On the Attainability of Fusion Temperatures under High Densities by Impact Shock Waves of Small Solid Particles Accelerated to Hypervelocities

1964 ◽  
Vol 19 (2) ◽  
pp. 231-239 ◽  
Author(s):  
F. Winterberg
Keyword(s):  
Shock Waves ◽  
Heavy Particle ◽  
Target Material ◽  
Particle Beam ◽  
Solid Particles ◽  
Particle Accelerators ◽  
Bremsstrahlung Radiation ◽  
The Impact ◽  
Controllable Size ◽  
Impact Shock

In this paper it is shown that temperatures up to 108°K and under densities of the order 1 g/cm3 are attainable in liquid tritium-deuterium by the impact shock waves of small solid particles accelerated up to velocities of some 107 cm/s in heavy particle accelerators.The high temperatures occur in a focussed particle beam. It is shown that under feasible conditions, the particle beam will generate in the target material a shock wave of the required strength. The particles are charged electrically up to the limit of mechanical breakup and then are accelerated in linear particle accelerators to the required velocities.In order to cut down losses by Bremsstrahlung radiation, the particles must consist of low Z-value material. The most promissing substances in this regard are lithium and beryllium. The "guillotine factor” is of significance at high densities and reduces the Bremsstrahlung losses by a factor of about 1/3.The attainable temperatures are high enough to reach the lowest ignition temperatures for thermonuclear reactions.Apart from the interesting prospect of high temperature, high density experiments, the possibility cannot be excluded to ignite by this method a small fusion explosion of controllable size.

Specimen Preparation of Near Surface Ion Irradiated Samples

1985 ◽  
Vol 43 ◽  
pp. 170-171
Author(s):  
K. F. Russell ◽  
L. L. Horton
Keyword(s):  
Radiation Damage ◽  
Heavy Ions ◽  
Target Material ◽  
Metal Alloys ◽  
Specimen Surface ◽  
Specimen Preparation ◽  
Particle Accelerators ◽  
Near Surface ◽  
Graaff Accelerator ◽  
Van De Graaff

Beams of heavy ions from particle accelerators are used to produce radiation damage in metal alloys. The damaged layer extends several microns below the surface of the specimen with the maximum damage and depth dependent upon the energy of the ions, type of ions, and target material. Using 4 MeV heavy ions from a Van de Graaff accelerator causes peak damage approximately 1 μm below the specimen surface. To study this area, it is necessary to remove a thickness of approximately 1 μm of damaged metal from the surface (referred to as “sectioning“) and to electropolish this region to electron transparency from the unirradiated surface (referred to as “backthinning“). We have developed electropolishing techniques to obtain electron transparent regions at any depth below the surface of a standard TEM disk. These techniques may be applied wherever TEM information is needed at a specific subsurface position.

Experimental study of heat transfer in the boundary layer of a flat plate with the impact of weak shock waves on the leading edge

2020 ◽  
Author(s):  
V. L. Kocharin ◽  
A. A. Yatskikh ◽  
D. S. Prishchepova ◽  
A. V. Panina ◽  
Yu. G. Yermolaev ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Experimental Study ◽  
Shock Waves ◽  
Flat Plate ◽  
Leading Edge ◽  
Weak Shock ◽  
The Impact

A Model for the Effect of Velocity on Erosion of N80 Steel Tubing due to the Normal Impingement of Solid Particles

1992 ◽  
Vol 114 (1) ◽  
pp. 54-64 ◽  
Author(s):  
D. P. Chase ◽  
E. F. Rybicki ◽  
J. R. Shadley
Keyword(s):  
Solid Particle ◽  
Computational Study ◽  
Target Material ◽  
Target Surface ◽  
American Petroleum Institute ◽  
Solid Particles ◽  
Unknown Coefficient ◽  
Conservation Of Energy ◽  
Carrier Fluid ◽  
Erosion Behavior

As part of a combined experimental and computational study of erosion for gas and oil production conditions, a semi-empirical model has been developed to predict erosion ratio behaviors of metals due to solid particle impingement. One use of the model will be to reduce the total number of experiments needed to characterize erosion behavior. The model represents material property information associated with both the target material and the impinging particles, as well as impingement speed. Five different models are examined in terms of ability to predict erosion ratio behavior as a function of impingement speed. The model selected is based on a conservation of energy formulation and fracture mechanics considerations to predict the amount of material removed due to solid particle impingement. The resulting equation to predict the erosion ratio for a given particle size contains one unknown coefficient which is determined through comparison with experimental data. Illustrative examples are presented for data for two different sizes of glass bead solid particles in an oil carrier fluid impinging on an API (American Petroleum Institute) N80 grade steel target at an impingement angle 90 deg to the target surface. Using erosion data at one impingement speed to determine the unknown coefficient, the model was used to predict erosion behavior at a range of other speeds. Good agreement between the erosion ratio data and the values predicted by the model were found for two solid particle sizes. Recommendations for expanding the capabilities of the model are pointed out.

Erosion Mechanism and Sensitivity Parameter Analysis of Natural Gas Curved Pipeline

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Jie Zhang ◽  
Hao Yi ◽  
Zhuo Huang ◽  
Jiadai Du
Keyword(s):  
Natural Gas ◽  
Wear Rate ◽  
Shape Factor ◽  
Great Influence ◽  
Solid Particles ◽  
Parameter Analysis ◽  
Particle Collision ◽  
Erosion Wear ◽  
Gas Wells ◽  
The Impact

With the deepening of natural gas exploitation, the problem of sand production in gas wells is becoming more and more serious, especially in high-yield gas wells. The solid particles in natural gas are very likely to cause erosion and wear of downstream pipelines and throttling manifolds, which makes the pipeline ineffective. Once the pipeline is damaged, the natural gas leaks, which may cause serious catastrophic accidents. In this paper, the impact of sand particles on the pipeline wall is predicted by the analysis of the research on bent and continuous pipeline combined with particle collision model. The parameters of different particles (particle shape factor, particle velocity, and particle diameter), different bent parameters (angle, diameter, and curvature-to-diameter ratio), and the influence of different continuous pipeline parameters (assembly spacing and angle) are explored on the erosion and wear mechanism of curved pipeline. The results show that the shape of the particles has a great influence on the wear of the curved pipeline. As the shape factor of the particles decreases, the wear tends to decrease. The bent area is subject to erosion changes as the particle parameters and piping parameters. The increase in pipeline diameter is beneficial to reduce the maximum and the average erosion wear rate. When the bent angle of the pipeline is less than 90 deg, the maximum erosion wear rate is basically the same. But when it is greater than 90 deg, it decreases with the increase in the bent angle. When the assembly angle of double curved pipeline is between 0 deg and 60 deg, the elbow is subject to severe erosion wear. At the same time, increasing the assembly spacing is beneficial to reduce the erosion wear rate. The research can provide a theoretical support for subsequent engineering applications.

scholarly journals Impact of Different Components and Boundary Conditions on the Eigenfrequencies of a Magnet–Girder Assembly

Instruments ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 29
Author(s):  
Simone Andresen
Keyword(s):  
Boundary Conditions ◽  
Particle Beam ◽  
Design Development ◽  
Material Density ◽  
Electron Synchrotron ◽  
Support Points ◽  
Beam Stability ◽  
Development Processes ◽  
Large Triangle ◽  
The Impact

Synchrotron radiation facilities are very important in different areas of fundamental and applied science to investigate structures or processes at small scales. Magnet–girder assemblies play a key role for the performance of such accelerator machines. High structural eigenfrequencies of the magnet–girder assemblies are required to assure a sufficient particle beam stability. The objective of the present parametric study was to numerically investigate and quantify the impact of different boundary conditions and components on the magnet–girder eigenfrequencies. As case studies, two 3 m long girder designs following the specifications of the PETRA IV project at DESY (German Electron Synchrotron, Hamburg, Germany) were selected. High magnet–girder assembly eigenfrequencies were achieved by, e.g., positioning the magnets close to the upper girder surface, increasing the connection stiffness between the magnets and the girder and between the girder and the bases, and positioning the girder support points as high as possible in the shape of a large triangle. Comparing the E/ρ ratio (E: Young’s modulus, ρ: material density) of different materials was used as a first approach to evaluate different materials for application to the girder. Based on the findings, general principles are recommended to be considered in the future girder design development processes.

scholarly journals Ionization Dosimetry Principles for Conventional and Laser-Driven Clinical Particle Beams

2018 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Ionizing Radiation ◽  
Heavy Particle ◽  
Absorbed Dose ◽  
High Energy ◽  
Particle Energy ◽  
Particle Accelerators ◽  
Carbon Ions ◽  
Particle Beams ◽  
Radiation Fields ◽  
Number Of Particles

In this paper after mentioning the clinical radiation fields of 20 keV-450 MeV/u, they are characterized by the number of particles and their energy. Particle energy is the quantity that determines radiation penetration at the depth at which the tumor is situated (Fig. 1). The number of particles (or beam intensity) is the second major quantity that assures the administration of the absorbed dose in the tumor. The first application shows the radiation levels planned for various radiation fields. Prior to interacting with the medium, the intensity (or energy fluence rate) allows the determination of energy density, energy, power and relativistic force. In the interaction process, it determines the absorbed dose, kerma and exposure. Non-ionizing radiations in the EM spectrum are used as negative energy waves to accelerate particles charged into special installations called particle accelerators. The particles extracted from the accelerator are the source of the corpuscular radiation for high-energy radiotherapy. Of these, light particle beams (electrons and photons) for radiotherapy are generated by betatron, linac, microtron, and synchrotron and heavy particle beams (protons and heavy ions) are generated by cyclotron, isochronous cyclotron, synchro-cyclotron and synchrotron. The ionization dosimetry method used is the ionization chamber for both indirectly ionizing radiation (photons and neutrons) and for directly ionizing radiation (electrons, protons and carbon ions). Because the necessary energies for hadrons therapy are relatively high, 50-250 MeV for protons and 100-450 MeV/u for carbon ions, the alternative to replace non-ionizing radiation with relativistic laser radiation for generating clinical corpuscular radiation through radiation pressure acceleration mechanism (RPA) is presented.

scholarly journals An Attempt to Reduce the Emission of Spark-Ignition Engine with Mixtures of Bioethanol and Gasoline as Substitute Fuels

2019 ◽  
Vol 26 (3) ◽  
pp. 31-38
Author(s):  
Wojciech Gis ◽  
Maciej Gis ◽  
Piotr Wiśniowski ◽  
Mateusz Bednarski
Keyword(s):  
Carbon Dioxide ◽  
Fuel Consumption ◽  
Carbon Dioxide Emissions ◽  
Alternative Fuels ◽  
Negative Impact ◽  
Spark Ignition ◽  
Solid Particles ◽  
Spark Ignition Engine ◽  
Maximum Power ◽  
The Impact

Abstract Limiting emissions of harmful substances is a key task for vehicle manufacturers. Excessive emissions have a negative impact not only on the environment, but also on human life. A significant problem is the emission of nitrogen oxides as well as solid particles, in particular those up to a diameter of 2.5 microns. Carbon dioxide emissions are also a problem. Therefore, work is underway on the use of alternative fuels to power the vehicle engines. The importance of alternative fuels applies to spark ignition engines. The authors of the article have done simulation tests of the Renault K4M 1.6 16v traction engine for emissions for fuels with a volumetric concentration of bioethanol from 10 to 85 percent. The analysis was carried out for mixtures as substitute fuels – without doing any structural changes in the engine's crankshafts. Emission of carbon monoxide, carbon dioxide, hydrocarbons, oxygen at full throttle for selected rotational speeds as well as selected engine performance parameters such as maximum power, torque, hourly and unit fuel consumption were determined. On the basis of the simulation tests performed, the reasonableness of using the tested alternative fuels was determined on the example of the drive unit without affecting its constructions, in terms of e.g. issue. Maximum power, torque, and fuel consumption have also been examined and compared. Thus, the impact of alternative fuels will be determined not only in terms of emissions, but also in terms of impact on the parameters of the power unit.

A mixed contact model for an immersed collision between two solid surfaces

2008 ◽  
Vol 366 (1873) ◽  
pp. 2205-2218 ◽  
Author(s):  
Fu-Ling Yang ◽  
Melany L Hunt
Keyword(s):  
Surface Deformation ◽  
Elastohydrodynamic Lubrication ◽  
Solid Particles ◽  
Solid Surfaces ◽  
Additional Energy ◽  
Collision Model ◽  
Dry Granular Flow ◽  
Wide Range ◽  
The Impact ◽  
Surrounding Liquid

Experimental evidence shows that the presence of an ambient liquid can greatly modify the collision process between two solid surfaces. Interactions between the solid surfaces and the surrounding liquid result in energy dissipation at the particle level, which leads to solid–liquid mixture rheology deviating from dry granular flow behaviour. The present work investigates how the surrounding liquid modifies the impact and rebound of solid spheres. Existing collision models use elastohydrodynamic lubrication (EHL) theory to address the surface deformation under the developing lubrication pressure, thereby coupling the motion of the liquid and solid. With EHL theory, idealized smooth particles are made to rebound from a lubrication film. Modified EHL models, however, allow particles to rebound from mutual contacts of surface asperities, assuming negligible liquid effects. In this work, a new contact mechanism, ‘mixed contact’, is formulated, which considers the interplay between the asperities and the interstitial liquid as part of a hybrid rebound scheme. A recovery factor is further proposed to characterize the additional energy loss due to asperity–liquid interactions. The resulting collision model is evaluated through comparisons with experimental data, exhibiting a better performance than the existing models. In addition to the three non-dimensional numbers that result from the EHL analysis—the wet coefficient of restitution, the particle Stokes number and the elasticity parameter—a fourth parameter is introduced to correlate particle impact momentum to the EHL deformation impulse. This generalized collision model covers a wide range of impact conditions and could be employed in numerical codes to simulate the bulk motion of solid particles with non-negligible liquid effects.

Impact of Molecular Chain Structure of Suspension Phase on Giant Electrorheological Performance

2022 ◽  
Author(s):  
Hanqi Xu ◽  
Jinbo Wu ◽  
Yaying Hong ◽  
Weijia Wen
Keyword(s):  
Yield Stress ◽  
Chain Length ◽  
Colloidal Stability ◽  
Chain Structure ◽  
Solid Particles ◽  
High Yield ◽  
Suspension Stability ◽  
Chain Lengths ◽  
The Impact ◽  
Oil Particles

Abstract We demonstrate the impact of diester structure, in particular the alkyl chain length and branching structure, on the giant electrorheological (GER) effect and suspension stability. The existence of oil-particles interaction is of critical importance to induce the GER effect. To quantify GER performance and colloidal stability, we examine the yield stress, current density, field-off viscosity and sedimentation ratio with respect to the variation of chain length and branching structure. The oil-particles interaction is quantitatively analyzed by investigating the cluster size of particles in different diesters by a multiple light scattering analyzer, along with the wettability of different chain lengths of diesters and solid particles by the Washburn method. Our results indicate that long chain lengths favor the formation of particle agglomerates, thereby enhancing the GER effect (such as high yield stress). The attachment of branches on diester causes the formation of electronic correlation between branches and main chain, depending on the position of branches located, and hence results in superior GER performance and favorable suspension stability. An optimal GER fluid constituted by bis(2-ethylhexyl) sebacate is acquired with the achieved yield stress of 113 kPa at electric field strength of 4 kV/ mm and the prominent integrated GER properties.

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