity resulting from this dependence originated the confection of a series of diagrams. The diagrams correpond to the different physical magnitudes of interest in the analysis of nuclear reactions as a function of the projectile-target combination for terminal tensions similar to those expected to reach at the TANDAR. In each case, the curves are refered to the following physical magnitudes: Ecm/Bc Kinetic energy in the center of the mass system and Coulomb barrier for the projectile-target system, Lgr = angular momentum corresponding to the grazing collisions. Diagrams of the average projectile energy per nucleon for the different values of the terminal tensions with one or two solid strippers are included. The use of the diagrams in some practical applications is illustrated through four examples. The diagrams may be extended, if necesary, to other physical magnitudes, at different accelerator's operating conditions. (M.E.L.) [es

Bringing solid fuel ramjet projectiles closer to application - An overview of the TNO/RWMS technology demonstration programme

NARCIS (Netherlands)

Veraar, R.G.; Giusti, G.

2005-01-01

TNO executed a technology demonstration programme in co-operation with RWMS on the application of solid fuel ramjet propulsion technology to medium calibre air defence projectiles. From 2000 to 2004 a complete and integrated structural and aero-thermodynamic projectile design was conceived

On The Roman Domination Stable Graphs

Directory of Open Access Journals (Sweden)

Hajian Majid

2017-11-01

Full Text Available A Roman dominating function (or just RDF on a graph G = (V,E is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u = 0 is adjacent to at least one vertex v for which f(v = 2. The weight of an RDF f is the value f(V (G = Pu2V (G f(u. The Roman domination number of a graph G, denoted by R(G, is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal of any vertex. In this paper we present upper bounds for the Roman domination number in the class of Roman domination stable graphs, improving bounds posed in [V. Samodivkin, Roman domination in graphs: the class RUV R, Discrete Math. Algorithms Appl. 8 (2016 1650049].

CFD Simulations of a Finned Projectile with Microflaps for Flow Control

Directory of Open Access Journals (Sweden)

Jubaraj Sahu

2017-01-01

Full Text Available This research describes a computational study undertaken to determine the effect of a flow control mechanism and its associated aerodynamics for a finned projectile. The flow control system consists of small microflaps located between the rear fins of the projectile. These small microflaps alter the flow field in the aft finned region of the projectile, create asymmetric pressure distributions, and thus produce aerodynamic control forces and moments. A number of different geometric parameters, microflap locations, and the number of microflaps were varied in an attempt to maximize the control authority generated by the flaps. Steady-state Navier-Stokes computations were performed to obtain the control aerodynamic forces and moments associated with the microflaps. These results were used to optimize the control authority at a supersonic speed, M=2.5. Computed results showed not only the microflaps to be effective at this speed, but also configurations with 6 and 8 microflaps were found to generate 25%–50% more control force than a baseline 4-flap configuration. These results led to a new optimized 8-flap configuration that was further investigated for a range of Mach numbers from M=0.8 to 5.0 and was found to be a viable configuration effective in providing control at all of these speeds.

Bounds on area and charge for marginally trapped surfaces with a cosmological constant

International Nuclear Information System (INIS)

Simon, Walter

2012-01-01

We sharpen the known inequalities AΛ ≤ 4π(1 - g) (Hayward et al 1994 Phys. Rev. D 49 5080, Woolgar 1999 Class. Quantum Grav. 16 3005) and A ≤ 4πQ 2 (Dain et al 2012 Class. Quantum Grav. 29 035013) between the area A and the electric charge Q of a stable marginally outer-trapped surface (MOTS) of genus g in the presence of a cosmological constant Λ. In particular, instead of requiring stability we include the principal eigenvalue λ of the stability operator. For Λ* Λ+λ > 0, we obtain a lower and an upper bound for Λ*A in terms of Λ*Q 2 , as well as the upper bound Q≤1/(2√(Λ * )) for the charge, which reduces to Q≤1/(2√(Λ)) in the stable case λ ≥ 0. For Λ* < 0, there only remains a lower bound on A. In the spherically symmetric, static, stable case, one of our area inequalities is saturated iff the surface gravity vanishes. We also discuss implications of our inequalities for 'jumps' and mergers of charged MOTS. (fast track communication)

Study of the multiple ionization in the ion-atom collisions with highly charged sulfur as well as with neutral and lowly charged fluorine projectiles

International Nuclear Information System (INIS)

Konrad, J.

1986-01-01

With the collisional systems 115 MeV S +Q (Q=+13, +15, +16) on He, Ne, Ar, and Kr as well as 4 MeV F +Q (Q=-1, 0, +1) on Ne the multiple ionization in the ion-atom collision was studied. With the collisional system 4 MeV F +Q on Ne the multiple ionization of target and projectile was studied by coincidence measurement between the recoil ions and projectiles with the charge state Q' after the collision (Q'=-1 to +3). In the pure ionization (no change of the projectile charge) the measured ionization cross sections for the single positive and negative charged projectile are equally large, those of the neutral F projectiles are lower. The comparison with the point particles protons and electrons resulted that the ionization cross sections of the F projectiles are larger and more strongly higher charged recoil ions are produced. The measured ionization cross sections of the F projectile are larger than those of the Ne target atom which is to be reduced to the lower ionization energies of the F projectile. With the highly charged S projectiles the multiple ionization with capture into the projectile was studied. By the measurement of triple coincidcences between recoil ions, projectiles, and SKX-radiation the cases with and without capture into the K shell can be discriminated. The charge distribution with is shifted against that without capture into the K shell to higher charges. This shift is to be reduced to the decay of autoionization states which arise by the capture into the K shell. (orig./HSI) [de

A study on stimulation of DC high voltage power of LCC series parallel resonant in projectile velocity measurement system

Science.gov (United States)

Lu, Dong-dong; Gu, Jin-liang; Luo, Hong-e.; Xia, Yan

2017-10-01

According to specific requirements of the X-ray machine system for measuring velocity of outfield projectile, a DC high voltage power supply system is designed for the high voltage or the smaller current. The system comprises: a series resonant circuit is selected as a full-bridge inverter circuit; a high-frequency zero-current soft switching of a high-voltage power supply is realized by PWM output by STM32; a nanocrystalline alloy transformer is chosen as a high-frequency booster transformer; and the related parameters of an LCC series-parallel resonant are determined according to the preset parameters of the transformer. The concrete method includes: a LCC series parallel resonant circuit and a voltage doubling circuit are stimulated by using MULTISM and MATLAB; selecting an optimal solution and an optimal parameter of all parts after stimulation analysis; and finally verifying the correctness of the parameter by stimulation of the whole system. Through stimulation analysis, the output voltage of the series-parallel resonant circuit gets to 10KV in 28s: then passing through the voltage doubling circuit, the output voltage gets to 120KV in one hour. According to the system, the wave range of the output voltage is so small as to provide the stable X-ray supply for the X-ray machine for measuring velocity of outfield projectile. It is fast in charging and high in efficiency.

Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

Science.gov (United States)

Cernusca, S.; Winter, HP.; Aumayr, F.; Díez Muiño, R.; Juaristi, J. I.

2003-04-01

Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to "projectile molecular effects" (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials.

Devices for launching 0.1-g projectiles to 150 km/s or more to initiate fusion. Part 1. Magnetic-gradient and electrostatic accelerators

International Nuclear Information System (INIS)

Brittingham, J.N.

1979-01-01

The feasibility of using magnetic-gradient and electrostatic accelerators to launch a 0.1-g projectile to hypervelocities (150 km/s or more) is studied. Such hypervelocity projectiles could be used to ignite deuterium-tritium fuel pellets in a fusion reactor. For the magnetic-gradient accelerator, several types of projectile were studied: shielded and unshielded copper, ferromagnetic, and superconducting. The calculations revealed the superconducting projectile to be the best of those materials. It would require a 3.2-km-long magnetic-gradient accelerator and achieve a 92% efficiency. This accelerator-projectile combination would be the one most likely to launch a 0.1-g projectile to 150 km/s or more. Its components would cost $58.9 million. The electrostatic accelerator was found to be impractical because of its excessive length of 23 km

Fragmentation of small molecules induced by 46 keV/amu N+ and N2+ projectiles

International Nuclear Information System (INIS)

Kovacs, S.T.S.; Juhasz, Z.; Herczku, P.; Sulik, B.

2012-01-01

Complete text of publication follows. Collisional molecule fragmentation experiments has gain increasing attention in several research and applied fields. In order to understand the fundamental processes of molecule fragmentation one has to start with collisions of small few-atomic molecules. Moreover, fragments of small molecules such as water can cause damages of large molecules (DNA) very effectively in living tissues. In the last few years a new experimental setup was developed at Atomki. It was designed especially for molecule fragmentation experiments. Now the measurements using this system are running routinely. In 2012 the studied targets were water vapor, methane and nitrogen gases, injected into the collision area by an effusive molecular gas jet system. 650 keV N + and 1,3 MeV N 2 + ions were used as projectiles produced by the VdG-5 electrostatic accelerator. The velocity of the two types of projectiles was the same. Energy and angular distribution of the produced fragments was measured by an energy dispersive electrostatic spectrometer. For atomic ionization a symmetric, diatomic molecular projectile (e.g. N 2 + ) yields about twice more electrons compared to those of singly charged ion projectiles of the same atom (N + ) at the same velocity. In such cases the two atomic centers in the molecular ion can be considered as two individual atomic centers. For the fragmentation of molecular targets the picture is not so simple because in this case close collision of two extended systems is investigated. As figure 1 and 2 show, the measured yields for molecular projectile is not simply twice of the ones for atomic projectile. The shape of the energy spectra are different. The measured data are under evaluation. Acknowledgements. This work was supported by the Hungarian National Science Foundation OTKA (Grant: K73703) and by the TAMOP-4.2.2/B-10/1-2010-0024 project. The project is cofinanced by the European Union and the European Social Fund.

Research on Ground Motion Metal Target Based on Rocket Projectile by Using Millimeter Wave Radiometer Technology

Directory of Open Access Journals (Sweden)

Zhang Dongyang

2014-06-01

Full Text Available How to detect the ground motion metal target effectively is an important guarantee for precision strike in the process of Rocket Projectile flight. Accordingly and in view of the millimeter- wave radiation characteristic of the ground motion metal target, a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the ground motion metal target. Through changing various parameters in the process of Rocket Projectile flight, the detection model was studied by simulation. The parameters variation and effective range of millimeter wave radiometer were obtained in the process of rotation and horizontal flight. So a certain theoretical basis was formed for the precision strike to the ground motion metal target.

Fusion of a polarized projectile with a polarized target

International Nuclear Information System (INIS)

Christley, J.A.; Johnson, R.C.; Thompson, I.J.

1995-01-01

The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

Penetration of a Small Caliber Projectile into Single and Multi-layered Targets

Directory of Open Access Journals (Sweden)

Riad A.M.

2010-06-01

Full Text Available The normal penetration of armor-piercing projectiles into single and multi-layered steel plates has been investigated. An experimental program has been conducted to study the effect of spaced and in-contact layered targets on their ballistic resistance. Armor piercing projectiles with caliber of 7.62 mm were fired against a series of single and multi-layered steel targets. The projectile impact velocities were ranged from 300-600 m/s, whereas the total thicknesses of the tested single, spaced and in-contact layered steel targets were 3 mm. The penetration process of different tested target configurations has been simulated using Autodayn-2D hydrocode. The experimental measurements of the present work were used to discuss the effect of impact velocity, target configurations and number of layers of different spaced and in-contact layered steel targets on their ballistic resistance. In addition, the post-firing examination of the tested targets over the used impact velocity range showed that the single and each layer of spaced and in-contact laminated steel targets were failed by petalling. Finally, the obtained experimental measurements were compared with the corresponding numerical results of Autodyn-2D hydrocode, good agreement was generally obtained.

Projectile electron loss in collisions of light charged ions with helium

International Nuclear Information System (INIS)

Yin Yong-Zhi; Chen Xi-Meng; Wang Yun

2014-01-01

We investigate the single-electron loss processes of light charged ions (Li 1+,2+ , C 2+,3+,5+ , and O 2+,3+ ) in collisions with helium. To better understand the experimental results, we propose a theoretical model to calculate the cross section of projectile electron loss. In this model, an ionization radius of the incident ion was defined under the classical over-barrier model, and we developed ''strings'' to explain the processes of projectile electron loss, which is similar with the molecular over-barrier model. Theoretical calculations are in good agreement with the experimental results for the cross section of single-electron loss and the ratio of double-to-single ionization of helium associated with one-electron loss. (atomic and molecular physics)

Stable Superstring Relics and Ultrahigh Energy Cosmic Rays

CERN Document Server

Coriano, Claudio; Plumacher, Michael; Coriano, Claudio; Faraggi, Alon E.; Plumacher, Michael

2001-01-01

One of the most intriguing experimental results of recent years is the observation of Ultrahigh Energy Cosmic Rays (UHECRs) above the GZK cutoff. Plausible candidates for the UHECR primaries are the decay products of a meta--stable matter state with mass of order O(10^{12-15 GeV}), which simultaneously is a good cold dark matter candidate. We study possible meta-stable matter states that arise from Wilson line breaking of GUT symmetries in semi-realistic heterotic string models. In the models that we study the exotic matter states can be classified according to patterns of SO(10) symmetry breaking. We show that cryptons, which are states that carry fractional electric charge $\\pm1/2$, and are confined by a hidden gauge group cannot produce viable dark matter. This is due to the fact that, in addition to the lightest neutral bound state, cryptons give rise to meta-stable charged bound states. However, these states may still account for the UHECR events. We argue that the uniton, which is an exotic Standard Mod...

Projectile and target fragmentation at intermediate energies (20 MeV <= E/A <= 100 MeV)

International Nuclear Information System (INIS)

Dayras, R.A.

1985-04-01

In order to follow the evolution of the reaction mechanisms in the transition region of the intermediate energy range, detailed studies of projectile-like fragments from a 44 MeV/u 40 Ar projectile bombarding 27 Al and sup(NAT)T: targets have been made. Experimental results are given. Discussion of the data is presented: transfer reactions, isotopic distributions, the fragmentation model, and abrasion model are used in the discussion

Radiative electron capture into the K-, L-, and M-shell of decelerated, hydrogenic Ge projectiles

International Nuclear Information System (INIS)

Stoehlker, T.; Kozhuharov, C.; Livingston, A.E.; Mokler, P.H.; Stachura, Z.; Warczak, A.

1991-12-01

Radiative Electron Capture (REC) in 4 to 12 MeV/u Ge 31+ →H 2 collisions has been studied using an X-ray/particle coincidence technique. This technique allowed a systematic investigation of K-shell REC as well as a separation of REC into the projectile L- and M-shells. The cross sections are discussed within a general scaling picture based on the reduced projectile velocity. (orig.)

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

International Nuclear Information System (INIS)

Er-Qin, Wang; Fu-Hu, Liu; Jian-Xin, Sun; Rahim, Magda A.; Fakhraddin, S.

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. (nuclear physics)

Assessment of empirical formulae for local response of concrete structures to hard projectile impact

International Nuclear Information System (INIS)

Buzaud, E.; Cazaubon, Ch.; Chauvel, D.

2007-01-01

The outcome of the impact of a hard projectile on a reinforced concrete structure is affected by different parameters such as the configuration of the interaction, the projectile geometry, mass and velocity and the target geometry, reinforcement, and concrete mechanical properties. Those parameters have been investigated experimentally during the last 30 years, hence providing a basis of simplified mathematical models like empirical formulae. The aim of the authors is to assess the relative performances of classical and more recent empirical formulae. (authors)

Reduced conservatism in stability robustness bounds by state transformation

Science.gov (United States)

Yedavalli, R. K.; Liang, Z.

1986-01-01

This note addresses the issue of 'conservatism' in the time domain stability robustness bounds obtained by the Liapunov approach. A state transformation is employed to improve the upper bounds on the linear time-varying perturbation of an asymptotically stable linear time-invariant system for robust stability. This improvement is due to the variance of the conservatism of the Liapunov approach with respect to the basis of the vector space in which the Liapunov function is constructed. Improved bounds are obtained, using a transformation, on elemental and vector norms of perturbations (i.e., structured perturbations) as well as on a matrix norm of perturbations (i.e., unstructured perturbations). For the case of a diagonal transformation, an algorithm is proposed to find the 'optimal' transformation. Several examples are presented to illustrate the proposed analysis.

Single capture and transfer ionization in collisions of Clq+ projectile ions incident on helium

International Nuclear Information System (INIS)

Wong, K.L.; Ben-Itzhak, I.; Cocke, C.L.; Giese, J.P.; Richard, P.

1995-01-01

The Kansas State University linac has been used to measure the ratio of the cross sections for the processes of transfer ionization (TI) and single capture (SC) for 2 MeV/amu Cl q+ where q=7, 9, 13, 14, and 15 projectile ions incident on a helium target. The ratio was determined using a helium gas jet target by measuring coincidences between projectile-ion and recoil-ion final charge states. The σ TI /σ SC for Cl q+ were compared to measurements of bare F 9+ and hydrogenlike F 8+ and O 7+ taken at the same velocity. The ratios deviate from a q 2 scaling which is predicted in the perturbative regime. This deviation is attributed to screening by the projectile electrons for low q=7 and 9, and to the collision being non-perturbative for high q. A possible saturation effect in the ratio was observed for q similar 14. (orig.)

Strongest model-independent bound on the lifetime of Dark Matter

CERN Document Server

Audren, Benjamin; Mangano, Gianpiero; Serpico, Pasquale Dario; Tram, Thomas

2014-01-01

Dark Matter is essential for structure formation in the late Universe so it must be stable on cosmological time scales. But how stable exactly? Only assuming decays into relativistic particles, we report an otherwise model independent bound on the lifetime of Dark Matter using current cosmological data. Since these decays affect only the low-$\\ell$ multipoles of the CMB, the Dark Matter lifetime is expected to correlate with the tensor-to-scalar ratio $r$ as well as curvature $\\Omega_k$. We consider two models, including $r$ and $r+\\Omega_k$ respectively, versus data from Planck, WMAP, WiggleZ and Baryon Acoustic Oscillations, with or without the BICEP2 data (if interpreted in terms of primordial gravitational waves). This results in a lower bound on the lifetime of CDM given by 160Gyr (without BICEP2) or 200Gyr (with BICEP2) at 95% confidence level.

Backward ejected electrons from collisions of 1 MeV/u Oq+ projectiles with argon gas

International Nuclear Information System (INIS)

Berryman, J.W.; Breinig, M.; Segner, F.; Desai, D.

1993-01-01

We will be presenting results from a series of experiments measuring the yields and energy distributions of electrons emitted at 1800 with respect to the 1 MeV/u O q+ [q=3-8] ion beam. We have systematically studied the yield per incident ion and the energy distribution of electrons as a function of the incident projectile charge state. The energy distributions show two prominent structures: a narrow peak due to target LMM Auger electrons and a broad hump due to projectile binary-encounter electrons. The shapes and yields of the Auger electron peaks are nearly independent of the incident charge state. The shapes and yields of the binary-encounter electron peaks are sensitive functions of the number of projectile electrons carried into the collision. A well defined binary-encounter electron peak appears only for charge states q=3, 4, and 5

Signatures of projectile-nucleus scattering in three-dimensional (e,2e) cross sections for argon

Energy Technology Data Exchange (ETDEWEB)

Ren Xueguang; Senftleben, Arne; Pflueger, Thomas; Dorn, Alexander; Ullrich, Joachim [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Bartschat, Klaus, E-mail: Xueguang.Ren@mpi-hd.mpg.d, E-mail: Alexander.Dorn@mpi-hd.mpg.d [Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311 (United States)

2010-02-14

Electron impact ionization (E{sub 0} = 195 eV) of the 3p-orbital in argon is investigated experimentally and theoretically. The triple-differential cross sections (TDCS) obtained using a multi-particle momentum spectrometer (reaction microscope) cover more than 80% of the full solid angle for the slow emitted electron up to an energy of 25 eV and a range of projectile scattering angles from -5 deg. to -15 deg. Inside the projectile scattering plane the TDCS shape is in rather good agreement with a hybrid distorted-wave plus R-matrix (DWBA-RM) calculation. Outside the scattering plane relatively strong electron emission is observed which is reproduced by theory in magnitude but not in shape. A systematic study of the TDCS behaviour and structure in this region indicates that its origin lies in high-order projectile-target interaction.

Occult lawn mower projectile injury presenting with hemoptysis

Directory of Open Access Journals (Sweden)

Patric J. Darvie, BS

2017-12-01

Full Text Available We present the case of a 72-year-old man with hemoptysis after a thoracic projectile injury, which occurred while mowing the lawn. Chest radiograph followed by a computed tomography angiogram revealed a metallic foreign body in the right middle lobe of the lung. The patient underwent a right anterolateral thoracotomy where the object was successfully retrieved. The patient had an uneventful postoperative recovery.

Occult lawn mower projectile injury presenting with hemoptysis.

Science.gov (United States)

Darvie, Patric J; Ballard, David H; Harris, Nicholas; Bhargava, Peeyush; Rao, Vyas R; Samra, Navdeep S

2017-12-01

We present the case of a 72-year-old man with hemoptysis after a thoracic projectile injury, which occurred while mowing the lawn. Chest radiograph followed by a computed tomography angiogram revealed a metallic foreign body in the right middle lobe of the lung. The patient underwent a right anterolateral thoracotomy where the object was successfully retrieved. The patient had an uneventful postoperative recovery.

Occult lawn mower projectile injury presenting with hemoptysis

OpenAIRE

Patric J. Darvie, BS; David H. Ballard, MD; Nicholas Harris, MD; Peeyush Bhargava, MD, MBA; Vyas R. Rao, MD; Navdeep S. Samra, MD

2017-01-01

We present the case of a 72-year-old man with hemoptysis after a thoracic projectile injury, which occurred while mowing the lawn. Chest radiograph followed by a computed tomography angiogram revealed a metallic foreign body in the right middle lobe of the lung. The patient underwent a right anterolateral thoracotomy where the object was successfully retrieved. The patient had an uneventful postoperative recovery.

Numerical simulation of 3-D incompressible, multi-phase flows over cavitating projectiles

Energy Technology Data Exchange (ETDEWEB)

Owis, F.M.; Nayfeh, A.H. [Blacksburg State University, Dept. of Engineering Science and Mechanics, MC 0219, Virginia Polytechnic Institute, VA (United States)

2004-04-01

The hydrodynamic cavitation over axisymmetric projectiles is computed using the unsteady incompressible Navier-Stokes equations for multi-fluid elements. The governing equations are discretized on a structured grid using an upwind difference scheme with flux limits. A preconditioning dual-time stepping method is used for the unsteady computations. The Eigen-system is derived for the Jacobian matrices. This Eigen-system is suitable for high-density ratio multi-fluid flows and it provides high numerical stability and fast convergence. This method can be used to compute single- as well as multi-phase flows. Cavitating flows over projectiles with different geometries are computed and the results are in good agreement with available experimental data and other published computations. (authors)

Multifragmentation induced by light relativistic projectiles and heavy ions: similarities and differences

International Nuclear Information System (INIS)

Karnaukhov, V.A.; Avdeev, S.P.; Kuznetsov, V.D.

1998-01-01

The experimental data on fragment multiplicities, their energy and charge distributions, the emission times are considered for the nuclear multifragmentation process induced by relativistic light projectiles (protons, helium) and heavy ions. With light projectiles, the multifragmentation is a pure 'thermal' process, well described by the statistical models. Heavy-ion-induced multifragmentation is influenced by dynamic effects related first of all to the compression of the system in the collision. But statistical models can also be applied to rendering the partition of the system if the excitation energy is less than 10 MeV/nucleon and compression is modest. For the central collision of heavy ions the statistical approach fails to describe the data

Projectile excitation energy evolution in peripheral collisions for 16O + 197Au at 32.5, 50 and 70 MeV/N

International Nuclear Information System (INIS)

Pouliot, J.; Dore, D.; Houde, S.; Laforest, R.; Roy, R.; St-Pierre, C.; Chan, Y.; Horn, D.; Horn, D.

1991-01-01

A comparison of the multiple breakup of 16 O projectiles scattered by a Au target at three different energies (32.5, 50 and 70 MeV/N) is presented. The excitation energy spectra of the primary projectile-like nuclei decaying into specific output channels were reconstructed. The excitation energy of the target is found to increase faster with beam energy than the one for the quasi-projectile

Projectile break-up of 14N at 62,7 MeV

International Nuclear Information System (INIS)

Bozek, E.; Cassagnou, Y.; Dayras, R.; Legrain, R.; Pagano, A.; Rodriguez, L.; Lanzano, G.; Palmeri, A.; Pappalardo, G.

1983-01-01

In plane and out of plane angular correlations between light particles and heavy ions have been measured in the reaction 14 N + 12 C at 62.7 MeV bombarding energy. Special attention has been given to the break-up of 14 N into 13 C + p, 12 C + d and 10 B + α. The observed correlations are consistent with sequential break-up of the 14 N projectile. A Monte-Carlo calculation assuming isotropic emission of particles in the rest frame of the projectile from well defined states in 14 N is in good agreement with the experimental angular correlations. From a comparison between calculated and experimental boron and carbon single energy spectra, it appears that after transfer reactions, sequential break-up of 14 N is the dominant process to produce these nuclei

When Does Air Resistance Become Significant in Projectile Motion?

Science.gov (United States)

Mohazzabi, Pirooz

2018-01-01

In an article in this journal, it was shown that air resistance could never be a significant source of error in typical free-fall experiments in introductory physics laboratories. Since projectile motion is the two-dimensional version of the free-fall experiment and usually follows the former experiment in such laboratories, it seemed natural to…

Simulations of the Penetration of 6061-T6511 Aluminum Targets by Spherical-Nosed VAR 4340 Steel Projectiles

Energy Technology Data Exchange (ETDEWEB)

Tabbara, M.R.; Warren, T.L.

1998-10-21

In certain penetration events it is proposed that the primary mode of deformation of the target can be approximated by known analytical expressions. In the context of an analysis code, this approximation eliminates the need for discretizing the target as well as the need for a contact algorithm. Thus, this method substantially reduces the computer time and memory requirements. In this paper a forcing function which is derived from a spherical-cavity expansion (SCE) analysis has been implemented in a transient dynamic finite element code. This irnplementation is capable of computing the structural and component responses of a projectile due to a three dimensional penetration event. Simulations are presented for 7.1 l-mm-diameter, 74.7-mm-long, spherical-nose, vacuum- arc-remelted (VAR) 4340 steel projectiles that penetrate 6061-T6511 aluminum targets. Final projectile configurations obtained from the simulations are compared with post-test radiographs obtained from the corresponding experiments. It is shown that the simulations accurately predict the permanent projectile deformation for three dimensional loadings due to incident pitch and yaw over a wide range of striking velocities.

Comparison of high speed movie and flash x-ray measurement of the translational and rotational motions of projectiles penetrating gelatin

International Nuclear Information System (INIS)

Roecker, E.T.

1979-01-01

Projectiles penetrating a gelatin block were simultaneously measured by a high speed movie camera, Dynafax, and by a sequential, orthogonal, flash x-ray system. The eight orthogonal views of the x-ray system provided position and orientation of the projectiles vs. time. From onset of tumble in the gelatin, owing to gyroscopic instability, the growth of yaw was the same for each round in a replicated set. This phenomenon provided a legitimate procedure for pooling the x-ray data, giving well determined curves of velocity decay and yaw growth. The movie camera observed the progress of the cavity formed by the projectile. The resulting velocity decay of the cavity tip was compared to that of the projectile as measured by the x-ray technique. (author)

Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

International Nuclear Information System (INIS)

Cernusca, S.; Winter, H.P.; Aumayr, F.; Diez Muino, R.; Juaristi, J.I.

2003-01-01

Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy <10 keV) on atomically clean surfaces of carbon-fiber inforced graphite used as first-wall armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to 'projectile molecular effects' (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials

Angular distributions of projectiles following electron capture from C60 by 2.5-keV Ar8+

International Nuclear Information System (INIS)

Walch, B.; Thumm, U.; Stoeckli, M.; Cocke, C.L.; Klawikowski, S.

1998-01-01

Experimental measurements of the projectile angular distributions for 2.5-keV Ar 8+ ions capturing one to five electrons from a gas-phase C 60 target are presented. The number of captured electrons was determined by demanding a coincidence between the scattered projectile and a charge-state-analyzed intact C 60 recoil ion. The results are compared to calculations based on a dynamical classical overbarrier model. Good agreement is obtained only if the influence on the projectile trajectory by the large polarizability of the C 60 target is taken into account, thereby making the collective dielectric response of the cluster target observable in a scattering experiment. copyright 1998 The American Physical Society

Molecular projectile effects for kinetic electron emission from carbon- and metal-surfaces bombarded by slow hydrogen ions

CERN Document Server

Cernusca, S; Aumayr, F; Diez-Muino, R; Juaristi, J I

2003-01-01

Total yields for kinetic electron emission (KE) have been determined for impact of hydrogen monomer-, dimer- and trimer-ions (impact energy <10 keV) on atomically clean surfaces of carbon-fiber inforced graphite used as first-wall armour in magnetic fusion devices. The data are compared with KE yields for impact of same projectile ions on atomically clean highly oriented pyrolytic graphite and polycrystalline gold. We discuss KE yields for the different targets if bombarded by equally fast molecular and atomic ions in view to 'projectile molecular effects' (different yields per proton for equally fast atomic and molecular ions), which are expected from calculated electronic projectile energy losses in these target materials.

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.

Study of atomic excitations in sputtering with the use of N, O, F, Ne, Na, Cl, and Ar projectiles

International Nuclear Information System (INIS)

Jensen, H.K.; Veje, E.

1985-01-01

Solid magnesium has been bombarded with 80 keV ions of N, O, F, Ne, Na, Cl, and Ar, and excitation of sputtered magnesium atoms and ions has been studied. Relative level excitation probabilities depend strongly on the projectile, the dependences for Mg I levels being different from those for Mg II levels. With all projectiles, the resonance level in Mg II is excited stronger than the resonance level in Mg I. Very little radiation is observed from the projectiles except for sodium. The results are discussed. (orig.)

Systematic investigation of electromagnetic properties of all stable hafnium isotopes

International Nuclear Information System (INIS)

Napiorkowski, T.J.; Choinski, J.; Czosnyka, T.; Iwanicki, J.; Kownacki, J.; Zemlo, L.; Srebrny, J.; Starosta, K.; Boer, J. de.; Gollwitzer, A.; Loewe, M.; Wuerkner, M.; Guenther, C.; Weber, T.; Hagemann, G.; Sletten, G.

1996-01-01

In a systematic investigation of the electromagnetic structure of hafnium stable isotopes enriched targets of 176, 177, 178, 179, 180 Hf were Coulomb exciting using: 67 MeV 19 F beam from NBITAL FN Tandem, 125 MeV 32 S beam from MP Tandem in Accelerator Laboratory LMU and TU Munich, 225 MeV 58 Ni beam from NBITAL FN Tandem plus 2 Liniac Boosters complex. Scattered particle-gamma as well as p-γ-γ coincidence were registered. A further simultaneous analysis of Coulomb excitation cross section as a function of scattering angle of 19 F, 32 S, 58 Ni projectiles should be sufficient to deduce reduced probabilities of E2 transitions in ground state band

Information-entropic method for studying the stability bound of nonrelativistic polytropic stars within modified gravity theories

Science.gov (United States)

Wibisono, C.; Sulaksono, A.

We study the stability of nonrelativistic polytropic stars within two modified gravity theories, i.e. beyond Horndeski gravity and Eddington-inspired Born-Infeld theories, using the configuration entropy method. We use the spatially localized bounded function of energy density as solutions from stellar effective equations to construct the corresponding configuration entropy. We use the same argument as the one used by Gleiser and coworkers [M. Gleiser and D. Sowinski, Phys. Lett. B 727 (2013) 272; M. Gleiser and N. Jiang, Phys. Rev. D 92 (2015) 044046] that the stars are stable if there is a peak in configuration entropy as a function of adiabatic index curve. Specifically, the boundary between stable and unstable regions which corresponds to Chandrasekhar stability bound is indicated from the existence of the maximum peak while the most stable polytropic stars are indicated by the minimum peak in the corresponding curve. We have found that the values of critical adiabatic indexes of Chandrasekhar stability bound and the most stable polytropic stars predicted by the nonrelativistic limits of beyond Horndeski gravity and Eddington-inspired Born-Infeld theories are different to those predicted by general relativity where the corresponding differences depend on the free parameters of both theories.

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

Science.gov (United States)

Sant'Anna, M. M.; Zappa, F.; Santos, A. C. F.; de Barros, A. L. F.; Wolff, W.; Coelho, L. F. S.; de Castro Faria, N. V.

2004-07-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F-, Cl-, Br- and I- ions incident on N2, in the 0.94-74 keV u-1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u-1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested.

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

International Nuclear Information System (INIS)

Sant'Anna, M M; Zappa, F; Santos, A C F; Barros, A L F de; Wolff, W; Coelho, L F S; Faria, N V de Castro

2004-01-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F - , Cl - , Br - and I - ions incident on N 2 , in the 0.94-74 keV u -1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u -1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested

L and M shell coulomb ionization by heavy charged projectiles

International Nuclear Information System (INIS)

Karmaker, R.

1980-01-01

Universal cross sections for L and M shell ionization have been extracted from the semiclassical approximation (SCA) model in the straight line path approximation of the projectile. It has been shown that it is possible to organise the calculation of the SCA in a suitable way so that it is not necessary to calculate the cross section for different targets. The agreement between the theoretical curve in the SCA model and the available experimental data for different target elements, is reasonably good. Cross sections for L and M shell ionization in the straight line path of the projectile in the SCA model for Pb, Au and U targets by the impact of protons have been calculated. The results have been compared with those calculated in the Binary Encounter Approximation (BEA) and the Plane Wave Born Approximation (PWBA) as well as with the available experimental results. The present calculations are in good agreement with the existing theoretical and the experimental results. (author)

Devices for launching 0.1-g projectiles to 150 km/s or more to initiate fusion. Part 2. Railgun accelerators

International Nuclear Information System (INIS)

Hawke, R.S.

1979-01-01

The possibility of using a railgun accelerator to launch 0.1-g projectiles to hypervelocities (150 km/s or more) to initiate thermonuclear fusion is studied. The analysis revealed that a railgun with a plasma-arc armature is a viable approach to the goal. When calculating the railgun's probable performance, it was discovered that this launch system might possibly be designed to avoid adverse effects from boundary layer drag. An appendix provided by A.C. Buckingham summarizes his calculations that predict the amount of erosive drag between projectile and rail. Finally, it was found that certain properties of railgun and projectile materials can impose operational limits. Using these limits, single- and multistage accelerators were designed. Within such limits, a railgun could accelerate a 0.1-g projectile to hypervelocities

New projectiles: multicharged metal clusters and biopolymers

International Nuclear Information System (INIS)

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

1991-01-01

Metal clusters and molecules are the one mean to realize simultaneous impacts of several atoms on a reduced surface(∼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

Ionization of atoms by bare ion projectiles

International Nuclear Information System (INIS)

Tribedi, L.C.

1997-01-01

The double differential cross sections (DDCS) for low energy electron emission can provide stringent tests to the theoretical models for ionization in ion-atom collision. The two-center effects and the post collision interactions play a major role in ionization by highly charged, high Z projectiles. We close-quote ll review the recent developments in this field and describe our efforts to study the energy and angular distributions of the low energy electrons emitted in ion-atom ionization. copyright 1997 American Institute of Physics

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.

Angry Birds realized: water balloon launcher for teaching projectile motion with drag

International Nuclear Information System (INIS)

Edwards, Boyd F; Sam, David D; Christiansen, Michael A; Booth, William A; Jessup, Leslie O

2014-01-01

A simple, collapsible design for a large water balloon slingshot launcher features a fully adjustable initial velocity vector and a balanced launch platform. The design facilitates quantitative explorations of the dependence of the balloon range and time of flight on the initial speed, launch angle, and projectile mass, in an environment where quadratic air drag is important. Presented are theory and experiments that characterize this drag, and theory and experiments that characterize the nonlinear elastic energy and hysteresis of the latex tubing used in the slingshot. The experiments can be carried out with inexpensive and readily available tools and materials. The launcher provides an engaging way to teach projectile motion and elastic energy to students of a wide variety of ages. (paper)

Effects of dust-charge fluctuations on the potential of an array of projectiles in a partially ionized dusty plasma

International Nuclear Information System (INIS)

Ali, S.; Nasim, M.H.; Murtaza, G.

2003-01-01

The expressions for the Debye and the wake potential are derived by incorporating dust-charge fluctuations of a single projectile, as well as of an array of dust grain projectiles, propagating through a partially ionized dusty plasma with a constant velocity. Numerically, the effects of the dust-charge fluctuations and the dust-neutral collisions on the electrostatic potential for a single, three, six and ten projectiles are examined. The dust-charge relaxation rate modifies the shape of the Debye as well as the wake potential. For smaller values of the relaxation rates a potential well is formed instead of Debye potential

Isotopic distribution of the projectile-like products in the reaction 36Ar + 124Sn at 35 MeV/u

International Nuclear Information System (INIS)

Xiao Zhigang; Jin Genming; Wu Heyu; Hu Rongjiang; Wang Hongwei; Li Zuyu; Duan Limin; Wang Sufang; Wei Zhiyong; Zhang Baoguo; Liu Jianye; Zhu Yongtai

2003-01-01

The projectile-like products at 5.3 degree in the reaction 35 MeV/u 36 Ar + 124 Sn were inclusively measured with good isotopic identification. With increasing kinetic energy, the average N/Z ratio of the products gradually decreases, approaching to that of the projectile. It is shown from the isospin dependent quantum mechanics (IQMD) that with the increasing of reaction time, the average kinetic energy of the projectile-like products decreases, while the N/Z ratio increases gradually. Moreover, the isotropic composition is obviously dependent on the impact parameter, and the N/Z radio is becoming smaller with increasing collision centrality

Projectile fragmentation of neutron-rich nuclei on light target (momentum distribution and nucleon-removal cross section)

International Nuclear Information System (INIS)

Kobayashi, T.; Tanihata, I.; Suzuki, T.

1992-01-01

Transverse momentum distributions of the projectile fragments from β-unstable nuclei have been measured with various projectile and target combinations. The momentum correlation of two neutrons in the neutron halo is extracted from the P c t distribution of 9 Li and hat of the neutrons. It is found that the two neutrons are moving in the same direction on average and thus strongly suggests the formation of a di-neutron in 11 Li. (Author)

Projectile deformation effects in the breakup of 37Mg

Directory of Open Access Journals (Sweden)

Shubhchintak

2016-01-01

Full Text Available We study the breakup of 37Mg on Pb at 244MeV/u with the recently developed extended theory of Coulomb breakup within the postform finite range distorted wave Born approximation that includes deformation of the projectile. Comparing our calculated cross section with the available Coulomb breakup data we determine the possible ground state configuration of 37Mg.

Rigorous Statistical Bounds in Uncertainty Quantification for One-Layer Turbulent Geophysical Flows

Science.gov (United States)

Qi, Di; Majda, Andrew J.

2018-04-01

Statistical bounds controlling the total fluctuations in mean and variance about a basic steady-state solution are developed for the truncated barotropic flow over topography. Statistical ensemble prediction is an important topic in weather and climate research. Here, the evolution of an ensemble of trajectories is considered using statistical instability analysis and is compared and contrasted with the classical deterministic instability for the growth of perturbations in one pointwise trajectory. The maximum growth of the total statistics in fluctuations is derived relying on the statistical conservation principle of the pseudo-energy. The saturation bound of the statistical mean fluctuation and variance in the unstable regimes with non-positive-definite pseudo-energy is achieved by linking with a class of stable reference states and minimizing the stable statistical energy. Two cases with dependence on initial statistical uncertainty and on external forcing and dissipation are compared and unified under a consistent statistical stability framework. The flow structures and statistical stability bounds are illustrated and verified by numerical simulations among a wide range of dynamical regimes, where subtle transient statistical instability exists in general with positive short-time exponential growth in the covariance even when the pseudo-energy is positive-definite. Among the various scenarios in this paper, there exist strong forward and backward energy exchanges between different scales which are estimated by the rigorous statistical bounds.

Algorithm-Dependent Generalization Bounds for Multi-Task Learning.

Science.gov (United States)

Liu, Tongliang; Tao, Dacheng; Song, Mingli; Maybank, Stephen J

2017-02-01

Often, tasks are collected for multi-task learning (MTL) because they share similar feature structures. Based on this observation, in this paper, we present novel algorithm-dependent generalization bounds for MTL by exploiting the notion of algorithmic stability. We focus on the performance of one particular task and the average performance over multiple tasks by analyzing the generalization ability of a common parameter that is shared in MTL. When focusing on one particular task, with the help of a mild assumption on the feature structures, we interpret the function of the other tasks as a regularizer that produces a specific inductive bias. The algorithm for learning the common parameter, as well as the predictor, is thereby uniformly stable with respect to the domain of the particular task and has a generalization bound with a fast convergence rate of order O(1/n), where n is the sample size of the particular task. When focusing on the average performance over multiple tasks, we prove that a similar inductive bias exists under certain conditions on the feature structures. Thus, the corresponding algorithm for learning the common parameter is also uniformly stable with respect to the domains of the multiple tasks, and its generalization bound is of the order O(1/T), where T is the number of tasks. These theoretical analyses naturally show that the similarity of feature structures in MTL will lead to specific regularizations for predicting, which enables the learning algorithms to generalize fast and correctly from a few examples.

''Theta gun,'' a multistage, coaxial, magnetic induction projectile accelerator

International Nuclear Information System (INIS)

Burgess, T.J.; Duggin, B.W.; Cowan, M. Jr.

1985-11-01

We experimentally and theoretically studied a multistage coaxial magnetic induction projectile accelerator. We call this system a ''theta gun'' to differentiate it from other coaxial accelerator concepts such as the mass driver. We conclude that this system can theoretically attain railgun performance only for large caliber or very high injection velocity and, even then, only for long coil geometry. Our experiments with a three-stage, capactor bank-driven accelerator are described. The experiments are modeled with a 1-1/2 dimensional equivalent circuit-hydrodynamics code which is also described. We derive an expression for the conditions of coaxial accelerator-railgun ''velocity breakeven'' in the absence of ohmic and hydrodynamic effects. This, in conjunction with an expression for the magnetic coupling coefficient, defines a set of geometric relations which the coaxial system must simultaneously satisfy. Conclusions concerning both the existence and configuration of a breakeven coaxial system follow from this requirement. The relative advantages and disadvantages of the coaxial induction projectile accelerator, previously cited in the literature, are critiqued from the viewpoint of our analysis and experimental results. We find that the advantages vis-a-vis the railgun have been overstated. 13 refs., 17 figs

On the Horizontal Deviation of a Spinning Projectile Penetrating into Granular Systems

Directory of Open Access Journals (Sweden)

Waseem Ghazi Alshanti

2017-01-01

Full Text Available The absence of a general theory that describes the dynamical behavior of the particulate materials makes the numerical simulations the most current powerful tool that can grasp many mechanical problems relevant to the granular materials. In this paper, based on a two-dimensional soft particle discrete element method (DEM, a numerical approach is developed to investigate the consequence of the orthogonal impact into various granular beds of projectile rotating in both clockwise (CW and counterclockwise (CCW directions. Our results reveal that, depending on the rotation direction, there is a significant deviation of the x-coordinate of the final stopping point of a spinning projectile from that of its original impact point. For CW rotations, a deviation to the right occurs while a left deviation has been recorded for CCW rotation case.

Investigations in atomic physics by heavy ion projectiles

International Nuclear Information System (INIS)

Berenyi, D.

1983-01-01

The utilization of heavy ion reactions in atomic physics is surveyed. The basic collision mechanisms and their consequences in atomic physics are summarized. The atomic and electronic processes during and after heavy ion collisions are reviewed as functions of the projectile energy. The main detection and measuring methods are described. Reviews of new information about the structure of electronic cloud and about fundamental processes based on the analysis of heavy ion reaction data are given. (D.Gy.)

Organizational coordination and costly communication with boundedly rational agents

DEFF Research Database (Denmark)

Dietrichson, Jens; Jochem, Torsten

How does costly communication affect organizational coordination? This paper develops a model of costly communication based on the weakest-link game and boundedly rational agents. Solving for the stochastically stable states, we find that communication increases the possibilities for efficient...... coordination compared to a setting where agents cannot communicate. But as agents face a trade-off between lowering the strategic uncertainty for the group and the costs of communication, the least efficient state is still the unique stochastically stable one for many parameter values. Simulations show...... that this is not just a long run phenomena, the stochastically stable state is the most frequent outcome also in the short run. Making communication mandatory induces efficient coordination, whereas letting a team leader handle communication increases efficiency when the leader expects others to follow and has enough...

Effect of projectile on incomplete fusion reactions at low energies

Directory of Open Access Journals (Sweden)

Sharma Vijay R.

2017-01-01

Full Text Available Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n excess projectile 13C (as compared to 12C results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B and forward (F α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

Effect of projectile on incomplete fusion reactions at low energies

Science.gov (United States)

Sharma, Vijay R.; Shuaib, Mohd.; Yadav, Abhishek; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Singh, Devendra P.; Singh, B. P.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.; Prasad, R.

2017-11-01

Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF) is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n) excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B) and forward (F) α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

Calculation of forces arising from impacting projectiles upon yielding structures

International Nuclear Information System (INIS)

Drittler, K.; Gruner, P.; Krivy, J.

1977-01-01

Calculations concerning the impact of airplanes upon nuclear power plant buildings usually imply that the building 'acts' as a rigid target. This assumption is justified for considerations concerning the structural integrity of the building being hit. However, for investigating induced vibrations of components within the structure, this approach might -in general- be too conservative. It is expected, that yielding of the structure during impact reduces the peak values of the loads and changes the temporal behavior of the load function which is obtained for a rigid target. To calculate the changes of the load function which are due to deformations of the structure, Riera's method is extended for the case of a yielding target. In view of the applications of the calculations to the impact of airplanes upon buildings which are constructed to withstand loads of this kind without serious damage and without large deformations, it is possible to simplify the calculations to some extent. That is, the investigations need not take into account in detail the behavior of the target during impact. The calculations are performed with a one-dimensional model for the projectile. The direction of impact is perpendicular to the target surface; direction of impact and projectile axis coincide. The calculations were performed for several initial velocities of the projectiles simulating a fast flying military airplane. Variations of the peak values of the load functions as compared to corresponding values for a rigid target do not exceed about 10%. The overall temporal behavior of the load curves turns out to be not very sensitive to the yielding of the target, though, in some cases displacements in time of the peak positions within a single load curve do arise

The motion of an arbitrarily rotating spherical projectile and its application to ball games

International Nuclear Information System (INIS)

Robinson, Garry; Robinson, Ian

2013-01-01

In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball. Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results. As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first

The motion of an arbitrarily rotating spherical projectile and its application to ball games

Science.gov (United States)

Robinson, Garry; Robinson, Ian

2013-07-01

In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball. Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results. As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first

Numerical Simulation of Projectile Impact on Mild Steel Armour Platesusing LS-DYNA, Part II: Parametric Studies

OpenAIRE

M. Raguraman; A. Deb; N. K. Gupta; D. K. Kharat

2008-01-01

In Part I of the current two-part series, a comprehensive simulation-based study of impact of jacketed projectiles on mild steel armour plates has been presented. Using the modelling procedures developed in Part I, a number of parametric studies have been carried out for the same mild steel plates considered in Part I and reported here in Part II. The current investigation includes determination of ballistic limits of a given target plate for different projectile diameters and impact velociti...

Rapid Assessment of Small Changes to Major Gun and Projectile Dynamic Parameters

National Research Council Canada - National Science Library

Erline, Thomas

1997-01-01

The U.S. Navy's 5-in 54-cal. (5"/54) gun system Mark (Mk) 45 was subjected to first-order dynamic analysis tools that allowed rapid assessment of ballistic dispersion of a typical naval high explosive projectile...

Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

Science.gov (United States)

Kaur, Gurpreet; Hagino, K.; Rowley, N.

2018-06-01

The vast knowledge regarding the strong influence of quadrupole deformation β2 of colliding nuclei in heavy-ion sub-barrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as β4 and β6 deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of β4 of the projectile nucleus in the fusion of the 28Si+92Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and value of the β4 parameter of the projectile, 28Si, and confirmed that the 28Si nucleus has a large positive β4. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult because of experimental constraints.

Investigations of nuclear projectile break-up reactions

International Nuclear Information System (INIS)

Rebel, H.

1986-10-01

The cross sections for radiative capture of α-particles, deuterons and protons by light nuclei at very low relative energies are of particular importance for the understanding of the nucleosynthesis of chemical elements and for determining the relative elemental abundances in stellar burning processes at various astrophysical sites. As example we quote the reactions α+d → 6 Li+γ, α+ 3 He → 7 Be+γ, or α+ 12 C → 16 O+γ. As an alternative to the direct experimental study of these processes we consider the inverse process, the photodisintegration, by means of the virtual photons provided by a nuclear Coulomb field: Z+a → Z+b+c. The radiative capture process b+c → a+γ is related to the inverse process, the photodisintegration γ+a → b+c by the detailed balance theorem. Except for the extreme case very close to the threshold the phase space favours the photodisintegration cross section as compared to the radiative capture. The Coulomb dissociation cross section proves to be enhanced due to the large virtual photon number, seen by the passing projectile, and the kinematics of the process leads to particular advantages for studies of the interaction of the two break-up fragments at small relative energies E bc . The conditions of dedicated experimental investigations are discussed and demonstrated by recent experimental and theoretical studies of the break-up of 156 MeV 6 Li projectiles. In addition, a brief review about general features of break-up processes of light ions in the field of atomic nuclei is given. (orig.) [de

Role of nuclear couplings in the inelastic excitation of weakly-bound neutron-rich nuclei

Energy Technology Data Exchange (ETDEWEB)

Dasso, C.H. [Niels Bohr Institute, Copenhagen (Denmark); Lenzi, S.M.; Vitturi, A. [Universita di Padova (Italy)

1996-12-31

Much effort is presently devoted to the study of nuclear systems far from the stability line. Particular emphasis has been placed in light systems such as {sup 11}Li, {sup 8}B and others, where the very small binding energy of the last particles causes their density distribution to extend considerably outside of the remaining nuclear core. Some of the properties associated with this feature are expected to characterize also heavier systems in the vicinity of the proton or neutron drip lines. It is by now well established that low-lying concentrations of multipole strength arise from pure configurations in which a peculiar matching between the wavelength of the continuum wavefunction of the particles and the range of the weakly-bound hole states occurs. To this end the authors consider the break-up of a weakly-bound system in a heavy-ion collision and focus attention in the inelastic excitation of the low-lying part of the continuum. They make use of the fact that previous investigations have shown that the multipole response in this region is not of a collective nature and describe their excited states as pure particle-hole configurations. Since the relevant parameter determining the strength distributions is the binding energy of the last bound orbital they find it most convenient to use single-particle wavefunctions generated by a sperical square-well potential with characteristic nuclear dimensions and whose depth has been adjusted to give rise to a situation in which the last occupied neutron orbital is loosely-bound. Spin-orbit couplings are, for the present purpose, ignored. The results of this investigation clearly indicate that nuclear couplings have the predominant role in causing projectile dissociation in many circumstances, even at bombarding energies remarkably below the Coulomb barrier.

Coincidence measurement between α-particles and projectile-like fragments in the reaction of 82.7 MeV 16O on 27Al

International Nuclear Information System (INIS)

Shen Wenqing; Zhan Wenlong; Zhu Yongtai

1988-01-01

In a coincidence measurement between α-particles and projectile-like fragments in the reaction of 82.7 MeV 16 O on 27 Al, the contour plot of Galilean-invariant cross section of the coincidence between C-fragments and α-particles in the velocity plane, and the coincident angular correlation have been obtained. The correlated α-particles measured at positive angles (on the same side of the beam as the projectile-like fragments) were emitted mainly from the projectile-like fragments;the α-particles at large negative angles were emitted from the target-like fragments;the α-particles at small negative angles came from the fragmentation of the 16 O projectile. A possible reaction mechanism in which the residue produced in the fragmentation of the projectile continues the dissipation process during the interaction with the target has been discussed. It is also pointed out that in the large yield of C-fragments observed in the inclusive experiment, the contribution of C-fragments produced by the excited 16 O of DIC product via α-emission is quite small

Tissue simulant response at projectile impact on flexible fabric armour systems

NARCIS (Netherlands)

Bree, J.L.M.J. van; Volker, A.; Heiden, N. van der

2006-01-01

Behind Armour Blunt Trauma is a phenomenon which has been studied extensively for rigid personal protective armour systems. These systems used in e.g. bullet proof vests manage to defeat high velocity small arms projectiles. Tissue simulants are used to study behind armour effects. At high velocity

CDW-EIS theoretical calculations of projectile deflection for single ionization in highly charged ion-atom collisions

International Nuclear Information System (INIS)

Rodriguez, V.D.

2003-01-01

We present continuum distorted wave-eikonal initial state (CDW-EIS) theoretical calculations for the projectile deflection in single ionization of helium by heavy-ion impact as a function of ionized electron energies. These calculations account for the helium passive electron shielding in the internuclear interaction improving standard CDW-EIS theory. The results are compared with recent experimental results by impact of 100 MeV/amu C 6+ and 3.6 MeV/amu Au 53+ . For highly charged projectiles there is a poor quantitative agreement between theory and experiment. However, this refined calculation does share some qualitative features with the data. In particular the variation of the effective charge of the residual He + ion from Z eff =1 to Z eff =2 when going from small to large projectile scattering angles is able to represent a shoulder observed in the double differential cross sections. Important qualitative differences are observed at the level of triple differential cross sections

Charm production yield from target nuclei filtering intrinsic projectile charm

International Nuclear Information System (INIS)

Quack, E.; Nemes, M.C.

1990-01-01

Estimating the process of filtering an intrinsic projectile charm component by a target nucleus as proposed earlier, we obtain upper limits for the cross sections of open charm and J/Ψ. Comparing with experiment, we conclude that this filtering mechanism is not sufficient to explain the observed A α-dependence at large final state momenta. (author)

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…

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…

Management of in-tube projectiles using acoustic channel

Science.gov (United States)

Kostina, M. A.; Bortalevich, S. I.; Loginov, E. L.; Shinyakov, Y. A.; Sukhorukov, M. P.

2018-03-01

The article describes the method of measuring the distance from the operator's console installed outside the pipe to the in-tube projectile. A method for measuring distance in the absence of an echo signal is proposed. To do this, two identical ultrasonic locators operating at different frequencies were installed inside and outside the pipeline. The change in the duration of an acoustic pulse propagating in a circular waveguide with rigid walls is shown, which leads to a decrease in the data transfer rate.

Excitation and ionization of ethylene by charged projectiles

International Nuclear Information System (INIS)

Wang Zhiping; Wang Jing; Zhang Fengshou

2010-01-01

Using the time dependent local density approximation, applied to valence electrons, coupled non-adiabatically to molecular dynamics of ions, the collision process between ethylene and fast charged projectiles is studied in the microscopic way. The impact of ionic motion on the ionization is explored to show the importance of treating electronic and ionic degrees of freedom simultaneously. The number of escaped electrons, ionization probabilities are obtained. Furthermore, it is found that the ionic extensions in different directions show the different patterns. (authors)

Projectile-z3 and -z4 corrections to basic Bethe-Bloch stopping power theory and mean excitation energies of Al, Si, Ni, Ge, Se, Y, Ag and Au

International Nuclear Information System (INIS)

Porter, L.E.; Bryan, S.R.

1980-01-01

Three independent sets of measurements of the stopping power of solid elemental targets for alpha particles were previously analyzed in terms of basic Bethe-Bloch theory with the low velocity projectile-z 3 correction term included. These data for Al, Si, Ni, Ge, Se, Y, Ag and Au have now been analyzed with the Bloch projectile-z 4 term and a revised projectile-z 3 term incorporated in the Bethe-Bloch formula, the projectile-z 3 revision having been effected by variation of the single free parameter of the projectile-z 3 effect formalism. The value of this parameter, fixed at 1.8 in previous studies, which counteracts inclusion of the projectile-z 4 term is 1.3 +- 0.1 for all target elements except Si. (orig.)

["Bolt projectiles" discharged from modified humane killers (author's transl)].

Science.gov (United States)

Pollak, S; Reiter, C

1981-01-01

Some common types of "humane killers" are supplied with rubber bushings and recoil springs holding back the bolt, which afterwards is rebound into the barrel. Removal of the rubber bush and withdrawal spring before firing can cause the bolt to break and become a free projectile. A suicide case is reported, in which a livestock stunner discharged a steel bolt penetrating the forehead and getting stuck in the skull.

Determine ISS Soyuz Orbital Module Ballistic Limits for Steel Projectiles Hypervelocity Impact Testing

Science.gov (United States)

Lyons, Frankel

2013-01-01

A new orbital debris environment model (ORDEM 3.0) defines the density distribution of the debris environment in terms of the fraction of debris that are low-density (plastic), medium-density (aluminum) or high-density (steel) particles. This hypervelocity impact (HVI) program focused on assessing ballistic limits (BLs) for steel projectiles impacting the enhanced Soyuz Orbital Module (OM) micrometeoroid and orbital debris (MMOD) shield configuration. The ballistic limit was defined as the projectile size on the threshold of failure of the OM pressure shell as a function of impact speeds and angle. The enhanced OM shield configuration was first introduced with Soyuz 30S (launched in May 2012) to improve the MMOD protection of Soyuz vehicles docked to the International Space Station (ISS). This test program provides HVI data on U.S. materials similar in composition and density to the Russian materials for the enhanced Soyuz OM shield configuration of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz OM penetration risk assessments. The objective of this hypervelocity impact test program was to determine the ballistic limit particle size for 440C stainless steel spherical projectiles on the Soyuz OM shielding at several impact conditions (velocity and angle combinations). This test report was prepared by NASA-JSC/ HVIT, upon completion of tests.

Excitation and Ionization of Ethylene by Charged Projectiles

International Nuclear Information System (INIS)

Zhi-Ping, Wang; Jing, Wang; Feng-Shou, Zhang

2010-01-01

Using the time dependent local density approximation, applied to valence electrons, coupled non-adiabatically to molecular dynamics of ions, the collision process between ethylene and fast charged projectiles is studied in the microscopic way. The impact of ionic motion on the ionization is explored to show the importance of treating electronic and ionic degrees of freedom simultaneously. The number of escaped electrons, ionization probabilities are obtained. Furthermore, it is found that the ionic extensions in different directions show the different patterns. (atomic and molecular physics)

Properties of a Bound Polaron under a Perpendicular Magnetic Field

International Nuclear Information System (INIS)

Liu Jia; Chen Ziyu; Xiao Jinglin; Huo Shufen

2007-01-01

We investigate the influence of a perpendicular magnetic field on a bound polaron near the interface of a polar-polar semiconductor with Rashba effect. The external magnetic field strongly changes the ground state binding energy of the polaron and the Rashba spin-orbit (SO) interaction originating from the inversion asymmetry in the heterostructure splits the ground state binding energy of the bound polaron. In this paper, we have shown how the ground state binding energy will be with the change of the external magnetic field, the location of a single impurity, the wave vector of the electron and the electron areal density, taking into account the SO coupling. Due to the presence of the phonons, whose energy gives negative contribution to the polaron's, the spin-splitting states of the bound polaron are more stable, and we find that in the condition of week magnetic field, the Zeeaman effect can be neglected.

The WRAIR projectile concussive impact model of mild traumatic brain injury: re-design, testing and preclinical validation.

Science.gov (United States)

Leung, Lai Yee; Larimore, Zachary; Holmes, Larry; Cartagena, Casandra; Mountney, Andrea; Deng-Bryant, Ying; Schmid, Kara; Shear, Deborah; Tortella, Frank

2014-08-01

The WRAIR projectile concussive impact (PCI) model was developed for preclinical study of concussion. It represents a truly non-invasive closed-head injury caused by a blunt impact. The original design, however, has several drawbacks that limit the manipulation of injury parameters. The present study describes engineering advancements made to the PCI injury model including helmet material testing, projectile impact energy/head kinematics and impact location. Material testing indicated that among the tested materials, 'fiber-glass/carbon' had the lowest elastic modulus and yield stress for providing an relative high percentage of load transfer from the projectile impact, resulting in significant hippocampal astrocyte activation. Impact energy testing of small projectiles, ranging in shape and size, showed the steel sphere produced the highest impact energy and the most consistent impact characteristics. Additional tests confirmed the steel sphere produced linear and rotational motions on the rat's head while remaining within a range that meets the criteria for mTBI. Finally, impact location testing results showed that PCI targeted at the temporoparietal surface of the rat head produced the most prominent gait abnormalities. Using the parameters defined above, pilot studies were conducted to provide initial validation of the PCI model demonstrating quantifiable and significant increases in righting reflex recovery time, axonal damage and astrocyte activation following single and multiple concussions.

Study of the multi-fragment production in asymmetric heavy ion reactions at E/A = 600 MeV

International Nuclear Information System (INIS)

Hubele, J.C.

1992-03-01

In this thesis the fragmentation of Au projectiles in collisions with light target nuclei ( 12 C, 27 Al, 64 Cu) is studied at a projectile energy of 600 MeV per nucleon. For the description of an event three observables are used: the multiplicity M lp of the light particles, the largest observed charge Z max of the projectile fragments, as well as a newly introduced obsevable Z bound , which is defined as the sum of all charge contained in complex projectile fragments (Z ≥ 2). By means of this observable different exit channels can be identified: the formation of a heavy residual nucleus by evaporation of light particles, the binary fission, the decay into IMF's (3 ≤ Z ≤ 30) and the complete decay into light particles. At the applied incident energy in the case of Au+Cu reactions each of these decay channels can be realized. The observables Z bound and M lpp are proved as suited quantities for the reconstruction of the impact parameter. Furthermore independently on the target a universal relation between Z bound and the multiplicity distribution of medium-heavy fragments is found. By simple model assumptions it is made plausible that Z bound is correlated both with the size of the projectile residue and in the mean with its excitation energy. For the characterization of the decay into IMF's the multiplicity M imf of these fragments is applied. For all three targets with increasing centrality first an increasing of the mean fragment multiplicities to maximal values of 3-4 is observed. In the case of the Cu target and suggestively also at the Al target in the most central collisions again a decreasing of the multiplicity is found. The universal Z bound behaviour is a hint to a - at least partial - equilibration of the primary projectile residue before the decay. (HSI) [de

Threshold anomaly in the elastic scattering of 6He on 209Bi

International Nuclear Information System (INIS)

Garcia, A. R.; Padron, I.; Lubian, J.; Gomes, P. R. S.; Lacerda, T.; Garcia, V. N.; Gomez-Camacho, A.; Aguilera, E. F.

2009-01-01

The energy dependence of the optical potential for the elastic scattering of 6 He on 209 Bi at near and subbarrier energies is studied. Elastic angular distributions and the reaction cross section were simultaneously fitted by performing some modifications in the ECIS code. A phenomenological optical model potential with the Woods-Saxon form was used. There are signatures that the so called breakup threshold anomaly (BTA) is present in this system having a halo projectile 6 He, as it had been found earlier for systems involving stable weakly bound nuclei. (Author)

Numerical simulation of projectile impact on mild steel armour plates using LS-DYNA, Part II: Parametric studies

OpenAIRE

Raguraman, M; Deb, A; Gupta, NK; Kharat, DK

2008-01-01

In Part I of the current two-part series, a comprehensive simulation-based study of impact of Jacketed projectiles on mild steel armour plates has been presented. Using the modelling procedures developed in Part I, a number of parametric studies have been carried out for the same mild steel plates considered in Part I and reported here in Part II. The current investigation includes determination of ballistic limits of a given target plate for different projectile diameters and impact velociti...

Considerations about projectile and target X-rays induced during heavy ion bombardment

Science.gov (United States)

Fernandes, F.; Bauer, D. V.; Duarte, A.; Ferrari, T. M.; Niekraszewicz, L. A. B.; Amaral, L.; Dias, J. F.

2018-02-01

In this work we present some results concerning the X-rays emitted by heavy ions during target bombardment. In this case, Cl4+ and Cl5+ ions with energies from 4 MeV to 10 MeV were employed to irradiate vitreous carbon planchets. Moreover, total X-ray production cross sections of titanium X-rays induced by chlorine ions were obtained as well for the same energy range. Only inner shell transitions were considered in the present work. The titanium target consisted of a thin film deposited over vitreous carbon planchets. The results indicate that the projectile X-ray yields increase as a function of the bombarding energy for the present energy range. Effects due to projectile charge state appears to be of minor importance at these low ion velocities. It is shown that a simple exponential function can represent the continuum background of such complex spectra. The chlorine transition rates Kβ/Kα obtained from chlorine acting as a projectile interacting with a carbon target are about half the value when compared to the chlorine Kβ/Kα ratios obtained when a LiCl target is bombarded with C+ and C3+ ions with energies from 2 MeV to 6 MeV. As far as the total X-ray production cross sections of Ti induced by chlorine ions are concerned, the ECPSSR theory underestimates the Ti total X-rays production cross sections by several orders of magnitude. The role of electron capture and possible mechanisms responsible for these effects are discussed.

The Response of Clamped Shallow Sandwich Arches with Metallic Foam Cores to Projectile Impact Loading

Directory of Open Access Journals (Sweden)

Yanping Fan

Full Text Available Abstract The dynamic response and energy absorption capabilities of clamped shallow sandwich arches with aluminum foam core were numerically investigated by impacting the arches at mid-span with metallic foam projectiles. The typical deformation modes, deflection response, and core compression of sandwich arches obtained from the tests were used to validate the computation model. The resistance to impact loading was quantified by the permanent transverse deflection at mid-span of the arches as a function of projectile momentum. The sandwich arches have a higher shock resistance than the monolithic arches of equal mass, and shock resistance could be significantly enhanced by optimizing geometrical configurations. Meanwhile, decreasing the face-sheet thickness and curvature radius could enhance the energy absorption capability of the sandwich arches. Finite element calculations indicated that the ratio of loading time to structural response time ranged from 0.1 to 0.4. The projectile momentum, which was solely used to quantify the structural response of sandwich arches, was insufficient. These findings could provide guidance in conducting further theoretical studies and producing the optimal design of metallic sandwich structures subjected to impact loading.

The Experimental Projectile Impact Chamber (EPIC) at Centro de Astrobiología, Spain: Reproducibility and verification of scaling relations.

Science.gov (United States)

Ormö, J.; Wünnemann, K.; Collins, G.; Melero Asensio, I.

2012-09-01

The Experimental Projectile Impact Chamber (EPIC) consists of a 20.5mm caliber, compressed gas gun and a 7m wide test bed. It is possible to vary the projectile size and density, the velocity up to about 5001n/"s, the impact angle. and the target composition. The EPIC is especially designed for the analysis of impacts into unconsolidated and liquid targets. i.e. allowing the use of gravity scaling. The general objective with the EPIC is to analyze the cratering and modification processes at wet-target (e.g. marinle) impacts. We have carried out 14 shots into dry sand targets with two projectile compositions (light and weak; heavy and strong), at two impact angles. at three impact velocities, and in both quarter-space and half- space geometries. We recorded the impacts with a high-speed camera and compared the results with numerical simulations using iSALE. The evaluation demonstrated that there are noticeable differences between the results from the two projectile types, but that the crater dimensions are consistent with scaling laws based on other impact experiments [1]. This proves the usefulness of the EPIC in the analysis of natural impacts.

Fragmentation of the projectile near the Fermi energy

International Nuclear Information System (INIS)

Dayras, R.

1986-05-01

The experimental data about projectile fragmentation around the Fermi energy are reviewed. Comparisons with low and high energy data suggest that this energy domain is indeed a transition region. Reaction mechanisms dominated by the mean field at low energy progressively give way to individual n-n collisions. In the present case, this transition manifests itself by a rapid decrease of transfer reactions for the benefit of fragmentation processes. A coherent description of the observed results requires to take into account mean field effects as well as individual n-n collisions

Effects of Re-heating Tissue Samples to Core Body Temperature on High-Velocity Ballistic Projectile-tissue Interactions.

Science.gov (United States)

Humphrey, Caitlin; Henneberg, Maciej; Wachsberger, Christian; Maiden, Nicholas; Kumaratilake, Jaliya

2017-11-01

Damage produced by high-speed projectiles on organic tissue will depend on the physical properties of the tissues. Conditioning organic tissue samples to human core body temperature (37°C) prior to conducting ballistic experiments enables their behavior to closely mimic that of living tissues. To minimize autolytic changes after death, the tissues are refrigerated soon after their removal from the body and re-heated to 37°C prior to testing. This research investigates whether heating 50-mm-cube samples of porcine liver, kidney, and heart to 37°C for varying durations (maximum 7 h) can affect the penetration response of a high-speed, steel sphere projectile. Longer conditioning times for heart and liver resulted in a slight loss of velocity/energy of the projectile, but the reverse effect occurred for the kidney. Possible reasons for these trends include autolytic changes causing softening (heart and liver) and dehydration causing an increase in density (kidney). © 2017 American Academy of Forensic Sciences.

Peripheral collisions of 2 GeV/nucleon Fe nuclei in nuclear emulsion. I. Light projectile fragments

International Nuclear Information System (INIS)

Friedlander, E.M.; Crawford, H.J.; Gimpel, R.W.; Greiner, D.E.; Heckman, H.H.; Lindstrom, P.J.

1978-01-01

Observations on 374 collisions of 1.88-GeV/nucleon Fe nuclei in Ilford G-5 nuclear track emulsion, in which at least one projectle fragment of Z > = 3 was emitted within a 6 0 cone, revealed several features of projectile breakup. The onset of copious multiple fragmentation was observed. The relatively high α-particle multiplicities allowed for the first time a study of the α multiplicity distribution; a Poisson distribution gave an excellent fit. The data showed a significant enhancement of α-particle pairs with very small relative momenta. The transverse momentum distributions, which should reflect best the thermal motion in the projectile system, are in flagrant discrepancy with theoretical predictions; the distributions show a marked target dependence. The charges of all projectile fragments up to B were determined by measurement of gap-length distributions. Events with N/sub h/ = 0 are a class apart from the rest of the events; between N/sub h/ = 1 and N/sub h/ = 9 there is surprisingly little change in most parameters. 4 figures

Nuclear reactions with radioactive and stable beams (Part I)

International Nuclear Information System (INIS)

Aguilera R, E.F.; Martinez Q, E.; Gomez C, A.

2004-12-01

At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: 6 He + 209 Bi, 8 Li + 208 Pb, 10 Be + 208 Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system 12 C + 4 He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like 18 O + 4 He, 12 C + 12 C, 12 C + 16 O, 16 O + 16 O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during 2004 are described.(Author)

Production of pions and anomalous projectile fragments in heavy ion collisions

International Nuclear Information System (INIS)

Noren, B.

1988-05-01

Results are presented from investigations of the mean free path (mfp) of multiply charged fragments, produced by 1.8 A GeV argon nuclei. The mfp's have been studied experimentally, and no dependence of the mfp on the distance from the preceeding collision is observed. In a Monte Carlo simulation, the mfp estimators are investigated for different statistics, with or without an enhanced reaction probability. Intermediate energy heavy ion collisions have been studied using the carbon beam produced at the CERN SC-accelerator. Cross-sections for pion + and pion - have been measured over a wide range of angles and targets. Also, coincidence measurements with projectile-like fragments have been performed. The pion - /pion + ratio has been studied for C+Li, C+C, C+Pb, C+ 116 Sn and C+ 124 Sn. Inconsistencies in the target mass dependence of the pion yield disappear if a correction for reabsorption in the target nucleus is included. The projectile breakup is significantly stronger for pion producing collisions than for the average collision, thus indicating a much stronger abundance of central collisions. (With 32 refs.) (author)

Function behavior of a gas-operated accelerator for kinetic energy projectiles

International Nuclear Information System (INIS)

Heine, H.

1979-01-01

The test facility - presented here - was designed and constructed in order to make investigations on the load case 'airplane crash'. The facility consists mainly of the accelerator on a rail track, an abutment, a control centre, and a measuring-bunker.To perform a test the two parts of the accelerator - a compression chamber and an expansion tube (diameter 613 mm) - are strongly connected after the projectile has been inserted into the tube. The chamber - closed by a steel membrane - is filled with a mixture of methane and compressed air. The mixture is ignited and expands. The membrane opens and the projectile is accelerated. The velocity range can be varied between 80 and 300 m/s.The reinforced concrete slabs that are impacted during the main test series have the dimensions of 6.00 m by 6.50 m and a maximum thickness of 90 cm. During the test the slab hangs at a cross beam so that there is no friction between the specimen and the abutment. (orig.)

The influence of projectile ion induced chemistry on surface pattern formation

Energy Technology Data Exchange (ETDEWEB)

Karmakar, Prasanta, E-mail: prasantak@vecc.gov.in [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Satpati, Biswarup [Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

2016-07-14

We report the critical role of projectile induced chemical inhomogeneity on surface nanostructure formation. Experimental inconsistency is common for low energy ion beam induced nanostructure formation in the presence of uncontrolled and complex contamination. To explore the precise role of contamination on such structure formation during low energy ion bombardment, a simple and clean experimental study is performed by selecting mono-element semiconductors as the target and chemically inert or reactive ion beams as the projectile as well as the source of controlled contamination. It is shown by Atomic Force Microscopy, Cross-sectional Transmission Electron Microscopy, and Electron Energy Loss Spectroscopy measurements that bombardment of nitrogen-like reactive ions on Silicon and Germanium surfaces forms a chemical compound at impact zones. Continuous bombardment of the same ions generates surface instability due to unequal sputtering and non-uniform re-arrangement of the elemental atom and compound. This instability leads to ripple formation during ion bombardment. For Argon-like chemically inert ion bombardment, the chemical inhomogeneity induced boost is absent; as a result, no ripples are observed in the same ion energy and fluence.

Decay patterns of target-like and projectile-like nuclei in 84Kr+197Au, natU reactions at E/A=150 MeV

International Nuclear Information System (INIS)

Quednau, B.M.; Galin, J.; Ledoux, X.; Crema, E.; Gebauer, B.; Hilscher, D.; Jahnke, U.; Jacquet, D.; Leray, S.; and others.

1996-01-01

The reactions 84 Kr+ 197 Au and 84 Kr+ nat U were studied at E/A=150 MeV employing the large-volume neutron multiplicity filter ORION at SATURNE. The observed correlations between the atomic number of projectile-like nuclei and neutron multiplicity indicate large excitation energies in the primary projectile- and target-like fragments. Angular correlations between the fission fragments of the U-like nucleus and the projectile-like fragments show a memory of the reaction plane, however no indications of spin effects are found. (author)

Equilibrium mercury isotope fractionation between dissolved Hg(II) species and thiol-bound Hg

NARCIS (Netherlands)

Wiederhold, Jan G.; Cramer, Christopher J.; Daniel, Kelly; Infante, Ivan; Bourdon, Bernard; Kretzschmar, Ruben

2010-01-01

Stable Hg isotope ratios provide a new tool to trace environmental Hg cycling. Thiols (-SH) are the dominant Hg-binding groups in natural organic matter. Here, we report experimental and computational results on equilibrium Hg isotope fractionation between dissolved Hg(II) species and thiol-bound

On the upper bound in the Bohm sheath criterion

Energy Technology Data Exchange (ETDEWEB)

Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.su; Skovorodin, D. I., E-mail: D.I.Skovorodin@inp.nsk.su [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2016-02-15

The question is discussed about the existence of an upper bound in the Bohm sheath criterion, according to which the Debye sheath at the interface between plasma and a negatively charged electrode is stable only if the ion flow velocity in plasma exceeds the ion sound velocity. It is stated that, with an exception of some artificial ionization models, the Bohm sheath criterion is satisfied as an equality at the lower bound and the ion flow velocity is equal to the speed of sound. In the one-dimensional theory, a supersonic flow appears in an unrealistic model of a localized ion source the size of which is less than the Debye length; however, supersonic flows seem to be possible in the two- and three-dimensional cases. In the available numerical codes used to simulate charged particle sources with a plasma emitter, the presence of the upper bound in the Bohm sheath criterion is not supposed; however, the correspondence with experimental data is usually achieved if the ion flow velocity in plasma is close to the ion sound velocity.

EFFECT OF BODY SHAPE ON THE AERODYNAMICS OF PROJECTILES AT SUPERSONIC SPEEDS

Directory of Open Access Journals (Sweden)

ABDULKAREEM SH. MAHDI

2008-12-01

Full Text Available An investigation has been made to predict the effects of forebody and afterbody shapes on the aerodynamic characteristics of several projectile bodies at supersonic speeds using analytical methods combined with semi-empirical design curves. The considered projectile bodies had a length-to-diameter ratio of 6.67 and included three variations of forebody shape and three variations of afterbody shape. The results, which are verified by comparison with available experimental data, indicated that the lowest drag was achieved with a cone-cylinder at the considered Mach number range. It is also shown that the drag can be reduced by boattailing the afterbody. The centre-of-pressure assumed a slightly rearward location for the ogive-cylinder configuration when compared to the configuration with boattailed afterbody where it was the most forward. With the exception of the boattailed afterbody, all the bodies indicated inherent static stability above Mach number 2 for a centre-of-gravity location at about 40% from the body nose.

Effect of projectile structure on evaporation residue yields in incomplete fusion reactions

CERN Document Server

Babu, K S; Sudarshan, K; Shrivastava, B D; Goswami, A; Tomar, B S

2003-01-01

The excitation functions of heavy residues, representing complete and incomplete fusion products, produced in the reaction of sup 1 sup 2 C and sup 1 sup 3 C on sup 1 sup 8 sup 1 Ta have been measured over the projectile energy range of 5 to 6.5 MeV/nucleon by the recoil catcher method and off-line gamma-ray spectrometry. Comparison of the measured excitation functions with those calculated using the PACE2 code based on the statistical model revealed the occurrence of incomplete fusion reactions in the formation of alpha emission products. The fraction of incomplete fusion cross sections in the sup 1 sup 2 C + sup 1 sup 8 sup 1 Ta reaction was found to be higher, by a factor of approx 2, than that in the sup 1 sup 3 C + sup 1 sup 8 sup 1 Ta reaction. The results have been discussed in terms of the effect of alpha cluster structure of the projectile on incomplete fusion reactions.

Penetrating chest trauma caused by a blank cartridge actuated rubber ball projectile: case presentation and ballistic investigation of an uncommon weapon type.

Science.gov (United States)

Frank, Matthias; Peters, Dieter; Klemm, Wolfram; Grossjohann, Rico; Ekkernkamp, Axel; Bockholdt, Britta; Seifert, Julia

2017-09-01

Recently, an increasing number of an uncommon weapon type based on a caliber 6-mm Flobert blank cartridge actuated revolver which discharges 10-mm-diameter rubber ball projectiles has been confiscated by police authorities following criminal offenses. A recent trauma case presenting with a penetrating chest injury occasioned an investigation into the basic ballistic parameters of this type of weapon. Kinetic energy E of the test projectiles was calculated between 5.8 and 12.5 J. Energy density ED of the test projectiles was close to or higher than the threshold energy density of human skin. It can be concluded that penetrating skin injuries due to free-flying rubber ball projectiles discharged at close range cannot be ruled out. However, in case of a contact shot, the main injury potential of this weapon type must be attributed to the high energy density of the muzzle gas jet which may, similar to well-known gas or alarm weapons, cause life-threatening or even lethal injuries.

Dependence of ion-electron emission from clean metals on the incidence angle of the projectile

International Nuclear Information System (INIS)

Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

1981-01-01

We have studied the dependence of electron yields γ from clean Cu and Au surfaces on the incidence angle theta of 5--50-keV He + , Ar + , and Xe + projectiles, in the angular range 0--80 0 , and under ultrahigh-vacuum conditions. We have found that, at small angles, γproportionalsec/sup f/theta, with f generally different from unity. For Xe + on Cu, γ(theta) presents an energy-dependence maximum, similar to that obtained for sputtering. The results are explained in terms of the anisotropy of the electron cascade in the solid, the depth distribution of the inelastic energy deposited by the projectile and by rapidly recoiling target atoms in the near-surface region of the solid

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.)

Breakup conditions of projectile spectators from dynamical observables

International Nuclear Information System (INIS)

Begemann-Blaich, M.; Lindenstruth, V.; Pochodzalla, J.

1998-03-01

Momenta and masses of heavy projectile fragments (Z ≥ 8), produced in collisions of 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 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.)

On the problem of bound states of pions and neutrons

International Nuclear Information System (INIS)

Gudima, K.K.; Karnaukhov, V.A.

1992-01-01

The problem of existence of the bound states of negative pions and neutrons has been widely discussed for the last years. It is considered possibilities of the experimental observation of pion-neutron clusters, if they do exist, in nucleus-nucleus collisions. The yields of exotic fragments π -Z n A in the interactions of 12 C and 56 Fe with 208 Pb at the energies from 0.3 to 3.7 GeV per nucleon are calculated. For 40 Ar+ 238 U and 139 La+ 238 U collisions the calculations were performed at the energied of 1.8 GeV and 1.3 GeV per nucleon, respectively. These calculations were performed in the framework of the coalescence mechanism with the differential cross sections for pion and neutron production generated by firestreak model. The differential cross sections for production of π -1 n -2 , π -2 N 2 , π - n 4 , π -4 n 6 , and π -12 n 6 were calculated. It is shown that the use of very heavy projectiles like 56 Fe and 139 La has a great advantage in the experimental search for the exotic clusters. 20 refs.; 8 figs

Circuit lower bounds in bounded arithmetics

Czech Academy of Sciences Publication Activity Database

Pich, Ján

2015-01-01

Roč. 166, č. 1 (2015), s. 29-45 ISSN 0168-0072 R&D Projects: GA AV ČR IAA100190902 Keywords : bounded arithmetic * circuit lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.582, year: 2015 http://www.sciencedirect.com/science/article/pii/S0168007214000888

Energy distributions of H+ fragments ejected by fast proton and electron projectiles in collision with H2O molecules

International Nuclear Information System (INIS)

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

2009-01-01

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

Impact basins on Ganymede and Callisto and implications for the large-projectile size distribution

Science.gov (United States)

Wagner, R.; Neukum, G.; Wolf, U.; Greeley, R.; Klemaszewski, J. E.

2003-04-01

It has been conjectured that the projectile family which impacted the Galilean Satellites of Jupiter was depleted in large projectiles, concluded from a ''dearth'' in large craters (> 60 km) (e.g. [1]). Geologic mapping, aided by spatial filtering of new Galileo as well as older Voyager data shows, however, that large projectiles have left an imprint of palimpsests and multi-ring structures on both Ganymede and Callisto (e. g. [2]). Most of these impact structures are heavily degraded and hence difficult to recognize. In this paper, we present (1) maps showing the outlines of these basins, and (2) derive updated crater size-frequency diagrams of the two satellites. The crater diameter from a palimpsest diameter was reconstructed using a formula derived by [3]. The calculation of the crater diameter Dc from the outer boundary Do of a multi-ring structure is much less constrained and on the order of Dc = k \\cdot Do , with k ≈ 0.25-0.3 [4]. Despite the uncertainties in locating the ''true'' crater rims, the resulting shape of the distribution in the range from kilometer-sized craters to sizes of ≈ 500 km is lunar-like and strongly suggests a collisionally evolved projectile family, very likely of asteroidal origin. An alternative explanation for this shape could be that comets are collisionally evolved bodies in a similar way as are asteroids, which as of yet is still uncertain and in discussion. Also, the crater size distributions on Ganymede and Callisto are shifted towards smaller crater sizes compared to the Moon, caused by a much lower impact velocity of impactors which preferentially were in planetocentric orbits [5]. References: [1] Strom et al., JGR 86, 8659-8674, 1981. [2] J. E. Klemaszewski et al., Ann. Geophys. 16, suppl. III, 1998. [3] Iaquinta-Ridolfi &Schenk, LPSC XXVI (abstr.), 651-652, 1995. [4] Schenk &Moore, LPSC XXX, abstr. No. 1786 [CD-Rom], 1999. [5] Horedt & Neukum, JGR 89, 10,405-10,410, 1984.

Projectile X-ray emission in relativistic ion-atom collisions

Energy Technology Data Exchange (ETDEWEB)

Salem, Shadi Mohammad Ibrahim

2010-03-16

This work reports on the study of the projectile X-ray emission in relativistic ion-atom collisions. Excitation of K-shell in He-like uranium ions, electron capture into H-like uranium ions and Simultaneous ionization and excitation of initially He-like uranium ions have been studied using the experimental storage ring at GSI. For the K{sub {alpha}}{sub 1} and K{sub {alpha}}{sub 2} transitions originating from the excitation of the He-like uranium ions, no alignment was observed. In contrast, the Ly{sub {alpha}}{sub 1} radiation from the simultaneous ionization-excitation process of the He-like uranium ions shows a clear alignment. The experimental value leads to the inclusion of a magnetic term in the interaction potential. The capture process of target electrons into the highly-charged heavy ions was studied using H-like uranium ions at an incident energy of 220 MeV/u, impinging on N{sub 2} gas-target. It was shown that, the strongly aligned electrons captured in 2p{sub 3/2} level couple with the available 1s{sub 1/2} electron which shows no initial directional preference. The magnetic sub-state population of the 2p{sub 3/2} electron is redistributed according to the coupling rules to the magnetic sub-states of the relevant two-electron states. This leads to the large anisotropy in the corresponding individual ground state transitions contributing to the K{sub {alpha}}{sub 1} emission. From the K{sub {alpha}}{sub 1}/K{sub {alpha}}{sub 2} ratio, the current results show that the incoherent addition of the E1 and M2 transition components yield to an almost isotropic emission of the total K{sub {alpha}}{sub 1}. In contrast to the radiative electron capture, the experimental results for the K-shell single excitation of He-like uranium ions indicate that only the {sup 1}P{sub 1} level contributes to the K{sub {alpha}}{sub 1} transition. For this case, the anisotropy parameter {beta}{sub 20} was found to be -0.20{+-}0.03. This work also reports on the study of a two

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}.

An analytic solution of projectile motion with the quadratic resistance law using the homotopy analysis method

International Nuclear Information System (INIS)

Yabushita, Kazuki; Yamashita, Mariko; Tsuboi, Kazuhiro

2007-01-01

We consider the problem of two-dimensional projectile motion in which the resistance acting on an object moving in air is proportional to the square of the velocity of the object (quadratic resistance law). It is well known that the quadratic resistance law is valid in the range of the Reynolds number: 1 x 10 3 ∼ 2 x 10 5 (for instance, a sphere) for practical situations, such as throwing a ball. It has been considered that the equations of motion of this case are unsolvable for a general projectile angle, although some solutions have been obtained for a small projectile angle using perturbation techniques. To obtain a general analytic solution, we apply Liao's homotopy analysis method to this problem. The homotopy analysis method, which is different from a perturbation technique, can be applied to a problem which does not include small parameters. We apply the homotopy analysis method for not only governing differential equations, but also an algebraic equation of a velocity vector to extend the radius of convergence. Ultimately, we obtain the analytic solution to this problem and investigate the validation of the solution

Acceleration of a solid-density plasma projectile to ultrahigh velocities by a short-pulse ultraviolet laser

Energy Technology Data Exchange (ETDEWEB)

Badziak, J.; Jablonski, S. [Institute of Plasma Physics and Laser Microfusion, Euratom Association, 01-497 Warsaw (Poland)

2011-08-15

It is shown by means of particle-in-cell simulations that a high-fluence ({>=}1 GJ/cm{sup 2}) solid-density plasma projectile can be accelerated up to sub-relativistic velocities by radiation pressure of an ultraviolet (UV) picosecond laser pulse of moderate values of dimensionless laser amplitude a{sub 0}{approx}10. The efficiency of acceleration by the UV laser is significantly higher than in the case of long-wavelength ({lambda} {approx} 1 {mu}m) driver of a comparable value of a{sub 0}, and the motion of the projectile is fairly well described by the ''Light Sail'' acceleration model.

The Kadanoff lower-bound variational renormalization group applied to an SU(2) lattice spin model

International Nuclear Information System (INIS)

Thorleifsson, G.; Damgaard, P.H.

1990-07-01

We apply the variational lower-bound Renormalization Group transformation of Kadanoff to an SU(2) lattice spin model in 2 and 3 dimensions. Even in the one-hypercube framework of this renormalization group transformation the present model is characterised by having an infinite basis of fundamental operators. We investigate whether the lower-bound variational renormalization group transformation yields results stable under truncations of this operator basis. Our results show that for this particular spin model this is not the case. (orig.)

Higgs boson mass bounds in the presence of a heavy fourth quark family

Energy Technology Data Exchange (ETDEWEB)

Bulava, John [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Gerhold, Philipp; Kallarackal, Jim; Nagy, Attila [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

2013-01-15

We present Higgs boson mass bounds in a lattice regularization allowing thus for non-perturbative investigations. In particular, we employ a lattice modified chiral invariant Higgs-Yukawa model using the overlap operator. We show results for the upper and lower Higgs boson mass bounds in the presence of a heavy mass-degenerate quark doublet with masses ranging up to 700 GeV. We perform infinite volume extrapolations in most cases, and examine several values of the lattice cutoff. Furthermore, we argue that the lower Higgs boson mass bound is stable with respect to the addition of higher dimensional operators to the scalar field potential. Our results have severe consequences for the phenomenology of a fourth generation of quarks if a light Higgs boson is discovered at the LHC.

Higgs boson mass bounds in the presence of a heavy fourth quark family

CERN Document Server

Bulava, John; Nagy, Attila; Kallarackal, Jim; Jansen, Karl

2012-01-01

We present Higgs boson mass bounds in a lattice regularization allowing thus for non-perturbative investigations. In particular, we employ a lattice modified chiral invariant Higgs-Yukawa model using the overlap operator. We show results for the upper and lower Higgs boson mass bounds in the presence of a heavy mass-degenerate quark doublet with masses ranging up to 700 GeV. We perform infinite volume extrapolations in most cases, and examine several values of the lattice cutoff. Furthermore, we argue that the lower Higgs boson mass bound is stable with respect to the addition of higher dimensional operators to the scalar field potential. Our results have severe consequences for the phenomenology of a fourth generation of quarks if a light Higgs boson is discovered at the LHC.

Lysine-Derived Protein-Bound Heyns Compounds in Bakery Products.

Science.gov (United States)

Treibmann, Stephanie; Hellwig, Anne; Hellwig, Michael; Henle, Thomas

2017-12-06

Fructose and dicarbonyl compounds resulting from fructose in heated foods have been linked to pathophysiological pathways of several metabolic disorders. Up to now, very little has been known about the Maillard reaction of fructose in food. Heyns rearrangement compounds (HRCs), the first stable intermediates of the Maillard reaction between amino components and fructose, have not yet been quantitated as protein-bound products in food. Therefore, the HRCs glucosyllysine and mannosyllysine were synthesized and characterized by NMR. Protein-bound HRCs in cookies containing various sugars and in commercial bakery products were quantitated after enzymatic hydrolysis by RP-HPLC-ESI-MS/MS in the multiple reaction monitoring mode through application of the standard addition method. Protein-bound HRCs were quantitated for the first time in model cookies and in commercial bakery products containing honey, banana, and invert sugar syrup. Concentrations of HRCs from 19 to 287 mg/kg were found, which were similar to or exceeded the content of other frequently analyzed Maillard reaction products, such as N-ε-carboxymethyllysine (10-76 mg/kg), N-ε-carboxyethyllysine (2.5-53 mg/kg), and methylglyoxal-derived hydroimidazolone 1 (10-218 mg/kg) in the analyzed cookies. These results show that substantial amounts of HRCs form during food processing. Analysis of protein-bound HRCs in cookies is therefore useful to evaluate the Maillard reaction of fructose.

Instability of hot electroweak theory: Bounds on mH and mt

International Nuclear Information System (INIS)

Arnold, P.; Vokos, S.

1991-01-01

The electroweak vacuum need not be absolutely stable. For certain top-quark and Higgs-boson masses in the minimal standard model, it is instead metastable with a lifetime exceeding the present age of the Universe. The decay of our vacuum may be nucleated at low temperature by quantum tunneling or at high temperature by thermal excitation. We show that the requirement that the vacuum survive the high temperatures of the early Universe places the strongest constraints from vacuum stability on the top-quark and Higgs-boson masses in the minimal standard model. If a single Higgs boson is found experimentally, these constraints may place an upper bound on the scale of new physics beyond the minimal standard model. In contrast with other work, we examine temperatures very large compared to the scale of weak symmetry restoration and find much stronger bounds. We also present a simple analytic approximation that directly relates the bounds to the running coupling constants of the minimal standard model

Dependence of ion-electron emission from clean metals on the incidence angle of the projectile

Energy Technology Data Exchange (ETDEWEB)

Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

1981-10-15

We have studied the dependence of electron yields ..gamma.. from clean Cu and Au surfaces on the incidence angle theta of 5--50-keV He/sup +/, Ar/sup +/, and Xe/sup +/ projectiles, in the angular range 0--80 /sup 0/, and under ultrahigh-vacuum conditions. We have found that, at small angles, ..gamma..proportionalsec/sup f/theta, with f generally different from unity. For Xe/sup +/ on Cu, ..gamma..(theta) presents an energy-dependence maximum, similar to that obtained for sputtering. The results are explained in terms of the anisotropy of the electron cascade in the solid, the depth distribution of the inelastic energy deposited by the projectile and by rapidly recoiling target atoms in the near-surface region of the solid.

Rubber mixing process and its relationship with bound rubber and crosslink density

Science.gov (United States)

Hasan, A.; Rochmadi; Sulistyo, H.; Honggokusumo, S.

2017-06-01

This research studied the relationship between bound rubber and crosslink density based on rubber mixing process. Bound rubber was obtained after natural rubber was masticated and mixed with rubber chemicals and filler while crosslink density was collected after rubber compound was vulcanized. Four methods are used and each method refers to four ways of incorporating carbon black during mixing. The first method, after rubber was masticated for 5 minutes, the addition of rubber chemicals and filler was done simultaneously. Rubber was masticated for 1 minute and continued mixing of rubber chemicals and filler where mixing was different from first method. This was the second method. The third method was the same as the second method but the filler used N 660 while in the second method N 330. The last method is not the same as the first and second, the rubber is only masticated for 3 minutes and then mixed with filler and followed by rubber chemicals sequentially. The results showed that bound rubber and crosslink density were influenced by mixing and mastication process. Bound rubber dropped and crosslink density was relatively stable in the first three mixing methods for increasing carbon black at the beginning of the mixing process. Bound rubber and crosslink density stated opposite results in the fourth mixing method. The higher the bound rubber the lower the crosslink density. Without regard to mixing methods, there is a non-linear relationship between bound rubber formation and crosslink density determination

In situ flash X-ray observation of projectile penetration processes and crater cavity growth in porous gypsum target analogous to low-density asteroids

Science.gov (United States)

Yasui, Minami; Arakawa, Masahiko; Hasegawa, Sunao; Fujita, Yukihiro; Kadono, Toshihiko

2012-11-01

Recent studies of impact craters formed on low-density asteroids led to the proposal of a new crater formation mechanism dominated by pore collapse and compaction. Thus, it is important to study the crater formation process associated with the projectile penetration on porous cohesive targets. Laboratory impact experiments were conducted for a porous gypsum target with porosity of 50%, and flash X-rays were used to visualize the interior of the target for in situ observation of crater formation and projectile penetration. Spherical projectiles made of three different materials, stainless steel, aluminum, and nylon were impacted at 1.9-2.4 km/s (low-velocity impact) and 5.6-6.4 km/s (high-velocity impact) by using a two-stage light-gas gun. Two imaging plates were used to take two X-ray images at a different delay time from the impact moment for one shot. Two types of crater cavity shape were found on the porous gypsum target, that is, penetration holes or hemispherical cavities, depending on the projectile size and density, and the impact velocity. The drag coefficient of a projectile was determined by measuring the penetration depth changing with time, and we found that it was closely related to the crater cavity shape: it was about 0.9 for a penetration hole, while it was 2.3-3.9 for a hemispherical cavity. This large value for a hemispherical cavity could have been caused by the deformation or the disruption of the projectile. The cratering efficiency, ρtVcr(t)/mp, was found to have a power law relationship to the scaling time for crater growth, πt = vit/rp, where vi is the impact velocity, rp is the projectile radius, and t is the time after the impact, and all data for stainless steel and aluminum projectiles merged completely and could be fitted by a power-law equation of ρtVcr(t)/mp=2.69×10-1πt1.10. Furthermore, the scaled crater volume, πV = Vcr_finalρt/mp, where Vcr_final is the final crater cavity volume, ρt is the target density, and mp is the

Atomic Nuclei Utter Disintegration into Nucleons by High Energy Nuclear Projectiles

International Nuclear Information System (INIS)

Strugalski, Z.

1994-01-01

The disintegration process of atomic nuclei by high energy nuclear projectiles is described. The physical basis for this process is the passage of hadrons through layers of intranuclear matter accompanied by the nucleon emission from the target nuclei observed in experiments; kinetic energies of the nucleons are from about 20 up to about 400 MeV - in the target nucleus reference system. 22 refs., 3 tabs

Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration

Energy Technology Data Exchange (ETDEWEB)

Taylor, Paul A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cooper, Candice Frances [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-09-01

Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is virtually nonexistent but necessary to ensure adequate protection against injury to the heart and lungs. In this report, we discuss the development of a high-fidelity human torso model, it's merging with the existing Sandia Human Head-Neck Model, and development of the modeling & simulation (M&S) capabilities necessary to simulate wound injury scenarios. Using the new Sandia Human Torso Model, we demonstrate the advantage of virtual simulation in the investigation of wound injury as it relates to the warfighter experience. We present the results of virtual simulations of blast loading and ballistic projectile impact to the tors o with and without notional protective armor. In this manner, we demonstrate the ad vantages of applying a modeling and simulation approach to the investigation of wound injury and relative merit assessments of protective body armor without the need for trial-and-error testing.

Lithic raw material procurement for projectiles points in the prehistory of Uruguay

Directory of Open Access Journals (Sweden)

José María López Mazz

2015-03-01

Full Text Available This paper focuses on current research on early colonisation of the Atlantic coast of South America during the early Holocene. We present advances in the investigation of raw material procurement at the Rincón de los Indios site, located in the eastern part of Uruguay. The technological studies suggest that some aspects of different styles of projectile points are related with environmental adaptation processes, experienced by the first American people in the New World. The occupation of new spaces and new forms of exploitation of resources changes the organisation of lithic technology. The distance to good quality rocks were critical for the opportunities and economic organisation of hunting groups. The study of changes in lithic procurement strategies for projectile points helps us develop a more comprehensive knowledge of this important social adaptation process which occurred during this period. These patterns started to become stabilised in the latter part of the early Holocene across the extended territory and confirm the efficient land occupation associated an intensive hunter-gatherer economies.

Resonance effects in projectile-electron loss in relativistic collisions with excited atoms

International Nuclear Information System (INIS)

Voitkiv, A B

2005-01-01

The theory of electron loss from projectile-ions in relativistic ion-atom collisions is extended to the case of collisions with excited atoms. The main feature of such collisions is a resonance which can emerge between electron transitions in the ion and atom. The resonance becomes possible due to the Doppler effect and has a well-defined impact energy threshold. In the resonance case, the ion-atom interaction is transmitted by the radiation field and the range of this interaction becomes extremely long. Because of this the presence of other atoms in the target medium and the size of the space occupied by the medium have to be taken into account and it turns out that microscopic loss cross sections may be strongly dependent on such macroscopic parameters as the target density, temperature and size. We consider both the total and differential loss cross sections and show that the resonance can have a strong impact on the angular and energy distributions of electrons emitted from the projectiles and the total number of electron loss events

Experimental and numerical study of water-filled vessel impacted by flat projectiles

Science.gov (United States)

Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yu Bo

2014-05-01

To understand the failure modes and impact resistance of double-layer plates separated by water, a flat-nosed projectile was accelerated by a two-stage light gas gun against a water-filled vessel which was placed in an air-filled tank. Targets consisted of a tank made of two flat 5A06 aluminum alloy plates held by a high strength steel frame. The penetration process was recorded by a digital high-speed camera. The same projectile-target system was also used to fire the targets placed directly in air for comparison. Parallel numerical tests were also carried out. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were able to capture the main physical behavior. It was also found that the impact resistance of double layer plates separated by water was lager than that of the target plates in air. Tearing was the main failure models of the water-filled vessel targets which was different from that of the target plates in air where the shear plugging was in dominate.

Study of uranium dioxyde sputtering induced by multicharged heavy ions at low and very low kinetic energy: projectile charge effect

International Nuclear Information System (INIS)

Haranger, F.

2003-12-01

Ion beam irradiation of a solid can lead to the emission of neutral or ionized atoms, molecules or clusters from the surface. This comes as a result of the atomic motion in the vicinity of the surface, induced by the transfer of the projectile energy. Then, the study of the sputtering process appears as a means to get a better understanding of the excited matter state around the projectile trajectory. In the case of slow multicharged ions, a strong electronic excitation can be achieved by the projectile neutralization above the solid surface and / or its deexcitation below the surface. Parallel to this, the slowing down of such ions is essentially related to elastic collision with the target atoms. The study of the effect of the initial charge state of slow multicharged ions, in the sputtering process, has been carried out by measuring the absolute angular distributions of emission of uranium atoms from a uranium dioxide surface. The experiments have been performed in two steps. First, the emitted particles are collected onto a substrate during irradiation. Secondly, the surface of the collectors is analyzed by Rutherford Backscattering Spectrometry (RBS). This method allows the characterization of the emission of neutrals, which are the vast majority of the sputtered particles. The results obtained provide an access to the evolution of the sputtering process as a function of xenon projectile ions charge state. The measurements have been performed over a wide kinetic energy range, from 81 down to 1.5 keV. This allowed a clear separation of the contribution of the kinetic energy and initial projectile charge state to the sputtering phenomenon. (author)

Perceptron Mistake Bounds

OpenAIRE

Mohri, Mehryar; Rostamizadeh, Afshin

2013-01-01

We present a brief survey of existing mistake bounds and introduce novel bounds for the Perceptron or the kernel Perceptron algorithm. Our novel bounds generalize beyond standard margin-loss type bounds, allow for any convex and Lipschitz loss function, and admit a very simple proof.

Smart Projectiles: Design Guidelines and Development Process Keys to Success

Science.gov (United States)

2010-10-01

about its principal axis. Set forward is the unspringing of the projectile as it leaves the muzzle of the weapon as described in reference 1. In...material properties at even room temperature are unknown or depend upon the mixing of two or more ingredients. The only solution is to create dog ...to setback or are required to hold in tension during set- forward ( muzzle exit), cracks or voids in the explosive that may be compressed and

Destructive behavior of iron oxide in projectile impact

Science.gov (United States)

Shang, Wang; Xiaochen, Wang; Quan, Yang; Zhongde, Shan

2017-12-01

The damage strain values of Q235-A surface oxide scale were obtained by scanning electron microscopy (SEM/EDS) and universal tensile testing machine. The finite element simulation was carried out to study the destruction effects of oxidation at different impact rates. The results show that the damage value of the oxide strain is 0.08%. With the increase of the projectile velocity, the damage area of the oxide scale is increased, and the damage area is composed of the direct destruction area and the indirect failure area. The indirect damage area is caused by the stress/strain to the surrounding expansion after the impact of the steel body.

Nonlinear behaviors of a bounded electron beam-plasma system

International Nuclear Information System (INIS)

Iizuka, Satoru; Saeki, Koichi; Sato, Noriyoshi; Hatta, Yoshisuke

1985-01-01

Nonlinear developments of a bounded electron beam-plasma system including stationary electrons are investigated experimentally. A stable double layer is formed as a result of ion trapping in a growing negative potential dip induced by the Pierce instability above the current regime of the Buneman instability. In the in-between regime of the Buneman and Pierce instabilities, energetic ions are observed. This effective ion heating is caused by ion detrapping due to double-layer disruption, being consistent with computer simulation. (author)

Effects of control parameters of three-point initiation on the formation of an explosively formed projectile with fins

Science.gov (United States)

Li, R.; Li, W. B.; Wang, X. M.; Li, W. B.

2018-03-01

The effects of the initiation diameter and synchronicity error on the formation of fins and stable-flight velocity of an explosively formed projectile (EFP) with three-point initiation are investigated. The pressure and area of the Mach wave acting on the metal liner at different initiation diameters are calculated employing the Whitham method. LS-DYNA software is used to investigate the asymmetric collision of detonation waves resulting from three-point initiation synchronicity error, the distortion characteristics of the liner resulting from the composite detonation waves, and the performance parameters of the EFP with fins. Results indicate that deviations of the Y-shaped high-pressure zone and central ultrahigh-pressure zone from the liner center can be attributed to the error of three-point initiation, which leads to the irregular formation of EFP fins. It is noted that the area of the Mach wave decreases, but the pressure of the Mach wave and the final speed and length-to-diameter ( L/ D) ratio of the EFP increase, benefiting the formation of the EFP fins, as the initiation diameter increases.

High energy nuclear collisions in the few GeV/nucleon region: projectile and target fragmentation

International Nuclear Information System (INIS)

Schroeder, L.S.

1980-06-01

A general review of nucleon-nucleus and nucleus-nucleus collisions for incident energies <10 GeV/nucleon is presented. The division of these interactions into peripheral and central collisions is briefly discussed. Subjects treated include the following: target and projectile fragmentation systematics, production of exotic nuclear fragments, studies of multiparticle final states, total cross section measurements, results from an experiment that indicate the production of projectile fragments with an anomalously short reaction mean free path, high-energy particle production at backward angles beyond simple N-N kinematic limits, and recent results on backward particle emission in studies with the Berkeley streamer chamber. Both the particle and nuclear physics aspects that are present are considered. A brief discussion of future trends in this energy range ends the presentation. 65 references, 37 figures

Investigation of Inertia Welding Process for Applying Gilding Metal Rotating Bands to Projectile, 155-mm, M483A1.

Science.gov (United States)

1978-07-01

AISI 4140 steel body, but additional work remains to be done because pure copper behaves differently than gilding metal when subjected to the inertia...bands to AISI 1340 steel bodies used with the 155-mm, M483A1 Projectile. As a result of the effort it was demon- strated that the process is practical...rotating bands to AISI 1340 steel bodies used with the 155-mm, M483A1 Projectile. As a result of the effort it was demonstrated that the process is

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

OpenAIRE

Vonta, N.; Souliotis, G. A.; 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 Tr...

Fragmentation cross section measurements of iron projectiles using CR-39 plastic nuclear track detectors

CERN Document Server

Flesch, F; Huentrup, G; Roecher, H; Streibel, T; Winkel, E; Heinrich, W

1999-01-01

For long term space missions in which larger radiation doses are accumulated it is necessary to improve the precision of models predicting the space radiation environment. Different models are available to determine the flux of cosmic ray heavy ions behind shielding material. The accuracy of these predictions depends on the knowledge of the fragmentation cross sections, especially at energies of several hundred MeV/nucleon, where the particle flux is at a maximum and especially for those particles with high LET, i.e. iron nuclei. We have measured fragmentation cross sections of sup 5 sup 6 Fe projectiles at beam energies of 700 and 1700 A MeV using experimental set-ups with plastic nuclear track detectors. In this paper we describe the experimental technique to study the fragmentation reactions of sup 5 sup 6 Fe projectiles using CR-39 plastic nuclear track detectors. Results for different targets are presented.

Effect of a viscoelastic target on the impact response of a flat-nosed projectile

Science.gov (United States)

Liu, Hu; Yang, Jialing; Liu, Hua

2018-02-01

Taylor impact is a widely used strategy in which a flat-nosed projectile is fired onto a rigid anvil directly to determine the dynamic strength of rod specimens. Nowadays, the rigid anvil is often replaced by an output target bar to ensure the accuracy of measurement via recording strain signals in the output bar. For testing the dynamic strength of low-density materials, a low-impedance target bar, which exhibits viscoelastic characteristics is often employed. In this paper, an extended Taylor model is proposed to improve the idealization of treating the target bar as perfectly rigid material in the classic Taylor model, and the viscoelastic effect of the target bar is incorporated. The viscoelastic target bar is depicted by two elastic springs and one dashpot. Based on the plastic shock wave theory in the flat-nosed projectile associated with the viscoelastic wave analysis in the target bar, the viscoelastic effect of the target bar on the impact response of the flat-nosed projectile is investigated. The finite element simulation is also carried out to verify the theoretical model, and good agreement is found. The present theoretical model is also called the Taylor-cylinder Hopkinson impact, which provides a more accurate way to identify the dynamic material parameters. The dynamic responses of the present model are further compared with previous elastic and rigid target bar models. It is found that the viscoelastic effect of the target bar should be taken into consideration in the Taylor-cylinder Hopkinson impact test for low-impedance materials.

Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large-Caliber Projectiles

Science.gov (United States)

2015-05-01

process parameters used during the initial deposition of copper material, given the observation that these initial copper rotating bands tended to “ flake ...ARL-TR-7299 ● MAY 2015 US Army Research Laboratory Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large...Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large-Caliber Projectiles by Michael A Minnicino Weapons and Materials Research

Nuclear reactions with radioactive and stable beams (Part II); Reacciones nucleares con haces radiactivos y estables (Parte II)

Energy Technology Data Exchange (ETDEWEB)

Aguilera R, E.F.; Martinez Q, E.; Gomez C, A.; Lizcano, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2005-12-15

At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: {sup 6}He + {sup 209}Bi, {sup 8}Li + {sup 208}Pb, {sup 10}Be + {sup 208}Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system {sup 12}C + {sup 4}He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like {sup 18}O + {sup 4}He, {sup 12}C + {sup 12}C, {sup 12}C + {sup 16}O, {sup 16}O + {sup 16}O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during the second stage of this project, considered for 2005 are described. Also in that year, our group carries out a research stay in the University of Notre Dame, during this stay, the angular distribution of the projectiles of {sup 8}B dispersed in an enriched target of {sup 58}Ni was measured. The same as in the previous experiments, in this occasion it was also possible to measure those angular distributions of the projectiles of {sup 7}Be and {sup 6}Li dispersed in this same target. In this same one our stay group participates in other three experiments proposed by collaborators of

New approach to the nuclear in beam γ spectroscopy of neutron rich nuclei at N=20 using projectile fragmentation

International Nuclear Information System (INIS)

Lopez-Jimenez, M.J.; Saint-Laurent, M.G.; Achouri, L.; Daugas, J.M.; Belleguic, M.; Azaiez, F.; Bourgeois, C.; Angelique, J.C.

1999-01-01

The structure of nuclei far from stability around 32 Mg have been recently investigated by means of a novel method. In-beam γ-decay spectroscopy of a large number of exotic neutron-rich nuclei produced by projectile fragmentation of a 36 S projectile has been performed, using coincidences between the recoil fragments collected at the focal plane of SPEG spectrometer and γ-rays emitted at the target location. Preliminary results on both the population mechanism and the decay of excited states in nuclei around 32 Mg are presented. (author)

Role of projectile charge state in convoy electron emission by fast protons colliding with LiF(0 0 1)

Energy Technology Data Exchange (ETDEWEB)

Aldazabal, I. [Departamento de Fisica de Materiales, Facultad de Quimicas UPV/EHU, Apartado 1072, 20080 San Sebastian (Spain)]. E-mail: ialdazabal@sq.ehu.es; Gravielle, M.S. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C.C. 67, Suc. 28, 1428 Buenos Aires (Argentina); Miraglia, J.E. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C.C. 67, Suc. 28, 1428 Buenos Aires (Argentina); Arnau, A. [Centro Mixto CSIC-UPV/EHU, Apartado 1072, 20080 San Sebastian (Spain); Ponce, V.H. [Donostia International Physics Center DIPC, San Sebastian (Spain); Centro Atomico Bariloche, Bariloche (Argentina)

2005-05-01

Target ionization and projectile ionization differential cross sections are used to calculate the electron emission spectra by fast proton impact on ionic crystal surfaces under grazing incidence conditions. Both bare protons and neutral hydrogen species are considered. We use a planar potential approach to determine the projectile trajectory that later on allows us to calculate the charge state fractions. We show that, although the fraction of protons is significantly higher, the contribution from neutral hydrogen ionization has to be considered. The energy and angular dependence of the spectra is analyzed.

Role of projectile charge state in convoy electron emission by fast protons colliding with LiF(0 0 1)

International Nuclear Information System (INIS)

Aldazabal, I.; Gravielle, M.S.; Miraglia, J.E.; Arnau, A.; Ponce, V.H.

2005-01-01

Target ionization and projectile ionization differential cross sections are used to calculate the electron emission spectra by fast proton impact on ionic crystal surfaces under grazing incidence conditions. Both bare protons and neutral hydrogen species are considered. We use a planar potential approach to determine the projectile trajectory that later on allows us to calculate the charge state fractions. We show that, although the fraction of protons is significantly higher, the contribution from neutral hydrogen ionization has to be considered. The energy and angular dependence of the spectra is analyzed

Influence of the embedded structure on the efp formation of compact terminal sensitive projectile

NARCIS (Netherlands)

Boyang, Xing; Rongzhong, Liu; Rui, Guo; Liang, Chen; Hao, Zhou; Yongliang, Yang; Lei, Liu

2017-01-01

To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead, it is vital to understand how the embedded structure (ES) affects the EFP forming performance. In this paper, the corresponding numerical investigation is focused on, in which the fluid-structure interaction

Influence of the embedded structure on the EFP formation of compact terminal sensitive projectile

NARCIS (Netherlands)

Xing, Bo yang; Liu, Rong zhong; Guo, Rui; Chen, Liang; Zhou, Hao; Yang, Yong liang; Liu, Lei

2017-01-01

To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead, it is vital to understand how the embedded structure (ES) affects the EFP forming performance. In this paper, the corresponding numerical investigation is focused on, in which the fluid-structure interaction

Influences of the embedded structure on the efp formation of compact terminal sensitive projectile

NARCIS (Netherlands)

Boyang, Xing; Rongzhong, Liu; Rui, Guo; Liang, Chen; Hao, Zhou; Yongliang, Yang; Lei, Liu

2017-01-01

To improve the damage efficiency of the compact terminal sensitive projectile with EFP warhead, it is vital to understand how the embedded structure (ES) affects the EFP forming performance. In this paper, the corresponding numerical investigation is focused on, where the fluid-structure interaction

Prioritizing the effective factors on projectile performance by combination of Analytical Hierarchy Process (AHP method and design of experiment of Taguchi Case study: selected aerospace industries

Directory of Open Access Journals (Sweden)

saberreza bahrami

2016-02-01

Full Text Available The purpose of this research is to prioritize the effective factors in projectile performance. Prioritizing of these factors whit combination of Analytical Hierarchy Process (AHP method and design of experiment Of Taguchi help designers to develop the performance of projectile structure. According to this that since now, researcher tried to increase the performance of projectile whit change in every factors separately, so in this paper tried whit combination of AHP method and design of experiment of Taguchi , analyzed and prioritized all the effective factors in projectile performance simultaneously. For this purpose first by design of experiment Of Taguchi the influence of every these factors on two criteria of range and drift were calculated and then by AHP method these factors were prioritized. By considering of equal weight for both range and drift, the result shows between 11 factors, Firing Angle whit value of 0.3398, Muzzle Velocity whit value of 0.2918 and Burning Time whit value of 0.1257 were the most influenced factors in projectile performance respectively. Propellant Weight and Wind Velocity factors whit value of 0.0104 and 0.00092 were ranked in tenth and eleventh priority respectively.

Entropy stable high order discontinuous Galerkin methods for ideal compressible MHD on structured meshes

Science.gov (United States)

Liu, Yong; Shu, Chi-Wang; Zhang, Mengping

2018-02-01

We present a discontinuous Galerkin (DG) scheme with suitable quadrature rules [15] for ideal compressible magnetohydrodynamic (MHD) equations on structural meshes. The semi-discrete scheme is analyzed to be entropy stable by using the symmetrizable version of the equations as introduced by Godunov [32], the entropy stable DG framework with suitable quadrature rules [15], the entropy conservative flux in [14] inside each cell and the entropy dissipative approximate Godunov type numerical flux at cell interfaces to make the scheme entropy stable. The main difficulty in the generalization of the results in [15] is the appearance of the non-conservative "source terms" added in the modified MHD model introduced by Godunov [32], which do not exist in the general hyperbolic system studied in [15]. Special care must be taken to discretize these "source terms" adequately so that the resulting DG scheme satisfies entropy stability. Total variation diminishing / bounded (TVD/TVB) limiters and bound-preserving limiters are applied to control spurious oscillations. We demonstrate the accuracy and robustness of this new scheme on standard MHD examples.

Charged-particle spectroscopy in the microsecond range following projectile fragmentation

CERN Document Server

Pfützner, M; Grzywacz, R; Janas, Z; Momayezi, M; Bingham, C; Blank, B; Chartier, M; Geissel, H; Giovinazzo, J; Hellström, M; Kurcewicz, J; Lalleman, A S; Mazzocchi, C; Mukha, I; Plettner, C; Roeckl, E; Rykaczewski, K; Schmidt, K; Simon, R S; Stanoiu, M; Thomas, J C

2002-01-01

We present a new approach to charged-particle spectroscopy of short-lived nuclei produced by relativistic projectile fragmentation. The system based on digital DGF-4C CAMAC modules and newly developed fast-reset preamplifiers was tested at the Fragment Separator of GSI. We were able to detect low-energy (approx 1 MeV) decay signals occurring a few microseconds after a heavy-ion implantation accompanied by a release of approx 1 GeV energy. Applications for the study of one- and two-proton radioactivity are discussed.

Evaluation of the performance of three elastomers for non-lethal projectile applications

Science.gov (United States)

Thota, N.; Epaarachchi, J.; Lau, K. T.

2015-09-01

Less lethal kinetic ammunitions with soft noses such as eXact iMpact 1006, National Sports Spartan and B&T have been commonly used by military and law enforcement officers in the situations where lethal force is not warranted. In order to explore new materials to be used as nose in such ammunitions, a scholastic study using finite element simulations has been carried out to evaluate the effectiveness of two rubber like elastomers and a polyolefinic foam (low density, highly compressible, stiff and closed cell type of thermos plastic elastomer). State-of-the art thorax surrogate MTHOTA has been employed for the evaluation of blunt thoracic trauma. Force-rigid wall method was employed for the evaluation of head damage curves for each material. XM 1006 has been used as the benchmark projectile for the purpose of comparison. Both blunt thoracic trauma and head damage criterion point of view, both rubbers (R1 and R2) have yielded high values of VCmax and peak impact force. Polyolefinic foam (F1) considered in the study has yielded very promising VCmax values and very less peak impact force when compared with those of bench mark projectile XM 1006.

Study of uranium dioxyde sputtering induced by multicharged heavy ions at low and very low kinetic energy: projectile charge effect; Etude de la pulverisation du dioxyde d'uranium induite par des ions lourds multicharges de basse et tres basse energie cinetique; effet de la charge du projectile

Energy Technology Data Exchange (ETDEWEB)

Haranger, F

2003-12-01

Ion beam irradiation of a solid can lead to the emission of neutral or ionized atoms, molecules or clusters from the surface. This comes as a result of the atomic motion in the vicinity of the surface, induced by the transfer of the projectile energy. Then, the study of the sputtering process appears as a means to get a better understanding of the excited matter state around the projectile trajectory. In the case of slow multicharged ions, a strong electronic excitation can be achieved by the projectile neutralization above the solid surface and / or its deexcitation below the surface. Parallel to this, the slowing down of such ions is essentially related to elastic collision with the target atoms. The study of the effect of the initial charge state of slow multicharged ions, in the sputtering process, has been carried out by measuring the absolute angular distributions of emission of uranium atoms from a uranium dioxide surface. The experiments have been performed in two steps. First, the emitted particles are collected onto a substrate during irradiation. Secondly, the surface of the collectors is analyzed by Rutherford Backscattering Spectrometry (RBS). This method allows the characterization of the emission of neutrals, which are the vast majority of the sputtered particles. The results obtained provide an access to the evolution of the sputtering process as a function of xenon projectile ions charge state. The measurements have been performed over a wide kinetic energy range, from 81 down to 1.5 keV. This allowed a clear separation of the contribution of the kinetic energy and initial projectile charge state to the sputtering phenomenon. (author)

Local Impact Simulation of SC Wall Structures using Aircraft Engine Projectile

International Nuclear Information System (INIS)

Chung, Chulhun; Lee, Jungwhee; Lee, Hanjoo; Jung, Raeyoung; Hyun, Changhun

2013-01-01

SC wall structure developed for nuclear power plant buildings consists of plain concrete and two steel plates on both surface of the concrete, while RC structure consists of re bar and concrete. SC structure has higher scabbing resistance than RC structure due to the action of steel plate on the rear side of impact. Therefore SC structure is known as more effective structure from the viewpoint of aircraft crash than RC structure. However, most of the recent researches and experiments about local impact damage deal with RC structures, and the effect of re bar and steel plate is not considered reasonably. Although Walter et al. and Make-work et al. suggested a formula for evaluating perforation depth of steel plate covered RC walls, most of the previous researches about SC structure are focused on perforation and scabbing due to the impact of hard projectile, rather than soft projectile such as an aircraft. In this research a soft projectile, i. e. aircraft engine, is utilized for impact simulation of RC and SC walls. To evaluate local damage of SC wall structures, parametric study with the variables of wall thickness and steel ratio of the cover plate is performed, and the results are compared with those of RC structures. Since scabbing was prevented by the steel plates, penetration mode of damage was observed in SC walls while scabbing damage was occurred in RC walls. It is confirmed that the rear steel plate not only contains concrete debris, but also reduces the internal damage of the concrete walls. Penetration depth of SC walls did not largely vary due to the increasing steel ratio, and similar results to RC walls were observed when the wall thickness is larger than a certain value since the impact resistance of SC wall is mainly governed by the thickness of concrete part. Therefore, it is expected that similar level of impact resistance to RC structure can be produced with the minimum thickness of steel plates of SC structure. According to these results, SC

Observation of stable bound soliton with dual-wavelength in a passively mode-locked Er-doped fiber laser

International Nuclear Information System (INIS)

Zheng Yu; Tian Jin-Rong; Dong Zi-Kai; Xu Run-Qin; Li Ke-Xuan; Song Yan-Rong

2017-01-01

A phase-locked bound state soliton with dual-wavelength is observed experimentally in a passively mode-locked Er-doped fiber (EDF) laser with a fiber loop mirror (FLM). The pulse duration of the soliton is 15 ps and the peak-to-peak separation is 125 ps. The repetition rate of the pulse sequence is 3.47 MHz. The output power is 11.8 mW at the pump power of 128 mW, corresponding to the pulse energy of 1.52 nJ. The FLM with a polarization controller can produce a comb spectrum, which acts as a filter. By adjusting the polarization controller or varying the pump power, the central wavelength of the comb spectrum can be tuned. When it combines with the reflective spectrum of the fiber Bragg grating, the total spectrum of the cavity can be cleaved into two parts, then the bound state soliton with dual-wavelength at 1549.7 nm and 1550.4 nm is obtained. (paper)

First observation of bound excited states in the A/Z = 3 nucleus 15B

International Nuclear Information System (INIS)

Dobradi, Zs.; Sohler, D.; Azaiez, F.

2004-01-01

Complete text of publication follows. Structure of strongly neutron rich nuclei, especially of those lying close to the neutron drip line came into the focus of interest. Among others, the structure of neutron rich Boron isotopes also attracted attention in the last decade. The nuclei 15 B, 17 B and 19 B are particle stable, while the isotopes with even mass number are unstable against neutron emission. Even the neutron rich Boron isotopes with odd mass number have a low neutron binding energy, which is a sign of their weakly bound nature. As a common effect of the weak binding and of the large neutron excess, neutron skin or halo can also develop already in the isotope 15 B with A/Z = 3. Structure of the nucleus 15 B has been investigated by in-beam γ-spectroscopic study of the 9 Be + 36 S fragmentation reaction at GANIL, France. The emerging fragments were identified by use of a standard ΔE-time-of-fight technique with help of the SPEG spectrograph. γ-ray energies, intensities and γγ coincidences have been measured in coincidence with the projectile like fragments by 74 BaF 2 detectors of the Chateau de crystal. On the basis of the γ-spectroscopic information the level scheme presented in Figure 1 was constructed. The level scheme is shown together with the results of di rent model calculations. The common in predictions of these models is that all of them suggest a ground state band with the spin sequence 3/2 - , 5/2 - and 7/2 - , as well as a 1/2 - state, which involves a proton single particle excitation. The shell model calculations (SM) predict similar moments of inertia, strongly different from that of the antisymmetrized molecular dynamics calculations (AMD). The experimentally observed states can be assigned to the members of the rotational band on the basis of their decay properties. The experimental results confirm the predictions of the shell model. (author)

Hybridization thermodynamics of DNA bound to gold nanoparticles

International Nuclear Information System (INIS)

Lang, Brian

2010-01-01

Isothermal Titration Calorimetry (ITC) was used to study the thermodynamics of hybridization on DNA-functionalized colloidal gold nanoparticles. When compared to the thermodynamics of hybridization of DNA that is free in solution, the differences in the values of the Gibbs free energy of reaction, Δ r G o , the enthalpy, Δ r H o , and entropy, Δ r S o , were small. The change in Δ r G o between the free and bound states was always positive but with statistical significance outside the 95% confidence interval, implying the free DNA is slightly more stable than when in the bound state. Additionally, ITC was also able to reveal information about the binding stoichiometry of the hybridization reactions on the DNA-functionalized gold nanoparticles, and indicates that there is a significant fraction of the DNA on gold nanoparticle surface that is unavailable for DNA hybridization. Furthermore, the fraction of available DNA is dependent on the spacer group on the DNA that is used to span the gold surface from that to the probe DNA.

Scattering of polarized 7Li by 120Sn and projectile-target spin-dependent interactions

International Nuclear Information System (INIS)

Sakuragi, Y.; Yahiro, M.; Kamimura, M.; Tanifuji, M.

1986-07-01

Scattering of 7 Li by 120 Sn targets at E lab = 44 MeV is investigated in the coupled-channel frame by taking account of the projectile virtual excitations to the lowest three excited states. Calculations are performed by the cluster-folding (CF) interactions and the double-folding (DF) one. Both interactions reproduce very well the expeimental data on the cross section, the vector analyzing power, the second-rank tensor ones and the third-rank tensor one in elastic and projectile inelastic scattering, although some differences are found between the CF results and the DF ones. In the calculation, the virtual excitations of the projectile are important for most of the analyzing powers and the spin-orbit interaction is indispensable for the vector analyzing power. These features are in contrast to those in 7 Li - 58 Ni scattering at 20 MeV and are interpreted as over-Coulomb-barrier effects. The scattering amplitudes and the analyzing powers are investigated by the invariant amplitude method, which provides a key connecting the spin-dependent interactions to the analyzing powers. The method proposes an important relationship between the tensor analyzing powers, which is useful in analyses of both theoretical and experimental results. Finally, it is found that in the elastic scattering the second-rank tensor analyzing powers are proportional to the strength of the second-rank tensor interaction and the vector and third-rank tensor analyzing powers to the square or cube of the strength of this interaction, while in the inelastic scattering the cross section is proportional to the square of the strength of the tensor interaction, other quantities being weakly dependent on the strength. (author)

Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique

Energy Technology Data Exchange (ETDEWEB)

Ichikawa, Y., E-mail: yuichikawa@phys.titech.ac.jp [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H. [RIKEN Nishina Center (Japan); Ishii, Y. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Kameda, D.; Watanabe, H.; Aoi, N. [RIKEN Nishina Center (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Balabanski, D. L. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Chevrier, R.; Daugas, J. M. [CEA, DAM, DIF (France); Fukuda, N. [RIKEN Nishina Center (Japan); Georgiev, G. [CSNSM, IN2P3-CNRS, Universite Paris-sud (France); Hayashi, H.; Iijima, H. [Tokyo Institute of Technology, Department of Physics (Japan); Inabe, N. [RIKEN Nishina Center (Japan); Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Ishihara, M.; Kubo, T. [RIKEN Nishina Center (Japan); and others

2013-05-15

A novel method to produce spin-aligned rare-isotope (RI) beam has been developed, that is the two-step projectile fragmentation method with a technique of dispersion matching. The present method was verified in an experiment at the RIKEN RIBF, where an RI beam of {sup 32}Al with spin alignment of 8(1) % was successfully produced from a primary beam of {sup 48}Ca, with {sup 33}Al as an intermediate nucleus. Figure of merit of the present method was found to be improved by a factor larger than 50 compared with a conventional method employing single-step projectile fragmentation.

Virial Expansion Bounds

Science.gov (United States)

Tate, Stephen James

2013-10-01

In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.

Upper bounds on superpartner masses from upper bounds on the Higgs boson mass.

Science.gov (United States)

Cabrera, M E; Casas, J A; Delgado, A

2012-01-13

The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanβ, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11)  GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.

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

International Nuclear Information System (INIS)

Fakhraddin, S; Rahim, Magda A

2008-01-01

The results of our systematic studies of projectile fragments (PFs) multiplicity distributions in interactions of 4 He, 12 C, 16 O, 22 Ne and 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 p , as well as the dependence of the PFs on target groups (H, CNO and AgBr), has been investigated

Selected Screen for Engaging Students in Projectile Motion

Science.gov (United States)

Dramae, A.; Toedtanya, K.; Wuttiprom, S.

2017-09-01

Connecting physics concepts to activities that are interesting to students or what they encounter in everyday life will help students build a strong foundation. When there is an interesting activity for the student, it will result in the student responding, engaging, and enthusiasm in learning. Learning activities that are based on what students are interested in and regularly experience will enable students to understand the long and memorable experience. Both of these will enhance the student’s learning experience. One of the activities that can be described in this research used the learning activity through movies, which is the application of the basic motion projectile for students to understand the characteristics of such movement. It also aims to further develop critical thinking skills of learners.

Energy consumption and economic growth nexus in Tanzania: An ARDL bounds testing approach

International Nuclear Information System (INIS)

Odhiambo, Nicholas M.

2009-01-01

In this paper, we examine the intertemporal causal relationship between energy consumption and economic growth in Tanzania during the period of 1971-2006. Unlike the majority of the previous studies, we employ the newly developed autoregressive distributed lag (ARDL)-bounds testing approach by Pesaran et al. [2001. Bounds testing approaches to the analysis of level relationships. Journal of Applied Econometrics 16, 289-326] to examine this linkage. We also use two proxies of energy consumption, namely total energy consumption per capita and electricity consumption per capita. The results of the bounds test show that there is a stable long-run relationship between each of the proxies of energy consumption and economic growth. The results of the causality test, on the other hand, show that there is a unidirectional causal flow from total energy consumption to economic growth and a prima-facie causal flow from electricity consumption to economic growth. Overall, the study finds that energy consumption spurs economic growth in Tanzania

Energy consumption and economic growth nexus in Tanzania. An ARDL bounds testing approach

Energy Technology Data Exchange (ETDEWEB)

Odhiambo, Nicholas M. [Economics Department, University of South Africa (UNISA), P.O. Box 392, UNISA, 0003, Pretoria (South Africa)

2009-02-15

In this paper, we examine the intertemporal causal relationship between energy consumption and economic growth in Tanzania during the period of 1971-2006. Unlike the majority of the previous studies, we employ the newly developed autoregressive distributed lag (ARDL)-bounds testing approach by Pesaran et al. [2001. Bounds testing approaches to the analysis of level relationships. Journal of Applied Econometrics 16, 289-326] to examine this linkage. We also use two proxies of energy consumption, namely total energy consumption per capita and electricity consumption per capita. The results of the bounds test show that there is a stable long-run relationship between each of the proxies of energy consumption and economic growth. The results of the causality test, on the other hand, show that there is a unidirectional causal flow from total energy consumption to economic growth and a prima-facie causal flow from electricity consumption to economic growth. Overall, the study finds that energy consumption spurs economic growth in Tanzania. (author)

Energy consumption and economic growth nexus in Tanzania: An ARDL bounds testing approach

Energy Technology Data Exchange (ETDEWEB)

Odhiambo, Nicholas M. [Economics Department, University of South Africa (UNISA), P.O. Box 392, UNISA, 0003, Pretoria (South Africa)], E-mail: nmbaya99@yahoo.com

2009-02-15

In this paper, we examine the intertemporal causal relationship between energy consumption and economic growth in Tanzania during the period of 1971-2006. Unlike the majority of the previous studies, we employ the newly developed autoregressive distributed lag (ARDL)-bounds testing approach by Pesaran et al. [2001. Bounds testing approaches to the analysis of level relationships. Journal of Applied Econometrics 16, 289-326] to examine this linkage. We also use two proxies of energy consumption, namely total energy consumption per capita and electricity consumption per capita. The results of the bounds test show that there is a stable long-run relationship between each of the proxies of energy consumption and economic growth. The results of the causality test, on the other hand, show that there is a unidirectional causal flow from total energy consumption to economic growth and a prima-facie causal flow from electricity consumption to economic growth. Overall, the study finds that energy consumption spurs economic growth in Tanzania.

The DMM Bound

DEFF Research Database (Denmark)

Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias

2010-01-01

) resultant by means of mixed volume, as well as recent advances on aggregate root bounds for univariate polynomials, and are applicable to arbitrary positive dimensional systems. We improve upon Canny's gap theorem [7] by a factor of O(dn-1), where d bounds the degree of the polynomials, and n is the number...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....

Phenomenology and Astrophysics of Gravitationally-Bound Condensates of Axion-Like Particles

Energy Technology Data Exchange (ETDEWEB)

Eby, Joshua Armstrong [Univ. of Cincinnati, OH (United States)

2017-01-01

Light, spin-0 particles are ubiquitous in theories of physics beyond the Standard Model, and many of these make good candidates for the identity of dark matter. One very well-motivated candidate of this type is the axion. Due to their small mass and adherence to Bose statistics, axions can coalesce into heavy, gravitationally-bound condensates known as boson stars, also known as axion stars (in particular). In this work, we outline our recent progress in attempts to determine the properties of axion stars. We begin with a brief overview of the Standard Model, axions, and bosonic condensates in general. Then, in the context of axion stars, we will present our recent work, which includes: numerical estimates of the macroscopic properties (mass, radius, and particle number) of gravitationally stable axion stars; a calculation of their decay lifetime through number-changing interactions; an analysis of the gravitational collapse process for very heavy states; and an investigation of the implications of axion stars as dark matter. The basic conclusions of our work are that weakly-bound axion stars are only stable up to some calculable maximum mass, whereas states with larger masses collapse to a small radius, but do not form black holes. During collapse, a rapidly increasing binding energy implies a fast rate of decay to relativistic particles, giving rise to a Bosenova. Axion stars that are otherwise stable could be caused to collapse either by accretion of free particles to masses above the maximum, or through astrophysical collisions; in the latter case, we estimate the rate of collisions and the parameter space relevant to induced collapse.

Solar-bound weakly interacting massive particles a no-frills phenomenology

CERN Document Server

Collar, J I

1999-01-01

The case for a stable population of solar-bound Earth-crossing Weakly Interacting Massive Particles (WIMPs) is reviewed. A practical general expression for their speed distribution in the laboratory frame is derived under basic assumptions. If such a population exists -even with a conservative phase-space density-, the next generation of large-mass, low-threshold underground bolometers should bring about a sizable enhancement in WIMP sensitivity. Finally, a characteristic yearly modulation in their recoil signal, arising from the ellipticity of the Earth's orbit, is presented.

Study of the peripheral projectile-like fragments from the reaction 129Xe on 27Al, natCu, 139La and 165Ho, at E/A = 50 MeV

International Nuclear Information System (INIS)

Garcia-Solis, E.J.; Russ, D.E.; Madani, H.

1996-01-01

There are several reaction mechanisms identified for peripheral heavy-ion collisions. For low bombarding energies (E/A ∼ 10 MeV) the predominant reaction channel is the deep-inelastic reaction mechanism. In this process, the projectile and target form a rotating binary system, interchanging nucleons and angular momentum until they separate. At higher bombarding energies (E/A ∼ 50 to 100 MeV) incomplete fusion is thought to be the prevailing reaction channel. In this type of interaction part of the projectile merges with the target during the collision. Finally, for energies greater than 100 MeV/A, the main reaction channel is characterized by the formation of a highly-excited separate fragment (fireball) produced during the overlap between the projectile and the target. The data set studied was from an experiment designed to characterize the projectile-like products of the 27 Al, nat Cu, 139 La, and 165 Ho reactions at E/A = 50 MeV, which was performed at the Michigan State University Super Cyclotron Laboratory (MSU-NSCL). The Maryland Forward Array (MFA), was used to measure projectile-like fragments in coincidence with target-like fragments and light-charge particles in the MSU 4π detector

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.

Penetration Evaluation of Explosively Formed Projectiles Through Air and Water Using Insensitive Munition: Simulative and Experimental Studies

Directory of Open Access Journals (Sweden)

M. Ahmed

2016-02-01

Full Text Available The process of formation, flying, penetration of explosively-formed projectiles (EFP and the effect of water on performance of the charge for underwater applications is simulated by Ansysis Autodyn 2D-Hydro code. The main objective of an explosively formed projectile designed for underwater applications is to disintegrate the target at longer standoff distances. In this paper we have simulated the explosively formed projectile from OFHC-Copper liner for 1200 conical angle. The Affect of water on the penetration of EFP is determined by simulations from Ansysis Autodyn 2-D Hydrocode and by varying depth of water from 1CD-5CD. The depth of penetration against steel target is measured experimentally. Flash X-Ray Radiography (FXR is used to capture EFP jet formation and its penetration against target is measured by depth of penetration experiments. Simulation results are compared with experimental results. The difference in simulated and experimental results for depth of penetration is about 7 mm, which lies within favorable range of error. The jet formation captured from FXR is quite clear and jet velocity determined from Flash X-ray radiography is the same as the ones obtained by using other high explosives. Therefore, it is indicated that Insensitive Munition (8701 can be utilized instead of Polymer Bonded Explosives (PBX for air and underwater environments with great reliability and without any hazard.

Organically bound tritium

International Nuclear Information System (INIS)

Diabate, S.; Strack, S.

1993-01-01

Tritium released into the environment may be incorporated into organic matter. Organically bound tritium in that case will show retention times in organisms that are considerably longer than those of tritiated water which has significant consequences on dose estimates. This article reviews the most important processes of organically bound tritium production and transport through food networks. Metabolic reactions in plant and animal organisms with tritiated water as a reaction partner are of great importance in this respect. The most important production process, in quantitative terms, is photosynthesis in green plants. The translocation of organically bound tritium from the leaves to edible parts of crop plants should be considered in models of organically bound tritium behavior. Organically bound tritium enters the human body on several pathways, either from the primary producers (vegetable food) or at a higher tropic level (animal food). Animal experiments have shown that the dose due to ingestion of organically bound tritium can be up to twice as high as a comparable intake of tritiated water in gaseous or liquid form. In the environment, organically bound tritium in plants and animals is often found to have higher specific tritium concentrations than tissue water. This is not due to some tritium enrichment effects but to the fact that no equilibrium conditions are reached under natural conditions. 66 refs

Flash X-ray cinematography analysis of dwell and penetration of small caliber projectiles with three types of SiC ceramics

Directory of Open Access Journals (Sweden)

Elmar Strassburger

2016-06-01

Full Text Available In order to improve the performance of ceramic composite armor it is essential to know the mechanisms during each phase of the projectile–target interaction and their influence on the penetration resistance. Since the view on the crater zone and the tip of a projectile penetrating a ceramic is rapidly getting obscured by damaged material, a flash X-ray technique has to be applied in order to visualize projectile penetration. For this purpose, usually several flash X-ray tubes are arranged around the target and the radiographs are recorded on film. At EMI a flash X-ray imaging method has been developed, which provides up to eight flash radiographs in one experiment. A multi-anode 450 kV flash X-ray tube is utilized with this method. The radiation transmitted through the target is then detected on a fluorescent screen. The fluorescent screen converts the radiograph into an image in the visible wavelength range, which is photographed by means of a high-speed camera. This technique has been applied to visualize and analyze the penetration of 7.62 mm AP projectiles into three different types of SiC ceramics. Two commercial SiC grades and MICASIC (Metal Infiltrated Carbon derived SiC, a C-SiSiC ceramic developed by DLR, have been studied. The influences, not only of the ceramic but also the backing material, on dwell time and projectile erosion have been studied. Penetration curves have been determined and their relevance to the ballistic resistance is discussed.

Performance of primary repair on colon injuries sustained from low-versus high-energy projectiles.

Science.gov (United States)

Lazovic, Ranko; Radojevic, Nemanja; Curovic, Ivana

2016-04-01

Among various reasons, colon injuries may be caused by low- or high-energy firearm bullets, with the latter producing a temporary cavitation phenomenon. The available treatment options include primary repair and two-stage management, but recent studies have shown that primary repair can be widely used with a high success rate. This paper investigates the differences in performance of primary repair on these two types of colon injuries. Two groups of patients who sustained colon injuries due to single gunshot wounds, were retrospectively categorized based on the type of bullet. Primary colon repair was performed in all patients selected based on the inclusion and exclusion criteria (Stone and Fabian's criteria). An almost absolute homogeneity was attained among the groups in terms of age, latent time before surgery, and four trauma indexes. Only one patient from the low-energy firearm projectile group (4%) developed a postsurgical complication versus nine patients (25.8%) from the high-energy group, showing statistically significant difference (p = 0.03). These nine patients experienced the following postsurgical complications: pneumonia, abscess, fistula, suture leakage, and one multiorgan failure with sepsis. Previous studies concluded that one-stage primary repair is the best treatment option for colon injuries. However, terminal ballistics testing determined the projectile's path through the body and revealed that low-energy projectiles caused considerably lesser damage than their high-energy counterparts. Primary colon repair must be performed definitely for low-energy short firearm injuries but very carefully for high-energy injuries. Given these findings, we suggest that the treatment option should be determined based not only on the bullet type alone but also on other clinical findings. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Impact Behaviour of Soft Body Projectiles

Science.gov (United States)

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

2018-02-01

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.

Energy changes in massive target-nuclei, induced by high-energy hadronic projectiles

International Nuclear Information System (INIS)

Strugalski, Z.; Strugalska-Gola, E.

1997-01-01

Now it turned out that it is real to estimate by experiments the energy changes in massive target-nuclei, induced by high-energy hadronic projectiles. The subject matter in this work is to present results of the quantitative estimations of the energy changes in intranuclear matter at various stages of hadron-nucleus collision reactions. Appropriate formulas are proposed for the energy balances - as following from the experimentally based mechanism of the hadron-nucleus collision reactions

Physical Uncertainty Bounds (PUB)

Energy Technology Data Exchange (ETDEWEB)

Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-03-19

This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l'impact de projectiles H0, H2+, H3+ d'energie de l'ordre du MeV

Energy Technology Data Exchange (ETDEWEB)

Vidovic, Z

1997-06-15

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. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and 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 atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the 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 these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

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.

Present analytical possibilities in prompt γ-ray spectrometry with charged projectiles

International Nuclear Information System (INIS)

Borderie, B.

1980-01-01

This review article deals with γ-rays following bombardment by charged projectiles and the use of this process as an analytical method. A general enumeration of analytical possibilities with expected sensitivities is given. The basic principles and the different possible productions are summarized. A discussion of the physical background is included. Methods for quantitative analysis are discussed. Experimental arrangements are indicated and factors affecting the accuracy of analysis are considered. A number of applications are briefly described and a comparison with X-ray emission (PIXE) is made

Single electron capture by state-prepared Ar2+ projectiles in Ar

International Nuclear Information System (INIS)

Puerta, J.; Huber, B.A.

1985-03-01

Electron capture by state-selected Ar 2+ projectiles in Ar has been studied at low collision energies ( 2+ ions are measured explaining existing discrepancies of partial and total cross sections in the Ar 2+ /Ar collision system. Although highly excited metastable ions ( 5 D 4 0 , 3 F 4 0 ) represent a minor contamination of a non-prepared Ar 2+ beam (proportional1%), their contributions are found to dominate the capture process due to cross section values larger than 10 -15 cm 2 . (orig.)

Neutron emission from projectile-like and target-like fragments in the 18O+48Ti reaction at E(18O)=116 MeV

International Nuclear Information System (INIS)

Chambon, B.; Drain, D.; Pastor, C.; Dauchy, A.; Giorni, A.; Morand, C.

1982-07-01

Angular correlations between neutrons and projectile-like fragments detected near the grazing angle were analysed by assuming two incoherent neutrons sources. One source describes slower neutrons evaporated by target-like fragments in equilibrium. The faster, forward-peaked neutrons originate from a second source strongly correlated with the projectile-like fragments with regards to velocity and direction. In some cases neutron emission may even be attributed to known neutron emitter levels in excited ejectiles

Lower Bound on the Energy Density in Classical and Quantum Field Theories.

Science.gov (United States)

Wall, Aron C

2017-04-14

A novel method for deriving energy conditions in stable field theories is described. In a local classical theory with one spatial dimension, a local energy condition always exists. For a relativistic field theory, one obtains the dominant energy condition. In a quantum field theory, there instead exists a quantum energy condition, i.e., a lower bound on the energy density that depends on information-theoretic quantities. Some extensions to higher dimensions are briefly discussed.

Ab initio investigation on the valence and dipole-bound states of CNa - and SiNa -

Science.gov (United States)

Kalcher, Josef; Sax, Alexander F.

2000-08-01

CNa - and SiNa - have been studied by the CAS-ACPF method. The 3Σ- ground states have binding energies of 5420 and 7517 cm -1, respectively. The 5Σ- excited states are 494 and 1551 cm -1 above the respective ground states. The 1Δ , 3Π , and 1Π valence-excited states for SiNa - should be at least metastable. CNa - and SiNa - possess dipole-bound 5Σ- and 3Σ- states. Binding energies of these states in CNa - are 217 and 236 cm -1, respectively. SiNa - has two stable 5Σ- dipole-bound states, whose binding energies are 246 and 118 cm -1, respectively.

High-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei by pion-transfer reactions of inverse kinematics using the GSI cooler ring ESR

International Nuclear Information System (INIS)

Yamazaki, Toshimitsu.

1991-02-01

Many studies published in the past are reviewed first in relation to high-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei. The report then describes a procedure for applying the method of inverse kinematics to the case of (d, 3 He) reactions. The (d, 3 He) reaction in inverse kinematics is feasible from practical viewpoints. Thus a discussion is made of the inverse kinematics in which a heavy-ion beam ( 208 Pb for instance) with a projectile kinetic energy hits a deuteron target and ejected recoil 3 He nuclei are measured in the forward direction. The recoil momentum is calculated as a function of the Q value. Analysis shows that the recoil spectroscopy with inverse kinematics can be applied to the case of (d, 3 He) reaction, which will yield a very high mass resolution. The experimental setup for use in the first stage is then outlined, and a simple detector configuration free of magnetic field is discussed. These investigations demonstrate that the (d, 3 He) reaction in inverse kinematics provides a promising tool for obtaining high-resolution spectra of deeply-bound pionic atoms. (N.K.)

Protein-bound solute removal during extended multipass versus standard hemodialysis

DEFF Research Database (Denmark)

Eloot, Sunny; Van Biesen, Wim; Axelsen, Mette

2015-01-01

and middle molecules compared to standard hemodialysis (SHD). Since protein-bound solutes (PBS) exert important pathophysiological effects, we investigated whether MPHD results in improved removal of PBS as well. METHODS: A cross-over study (Clinical Trial NCT01267760) was performed in nine stable HD......), hippuric acid (HA), indole acetic acid (IAA), indoxyl sulfate (IS), and p-cresylsulfate (PCS). Dialyser extraction ratio, reduction ratio, and solute removal were calculated for these solutes. RESULTS: Already at 60 min after dialysis start, the extraction ratio in the hemodialyser was a factor 1.4-4 lower...

Experimental study of hydraulic ram effects on a liquid storage tank: Analysis of overpressure and cavitation induced by a high-speed projectile.

Science.gov (United States)

Lecysyn, Nicolas; Bony-Dandrieux, Aurélia; Aprin, Laurent; Heymes, Frédéric; Slangen, Pierre; Dusserre, Gilles; Munier, Laurent; Le Gallic, Christian

2010-06-15

This work is part of a project for evaluating catastrophic tank failures caused by impacts with a high-speed solid body. Previous studies on shock overpressure and drag events have provided analytical predictions, but they are not sufficient to explain ejection of liquid from the tank. This study focuses on the hydrodynamic behavior of the liquid after collision to explain subsequent ejection of liquid. The study is characterized by use of high-velocity projectiles and analysis of projectile dynamics in terms of energy loss to tank contents. New tests were performed at two projectile velocities (963 and 1255 m s(-1)) and over a range of viscosities (from 1 to 23.66 mPa s) of the target liquid. Based on data obtained from a high-speed video recorder, a phenomenological description is proposed for the evolution of intense pressure waves and cavitation in the target liquids. Copyright 2010 Elsevier B.V. All rights reserved.

Ramifications of projectile velocity on the ballistic dart penetration of sand

Science.gov (United States)

Sable, Peter Anthony

With the advent of novel in-situ experimental measurement techniques, highly resolved quantitative observations of dynamic events within granular media can now be made. In particular, high speed imagery and digital analysis now allow for the ballistic behaviors of sand to be examined not only across a range of event velocities but across multiple length scales. In an attempt to further understand the dynamic behavior of granular media, these new experimental developments were implemented utilizing high speed photography coupled with piezo-electric stress gauges to observe visually accessible ballistic events of a dart penetrating Ottawa sand. Projectile velocities ranged from 100 to over 300 meters per second with two distinct chosen fields of view to capture bulk and grain-scale behaviors. Each event was analyzed using the digital image correlation technique, particle image velocimetry from which two dimensional, temporally resolved, velocity fields were extracted, from which bulk granular flow and compaction wave propagation were observed and quantified. By comparing bulk, in situ, velocity field behavior resultant from dart penetration, momentum transfer could be quantified measuring radius of influence or dilatant fluid approximations from which a positive correlation was found across the explored velocity regime, including self similar tendencies. This was, however, not absolute as persistent scatter was observed attributed to granular heterogeneous effects. These were tentatively measured in terms of an irreversible energy amount calculated via energy balance. Grain scale analysis reveals analogous behavior to the bulk response with more chaotic structure, though conclusions were limited by the image processing method to qualitative observations. Even so, critical granular behaviors could be seen, such as densification, pore collapse, and grain fracture from which basic heterogeneous phenomena could be examined. These particularly dominated near nose

Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l'impact de projectiles H0, H2+, H3+ d'energie de l'ordre du MeV

Energy Technology Data Exchange (ETDEWEB)

Vidovic, Z

1997-06-15

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. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and 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 atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the 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 these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

Science.gov (United States)

2013-03-26

...; Comment Request; Upward Bound and Upward Bound Math Science Annual Performance Report AGENCY: The Office... considered public records. Title of Collection: Upward Bound and Upward Bound Math Science Annual Performance...) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new APR because of...

Assessing the Blunt Trauma Potential of Free Flying Projectiles for Development and Safety Certification of Non-Lethal Kinetic Impactors

National Research Council Canada - National Science Library

Widder, Jeffrey

1997-01-01

The primary performance objective for non-lethal, antipersonnel kinetic energy impact projectiles is to reliably deter or incapacitate without causing injuries that require medical treatment beyond...

Universal bounds on current fluctuations.

Science.gov (United States)

Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

2016-05-01

For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

Improved bounds on the epidemic threshold of exact SIS models on complex networks

KAUST Repository

Ruhi, Navid Azizan; Thrampoulidis, Christos; Hassibi, Babak

2017-01-01

The SIS (susceptible-infected-susceptible) epidemic model on an arbitrary network, without making approximations, is a 2n-state Markov chain with a unique absorbing state (the all-healthy state). This makes analysis of the SIS model and, in particular, determining the threshold of epidemic spread quite challenging. It has been shown that the exact marginal probabilities of infection can be upper bounded by an n-dimensional linear time-invariant system, a consequence of which is that the Markov chain is “fast-mixing” when the LTI system is stable, i.e. when equation (where β is the infection rate per link, δ is the recovery rate, and λmax(A) is the largest eigenvalue of the network's adjacency matrix). This well-known threshold has been recently shown not to be tight in several cases, such as in a star network. In this paper, we provide tighter upper bounds on the exact marginal probabilities of infection, by also taking pairwise infection probabilities into account. Based on this improved bound, we derive tighter eigenvalue conditions that guarantee fast mixing (i.e., logarithmic mixing time) of the chain. We demonstrate the improvement of the threshold condition by comparing the new bound with the known one on various networks with various epidemic parameters.

Improved bounds on the epidemic threshold of exact SIS models on complex networks

KAUST Repository

Ruhi, Navid Azizan

2017-01-05

The SIS (susceptible-infected-susceptible) epidemic model on an arbitrary network, without making approximations, is a 2n-state Markov chain with a unique absorbing state (the all-healthy state). This makes analysis of the SIS model and, in particular, determining the threshold of epidemic spread quite challenging. It has been shown that the exact marginal probabilities of infection can be upper bounded by an n-dimensional linear time-invariant system, a consequence of which is that the Markov chain is “fast-mixing” when the LTI system is stable, i.e. when equation (where β is the infection rate per link, δ is the recovery rate, and λmax(A) is the largest eigenvalue of the network\\'s adjacency matrix). This well-known threshold has been recently shown not to be tight in several cases, such as in a star network. In this paper, we provide tighter upper bounds on the exact marginal probabilities of infection, by also taking pairwise infection probabilities into account. Based on this improved bound, we derive tighter eigenvalue conditions that guarantee fast mixing (i.e., logarithmic mixing time) of the chain. We demonstrate the improvement of the threshold condition by comparing the new bound with the known one on various networks with various epidemic parameters.

Quivers of Bound Path Algebras and Bound Path Coalgebras

Directory of Open Access Journals (Sweden)

Dr. Intan Muchtadi

2010-09-01

Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

Production cross sections and momentum distributions of the projectile fragments of a 500 MeV/u 86Kr beam

International Nuclear Information System (INIS)

Weber, M.

1993-07-01

The projectile fragmentation of a 500 MeV/u 86 Kr beam in a beryllium, copper, respectively tantalum target was studied at the projectile-fragment separator of the GSI. The new neutron-rich isotopes 58 Ti, 61 V, 63 Cr, 66 Mn, 69 Fe, and 71 Co could be uniquely identified, furthermore a hint on the existence of 64 Cr, 72 Co, and 75 Ni resulted. The experimental production cross sections, which were determined for a large A and Z range, were compared with the predictions of three different models. The studies presented in the present thesis allow an extrapolation of the production cross section for the double-magic nucleus 78 Ni of only 0.6 pb. With increasing nuclear-charge number of the target material a larger production cross section for light fragments was observed. From these data it can be concluded that projectile-like fragments arise in peripheral and light fragments in central reactions. Furthermore production cross sections and parallel momentum distributions of the rubidium isotopes and the 86 Br were measured. To the experimentally observed charge-exchange products two possible processes can be assigned, namely the quasi-free nucleon-nucleon collision respectively the excitation of a Δresonance. (HSI)

Fragmentation of a 500 MeV/nucleon 86Kr beam, investigated at the GSI projectile fragment separator

International Nuclear Information System (INIS)

Weber, M.; Donzaud, C.; Geissel, H.; Grewe, A.; Lewitowicz, M.; Magel, A.; Mueller, A.C.; Nickel, F.; Pfuetzner, M.; Piechaczek, A.; Pravikoff, M.; Roeckl, E.; Rykaczewski, K.; Saint-Laurent, M.G.; Schall, I.; Stephan, C.; Tassan-Got, L.; Voss, B.

1993-10-01

Production cross-sections and longitudinal momentum distributions have been investigated for reactions between a 500 MeV/nucleon 86 Kr beam and beryllium, copper and tantalum targets. Fragments in a wide A/Z range were studied at the projectile-fragment separator FRS at GSI. The experimental production cross-sections have been used for testing the predictions obtained from a semi-empirical parameterization, a statistical abrasion model and an intranuclear-cascade model. The present study allows to extrapolate the production cross-sections towards very neutron-rich isotopes such as the doubly magic nucleus 78 Ni. For fragments close to the projectile the measured longitudinal momentum distributions agrees qualitatively with a semi-empirical parameterization, which is based on the two-step picture of the fragmentation process. The momentum widths of lighter fragments, however, show deviations from this simple picture. (orig.)

The Effect of Cooperative Learning on Grade 12 Learners' Performance in Projectile Motions, South Africa

Science.gov (United States)

Kibirige, Israel; Lehong, Moyahabo Jeridah

2016-01-01

The study explored the effect of cooperative learning on Grade 12 learners' performance in projectile motions. A quasi-experimental research design with non-equivalent control group was used. Two schools were purposively selected from Maleboho Central circuit in South Africa based on their performance in Physical Sciences Grade 12 results of 2011.…

Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with Microflaps for Flow Control

Science.gov (United States)

2016-04-01

multigrid approach as the means to efficiently solve the linear algebra problem that results in applying an implicit scheme to both steady-state and...projectile, CFD applications , microflaps, optimized control force 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18...counterparts, and successive relaxation allows update of cells as information becomes available and thus aids convergence. CFD++ uses an algebraic

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

NARCIS (Netherlands)

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.; Knoebel, R.; Kurcewicz, J.; Lang, J.; Moore, I.; Mukha, I.; Nociforo, C.; Petrick, M.; Pfuetzner, M.; Pietri, S.; Prochazka, A.; Rink, A. -K.; Rinta-Antila, S.; Schaefer, D.; Scheidenberger, C.; Takechi, M.; Tanaka, Y. K.; Winfield, J. S.; Yavor, M. I.

2013-01-01

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

Imaging of continuum states of the He22+ quasimolecule

International Nuclear Information System (INIS)

Schmidt, L. Ph. H.; Schoeffler, M. S.; Stiebing, K. E.; Schmidt-Boecking, H.; Doerner, R.; Afaneh, F.; Weber, Th.

2007-01-01

Using cold target recoil ion momentum spectroscopy (COLTRIMS) we have investigated the production of one free electron in slow He 2+ +He(1s 2 ) collisions. At projectile velocities between 0.6 and 1.06 a.u. (9-28 keV/u), the fully differential cross section was measured state selective with respect to the second electron, which is bound either at the target or the projectile. We provide a comprehensive data set comprising state selective total cross section, scattering angle dependent single differential cross sections, and fully differential cross section. We show that the momentum distribution of the electron in the continuum image the relevant molecular orbitals for the reaction channel under consideration. By choosing the bound electron final state at the target or projectile and the impact parameter we can select these orbitals and manipulate their relative phase

Influence of the power supply parameters on the projectile energy in the permanent magnet electrodynamic accelerator

Science.gov (United States)

Waindok, Andrzej; Piekielny, Paweł

2017-10-01

The main objective of the research is to investigate, how the power supply parameters influence the kinetic energy of the movable element, called commonly a projectile or bullet. A calculation and measurement results of transient characteristics for an electrodynamic accelerator with permanent magnet support were presented in the paper. The calculations were made with using field-circuit model, which includes the parameters of the power supply, mass of the bullet and friction phenomenon. Characteristics of energy and muzzle velocity verso supply voltage (50 V to 350 V) and capacitance value (60 mF to 340.5 mF) were determined, as well. A measurement verification of selected points of calculation characteristics were carried out for investigated values of muzzle velocity. A good conformity between calculation and measurement results was obtained. Concluding, presented characteristics of the muzzle velocity and energy of the projectile vs. power supply parameters indicate, that accelerators could be used for fatigue testing of materials.

Influence of the power supply parameters on the projectile energy in the permanent magnet electrodynamic accelerator

Directory of Open Access Journals (Sweden)

Waindok Andrzej

2017-01-01

Full Text Available The main objective of the research is to investigate, how the power supply parameters influence the kinetic energy of the movable element, called commonly a projectile or bullet. A calculation and measurement results of transient characteristics for an electrodynamic accelerator with permanent magnet support were presented in the paper. The calculations were made with using field-circuit model, which includes the parameters of the power supply, mass of the bullet and friction phenomenon. Characteristics of energy and muzzle velocity verso supply voltage (50 V to 350 V and capacitance value (60 mF to 340.5 mF were determined, as well. A measurement verification of selected points of calculation characteristics were carried out for investigated values of muzzle velocity. A good conformity between calculation and measurement results was obtained. Concluding, presented characteristics of the muzzle velocity and energy of the projectile vs. power supply parameters indicate, that accelerators could be used for fatigue testing of materials.

Stable cosmology in chameleon bigravity

Science.gov (United States)

De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

2018-02-01

The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

Ionization, evaporation and fragmentation of C{sub 60} in collisions with highly charged C, O and F ions-effect of projectile charge state

Energy Technology Data Exchange (ETDEWEB)

Kelkar, A H; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

2007-09-15

We study the various inelastic processes such ionization, fragmentation and evaporation of C{sub 60} molecule in collisions with fast heavy ions. We have used 2.33 MeV/u C, O and F projectile ion beams. Various ionization and fragmentation products were detected using time-of-flight mass spectrometer. The multiply charged C{sub 60}{sup r+} ions were detected for maximum r = 4. The projectile charge state (q{sub p}) dependence of the single and double ionization cross sections is well reproduced by a model based on the giant dipole plasmon resonance (GDPR). The q{sub p}-dependence of the fragmentation yields, was found to be linear. Variation of relative yields of the evaporation products of C{sub 60}{sup 2+} (i.e. C{sub 58}{sup 2+}, C{sub 56}{sup 2+} etc) and C{sub 60}{sup 3+} (i.e. C{sub 58}{sup 3+}, C{sub 56}{sup 3+} etc) with q{sub p} has also been investigated for various projectiles.

Photon virtual bound state

International Nuclear Information System (INIS)

Inoue, J.; Ohtaka, K.

2004-01-01

We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

Something To Rely On : The Influence of Stable and Fleeting Drivers on Moral Behavior

NARCIS (Netherlands)

G.G. van Houwelingen (Gijs)

2015-01-01

markdownabstract__Abstract__ In virtually any situation we are bound to encounter short-lived influences that lure us to act in a certain way. The influence of such ‘fleeting drivers’ may or may not be in line our long-term goals and commitments (‘stable drivers’). Moral behaviour in particular

Decay analysis of compound nuclei formed in reactions with exotic neutron-rich 9Li projectile and the synthesis of 217At* within the dynamical cluster-decay model

Science.gov (United States)

Kaur, Arshdeep; Kaushal, Pooja; Hemdeep; Gupta, Raj K.

2018-01-01

The decay of various compound nuclei formed via exotic neutron-rich 9Li projectile is studied within the dynamical cluster-decay model (DCM). Following the earlier work of one of us (RKG) and collaborators (M. Kaur et al. (2015) [1]), for an empirically fixed neck-length parameter ΔRemp, the only parameter in the DCM, at a given incident laboratory energy ELab, we are able to fit almost exactly the (total) fusion cross section σfus =∑x=16σxn for 9Li projectile on 208Pb and other targets, with σfus depending strongly on the target mass of the most abundant isotope and its (magic) shell structure. This result shows the predictable nature of the DCM. The neck-length parameter ΔRemp is fixed empirically for the decay of 217At* formed in 9Li + 208Pb reaction at a fixed laboratory energy ELab, and then the total fusion cross section σfus calculated for all other reactions using 9Li as a projectile on different targets. Apparently, this procedure could be used to predict σfus for 9Li-induced reactions where experimental data are not available. Furthermore, optimum choice of "cold" target-projectile combinations, forming "hot" compact configurations, are predicted for the synthesis of compound nucleus 217At* with 8Li + 209Pb as one of the target-projectile combination, or another (t , p) combination 48Ca + 169Tb, with a doubly magic 48Ca, as the best possibility.

Selenolate complexes of CYP101 and the heme-bound hHO-1/H25A proximal cavity mutant.

Science.gov (United States)

Jiang, Yongying; Ortiz de Montellano, Paul R

2008-05-05

Thiolate and selenolate complexes of CYP101 (P450cam) and the H25A proximal cavity mutant of heme-bound human heme oxygenase-1 (hHO-1) have been examined by UV-vis spectroscopy. Both thiolate and selenolate ligands bound to the heme distal side in CYP101 and gave rise to characteristic hyperporphyrin spectra. Thiolate ligands also bound to the proximal side of the heme in the cavity created by the H25A mutation in hHO-1, giving a Soret absorption similar to that of the H25C hHO-1 mutant. Selenolate ligands also bound to this cavity mutant under anaerobic conditions but reduced the heme iron to the ferrous state, as shown by the formation of a ferrous CO complex. Under aerobic conditions, the selenolate ligand but not the thiolate ligand was rapidly oxidized. These results indicate that selenocysteine-coordinated heme proteins will not be stable species in the absence of a redox potential stabilizing effect.

Astrophysics-independent bounds on the annual modulation of dark matter signals.

Science.gov (United States)

Herrero-Garcia, Juan; Schwetz, Thomas; Zupan, Jure

2012-10-05

We show how constraints on the time integrated event rate from a given dark matter (DM) direct detection experiment can be used to bound the amplitude of the annual modulation signal in another experiment. The method requires only mild assumptions about the properties of the local DM distribution: that it is temporally stable on the scale of months and spatially homogeneous on the ecliptic. We apply the method to the annual modulation signal in DAMA/LIBRA, which we compare to the bounds derived from XENON10, XENON100, cryogenic DM search, and SIMPLE data. Assuming a DM mass of 10 GeV, we show that under the above assumptions about the DM halo, a DM interpretation of the DAMA/LIBRA signal is excluded for several classes of models: at 6.3σ (4.6σ) for elastic isospin conserving (violating) spin-independent interactions, and at 4.9σ for elastic spin-dependent interactions on protons.

Off-shell gluon production in interaction of a projectile with 2 or 3 targets

Energy Technology Data Exchange (ETDEWEB)

Braun, M.A.; Salykin, M.Yu. [Saint-Petersburg State University, Department of High Energy physics, Saint Petersburg (Russian Federation)

2017-07-15

Within the effective QCD action for the Regge kinematics, the amplitudes for virtual gluon emission are studied in collision of a projectile with two and three targets. It is demonstrated that all non-Feynman singularities cancel between induced vertices and rescattering contributions. Formulas simplify considerably in a special gauge, which is a straightforward generalization of the light-cone gauge for emission of real gluons. (orig.)

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

Science.gov (United States)

2016-12-01

of offspring populations, the Student’s t-distribution is used as the convergence method. Equations 10–12 are the mean , variance , and standard...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

Asymptotically stable fourth-order accurate schemes for the diffusion equation on complex shapes

International Nuclear Information System (INIS)

Abarbanel, S.; Ditkowski, A.

1997-01-01

An algorithm which solves the multidimensional diffusion equation on complex shapes to fourth-order accuracy and is asymptotically stable in time is presented. This bounded-error result is achieved by constructing, on a rectangular grid, a differentiation matrix whose symmetric part is negative definite. The differentiation matrix accounts for the Dirichlet boundary condition by imposing penalty-like terms. Numerical examples in 2-D show that the method is effective even where standard schemes, stable by traditional definitions, fail. The ability of the paradigm to be applied to arbitrary geometric domains is an important feature of the algorithm. 5 refs., 14 figs

Towards an unambiguous determination of the excitation energy of the projectile in heavy-ion reactions?

Energy Technology Data Exchange (ETDEWEB)

Buta, A.M.; Steckmeyer, J.C. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, G. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)] [and others

2002-03-01

The excitation energy of the quasi-projectiles produced in heavy-ion collisions is determined for the {sup 58}Ni+{sup 197}Au reactions at 52 and 90 AMeV. A new method is proposed for isolating unambiguously the particles evaporated by the source. It consists in observing them at small angles along the flight direction of the source. (authors)

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

International Nuclear Information System (INIS)

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

1996-06-01

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

Experimental Determination of Ballistic Performance of Composite Material Kevlar 29 and Alumina Powder/ Epoxy by Spherical Projectile

Directory of Open Access Journals (Sweden)

Luay Hashem Abbud

2016-12-01

Full Text Available In this study, a response of hybrid composite laminate woven fiber Kevlar29 – Al2O3 Powder/ Epoxy subjected to high velocity impact loading is presented. The energy absorbed due to impact of small rigid projectile on composite materials targets is determined experimentally. The energy absorbed due to impact of hemispherical projectiles on the developed composite laminates is investigated. The results revealed the maximum ballistic limit at impact velocity is found to be 390.87 ± 6 m/s for an the 18 mm target thickness. The ballistic limit velocity predictions are based on the theoretical method presented from another article. The initial velocity and residual velocity results showed good is agreement compared with the predicted results of Ipson and Recht equations. With 5.4 % of accuracy based on the experimental value for the theoretical model for ballistic limit velocity.

Symmetric and Asymmetric Tendencies in Stable Complex Systems.

Science.gov (United States)

Tan, James P L

2016-08-22

A commonly used approach to study stability in a complex system is by analyzing the Jacobian matrix at an equilibrium point of a dynamical system. The equilibrium point is stable if all eigenvalues have negative real parts. Here, by obtaining eigenvalue bounds of the Jacobian, we show that stable complex systems will favor mutualistic and competitive relationships that are asymmetrical (non-reciprocative) and trophic relationships that are symmetrical (reciprocative). Additionally, we define a measure called the interdependence diversity that quantifies how distributed the dependencies are between the dynamical variables in the system. We find that increasing interdependence diversity has a destabilizing effect on the equilibrium point, and the effect is greater for trophic relationships than for mutualistic and competitive relationships. These predictions are consistent with empirical observations in ecology. More importantly, our findings suggest stabilization algorithms that can apply very generally to a variety of complex systems.

Projectile fragmentation in reactions induced by 19F at low energy

International Nuclear Information System (INIS)

Pop, A.; Cenja, M.; Duma, M.; Dumitrescu, R.; Isbasescu, A.; Magda, M.T.

1984-09-01

Light-particle emission was studied in 19 F + 12 C and 19 F + 27 Al reactions at 72 MeV. The spectral shape shows an important breakup component in the case of 2 H, 3 H and 3 He while in the case of 1 H and 4 He the statistical contribution is predominant. The emission of 6 He, 6 Li, 7 Li and 9 Be was also observed and explained by the projectile breakup mechanism within the Serber model. The experimental isotope yields are in good agreement with the theoretical predictions of the Friedman model. (authors)

Evidence for anomalous nuclei among relativistic projectile fragments at Bevalac energies

International Nuclear Information System (INIS)

Heckman, H.H.

1981-01-01

Two independent emulsion experiments using beams of 16 O and 56 Fe at approximately 2 GeV/nucleon find that the reaction mean free paths of projectile fragments (PF) with Z between 3 and 26 are shorter for a few centimeters after their emission than at larger distances, or than predicted from experiments on beam nuclei. Under the assumption that there are two populations of PF, a best fit to the data is obtained when approximately 6% of the PF have an anomalously short mean free path. The anomalous property of PF persists in subsequent fragmentation reactions. 6 figures

On Nash-Equilibria of Approximation-Stable Games

Science.gov (United States)

Awasthi, Pranjal; Balcan, Maria-Florina; Blum, Avrim; Sheffet, Or; Vempala, Santosh

One reason for wanting to compute an (approximate) Nash equilibrium of a game is to predict how players will play. However, if the game has multiple equilibria that are far apart, or ɛ-equilibria that are far in variation distance from the true Nash equilibrium strategies, then this prediction may not be possible even in principle. Motivated by this consideration, in this paper we define the notion of games that are approximation stable, meaning that all ɛ-approximate equilibria are contained inside a small ball of radius Δ around a true equilibrium, and investigate a number of their properties. Many natural small games such as matching pennies and rock-paper-scissors are indeed approximation stable. We show furthermore there exist 2-player n-by-n approximation-stable games in which the Nash equilibrium and all approximate equilibria have support Ω(log n). On the other hand, we show all (ɛ,Δ) approximation-stable games must have an ɛ-equilibrium of support O(Δ^{2-o(1)}/ɛ2{log n}), yielding an immediate n^{O(Δ^{2-o(1)}/ɛ^2log n)}-time algorithm, improving over the bound of [11] for games satisfying this condition. We in addition give a polynomial-time algorithm for the case that Δ and ɛ are sufficiently close together. We also consider an inverse property, namely that all non-approximate equilibria are far from some true equilibrium, and give an efficient algorithm for games satisfying that condition.

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

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...

Improved metastability bounds on the standard model Higgs mass

CERN Document Server

Espinosa, J R; Espinosa, J R; Quiros, M

1995-01-01

Depending on the Higgs-boson and top-quark masses, M_H and M_t, the effective potential of the Standard Model at finite (and zero) temperature can have a deep and unphysical stable minimum \\langle \\phi(T)\\rangle at values of the field much larger than G_F^{-1/2}. We have computed absolute lower bounds on M_H, as a function of M_t, imposing the condition of no decay by thermal fluctuations, or quantum tunnelling, to the stable minimum. Our effective potential at zero temperature includes all next-to-leading logarithmic corrections (making it extremely scale-independent), and we have used pole masses for the Higgs-boson and top-quark. Thermal corrections to the effective potential include plasma effects by one-loop ring resummation of Debye masses. All calculations, including the effective potential and the bubble nucleation rate, are performed numerically and so the results do not rely on any kind of analytical approximation. Easy-to-use fits are provided for the benefit of the reader. Conclusions on the possi...

Radioactive nuclear beam facilities based on projectile fragmentation

International Nuclear Information System (INIS)

Sherrill, B.M.

1992-01-01

The production of radioactive beams using direct separation techniques is discussed. The reaction mechanisms which can be used to produce radioactive beams with these techniques can be broadly divided into three groups, projectile fragmentation, nucleon transfer, and Coulomb disassociation. Radioactive nuclei produced in these ways have large forward momenta with relatively sharp angular distributions peaked near zero degrees which are suitable for collection with magnetic devices. Secondary beam intensities of up to a few percent of the primary beam intensity are possible, although depending on the production mechanism the beam emittance may be poor. Further beam purification can be achieved using atomic processes with profiled energy degraders. The features of the production reaction mechanism, separation techniques, and a review of world wide efforts are presented. The advantages and disadvantages of the method are presented, with discussion of techniques to overcome some of the disadvantages. (Author)

Stable Higgs Bosons - new candidate for cold dark matter

International Nuclear Information System (INIS)

Hosotani, Yutaka

2010-01-01

The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies momenta so that the way of detecting Higgs bosons must be altered.

8B + 208Pb Elastic Scattering at Coulomb Barrier Energies

Science.gov (United States)

La Commara, M.; Mazzocco, M.; Boiano, A.; Boiano, C.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Signorini, C.; Strano, E.; Torresi, D.; Yamaguchi, H.; Kahl, D.; Di Meo, P.; Grebosz, J.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Iwasa, N.; Jeong, S. C.; Jia, H. M.; Kim, Y. H.; Kimura, S.; Kubono, S.; Lin, C. J.; Miyatake, H.; Mukai, M.; Nakao, T.; Nicoletto, M.; Sakaguchi, Y.; Sánchez-Benítez, A. M.; Soramel, F.; Teranishi, T.; Wakabayashi, Y.; Watanabe, Y. X.; Yang, L.; Yang, Y. Y.

2018-02-01

The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (Sp = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.

Projectile-charge-state dependence of 0 degree binary-encounter electron production in 30-MeV Oq++O2 collisions

International Nuclear Information System (INIS)

Zouros, T.J.M.; Richard, P.; Wong, K.L.; Hidmi, H.I.; Sanders, J.M.; Liao, C.; Grabbe, S.; Bhalla, C.P.

1994-01-01

Double-differential cross sections (DDCS's) for the production of binary-encounter electrons (BEE's) are reported for 30-MeV O q+ +O 2 collisions. The BEE DDCS's were measured at θ=0 degree with respect to the beam direction for projectile charge states q=4--8. The measured BEE DDCS's were found to increase with decreasing charge state in agreement with other recent BEE results employing simpler H 2 and He targets. Impulse-approximation calculations of BEE production for θ=0 degree--45 degree are also presented, in which it is assumed that target electrons undergo elastic scattering in the screened Coulomb field of the projectile ion. These calculations are shown to be in agreement with our data at θ=0 degree where only 2s and 2p target electrons are considered

Curvature bound from gravitational catalysis

Science.gov (United States)

Gies, Holger; Martini, Riccardo

2018-04-01

We determine bounds on the curvature of local patches of spacetime from the requirement of intact long-range chiral symmetry. The bounds arise from a scale-dependent analysis of gravitational catalysis and its influence on the effective potential for the chiral order parameter, as induced by fermionic fluctuations on a curved spacetime with local hyperbolic properties. The bound is expressed in terms of the local curvature scalar measured in units of a gauge-invariant coarse-graining scale. We argue that any effective field theory of quantum gravity obeying this curvature bound is safe from chiral symmetry breaking through gravitational catalysis and thus compatible with the simultaneous existence of chiral fermions in the low-energy spectrum. With increasing number of dimensions, the curvature bound in terms of the hyperbolic scale parameter becomes stronger. Applying the curvature bound to the asymptotic safety scenario for quantum gravity in four spacetime dimensions translates into bounds on the matter content of particle physics models.

Radioreceptor assay for benzodiazepines in biological fluids using a new dry and stable receptor preparation

International Nuclear Information System (INIS)

Lund, J.

1981-01-01

A method for determination of benzodiazepines in human blood, plasma, saliva and urine has been developed. The method is based upon the competition between 3 H-flunitrazepam and biologically active benzodiazepines in biological fluids for brain specific receptors, prepared in a stable, dry form and easy to handle. The pharmacological specificity for benzodiazepines of the dry stable receptor preparation is closely similar to that of fresh membrane-bound rat brain receptors. The method is specific for biologically active benzodiazepines; it is relatively rapid, sensitive and reproducible, and can be performed at room temperature. (author)

Light particles emitted with very forward quasi-projectiles and the mechanism in the fragmentation of 44 MeV/a.m.u. 40Ar

International Nuclear Information System (INIS)

Roussel, P.; Bacri, Ch.O.; Borrel, V.; Stephan, C.; Tassan-Got, L.; Beaumel, D.; Bernas, M.; Clapier, F.; Mirea, M.

1998-01-01

The mechanism of projectile fragmentation in the Fermi-energy region has been investigated for fragments emitted in the incident beam direction by detecting fast protons and neutrons evaporated by the projectile-like fragments. The proton coincidence rate is shown to increase with fragment velocity loss. This increase is also correlated to the decrease of the fragment yield, with the coincident rate doubling when the yield decreases by a factor of 10. The coincidence rate is found to be also proportional to the fragment mass loss for fragments with the beam velocity. A two-step mechanism is sketched out to interpret these results. For fragments with the beam velocity, the projectile nucleon removal is equally shared between a first fast step and the second evaporative step, while for fragments at the tenth of the maximum yield, the nucleons are removed by evaporation. Finally, the experimental observation that the most probable velocity for forward fragments is very close to that of the beam may be the result of a strong forward/backward momentum asymmetry in a Goldhaber-type analysis. (author)

Deeply bound pionic atom

International Nuclear Information System (INIS)

Toki, Hiroshi; Yamazaki, Toshimitsu

1989-01-01

The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ - ) cross sections are estimated. (p, 2 Heπ - ) reaction would have cross sections similar to the cross section of (n, dπ - ) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)

Damage visualization and deformation measurement in glass laminates during projectile penetration

Directory of Open Access Journals (Sweden)

Elmar Strassburger

2014-06-01

Full Text Available Transparent armor consists of glass-polymer laminates in most cases. The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates. In order to clarify the course of events during projectile penetration, an experimental technique was developed, which allows visualizing the onset and propagation of damage in each single layer of the laminate. A telecentric objective lens was used together with a microsecond video camera that allows recording 100 frames at a maximum rate of 1 MHz in a backlit photography set-up. With this technique, the damage evolution could be visualized in glass laminates consisting of four glass layers with lateral dimensions 500 mm × 500 mm. Damage evolution was recorded during penetration of 7.62 mm AP projectiles with tungsten carbide core and a total mass of 11.1 g in the impact velocity range from 800 to 880 m/s. In order to measure the deformation of single glass plates within the laminates, a piece of reflecting tape was attached to the corresponding glass plate, and photonic Doppler velocimetry (PDV was applied. With the photonic Doppler velocimeter, an infrared laser is used to illuminate an object to be measured and the Doppler-shifted light is superimposed to a reference light beam at the detector. The simultaneous visualization and PDV measurement of the glass deformation allow determining the deformation at the time of the onset of fracture. The analysis of the experimental data was supported by numerical simulations, using the AUTODYN commercial hydro-code.

A semigroup approach to the strong ergodic theorem of the multistate stable population process.

Science.gov (United States)

Inaba, H

1988-01-01

"In this paper we first formulate the dynamics of multistate stable population processes as a partial differential equation. Next, we rewrite this equation as an abstract differential equation in a Banach space, and solve it by using the theory of strongly continuous semigroups of bounded linear operators. Subsequently, we investigate the asymptotic behavior of this semigroup to show the strong ergodic theorem which states that there exists a stable distribution independent of the initial distribution. Finally, we introduce the dual problem in order to obtain a logical definition for the reproductive value and we discuss its applications." (SUMMARY IN FRE) excerpt

Simulation of changes in temperature and pressure fields during high speed projectiles forming by explosion

Directory of Open Access Journals (Sweden)

Marković Miloš D.

2016-01-01

Full Text Available The Research in this paper considered the temperatures fields as the consequently influenced effects appeared by plastic deformation, in the explosively forming process aimed to design Explosively Formed Projectiles (henceforth EFP. As the special payloads of the missiles, used projectiles are packaged as the metal liners, joined with explosive charges, to design explosive propulsion effect. Their final form and velocity during shaping depend on distributed temperatures in explosively driven plastic deformation process. Developed simulation model consider forming process without metal cover of explosive charge, in aim to discover liner’s dynamical correlations of effective plastic strains and temperatures in the unconstrained detonation environment made by payload construction. The temperature fields of the liner’s copper material are considered in time, as the consequence of strain/stress displacements driven by explosion environmental thermodynamically fields of pressures and temperatures. Achieved final velocities and mass loses as the expected EFP performances are estimated regarding their dynamical shaping and thermal gradients behavior vs. effective plastic strains. Performances and parameters are presented vs. process time, numerically simulated by the Autodyne software package. [Projekat Ministarstva nauke Republike Srbije, br. III-47029

Bounding species distribution models

Directory of Open Access Journals (Sweden)

Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

2011-10-01

Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

Bounding Species Distribution Models

Science.gov (United States)

Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

2011-01-01

Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

A Correction to a Remark in a Paper by Procacci and Yuhjtman: New Lower Bounds for the Convergence Radius of the Virial Series

Science.gov (United States)

Procacci, Aldo

2017-09-01

In this note we deduce a new lower bound for the convergence radius of the Virial series of a continuous system of classical particles interacting via a stable and tempered pair potential using the estimates on the Mayer coefficients obtained in the recent paper by Procacci and Yuhjtman (Lett Math Phys 107:31-46, 2017). This corrects the wrongly optimistic lower bound for the same radius claimed (but not proved) in the above cited paper (in Remark 2 below Theorem 1). The lower bound for the convergence radius of the Virial series provided here represents a strong improvement on the classical estimate given by Lebowitz and Penrose in 1964.

Numeric Computation of the Radar Cross Section of In-flight Projectiles

Science.gov (United States)

2016-11-01

projectile axis after SPY is aligned with the vertical axis. The difference between these 2 frames is illustrated in Fig. 4. Approved for public release...the antenna effective length,11 h, defined as t rjksci e r IjZ hE 0 2 0 −= λ , (38) for the transmitter antenna, and sHroV Eh= , (39) for the...0.119 (at Mach = 0.7) CLα 2.41 2.00 CNpα 0.51 N/A Clp –0.024 N/A CMα 4.65 – 2 CMq –26 –22 V0 (m/s) 564 243 p0 (rad/s) 1143 0 φB0 (°) 40 50

Optimization of aerodynamic form of projectile for solving the problem of shooting range increasing

Science.gov (United States)

Lipanov, Alexey M.; Korolev, Stanislav A.; Rusyak, Ivan G.

2017-10-01

The article is devoted to the development of methods for solving the problem of external ballistics using a more complete system of motion equation taken into account the rotation and oscillation about the mass center and using aerodynamic coefficients of forces and moments which are calculated on the basis of modeling the hydrodynamics of flow around the projectile. Developed methods allows to study the basic ways of increasing the shooting range or artillery.

Universality of spectator fragmentation at relativistic bombarding energies

International Nuclear Information System (INIS)

Schuettauf, A.; Woerner, A.

1996-06-01

Multi-fragment decays of 129 Xe, 197 Au, and 238 U projectiles in collisions with Be, C, Al, Cu, In, Au, and U targets at energies between E/A=400 MeV and 1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By adding an array of 84 Si-CsI(Tl) telescopes the solid-angle coverage of the setup was extended to θ lab =16 . This permitted the complete detection of fragments from the projectile-spectator source. The dominant feature of the systematic set of data is the Z bound universality that is obeyed by the fragment multiplicities and correlations. These observables are invariant with respect to the entrance channel if plotted as a function of Z bound , where Z bound is the sum of the atomic numbers Z i of all projectile fragments with Z i ≥2. No significant dependence on the bombarding energy nor on the target mass is observed. The dependence of the fragment multiplicity on the projectile mass follows a linear scaling law. The reasons for and the limits of the observed universality of spectator fragmentation are explored within the realm of the available data and with model studies. It is found that the universal properties should persist up to much higher bombarding energies than explored in this work and that they are consistent with universal features exhibited by the intranuclear cascade and statistical multifragmentation models. (orig.)

Influence of projectile α-breakup threshold on complete fusion

International Nuclear Information System (INIS)

Mukherjee, A.; Subinit Roy; Pradhan, M.K.; Saha Sarkar, M.; Basu, P.; Dasmahapatra, B.; Bhattacharya, T.; Bhattacharya, S.; Basu, S.K.; Chatterjee, A.; Tripathi, V.; Kailas, S.

2006-01-01

Complete fusion excitation functions for B11,10+Tb159 have been measured at energies around the respective Coulomb barriers, and the existing complete fusion measurements for Li7+Tb159 have been extended to higher energies. The measurements show significant reduction of complete fusion cross sections at above-barrier energies for both the reactions, B10+Tb159 and Li7+Tb159, when compared to those for B11+Tb159. The comparison shows that the extent of suppression of complete fusion cross sections is correlated with the α-separation energies of the projectiles. Also, the two reactions, B10+Tb159 and Li7+Tb159 were found to produce incomplete fusion products at energies near the respective Coulomb barriers, with the α-particle emitting channel being the favoured incomplete fusion process in both the cases

Reassessing the Aurignacian of Slovenia: techno-economic behaviour and direct dating of osseous projectile points.

Science.gov (United States)

Moreau, Luc; Odar, Boštjan; Higham, Tom; Horvat, Aleksander; Pirkmajer, Darja; Turk, Peter

2015-01-01

The Palaeolithic of southern Central Europe has a long history of archaeological research. Particularly, the presence of numerous osseous projectile points in many early Upper Palaeolithic (EUP) assemblages in this region has attracted the attention of the international research community. However, the scarcity of properly identified and well-dated Aurignacian contexts represents an obstacle for investigation of the nature and timing of the Middle to Upper Palaeolithic transition. In this context, the question of whether Neandertals made Aurignacian osseous projectile points, either on their own or as a consequence of cultural interaction with anatomically modern humans (AMH), still remains an open issue. Here we reassess the EUP record of Slovenia by evaluating the Aurignacian character of the assemblages from Potočka zijalka, Mokriška jama and Divje babe I in the light of their suggested roots in the local Mousterian. We provide a comprehensive description of the lithic industry from Potočka zijalka, which represents one of the rare EUP assemblages of southern Central Europe with a representative number of lithic artefacts to be analysed from the perspective of lithic technology and raw material economy. Our re-analysis of the Slovenian assemblages is backed by a series of 11 new ultrafiltered collagen 14C dates obtained directly on associated osseous projectile points from the studied assemblages. The Aurignacian of Potočka zijalka underlines the remarkable consistency of the Early Aurignacian with low typo-technological variability across Europe, resulting from a marked dependence on transported toolkits and raw material conservation. The new radiocarbon determinations for the Aurignacian of Slovenia appear to post-date the 34-32 ka BP (thousands of years before present) threshold for the last Neandertals in the region. Although not falsified, the hypothesis of Aurignacian bone tools in southern Central Europe as a product of late Neandertals is not

Water Ice Radiolytic O2, H2, and H2O2 Yields for Any Projectile Species, Energy, or Temperature: A Model for Icy Astrophysical Bodies

Science.gov (United States)

Teolis, B. D.; Plainaki, C.; Cassidy, T. A.; Raut, U.

2017-10-01

O2, H2, and H2O2 radiolysis from water ice is pervasive on icy astrophysical bodies, but the lack of a self-consistent, quantitative model of the yields of these water products versus irradiation projectile species and energy has been an obstacle to estimating the radiolytic oxidant sources to the surfaces and exospheres of these objects. A major challenge is the wide variation of O2 radiolysis yields between laboratory experiments, ranging over 4 orders of magnitude from 5 × 10-7 to 5 × 10-3 molecules/eV for different particles and energies. We revisit decades of laboratory data to solve this long-standing puzzle, finding an inverse projectile range dependence in the O2 yields, due to preferential O2 formation from an 30 Å thick oxygenated surface layer. Highly penetrating projectile ions and electrons with ranges ≳30 Å are therefore less efficient at producing O2 than slow/heavy ions and low-energy electrons (≲ 400 eV) which deposit most energy near the surface. Unlike O2, the H2O2 yields from penetrating projectiles fall within a comparatively narrow range of (0.1-6) × 10-3 molecules/eV and do not depend on range, suggesting that H2O2 forms deep in the ice uniformly along the projectile track, e.g., by reactions of OH radicals. We develop an analytical model for O2, H2, and H2O2 yields from pure water ice for electrons and singly charged ions of any mass and energy and apply the model to estimate possible O2 source rates on several icy satellites. The yields are upper limits for icy bodies on which surface impurities may be present.

Labeling schemes for bounded degree graphs

DEFF Research Database (Denmark)

Adjiashvili, David; Rotbart, Noy Galil

2014-01-01

We investigate adjacency labeling schemes for graphs of bounded degree Δ = O(1). In particular, we present an optimal (up to an additive constant) log n + O(1) adjacency labeling scheme for bounded degree trees. The latter scheme is derived from a labeling scheme for bounded degree outerplanar...... graphs. Our results complement a similar bound recently obtained for bounded depth trees [Fraigniaud and Korman, SODA 2010], and may provide new insights for closing the long standing gap for adjacency in trees [Alstrup and Rauhe, FOCS 2002]. We also provide improved labeling schemes for bounded degree...

The mechanism of break-up reactions of light ions at non-relativistic and relativistic energies

International Nuclear Information System (INIS)

Baur, G.; Hoffmann, B.; Rosel, F.; Trautmann, D.; Shyam, R.

1984-01-01

Fragmentation processes is nuclear collisions are reviewed. The authors consider a three-body model, where a projectile a=b+x interacts with a target nucleus A. The interaction is described by means of optical potentials V/sub Aa/, V/sub Ab/ and V/sub Ax/ respectively. The projectile a is composed of two subsystems b (''spectator'') and x (''participant'') bound together by V/sub bx/

Fermionic bound states in Minkowski space. Light-cone singularities and structure

Energy Technology Data Exchange (ETDEWEB)

Paula, Wayne de; Frederico, Tobias; Pimentel, Rafael [Instituto Tecnologico de Aeronautica, DCTA, Dept. de Fisica, Sao Jose dos Campos, Sao Paulo (Brazil); Salme, Giovanni [Istituto Nazionale di Fisica Nucleare, Rome (Italy); Viviani, Michele [Istituto Nazionale di Fisica Nucleare, Pisa (Italy)

2017-11-15

The Bethe-Salpeter equation for two-body bound system with spin 1/2 constituent is addressed directly in the Minkowski space. In order to accomplish this aim we use the Nakanishi integral representation of the Bethe-Salpeter amplitude and exploit the formal tool represented by the exact projection onto the null-plane. This formal step allows one (i) to deal with end-point singularities one meets and (ii) to find stable results, up to strongly relativistic regimes, which settle in strongly bound systems. We apply this technique to obtain the numerical dependence of the binding energies upon the coupling constants and the light-front amplitudes for a fermion-fermion 0{sup +} state with interaction kernels, in ladder approximation, corresponding to scalar-, pseudoscalar- and vector-boson exchanges, respectively. After completing the numerical survey of the previous cases, we extend our approach to a quark-antiquark system in 0{sup -} state, taking both constituent-fermion and exchanged-boson masses, from lattice calculations. Interestingly, the calculated light-front amplitudes for such a mock pion show peculiar signatures of the spin degrees of freedom. (orig.)

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

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

International Nuclear Information System (INIS)

Reiter, Moritz Pascal

2015-01-01

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 "2"3"8U 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 "2"3"8U 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"2 helium during online

Active Fault Tolerant Control of Livestock Stable Ventilation System

DEFF Research Database (Denmark)

Gholami, Mehdi

2011-01-01

Modern stables and greenhouses are equipped with different components for providing a comfortable climate for animals and plant. A component malfunction may result in loss of production. Therefore, it is desirable to design a control system, which is stable, and is able to provide an acceptable d...... are not included, while due to the physical limitation, the input signal can not have any value. In continuing, a passive fault tolerant controller (PFTC) based on state feedback is proposed to track a reference signal while the control inputs are bounded....... of fault. Designing a fault tolerant control scheme for the climate control system. In the first step, a conceptual multi-zone model for climate control of a live-stock building is derived. The model is a nonlinear hybrid model. Hybrid systems contain both discrete and continuous components. The parameters...... affine (PWA) components such as dead-zones, saturation, etc or contain piecewise nonlinear models which is the case for the climate control systems of the stables. Fault tolerant controller (FTC) is based on a switching scheme between a set of predefined passive fault tolerant controller (PFTC...

Scattering by bound nucleons

International Nuclear Information System (INIS)

Tezuka, Hirokazu.

1984-10-01

Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)

Black hole bound on the number of species and quantum gravity at CERN LHC

International Nuclear Information System (INIS)

Dvali, Gia; Redi, Michele

2008-01-01

In theories with a large number N of particle species, black hole physics imposes an upper bound on the mass of the species equal to M Planck /√(N). This bound suggests a novel solution to the hierarchy problem in which there are N≅10 32 gravitationally coupled species, for example 10 32 copies of the standard model. The black hole bound forces them to be at the weak scale, hence providing a stable hierarchy. We present various arguments, that in such theories the effective gravitational cutoff is reduced to Λ G ≅M Planck /√(N) and a new description is needed around this scale. In particular, black holes smaller than Λ G -1 are already no longer semiclassical. The nature of the completion is model dependent. One natural possibility is that Λ G is the quantum gravity scale. We provide evidence that within this type of scenarios, contrary to the standard intuition, micro-black-holes have a (slowly fading) memory of the species of origin. Consequently, the black holes produced at LHC will predominantly decay into the standard model particles, and negligibly into the other species

Bounds for Asian basket options

Science.gov (United States)

Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle

2008-09-01

In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.

Market access through bound tariffs

DEFF Research Database (Denmark)

Sala, Davide; Yalcin, Erdal; Schröder, Philipp

2010-01-01

on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and longterm...

Market Access through Bound Tariffs

DEFF Research Database (Denmark)

Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal

on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and long...

Volume Stability of Bitumen Bound Building Blocks

Directory of Open Access Journals (Sweden)

Thanaya I.N.A.

2010-01-01

Full Text Available This paper covers results of laboratory investigations on the volume stability of masonry units incorporating waste materials bound with bitumen (Bitublocks, due to moisture adsorption, thermal exposure and vacuum saturation. The materials used were steel slag, crushed glass, coal fly ash, and 50 pen bitumen. The samples were produced in hot mix method, compacted, then exposed to moist and temperature. It was found that moisture adsorption from the environment caused the Bitublock to expand. The samples with less intense curing regime experienced lower expansion and became stable faster, and vice versa. Under thermal condition (at 70°C, the samples with less intense curing regime underwent higher expansion, and vice versa. They were also highly reversible. Their volume stability was found unique under water exposure. The expansion on first vacuum saturation cycle was irreversible, then largely reversible on the following cycles.

Ionization and excitation of lithium atoms by fast charged particle impact: identification of mechanisms for double K-shell vacancy production as a function of the projectile charge and velocity

International Nuclear Information System (INIS)

Rangama, J.

2002-11-01

Ionization and excitation of lithium atoms by fast charged particle impact: identification of mechanisms for double K-shell vacancy production as a function of projectile charge and velocity. Auger electron spectroscopy is used for an experimental investigation of ionization and excitation of lithium atoms by ions (Kr34 + and Ar18 + ) and electrons at high impact velocities (from 6 to 60 a.u.). In particular, relative contributions of the mechanisms responsible for lithium K-shell ionization-excitation are determined for various projectile charges Zp and velocities vp. A large range of perturbation parameters |Zp|/vp is explored (|Zp|/vp = 0,05 - 0,7 a.u.). From single K-shell excitation results, it appears that the projectile-electron interaction gives mainly rise to a dipole-like transition 1s -> np Concerning K-shell ionization-excitation, the separation of the TS2 (two independent projectile-electron interactions) and TS1 (one projectile-electron interaction) mechanisms responsible for the formation of the 2snp 1,3P and 2sns 1,3S lithium states is performed. In TS1 process, the projectile-electron interaction can be followed by an electron-electron interaction (dielectronic process) or by an internal rearrangement of the residual target after a sudden potential change (shake process). From Born theory, ab initio calculations are performed. The good agreement between theoretical and experimental results confirms the mechanism identification. For the production of P states, TS1 is found to be strongly dominant for small |Zp|/vp values and TS2 is found to be most important for large |Zp|/vp values. Since P states cannot be formed significantly via a shake process, the TS1 and TS2 separation provides a direct signature of the dielectronic process. On the other hand, the TS1 process is shown to be the unique process for producing the S states. At the moment, only the shake aspect of the TS1 process can explain the fact that the 2s3s configuration is preferentially

Comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles (EFPs)

International Nuclear Information System (INIS)

Hussain, G.; Sanaullah, K.

2009-01-01

A conventional shaped charge comprises a conical metal liner projecting a hyper velocity jet of metal that is able to penetrate to great depths into steel armour. However, misalignment problems exist in tandem with jet break up and spewing particles that greatly diminish its penetration power. An EFP, on the other hand, has a liner in the shape of a geometrical recess. The force of the blast molds the liner into a number of configurations, depending on the geometry and the explosive detonation characteristics. This paper presents comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles EFPs. Numerical simulations are carried out using AUTODYN 2D hydrocode to study effects of liner's materials on the shape, velocity, traveled distance, time, pressure, internal energy, temperature, yield stress, divergence or stability, density, compression, and length to diameter (L/D) ratio of EFPs. These parameters are estimated at the instants of maximum as well as at stable velocities. The parametric study reveals that aluminum has maximum velocity in shortest time among the liner materials. From this reason, it was concluded effective standoff was greater for aluminum than more denser metals. Maximum velocity and traveled distance of Tantalum EFP is found to be minimum which may be due to low thermal softening exponent and larger hardening exponent. The simulated yield stress and pressure developed in the Fe EFP reaches at maximum. The L/D ratio for Copper is found to be maximum which supports maximum penetration. From the stability point of view, 1006 MS is found to be the most reliable liner material due to minimum divergence. Generally all liner materials have similar effects of all parameters like pressure, internal energy, temperature, yield stress, divergence or stability, density, compression at the instants of maximum as well as at stable velocities except L/D ratio of EFPs. At the instant of maximum velocity, L

Angular distributions of light projectile fragments in deep inelastic Pb+Em interactions at 160 A GeV

CERN Document Server

Adamovich, M I; Alexandrov, Yu A; Andreeva, N P; Badyal, S K; Basova, E E; Bhalla, K B; Bhasin, A; Bhatia, V S; Bradnova, V; Bubnov, V I; Cai, X; Chasnikov, I Yu; Chen, G M; Chernova, L P; Chernyavsky, M M; Dhamija, S; El-Chenawi, K F; Felea, D; Feng, S Q; Gaitinov, A S; Ganssauge, E R; Garpman, S I A; Gerassimov, S G; Gheata, A; Gheata, M; Grote, J; Gulamov, K G; Sen-Gupta, S K; Gupta, V K; Henjes, U; Jakobsson, B; Kanygina, E K; Karabova, M; Kharlamov, S P; Kovalenko, A D; Krasnov, S A; Kumar, V; Larionova, V G; Lepekhin, F G; Levitskaya, O V; Li, Y X; Liu, L S; Lokanathan, S; Lord, J J; Lukicheva, N S; Lu, Y; Luo, S B; Mangotra, L K; Manhas, I; Mittra, I S; Musaeva, A K; Nasyrov, S Z; Navotny, V S; Nystrand, J; Otterlund, I; Peresadko, N G; Qian, W Y; Qin, Y M; Raniwala, R; Rao, N K; Röper, M D; Rusakova, V V; Saidkhanov, N; Salmanova, N A; Seitimbetov, A M; Seliverstov, D M; Simonov, B B; Sethi, R; Singh, B; Skelding, D; Söderström, K; Stenlund, E; Svechnikova, L N; Svensson, T; Tawfik, A M; Tothova, M; Tretyakova, M I; Trofimova, T P; Tuleeva, U I; Vashisht, V; Vokal, S; Vrláková, J; Wang, H Q; Wang, X R; Weng, Z Q; Wilkes, R J; Yang, C B; Yin, Z B; Yu, L Z; Zhang, D H; Zheng, P Y; Zhokhova, S I; Zhou, D C

1999-01-01

The nuclear emulsion was exposed at CERN by the lead projectile at 160 A GeV. The angles between any pair of fragments with Z=2-4 have been measured in the emulsion plane for the events which did not contain heavy fragments. The constant characterizing the normal angle ( phi ) distribution of the fragment momentum projection onto the emulsion plane with respect to initial projectile momentum p/sub 0/ is found to be sigma /sub phi /=(0.37+or-0.02) mrad. Corresponding value sigma /sub 0/=(121+or-6) MeV/c of nucleon momentum distribution in the lead nucleus coincides with that expected from Fermi momentum distribution for this nucleus. The peak in the pair-angle distribution of double-charged fragments, /sup 8/Be to 2 alpha , is presented for the region of small angles (<0.1 mrad). The fraction of alpha -particles coming from the decay of the ground state /sup 8/Be is found to be (13+or-2)601130f their whole number. (14 refs).

Bound and rebound states

International Nuclear Information System (INIS)

Orzalesi, C.A.

1979-01-01

In relativistic quantum theory, bound states generate forces in the crossed channel; such forces can affect the binding and self-consistent solutions should be sought for the bound-state problem. The author investigates how self-consistency can be achieved by successive approximations, in a simple scalar model and with successive relativistic eikonal approximations (EAs). Within the generalized ladder approximation, some exact properties of the resulting ''first generation'' bound states are discussed. The binding energies in this approximation are rather small even for rather large values of the primary coupling constant. The coupling of the constituent particles to the first-generation reggeon is determined by a suitable EA and a new generalized ladder amplitude is constructed with rungs given either by the primary gluons or by the first-generation reggeons. The resulting new (second-generation) bound states are found in a reggeized EA. The size of the corrections to the binding energies due to the rebinding effects is surprisingly large. The procedure is then iterated, so as to find - again in an EA - the third-generation bound states. The procedure is found to be self-consistent already at this stage: the third-generation bound states coincide with those of second generation, and no further rebinding takes place in the higher iterations of the approximation method. Features - good and bad - of the model are discussed, as well as the possible relevance of rebinding mechanisms in hadron dynamics. (author)

The continuous spectrum and the effect of parametric resonance. The case of bounded operators

International Nuclear Information System (INIS)

Skazka, V V

2014-01-01

The paper is concerned with the Mathieu-type differential equation u ″ =−A 2 u+εB(t)u in a Hilbert space H. It is assumed that A is a bounded self-adjoint operator which only has an absolutely continuous spectrum and B(t) is almost periodic operator-valued function. Sufficient conditions are obtained under which the Cauchy problem for this equation is stable for small ε and hence free of parametric resonance. Bibliography: 10 titles

Mathematical model for prediction of droplet sizes and distribution associated with impact of liquid-containing projectile

International Nuclear Information System (INIS)

Shelke, Ashish V.; Gera, B.; Maheshwari, N.K.; Singh, R.K.

2018-01-01

After the events of 9/11, the impact of fast flying commercial aircraft is considered as major hazard threatening the Nuclear Power Plant's (NPP) safety. The study of fuel spillage phenomenon and fireball formation is important to understand fire hazards due to burning of dispersed aviation fuel. The detailed analysis of fuel dispersion is very difficult to deliberate because both, large NPP structures and the large size of commercial aircrafts. Sandia National Laboratories, USA conducted impact tests using cylindrical projectiles filled with water to measure the associated parameters. Due to combustion properties and volatile nature of hydrocarbon fuels, the obtained parameters from impact studies using water are incomplete in fire analysis of flammable droplet clouds. A mathematical model is developed for prediction of droplet sizes and distribution associated with the impact of a liquid-containing projectile. The model can predict the transient behavior of droplet cloud. It is validated with experimental data available in literature. In the present study, the analysis has been performed using water and kerosene. The data obtained can be utilized as boundary and initial condition for CFD analysis. This information is useful for fire hazard analysis of aircraft impacts on NPP structures.

Experimental investigations of visco-plastic properties of the aluminium and tungsten alloys used in KE projectiles

Science.gov (United States)

Kruszka, L.; Magier, M.

2012-08-01

The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity) in function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it's particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot) and tungsten alloy (penetrator) are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2 ṡ 104s-1 (for aluminium alloy) and 6 ṡ 103s-1 (for tungsten alloy).

Experimental investigations of visco-plastic properties of the aluminium and tungsten alloys used in KE projectiles

Directory of Open Access Journals (Sweden)

Magier M.

2012-08-01

Full Text Available The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity in function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it’s particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot and tungsten alloy (penetrator are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2 ⋅ 104s−1 (for aluminium alloy and 6 ⋅ 103s−1 (for tungsten alloy.

Projectile-like fragments from 129Xe+natCu reactions at E/A = 40 MeV

International Nuclear Information System (INIS)

Russ, D.E.; Mignerey, A.C.; Garcia-Solis, E.J.

1996-01-01

The bombarding of heavy nuclei with energetic heavy projectiles has been one of the most important experimental tools for nuclear science. At low beam energies, (E/A) beam 100 MeV, these mean field effects are less important and nucleon-nucleon interactions dominate. Within the intermediate energy region, the situation is less clear because of both the mean field and nucleon-nucleon effects contribute. There is no consensus on the theoretical treatment of nuclear reaction in the intermediate energy regime and statistical, dynamical, and hybrid models have been used with limited success. Previous studies of 136 Xe + 209 Bi at E/A = 28 MeV carried out at Michigan State University (MSU) have been well described by a damped reaction mechanism. On the other hand, 129 Xe + nat Cu at E/A = 50 MeV also at MSU has been compared with a hybrid model with reasonable success. In order to see a transition from a damped reaction mechanism to more fragmentation-like processes, an experiment was carried out at MSU using 129 Xe beams at E/A = 30, 40, 50, and 60 MeV. The targets were Cu, Sc, and Au. The current study only looks at the projectile-like fragments (PLF) detected in the Maryland Forward Array (MFA)

Comparative biogeochemical behaviors of iron-55 and stable iron in the marine environment

International Nuclear Information System (INIS)

Weimer, W.C.; Langford, J.C.; Jenkins, C.E.

1978-01-01

Studies of atmospheric aerosols have demonstrated that much of the 55 Fe associated with the aerosol input to the oceans is present as either an amorphous or hydrous iron oxide or as very small particulate species attached to the surfaces of the large aerosol particles. By comparison, nearly all of the stable iron is bound in the mineral phase of aerosol particles. This difference in the chemical and physical forms of the radioactive and stable iron isotopes results in the 55 Fe being more biologically available than is the stable iron. This difference in availability is responsible for the transfer of a much higher specific activity 55 Fe to certain ocean organisms and man relative to the specific activity of the total aerosol or of sea water. This differential biological uptake of the radioactive element and its stable element counterpart points out that natural levels of stable elements in the marine environment may not effectively dilute radioelements or other stable elements of anthropogenic sources. The effectiveness of dilution by natural sources depends on the chemical and physical forms of the materials in both the source terms and the receiving environments. The large difference in specific activities of 55 Fe in aerosols and sea water relative to ocean organisms reflects the independent behaviors of 55 Fe and stable iron

Stable Blind Deconvolution over the Reals from Additional Autocorrelations

KAUST Repository

Walk, Philipp

2017-10-22

Recently the one-dimensional time-discrete blind deconvolution problem was shown to be solvable uniquely, up to a global phase, by a semi-definite program for almost any signal, provided its autocorrelation is known. We will show in this work that under a sufficient zero separation of the corresponding signal in the $z-$domain, a stable reconstruction against additive noise is possible. Moreover, the stability constant depends on the signal dimension and on the signals magnitude of the first and last coefficients. We give an analytical expression for this constant by using spectral bounds of Vandermonde matrices.