WorldWideScience

Sample records for antixi particles

  1. Xi0 and anti-Xi0 Polarization Measurements at 800-GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Abouzaid, E.; Alavi-Harati, A.; Alexopoulos, T.; Arenton, M.; Barker, A.R.; Bellantoni, L.; Bellavance, A.; Blucher, E.; Bock, G.J.; Bright, S.; Cheu, E.; /Arizona U.

    2006-08-01

    The polarization of {Xi}{sup 0} and {bar {Xi}}{sup 0} hyperons produced by 800 GeV/c protons on a BeO target at a fixed targeting angle of 4.8 mrad is measured by the KTeV experiment at Fermilab. The result of 9.7% for {Xi}{sup 0} polarization shows no significant energy dependence when compared to a result obtained at 400 GeV/c production energy and at twice the targeting angle. The polarization of the {Xi}{sup 0} is measured for the first time and found to be consistent with zero. They also examine the dependence of polarization on production p{sub t}.

  2. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  3. Particle-Particle-String Vertex

    OpenAIRE

    Ishibashi, Nobuyuki

    1996-01-01

    We study a theory of particles interacting with strings. Considering such a theory for Type IIA superstring will give some clue about M-theory. As a first step toward such a theory, we construct the particle-particle-string interaction vertex generalizing the D-particle boundary state.

  4. Particle energization

    Energy Technology Data Exchange (ETDEWEB)

    Gisler, G.

    1990-01-01

    A first-principles approach to the physics of particle energization is presented. The general physics of particle acceleration is then applied to a number of the classical astrophysical mechanisms for accelerating particles, with references to recent literature where these are used in specific circumstances. The solar flare is recommended as a microcosm for studying particle acceleration because many different processes seem to be occurring in close proximity, and there is abundant high time resolution data for diagnosing those processes. Finally, a list of possible sites and mechanisms for particle acceleration in spiral galaxies is presented. 66 refs., 6 figs., 3 tabs.

  5. Particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.

    1993-09-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.

  6. Particle therapy

    International Nuclear Information System (INIS)

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics

  7. Particle physics

    International Nuclear Information System (INIS)

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  8. Particle physics

    CERN Document Server

    Carlsmith, Duncan

    2012-01-01

    Particle Physics is the first book to connect theory and experiment in particle physics. Duncan Carlsmith provides the first accessible exposition of the standard model with sufficient mathematical depth to demystify the language of gauge theory and Feynman diagrams used by researchers in the field. Carlsmith also connects theories to past, present, and future experiments.

  9. Elementary particles

    Science.gov (United States)

    Fritzsch, Harald; Heusch, Karin

    Introduction -- Electrons and atomic nuclei -- Quantum properties of atoms and particles -- The knives of Democritus -- Quarks inside atomic nuclei -- Quantum electrodynamics -- Quantum chromodynamics -- Mesons, baryons, and quarks -- Electroweak interactions -- Grand unification -- Conclusion.

  10. Elementary Particles

    Science.gov (United States)

    Parham, R.

    1974-01-01

    Presents the text of a speech given to a conference of physics teachers in which the full spectrum of elementary particles is given, along with their classification. Also includes some teaching materials available on this topic. (PEB)

  11. Particle identification

    International Nuclear Information System (INIS)

    A variety of subjects are addressed within the general context of searching for limitations in capability of particle identification due to high average rates. Topics receiving attention included Cerenkov ring imaging, transition radiation, synchrotron radiation, time-of-flight, high P spectrometer, heavy quark tagging with leptons, general purpose muon and electron detector, and dE/dx. It is concluded that particle identification will probably not represent a primary obstacle at luminosities of 1033cm-2sec-1

  12. Higgs particles

    International Nuclear Information System (INIS)

    The theoretical work on models of the electroweak interaction and simple grand unified models with a nonstandard set of Higgs particles is reviewed. Emphasis is placed on light and even strictly massless Higgs particles: Goldstone and pseudo-Goldstone bosons. It is shown that such bosons arise in a natural way in the theory if the Higgs particles are in fact composite. The low-energy effective Lagrangian of these particles is studied. A detailed study is made of the problem of CP breaking in a strong interaction and of a natural solution of this problem through the introduction of a pseudo-Goldstone particle: an axion. The theory of the ''standard'' axion and its experimental status are reviewed. Possible ''invisible'' and ''visualized'' axions are discussed, as are certain astrophysical aspects of the existence of an axion. By analogy with the axion, an analysis is made of another hypothetical particle: the strictly massless Goldstone boson or arion. Model-independent properties of the arion are determined. The similarity between the arion fields and magnetic fields and the differences between these fields are shown. Possible methods for detecting an arion field are discussed. An experiment which has set a limit on the strength of the arion interaction is described. Neutral Goldstone bosons whose emission is accompanied by changes in fermion flavors (''familons'') are discussed. Two versions of the theory with a Goldstone boson (a majoron) which arises upon a spontaneous breaking of lepton number are described

  13. Carbon particles

    Science.gov (United States)

    Hunt, Arlon J.

    1984-01-01

    A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

  14. Particle detectors

    CERN Document Server

    Joram, Christian

    1998-01-01

    The lecture series will present and overview of the basic techniques and underlying physical principles of particle detectors, applied to current and future high energy physics experiments. Illustrating examples, mainly from the field of collider experiments, will demonstrate the performance and limitations of the various techniques. After and introduction we shall concentrate on particle tracking. Wire chambers, drift chambers, micro gaseous tracking devices and solid state trackers will be discussed. It follows and overview of scintillators, photon detection, fiber tracking and nuclear emulsions. One lecture will deal with the various techniques of calorimetry. Finally we shall focus on methods developed for particle identification. These comprise specific energy loss, time of flight Cherenkov and transition radiation detectors.

  15. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen; CERN. Geneva

    1991-01-01

    Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...

  16. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  17. Particle Physics

    CERN Multimedia

    2005-01-01

    While biomedicine and geoscience use grids to bring together many different sub-disciplines, particle physicists use grid computing to increase computing power and storage resources, and to access and analyze vast amounts of data collected from detectors at the world's most powerful accelerators (1 page)

  18. Particle blender

    International Nuclear Information System (INIS)

    An infinite blender that achieves a homogeneous mixture of fuel microspheres is provided. Blending is accomplished by directing respective groups of desired particles onto the apex of a stationary coaxial cone. The particles progress downward over the cone surface and deposit in a space at the base of the cone that is described by a flexible band provided with a wide portion traversing and in continuous contact with the circumference of the cone base and extending upwardly therefrom. The band, being attached to the cone at a narrow inner end thereof, causes the cone to rotate on its arbor when the band is subsequently pulled onto a take-up spool. As a point at the end of the wide portion of the band passes the point where it is tangent to the cone, the blended particles are released into a delivery tube leading directly into a mold, and a plate mounted on the lower portion of the cone and positioned between the end of the wide portion of the band and the cone assures release of the particles only at the tangent point

  19. Particle identification

    International Nuclear Information System (INIS)

    Particle IDentification (PID) is fundamental to particle physics experiments. This paper reviews PID strategies and methods used by the large LHC experiments, which provide outstanding examples of the state-of-the-art. The first part focuses on the general design of these experiments with respect to PID and the technologies used. Three PID techniques are discussed in more detail: ionization measurements, time-of-flight measurements and Cherenkov imaging. Four examples of the implementation of these techniques at the LHC are given, together with selections of relevant examples from other experiments and short overviews on new developments. Finally, the Alpha Magnetic Spectrometer (AMS 02) experiment is briefly described as an impressive example of a space-based experiment using a number of familiar PID techniques.

  20. Particle acceleration

    Science.gov (United States)

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  1. Particle hunters

    International Nuclear Information System (INIS)

    This century has been the century of atom constituents and of elementary particles. The electron was discovered at the very end of last century and now we are waiting for the experimental confirmation of the existence of Higgs boson. The discovery of neutrons in 1932 let out the existence of 2 new forces: the strong interaction that counterbalances the repulsive Coulomb force between protons inside the nucleus and the weak interaction that triggers the decay of the neutron. Another milestone in particle physics was the replacement of hadrons (more than 100 particles) by their constituents: a mere mix of 3 quarks and their antiparticles. The standard model was introduced in 1919 by H.Weyl, who later made it suitable for electromagnetism. This model was generalized in 1953 and in 1973-1975 it was proving fundamental for all the interactions but gravitation. Today theoretical speculations attempting to unify gravitation to the other interactions are made, they are based on super-cord and super-membrane models. The authors describe the progress of physics through this century. (A.C.)

  2. Particle physics

    International Nuclear Information System (INIS)

    The two main themes of this volume are the standard model of the fundamental interactions (and beyond) and astrophysics. The remarkable advances in the theoretical understanding and experimental confirmation of the standard model were reviewed in several lectures where the reader will find a thorough analysis of recent experiments as well as a detailed comparison of the standard model with experiment. On a more theoretical side, supersymmetry, supergravity and strings were discussed as well. The second theme concerns astrophysics where the school was quite successful in bridging the gap between this fascinating subject and more conventional particle physics

  3. New particles

    International Nuclear Information System (INIS)

    Current state of art in the discovery of new elementary particles is reviewed. At present, quarks and mesons are accepted as the basic constituents of matter. The charmonium model (canti-c system), and the 'open charm' are discussed. Explanations are offered for the recent discovery of the heavy lepton tau. Quark states such as the beauty and taste are also dealt with at length. The properties of the tanti-t bound system are speculated. It is concluded that the understanding of canti-c and banti-b families is facilitated by the assumption of the quarkonium model. Implications at the astrophysical level are indicated. (A.K.)

  4. Particle spectroscopy

    International Nuclear Information System (INIS)

    During the last years, particle spectroscopy has evolved into the spectroscopy of leptons and quarks. This era was initiated in 1974 by the discovery of J/psi mesons, quickly followed by new lepton Tau and finally Ypsilon mesons. In this report, talk is concentrated on one specific old hadrons, namely exotics. The main part is then devoted to the new quarks charm and beauty. As for the exotics, baryonium in its broad and narrow states, dibaryons, and exotic quantum numbers are described. There is no firm evidence for exotic quantum numbers so far. Consequently, both experiments and theory have to be improved. Next, new quark spectroscopy is described on quark charge, charm (charmonium, charm particles, F mesons), and beauty. Description of the beauty is further divided into Ypsilon parameters, event topology, quark jets, change of topology at the Ypsilon, other properties of events in the Ypsilon region, Ypsilon summary, and Ypsilon prime. As seen above, in addition to the charm quark, there is now ample evidence for the existence of a new heavy quark which is most probably of the 'beauty' type. To answer the question whether a 6th quark t would constitute perfect symmetry between leptons and quarks, again the answer can now only be: PETRA works and CESR and PEP will follow soon. (Wakatsuki, Y.)

  5. Azimuthal Anisotropy of Identified Hadrons in 200 GeV Au+Au Collisions

    CERN Document Server

    Oldenburg, M

    2006-01-01

    The azimuthal anisotropy parameter v2 has been measured with high statistics for identified hadrons in sqrt(s_NN) = 200 GeV Au+Au collisions with the STAR experiment. At high transverse momentum (pT) a strong v2 for pi+ + pi- and p + pbar is observed. In the intermediate pT region, number-of-constituent-quark scaling was tested to high precision. A detailed comparison of v2 for the multi-strange hadrons phi, Xi + anti-Xi, and Omega + anti-Omega with other particle species substantiates the development of collectivity among partons in the early phase of the collisions at RHIC.

  6. Nucleation of atmospheric particles

    OpenAIRE

    Curtius J

    2009-01-01

    Two types of particles exist in the atmosphere, primary and secondary particles. While primary particles such as soot, mineral dust, sea salt particles or pollen are introduced directly as particles into the atmosphere, secondary particles are formed in the atmosphere by condensation of gases. The formation of such new aerosol particles takes place frequently and at a broad variety of atmospheric conditions and geographic locations. A considerable fraction of the atmospheric particles is form...

  7. Microfabricated particle focusing device

    Energy Technology Data Exchange (ETDEWEB)

    Ravula, Surendra K.; Arrington, Christian L.; Sigman, Jennifer K.; Branch, Darren W.; Brener, Igal; Clem, Paul G.; James, Conrad D.; Hill, Martyn; Boltryk, Rosemary June

    2013-04-23

    A microfabricated particle focusing device comprises an acoustic portion to preconcentrate particles over large spatial dimensions into particle streams and a dielectrophoretic portion for finer particle focusing into single-file columns. The device can be used for high throughput assays for which it is necessary to isolate and investigate small bundles of particles and single particles.

  8. Particle kickers

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    These devices are designed to provide a current pulse of 5000 Amps which will in turn generate a fast magnetic pulse that steers the incoming beam into the LHC. Today, the comprehensive upgrade of the LHC injection kicker system is entering its final stages. The upgraded system will ensure the LHC can be refilled without needing to wait for the kicker magnets to cool, thus enhancing the performance of the whole accelerator.   An upgraded kicker magnet in its vacuum tank, with an upgraded beam screen. The LHC is equipped with two kicker systems installed at the injection points (near points 2 and 8, see schematic diagram) where the particle beams coming from the SPS are injected into the accelerator’s orbit. Each system comprises four magnets and four pulse generators in which the field rises to 0.12 Tesla in less than 900 nanoseconds and for a duration of approximately 8 microseconds. Although the injection kickers only pulse 12 times to fill the LHC up with beam, the LHC beam circ...

  9. Review of Particle Physics Particle Data Group

    OpenAIRE

    Beringer, J.; Arguin, J.-F.; R.M. Barnett; Copic, K.; Dahl, O; Groom, D. E.; Lin, C.-J.; Lys, J.; Murayama, H.; Wohl, C. G.; Yao, W.-M.; Zyla, P. A.; Amsler, C; Antonelli, M.; Asner, D. M.

    2012-01-01

    This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews...

  10. Particle-particle interactions in the Complex Particle Kinetics Method

    Science.gov (United States)

    Larson, David; Hewett, Dennis

    2004-11-01

    Unlike traditional particle-in-cell (PIC) simulation particles, the CPK (Complex Particle Kinetics) method [1] allows particles with a Gaussian spatial profile and a Mawellian velocity distribution to evolve self-consistently. Recent ideas for selective merging allow for adaptive resolution of highly dynamic regions. The combination of the CPK algorithm with a recently developed Coulomb collision algorithm [2] allows simulation of plasmas in the previously very costly partially-collisional regime. Plasmas with finite collisionality play a role in many AGEX, e.g. high-temperature hohlraums and fast igniter. A new algorithm for particle interaction allows the extension of the CPK method to the continuum regime. We will present progress towards our goal of simulating the transition from continuum to fully kinetic physics, including results from various 1 and 2D simulations. [1] D.W. Hewett, J. Comp. Phys. 189 (2003). [2] D. J. Larson, J. Comp. Phys. 188 (2003).

  11. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  12. Review of particle properties. Particle Data Group

    International Nuclear Information System (INIS)

    This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Rev. Mod. Phys. 48 (1976) No. 2, Part II; and Supplement, Phys. Lett. 68B (1977) 1]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available

  13. A fluid particle model

    OpenAIRE

    Español, Pep

    1997-01-01

    We present a mechanistic model for a Newtonian fluid called fluid particle dynamics. By analyzing the concept of ``fluid particle'' from the point of view of a Voronoi tessellation of a molecular fluid, we propose an heuristic derivation of a dissipative particle dynamics algorithm that incorporates shear forces between dissipative particles. The inclusion of these non-central shear forces requires the consideration of angular velocities of the dissipative particles in order to comply with th...

  14. Particle capture device

    Energy Technology Data Exchange (ETDEWEB)

    Jayne, John T.; Worsnop, Douglas R.

    2016-02-23

    In example embodiments, particle collection efficiency in aerosol analyzers and other particle measuring instruments is improved by a particle capture device that employs multiple collisions to decrease momentum of particles until the particles are collected (e.g., vaporized or come to rest). The particle collection device includes an aperture through which a focused particle beam enters. A collection enclosure is coupled to the aperture and has one or more internal surfaces against which particles of the focused beam collide. One or more features are employed in the collection enclosure to promote particles to collide multiple times within the enclosure, and thereby be vaporized or come to rest, rather than escape through the aperture.

  15. The Particle Hunters

    Science.gov (United States)

    Ne'eman, Yuval; Kirsh, Yoram

    1996-04-01

    Preface to the first edition; Preface to the second edition; 1. The building blocks of the atom; 2. Physical laws for small particles; 3. The discoveries of the 1930s and 1940s; 4. Particle accelerators - or from hunters to farmers; 5. Strange particles; 6. Basic forces and the classification of particles; 7. Conservation laws; 8. Short-lived particles; 9. To the quarks - via the eightfold way; 10. More quarks - or charm, truth and beauty; 11. The standard model and beyond; Appendix 1. Properties of semi-stable particles; Appendix 2. The Greek alphabet; Name index; Subject index.

  16. A spray of particles

    CERN Multimedia

    1982-01-01

    These tracks are produced by high energy particles that have been created in the collision of a proton and an antiproton in the SPS collider at CERN. Particle detectors use electronics and complicated devices to recreate the tracks left by real particles. Such detectors are usually embedded in a strong magnetic field, causing the charged particles to follow a curved path so that they can be identified and measurements can be made of their momentum.

  17. Classical confined particles

    Science.gov (United States)

    Horzela, Andrzej; Kapuscik, Edward

    1993-01-01

    An alternative picture of classical many body mechanics is proposed. In this picture particles possess individual kinematics but are deprived from individual dynamics. Dynamics exists only for the many particle system as a whole. The theory is complete and allows to determine the trajectories of each particle. It is proposed to use our picture as a classical prototype for a realistic theory of confined particles.

  18. Beyond the God particle

    CERN Document Server

    Lederman, Leon M

    2013-01-01

    On July 4, 2012, the long-sought Higgs Boson--aka "the God Particle"--was discovered at the world's largest particle accelerator, the LHC, in Geneva, Switzerland. On March 14, 2013, physicists at CERN confirmed it. This elusive subatomic particle forms a field that permeates the entire universe, creating the masses of the elementary particles that are the basic building blocks of everything in the known world--from viruses to elephants, from atoms to quasars.

  19. Review of particle physics

    OpenAIRE

    Beringer, J.; Arguin, JF; Barnett, RM; Copic, K.; Dahl, O; Groom, DE; Lin, CJ; Lys, J.; Murayama, H.; Wohl, CG; Yao, WM; Zyla, PA; Amsler, C; Antonelli, M.; Asner, DM

    2012-01-01

    This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews...

  20. When is a Particle?

    Science.gov (United States)

    Drell, Sidney D.

    1978-01-01

    Gives a new definition for the concept of the elementary particle in nuclear physics. Explains why the existance of the quark as an elementary particle could be an accepted fact even though it lacks what traditionally identifies a particle. Compares this with the development which took place during the discovery of the neutrino in the early…

  1. Anatomy of Particle Diffusion

    Science.gov (United States)

    Bringuier, E.

    2009-01-01

    The paper analyses particle diffusion from a thermodynamic standpoint. The main goal of the paper is to highlight the conceptual connection between particle diffusion, which belongs to non-equilibrium statistical physics, and mechanics, which deals with particle motion, at the level of third-year university courses. We start out from the fact…

  2. The Particle Enigma

    CERN Document Server

    Marsh, Gerald E

    2016-01-01

    The idea that particles are the basic constituents of all matter dates back to ancient times and formed the basis of physical thought well into modern times. The debate about whether light was a wave or a stream of particles also lasted until relatively recently. It was the advent of de Broglie's work and its implications that revolutionized the concept of an elementary particle -- but unfortunately did not banish the idea of a point particle despite its difficulties in both classical and quantum physics. Some of these problems are discussed in this essay, which covers chiral oscillations, Penrose's "zigzag" picture of particles satisfying the Dirac equation, and some ideas derived from string theory.

  3. Review of particle properties

    International Nuclear Information System (INIS)

    This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 2300 new measurements from 700 papers, we list evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, monopoles, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review

  4. Individual particle analyses

    Science.gov (United States)

    Cowen, James P.

    Marine particulate matter consists of a complex, heterogeneous population of reactive and interactive particles. In oligotrophic oceans, particles are produced primarily by phytoplankton within the euphotic zone. Secondary production by bacterioplankton is also an important source of particles and mid-water column chemolithoautotrophy or horizontal advection may provide additional new particles [Sorokin, 1971; Pomeroy, 1974; Sieburth, 1976; Lambert et al., 1981; Karl et al., 1984]. Aeolian input can be an important source of abiogenic particles such as clay minerals [Sutcliffe et al., 1963; Buat-Menard and Chesselet, 1979; Deuser et al., 1981, 1983] while other abiogenic particles may precipitate or flocculate in situ [McCave, 1984; Feely et al., 1990]. In coastal area rivers, runoff, and resuspension can provide additional important sources of particles.

  5. What is a particle?

    International Nuclear Information System (INIS)

    Theoretical developments related to gravitational interaction have questioned the notion of particle in quantum field theory (QFT). For instance, uniquely defined particle states do not exist in general, in QFT on a curved spacetime. More generally, particle states are difficult to define in a background-independent quantum theory of gravity. These difficulties have led some to suggest that in general QFT should not be interpreted in terms of particle states, but rather in terms of eigenstates of local operators. Still, it is not obvious how to reconcile this view with the empirically-observed ubiquitous particle-like behavior of quantum fields, apparent for instance in experimental high-energy physics, or 'particle' physics. Here we offer an element of clarification by observing that already in flat space there exist-strictly speaking-two distinct notions of particles: globally defined n-particle Fock-states and local particle states. The last describes the physical objects detected by finite-size particle detectors and are eigenstates of local field operators. In the limit in which the particle detectors are appropriately large, global and local particle states converge in a weak topology (but not in norm). This observation has little relevance for flat-space theories-it amounts to a reminder that there are boundary effects in realistic detectors-but is relevant for gravity. It reconciles the two points of view mentioned above. More importantly, it provides a definition of the local particle state that remains well defined even when the conventional global particle states are not defined. This definition plays an important role in quantum gravity.

  6. Fuzzy Logic Particle Tracking

    Science.gov (United States)

    2005-01-01

    A new all-electronic Particle Image Velocimetry technique that can efficiently map high speed gas flows has been developed in-house at the NASA Lewis Research Center. Particle Image Velocimetry is an optical technique for measuring the instantaneous two component velocity field across a planar region of a seeded flow field. A pulsed laser light sheet is used to illuminate the seed particles entrained in the flow field at two instances in time. One or more charged coupled device (CCD) cameras can be used to record the instantaneous positions of particles. Using the time between light sheet pulses and determining either the individual particle displacements or the average displacement of particles over a small subregion of the recorded image enables the calculation of the fluid velocity. Fuzzy logic minimizes the required operator intervention in identifying particles and computing velocity. Using two cameras that have the same view of the illumination plane yields two single exposure image frames. Two competing techniques that yield unambiguous velocity vector direction information have been widely used for reducing the single-exposure, multiple image frame data: (1) cross-correlation and (2) particle tracking. Correlation techniques yield averaged velocity estimates over subregions of the flow, whereas particle tracking techniques give individual particle velocity estimates. For the correlation technique, the correlation peak corresponding to the average displacement of particles across the subregion must be identified. Noise on the images and particle dropout result in misidentification of the true correlation peak. The subsequent velocity vector maps contain spurious vectors where the displacement peaks have been improperly identified. Typically these spurious vectors are replaced by a weighted average of the neighboring vectors, thereby decreasing the independence of the measurements. In this work, fuzzy logic techniques are used to determine the true

  7. Experiments with particle damping

    Science.gov (United States)

    Hollkamp, Joseph J.; Gordon, Robert W.

    1998-06-01

    High cycle fatigue in jet engines is a current military concern. The vibratory stresses that cause fatigue can be reduced by adding damping. However, the high temperatures that occur in the gas turbine greatly hinder the application of mature damping technologies. One technology which may perform in the harsh environment is particle damping. Particle damping involves placing metallic or ceramic particles inside structural cavities. As the cavity vibrates, energy is dissipated through particle collisions. Performance is influenced by many parameters including the type, shape, and size of the particles; the amount of free volume for the particles to move in; density of the particles; and the level of vibration. This paper presents results from a series of experiments designed to gain an appreciation of the important parameters. The experimental setup consists of a cantilever beam with drilled holes. These holes are partially filled with particles. The types of particles, location of the particles, fill level, and other parameters are varied. Damping is estimated for each configuration. Trends in the results are studied to determine the influence of the varied parameter.

  8. Lecture II. Charmed particle spectroscopy

    International Nuclear Information System (INIS)

    The discussion of charmed particle spectroscopy covers the particle properties and interrelations from a charmed quark composition point of view including SU(4)-symmetry generalities, mesons, baryons, charmed particle masses, and decays of charmed particles. 6 references

  9. Particle Swarm Optimization

    Science.gov (United States)

    Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw

    2002-01-01

    The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.

  10. Methods for forming particles

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  11. LHCb unveils new particles

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    The LHCb collaboration announces the observation of four “exotic” particles from its analysis of the LHC data.   The LHCb experimental cavern. On 28 June, the LHCb collaboration reported the observation of three new "exotic" particles and confirmation of the existence of a fourth one in data from the LHC. These particles each appear to be formed by four quarks (the fundamental constituents of the matter inside all the atoms of the universe): two quarks and two antiquarks (that is, a tetraquark). Due to their non-standard quark content, the newly observed particles have been included in the broad category of so-called exotic particles, although their exact theoretical interpretation is still under study.            The quark model, proposed by Murray Gell-Mann and George Zweig in 1964, is considered to be the most valid scheme for the classification of hadrons (all the composite particles) that has been fou...

  12. Light scattering by cosmic particles

    OpenAIRE

    Hovenier, J.W.; Min, M.

    2008-01-01

    We define cosmic particles as particles outside the Earth. Two types of cosmic particles can be distinguished, namely liquid and solid particles. The solid particles are often called grains or cosmic dust particles. Cosmic particles occur in a great variety of astronomical objects and environments. At light scattering conferences most attention is usually paid to Solar System bodies. The main purpose of this contribution is to provide a brief introduction to light scattering by cosmic particl...

  13. Music of elementary particles

    Energy Technology Data Exchange (ETDEWEB)

    Sternheimer, J.

    1983-12-12

    This note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter.

  14. Trapping of photophoretic particles

    CERN Document Server

    Magiera, Martin P

    2014-01-01

    A trapping mechanism for self-propelled particles based on an inhomogeneous drive is presented and studied analytically as well as by computer simulations. In experiments this method can be realized using photophoretic Janus particles driven by a light source, which shines through a shading mask and leads to an accumulation of the swimmers in the shaded part. The mechanism can be traced back to a finite penetration depth of particles impinging from the illuminated part of the system into the shaded part.

  15. Music of elementary particles

    International Nuclear Information System (INIS)

    This Note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter

  16. Feedback Particle Filter

    OpenAIRE

    Yang, Tao; Mehta, Prashant G.; Meyn, Sean P.

    2013-01-01

    A new formulation of the particle filter for nonlinear filtering is presented, based on concepts from optimal control, and from the mean-field game theory. The optimal control is chosen so that the posterior distribution of a particle matches as closely as possible the posterior distribution of the true state given the observations. This is achieved by introducing a cost function, defined by the Kullback-Leibler (K-L) divergence between the actual posterior, and the posterior of any particle....

  17. Anyons as spinning particles

    OpenAIRE

    Cortes, J. L.; Plyushchay, M. S.

    1995-01-01

    A model-independent formulation of anyons as spinning particles is presented. The general properties of the classical theory of (2+1)-dimensional relativistic fractional spin particles and some properties of their quantum theory are investigated. The relationship between all the known approaches to anyons as spinning particles is established. Some widespread misleading notions on the general properties of (2+1)-dimensional anyons are removed.

  18. Particle physics experiments 1983

    International Nuclear Information System (INIS)

    The report describes work carried out in 1983 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)

  19. Elementary particle theory

    International Nuclear Information System (INIS)

    The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references

  20. Particle separation by dielectrophoresis

    OpenAIRE

    Gascoyne, Peter R.C.; Vykoukal, Jody

    2002-01-01

    The application of dielectrophoresis to particle discrimination, separation, and fractionation is reviewed, some advantages and disadvantages of currently available approaches are considered, and some caveats are noted.

  1. Unstable Particles near Threshold

    CERN Document Server

    Chway, Dongjin; Kim, Hyung Do

    2015-01-01

    We explore physics of unstable particles when mother particle mass is around the sum of its daughter particle masses. In this case, the conventional wave function renormalization factor is ill-defined. We propose a simple resolution of the threshold singularity problem which still allows the use of narrow width approximation by defining branching ratio in terms of spectral density. The resonance peak and shape is different for different decay channels and no single decay width can be assigned to the unstable particles. Non-exponential decay happens in all time scales.

  2. Bioactivation of particles

    Science.gov (United States)

    Pinaud, Fabien; King, David; Weiss, Shimon

    2011-08-16

    Particles are bioactivated by attaching bioactivation peptides to the particle surface. The bioactivation peptides are peptide-based compounds that impart one or more biologically important functions to the particles. Each bioactivation peptide includes a molecular or surface recognition part that binds with the surface of the particle and one or more functional parts. The surface recognition part includes an amino-end and a carboxy-end and is composed of one or more hydrophobic spacers and one or more binding clusters. The functional part(s) is attached to the surface recognition part at the amino-end and/or said carboxy-end.

  3. Review of particle properties

    International Nuclear Information System (INIS)

    In this Review, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, the top quark, heavy neutrinos, monopoles, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some other sections of this full Review

  4. Particle Swarm Optimisation with Spatial Particle Extension

    DEFF Research Database (Denmark)

    Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques

    In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed to...

  5. RESEARCH IN PARTICLE PHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Kearns, Edward [Boston Universiy

    2013-07-12

    This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

  6. Teaching particle physics

    CERN Document Server

    Hanley, P

    2000-01-01

    Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students. (0 refs).

  7. When is a particle

    International Nuclear Information System (INIS)

    The concept of elementary constituents or ultimate building blocks of nature in recent years is reviewed. The quark hypothesis, neutrinos, color, hard collisions, psi and other recent resonances, flavor, quantum chromodynamics, the tau particle, and particle structure are among the ideas considered. 22 references

  8. Introduction to particle physics

    International Nuclear Information System (INIS)

    This book proposes an introduction to particle physics that requires only a high-school level mathematical knowledge. Elementary particles (leptons, quarks, bosons) are presented according to a modern view taking into account of their symmetries and interactions. The author shows how physicists have elaborated the standard model and what are its implications in cosmology. (J.S.)

  9. Particle physics instrumentation

    International Nuclear Information System (INIS)

    This report summarizes a series of three lectures aimed at giving an overview of basic particle detection principles, the interaction of particles with matter, the application of these principles in modern detector systems, as well techniques to read out detector signals in high-rate experiments. (author)

  10. Particle density fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, M.M.; Ahammed, Z.; Angelis, A.L.S.; Antonenko, V.; Arefiev, V.; Astakhov, V.; Avdeitchikov, V.; Awes, T.C.; Baba, P.V.K.S.; Badyal, S.K.; Bathe, S.; Batiounia, B.; Bernier, T.; Bhalla, K.B.; Bhatia, V.S.; Blume, C.; Bucher, D.; Buesching, H.; Carlen, L.; Chattopadhyay, S.; Das, A.C.; Decowski, M.P.; Donni, P.; Dubey, A.K.; Dutta Majumdar, M.R.; Enosawa, K.; Fokin, S.; Frolov, V.; Ganti, M.S.; Garpman, S.; Gavrishcuk, O.; Geurts, F.J.M.; Glasow, R.; Guskov, B.; Gustafsson, H.A.; Gutbrod, H.H.; Hrivnacova, I.; Ippolitov, M.; Kalechofsky, H.; Kamermans, R.; Karadjev, K.; Karpio, K.; Kolb, B.W.; Kosarev, I.; Koutcheryaev, I.; Kugler, A.; Kulinich, P.; Kurata, M.; Lebedev, A.; Loehner, H.; Mahapatra, D.P.; Manko, V.; Martin, M.; Miake, Y.; Mishra, G.C.; Mohanty, B.; Morrison, D.; Mukhopadhayay, D.S.; Naef, H.; Nandi, B.K.; Nayak, S.K.; Nayak, T.K.; Nianine, A.; Nikitine, V.; Nikolaev, S.; Nishimura, S.; Nomokov, P.; Petracek, V.; Plasil, F.; Purschke, M.L.; Rak, J.; Raniwala, R.; Raniwala, S.; Rao, N.K.; Retiere, F.; Reygers, K.; Roland, G.; Rosselet, L.; Roufanov, I.; Rubio, J.M.; Sambyal, S.S.; Santo, R.; Sato, S.; Schlagheck, H.; Schmidt, H.-R.; Schutz, Y.; Shabratova, G.; Sibiriak, I.; Siemiarczuk, T.; Sinha, B.C.; Slavine, N.; Soederstroem, K.; Sood, G.; Soerensen, S.P.; Stankus, P.; Steinberg, P.; Stenlund, E.; Sumbera, M.; Svensson, T.; Trivedi, M.D.; Tsvetkov, A.; Tykarski, L.; Urbahn, J.; Eijinhoven, N. van; Niewenhuizen, G.J. van; Vinogradov, A.; Viyogi, Y.P.; Vodopianov, A.; Voeroes, S.; Wyslouch, B.; Young, G.R

    2003-03-10

    Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals.

  11. Particle density fluctuations

    International Nuclear Information System (INIS)

    Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals

  12. Microchip Coulter particle counter

    DEFF Research Database (Denmark)

    Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.

    1997-01-01

    This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...

  13. Optics of charged particles

    International Nuclear Information System (INIS)

    Suitable for both the specialist and non-specialist, this book develops all statements from first principles. Key chapters of the book focus upon how to design particle-optical systems, the systematics of image abberations, the effects of fringing fields, systematics of beams, and solutions for particle-optical systems. An undergraduate background in physics and mathematics is required for this work

  14. Single-particle entanglement

    OpenAIRE

    Can, M. Ali; Klyachko, Alexander; SHUMOVSKY, Alexander

    2004-01-01

    Using the approach to quantum entanglement based on the quantum fluctuations of observables, we show the existence of perfect entangled states of a single "spin-1" particle. We give physical examples related to the photons, condensed matter physics, and particle physics.

  15. Imaging alpha particle detector

    Science.gov (United States)

    Anderson, D.F.

    1980-10-29

    A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  16. DEM Particle Fracture Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Boning [Univ. of Colorado, Boulder, CO (United States); Herbold, Eric B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homel, Michael A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Regueiro, Richard A. [Univ. of Colorado, Boulder, CO (United States)

    2015-12-01

    An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.

  17. Are All Particles Identical?

    CERN Document Server

    Goldstein, S; Tumulka, R; Zanghì, N; Goldstein, Sheldon; Taylor, James; Tumulka, Roderich; Zanghi, Nino

    2005-01-01

    We consider the possibility that all particles in the world are fundamentally identical, i.e., belong to the same species. Different masses, charges, spins, flavors, or colors then merely correspond to different quantum states of the same particle, just as spin-up and spin-down do. The implications of this viewpoint can be best appreciated within Bohmian mechanics, a precise formulation of quantum mechanics with particle trajectories. The implementation of this viewpoint in such a theory leads to trajectories different from those of the usual formulation, and thus to a version of Bohmian mechanics that is inequivalent to, though arguably empirically indistinguishable from, the usual one. The mathematical core of this viewpoint is however rather independent of the detailed dynamical scheme Bohmian mechanics provides, and it amounts to the assertion that the configuration space for N particles, even N ``distinguishable particles,'' is the set of all N-point subsets of physical 3-space.

  18. Energetic solar particle events

    International Nuclear Information System (INIS)

    Studies of the arrival directions of energetic solar particles during ground level enhancements (CLE's) observed by neutron monitors have shown that, in general, in the first hour of the event most of the particles arrive with a distribution of pitch angles peaked about the garden hose field direction in the vicinity of Earth. During the first hour some of the particles arrive from the antisolar direction, while in later stages of the event the intensity becomes more nearly isotropic as a result of scattering of particles in interplanetary space. An attempt is made to determine the arrival directions of the particles during the early stages of the GLE of 16 February 1984 using the data currently available from high latitude neutron monitors near sea level where the cut off is essentially atmospheric (approx. LGV)

  19. Macroscopic Quantum State Analyzed Particle by Particle

    OpenAIRE

    Beduini, Federica A.; Zielińska, Joanna A.; Lucivero, Vito G.; de Icaza Astiz, Yannick A.; Mitchell, Morgan W.

    2015-01-01

    Explaining how microscopic entities collectively produce macroscopic phenomena is a fundamental goal of many-body physics. Theory predicts that large-scale entanglement is responsible for exotic macroscopic phenomena, but observation of entangled particles in naturally occurring systems is extremely challenging. Synthetic quantum systems made of atoms in optical lattices have been con- structed with the goal of observing macroscopic quantum phenomena with single-atom resolution. Serious chall...

  20. General defocusing particle tracking.

    Science.gov (United States)

    Barnkob, Rune; Kähler, Christian J; Rossi, Massimiliano

    2015-09-01

    A General Defocusing Particle Tracking (GDPT) method is proposed for tracking the three-dimensional motion of particles in Lab-on-a-chip systems based on a set of calibration images and the normalized cross-correlation function. In comparison with other single-camera defocusing particle-tracking techniques, GDPT possesses a series of key advantages: it is applicable to particle images of arbitrary shapes, it is intuitive and easy to use, it can be used without advanced knowledge of optics and velocimetry theory, it is robust against outliers and overlapping particle images, and it requires only equipment which is standard in microfluidic laboratories. We demonstrate the method by tracking the three-dimensional motion of 2 μm spherical particles in a microfluidic channel using three different optical arrangements. The position of the particles was measured with an estimated uncertainty of 0.1 μm in the in-plane direction and 2 μm in the depth direction for a measurement volume of 1510 × 1270 × 160 μm(3). A ready-to-use GUI implementation of the method can be acquired on . PMID:26201498

  1. Detection of ''hot particles''

    International Nuclear Information System (INIS)

    Activities for this project include systematic analysis of the specialized literature and screening of the various subject-specific reports of studies performed in the CIS; identification of open questions, particularly relating to the ''hot particle'' measuring methods. Investigation of unresolved questions in connection with the measuring techniques and uncertainties resulting from inhomogenous radioactivity distributions due to the ''hot particles''; testing of the major measuring methods for assessment of error potentials due to ''hot particles'' in the material; cost/benefit analysis with respect to the relation of technical efforts/expense and results obtained with the various measuring techniques. (orig./CB)

  2. Search for new particles

    International Nuclear Information System (INIS)

    The following topics are discussed briefly: Free quarks, Axions, Right-handed charged weak currents, Higgs particles, Top quarks, Generations -sequential heavy leptons, - exotic heavy leptions, - neutrino counting, - familons, Supersymmetric particles, Composite leptons, Magnetic monopoles. The experiments which are reviewed here employ two different methods. One way is to study a known process very precisely. Another way is to plan an experiment or choose analysis parameters in accordance with the predicted characteristics of the particle in order to remove the background. Usually the latter method is sensitive to a few events, but the former can lead to an unexpected surprise. (orig./HSI)

  3. Sources for charged particles

    International Nuclear Information System (INIS)

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

  4. Universe of Particles

    CERN Multimedia

    CERN Video Productions

    2010-01-01

    The entire Universe is made up of particles. But where do they come from? What is the origin of the laws of nature? The permanent exhibition "Universe of Particles", installed on the ground floor of the Globe of Science and Innovation, invites you to discover CERN by taking you on a journey all the way back to the Big Bang. It will help you answer questions such as: What's the purpose of this research? How do you accelerate particles? How do you detect them? What are today's theories on matter and the Universe? How does this affect our daily life?

  5. Particle physics builds potential

    CERN Document Server

    Camporesi, Tiziano

    2004-01-01

    Surveys of the career prospects of particle physicists in Europe, such as that one carried out in 2000 at DELPHI, reveal that particle phycisists are much in demand. The findings are fairly independent of a student's nationality, despite the big differences in the education systems of different countries across the continent. According to the DELPHI survey, half of all physics students remain in an academic environment after graduation. For those particle physicists who leave academia, the DELPHI survey showed that about half find jobs in hi- tech industry. The bottom line is that a degree in physics offers very good job prospects and career opportunities. (Edited abstract).

  6. Particle physics experiments 1989

    International Nuclear Information System (INIS)

    This report describes work carried out in 1989 on experiments approved by the Particle Physics Experiments Selection Panel of Rutherford Appleton Laboratory. The contents consist of unedited contributions from each experiment. (author)

  7. Alpha-particle diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Young, K.M.

    1991-01-01

    This paper will focus on the state of development of diagnostics which are expected to provide the information needed for {alpha}- physics studies in the future. Conventional measurement of detailed temporal and spatial profiles of background plasma properties in DT will be essential for such aspects as determining heating effectiveness, shaping of the plasma profiles and effects of MHD, but will not be addressed here. This paper will address (1) the measurement of the neutron source, and hence {alpha}-particle birth profile, (2) measurement of the escaping {alpha}-particles and (3) measurement of the confined {alpha}-particles over their full energy range. There will also be a brief discussion of (4) the concerns about instabilities being generated by {alpha}-particles and the methods necessary for measuring these effects. 51 refs., 10 figs.

  8. Particle physics experiments 1987

    International Nuclear Information System (INIS)

    This report describes work carried out in 1987 on experiments approved by the Particle Physics Experiments Selection Panel (United Kingdom). The contents consist of unedited contributions from each experiment. (author)

  9. Search for Hidden Particles

    CERN Multimedia

    The SHiP Experiment is a new general-purpose fixed target facility at the SPS to search for hidden particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating dark matter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. Specifically, the experiment is aimed at searching for very weakly interacting long lived particles including Heavy Neutral Leptons - right-handed partners of the active neutrinos; light supersymmetric particles - sgoldstinos, etc.; scalar, axion and vector portals to the hidden sector. The high intensity of the SPS and in particular the large production of charm mesons with the 400 GeV beam allow accessing a wide variety of light long-lived exotic particles of such models and of SUSY. Moreover, the facility is ideally suited to study the interactions of tau neutrinos.

  10. Elementary particle interactions

    International Nuclear Information System (INIS)

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out

  11. When is a particle

    International Nuclear Information System (INIS)

    Particle physics, like poetry, no longer hews to its former rigid rules, hence the standard for accepting quarks as elementary consituents is less severe than the neutrino's was in the 1930's: in fact, we may never see a quark

  12. Particle physics experiments 1984

    International Nuclear Information System (INIS)

    The Rutherford Appleton laboratory report describes work carried out in 1984 on experiments approved by the Particle Physics selection panel. The contents consist of unedited contributions from each experiment. (author)

  13. Alpha-particle diagnostics

    International Nuclear Information System (INIS)

    This paper will focus on the state of development of diagnostics which are expected to provide the information needed for α- physics studies in the future. Conventional measurement of detailed temporal and spatial profiles of background plasma properties in DT will be essential for such aspects as determining heating effectiveness, shaping of the plasma profiles and effects of MHD, but will not be addressed here. This paper will address (1) the measurement of the neutron source, and hence α-particle birth profile, (2) measurement of the escaping α-particles and (3) measurement of the confined α-particles over their full energy range. There will also be a brief discussion of (4) the concerns about instabilities being generated by α-particles and the methods necessary for measuring these effects. 51 refs., 10 figs

  14. Particle physics experiments

    International Nuclear Information System (INIS)

    The report of the Rutherford Appleton Laboratory describes the work carried out in 1985 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)

  15. Lévy particles

    DEFF Research Database (Denmark)

    Hansen, Linda Vadgård; Thorarinsdottir, Thordis Linda; Gneiting, Tilmann

    Lévy particles provide a flexible framework for modelling and simulating threedimensional star-shaped random sets. The radial function of a Lévy particle arises from a kernel smoothing of a Lévy basis, and is associated with an isotropic random field on the sphere. If the kernel is proportional to...... a von Mises–Fisher density, or uniform on a spherical cap, the correlation function of the associated random field admits a closed form expression. Using a Gaussian basis, the fractal or Hausdorff dimension of the surface of the Lévy particle reflects the decay of the correlation function at the...... origin, as quantified by the fractal index. Under power kernels we obtain particles with boundaries of any Hausdorff dimension between 2 and 3....

  16. Virtual particle therapy centre

    CERN Multimedia

    2015-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. This advanced technique requires a multi-disciplinary team working in a specialised centre. 3D animation: Nymus3D

  17. Elementary particle physics

    Science.gov (United States)

    Perkins, D. H.

    1986-01-01

    Elementary particle physics is discussed. Status of the Standard Model of electroweak and strong interactions; phenomena beyond the Standard Model; new accelerator projects; and possible contributions from non-accelerator experiments are examined.

  18. The twistor particle programme

    International Nuclear Information System (INIS)

    Classification schemes for elementary particles are discussed using methods of twistor theory, with particular emphasis on the relationship of twistor theory to the Weinberg-Salam model and the Georgi-Glashow SU(5) model. (author)

  19. Blog: the God particle

    CERN Multimedia

    2007-01-01

    "Dateline video journalist Aaron Lewis this week reprots on the search to find the elusive "God particle", which, if found, could explain to scientists how everything in the world got its mass."(1/2 page)

  20. Particle Size Analysis.

    Science.gov (United States)

    Barth, Howard G.; Sun, Shao-Tang

    1989-01-01

    Presents a review of research focusing on scattering, elution techniques, electrozone sensing, filtration, centrifugation, comparison of techniques, data analysis, and particle size standards. The review covers the period 1986-1988. (MVL)

  1. The Least Particle Theory

    Science.gov (United States)

    Hartsock, Robert

    2011-10-01

    The Least Particle Theory states that the universe was cast as a great sea of energy. MaX Planck declared a quantum of energy to be the least value in the universe. We declare the quantum of energy to be the least particle in the universe. Stephen Hawking declared quantum mechanics to be of no value in todays gross mechanics. That's like saying the number 1 has no place in mathematics.

  2. Expectation Particle Belief Propagation

    OpenAIRE

    Lienart, Thibaut; Teh, Yee Whye; Doucet, Arnaud

    2015-01-01

    We propose an original particle-based implementation of the Loopy Belief Propagation (LPB) algorithm for pairwise Markov Random Fields (MRF) on a continuous state space. The algorithm constructs adaptively efficient proposal distributions approximating the local beliefs at each note of the MRF. This is achieved by considering proposal distributions in the exponential family whose parameters are updated iterately in an Expectation Propagation (EP) framework. The proposed particle scheme provid...

  3. Particle physics and cosmology

    International Nuclear Information System (INIS)

    During the past year, the research of the members of our group has spanned virtually all the topics at the interface of cosmology and particle physics: inflationary Universe scenarios, astrophysical and cosmological constraints on particle properties, ultra-high energy cosmic ray physics, quantum field theory in curved space-time, cosmology with extra dimensions, superstring cosmology, neutrino astronomy with large, underground detectors, and the formation of structure in the Universe

  4. Particle physics experiments 1986

    International Nuclear Information System (INIS)

    The paper presents research work carried out in 1986 on 52 elementary particle experiments approved by the Particle Physics Experiments Selection Panel. Most of the experiments were collaborative and involved research groups from different countries. About half of the experiments were conducted at CERN, the remaining experiments employed the accelerators: LAMPT, LEP, PETRA, SLAC, and HERA. The contents consist of unedited contributions from each experiment. (U.K.)

  5. Particles causing lung disease.

    OpenAIRE

    Kilburn, K H

    1984-01-01

    The lung has a limited number of patterns of reaction to inhaled particles. The disease observed depends upon the location: conducting airways, terminal bronchioles and alveoli, and upon the nature of inflammation induced: acute, subacute or chronic. Many different agents cause narrowing of conducting airways (asthma) and some of these cause permanent distortion or obliteration of airways as well. Terminal bronchioles appear to be particularly susceptible to particles which cause goblet cell ...

  6. ELEMENTARY PARTICLE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NOνA”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  7. Gradient Particle Magnetohydrodynamics

    OpenAIRE

    Maron, Jason L.; Howes, Gregory G.

    2001-01-01

    We introduce Gradient Particle Magnetohydrodynamics (GPM), a new Lagrangian method for magnetohydrodynamics based on gradients corrected for the locally disordered particle distribution. The development of a numerical code for MHD simulation using the GPM algorithm is outlined. Validation tests simulating linear and nonlinear sound waves, linear MHD waves, advection of magnetic fields in a magnetized vortex, hydrodynamical shocks, and three-dimensional collapse are presented, demonstrating th...

  8. Applications of particle accelerators

    International Nuclear Information System (INIS)

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  9. Motion of Confined Particles

    CERN Document Server

    Miller, David E

    2016-01-01

    We carry out numerical evaluations of the motion of classical particles in Minkowski Space $\\mathbb{M}^{4}$ which are confined to the inside of a bag. In particular, we analyze the structure of the paths evolving from the breaking of the dilatation symmetry, the conformal symmetry and the combination of both together. The confining forces arise directly from the corresponding nonconserved currents. We demonstrate in our evaluations that these particles under certain initial conditions move toward the interior of the bag.

  10. Big Bang Day: 5 Particles - 5. The Next Particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.

  11. On Characterizing Particle Shape

    Science.gov (United States)

    Ennis, Bryan J.; Rickman, Douglas; Rollins, A. Brent; Ennis, Brandon

    2014-01-01

    It is well known that particle shape affects flow characteristics of granular materials, as well as a variety of other solids processing issues such as compaction, rheology, filtration and other two-phase flow problems. The impact of shape crosses many diverse and commercially important applications, including pharmaceuticals, civil engineering, metallurgy, health, and food processing. Two applications studied here include the dry solids flow of lunar simulants (e.g. JSC-1, NU-LHT-2M, OB-1), and the flow properties of wet concrete, including final compressive strength. A multi-dimensional generalized, engineering method to quantitatively characterize particle shapes has been developed, applicable to both single particle orientation and multi-particle assemblies. The two-dimension, three dimension inversion problem is also treated, and the application of these methods to DEM model particles will be discussed. In the case of lunar simulants, flow properties of six lunar simulants have been measured, and the impact of particle shape on flowability - as characterized by the shape method developed here -- is discussed, especially in the context of three simulants of similar size range. In the context of concrete processing, concrete construction is a major contributor to greenhouse gas production, of which the major contributor is cement binding loading. Any optimization in concrete rheology and packing that can reduce cement loading and improve strength loading can also reduce currently required construction safety factors. The characterization approach here is also demonstrated for the impact of rock aggregate shape on concrete slump rheology and dry compressive strength.

  12. Localisation of 'hot particles'

    International Nuclear Information System (INIS)

    This report intends to advance procedures for decision whether environmental samples are contaminated with hot particles and to quantify the resulting measurement uncertainty. For that purpose the knowledge about various aspects of hot particles is summarised and made available in a classified bibliography. Two important areas of technical measuring problems are examined in detail by stochastic simulation and experiments. First, the methods of sample splitting and repeated mixing are tested for their suitability to proof the presence of hot particles in environmental samples. For both methods procedures are given according to which it is possible to quantify the probability that hot particles are included in the sample. Finally, the measuring uncertainty is determined for several measuring geometries which occur when hot particles are included in a sample. E.g., the potential error in radiocesium concentration range from 3.5 times overestimation to 3 times underestimation if the soil measured in the 1 liter Marinelli-beaker is contaminated by a single hot particle instead of a homogeneous activity. (orig.)

  13. Particle Accelerators Test Cosmological Theory.

    Science.gov (United States)

    Schramm, David N.; Steigman, Gary

    1988-01-01

    Discusses the symbiotic relationship of cosmology and elementary-particle physics. Presents a brief overview of particle physics. Explains how cosmological considerations set limits on the number of types of elementary particles. (RT)

  14. Active diffusion of motor particles

    OpenAIRE

    Klumpp, Stefan; Lipowsky, Reinhard

    2005-01-01

    The movement of motor particles consisting of one or several molecular motors bound to a cargo particle is studied theoretically. The particles move on patterns of immobilized filaments. Several patterns are described for which the motor particles undergo non-directed but enhanced diffusion. Depending on the walking distance of the particles and the mesh size of the patterns, the active diffusion coefficient exhibits three different regimes. For micrometer-sized motor particles in water, e.g....

  15. System for forming janus particles

    Science.gov (United States)

    Hong, Liang; Jiang, Shan; Granick, Steve

    2011-01-25

    The invention is a method of forming Janus particles, that includes forming an emulsion that contains initial particles, a first liquid, and a second liquid; solidifying the first liquid to form a solid that contains at least a portion of the initial particles on a surface of the solid; and treating the exposed particle sides with a first surface modifying agent, to form the Janus particles. Each of the initial particles on the surface has an exposed particle side and a blocked particle side.

  16. Proton: The Particle

    International Nuclear Information System (INIS)

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈1080. Protons were created at 10−6 –1 second after the Big Bang at ≈1.37 × 1010 years beforethe present. Proton life span has been experimentally determined to be ≥1034 years; that is, the age of the universe is 10−24th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W+, W−, Z0, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter

  17. New particle searches

    International Nuclear Information System (INIS)

    The Standard Model is a remarkable result of decades of work in particle physics, but it is clearly an incomplete representation of the world. Exploring possibilities beyond the Standard Model is a major preoccupation of both theorists and experimentalists. Despite the many suggestions that are extant about the missing links within the Standard Model as well as extensions beyond it, no hard experimental evidence exists. In particular, in more than five years of experimentation both at PETRA and PEP no new particles have been found that would indicate new physics. Several reasons are possible for these negative results: the particles may be too heavy; the experiments may not be looking in the proper way; the cross sections may be too small or finally the particles may not exist. A continuing PEP program, at high luminosity will ensure that the second and third reason continue to be addressed. The higher energy e+e- storage rings such as TRISTAN and LEP will extend the mass limits. High mass particles can also be produced at the CERN collider and soon with the Tevatron collider. A concise summary of the mass limits from the PETRA experiments has been given in a recent Mark J publication. The results shown provide a convenient yardstick against which to measure future search experiments

  18. Particles and Shells

    CERN Document Server

    Palazzi, P

    2003-01-01

    The current understanding of particle masses in terms of quarks and their binding energy is not satisfactory. Both in atoms and in nuclei the organizing principle of stability is the shell structure, while this does not seem to play any role for particles. In order to explore the possibility that shells might also be relevant at this inner level of aggregation, atomic and nuclear stability are expressed by "stablines", alignments of the 1/3 power of the total number of constituents of the most stable configurations. Could similar patterns be found in the particle spectrum? By analyzing the distribution of particle lifetimes as a function of mass, stability peaks are recognized for mesons and for baryons and indeed the cube roots of their masses follow two distinct stablines. Such alignments would be a strong indication that the particles themselves are shell structured assuming only that each constituent contributes a constant amount to the total mass. This is incompatible with the prevalent view that the par...

  19. Particle physics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, E.W.

    1986-10-01

    This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs.

  20. Large Particle Titanate Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-08

    This research project was aimed at developing a synthesis technique for producing large particle size monosodium titanate (MST) to benefit high level waste (HLW) processing at the Savannah River Site (SRS). Two applications were targeted, first increasing the size of the powdered MST used in batch contact processing to improve the filtration performance of the material, and second preparing a form of MST suitable for deployment in a column configuration. Increasing the particle size should lead to improvements in filtration flux, and decreased frequency of filter cleaning leading to improved throughput. Deployment of MST in a column configuration would allow for movement from a batch process to a more continuous process. Modifications to the typical MST synthesis led to an increase in the average particle size. Filtration testing on dead-end filters showed improved filtration rates with the larger particle material; however, no improvement in filtration rate was realized on a crossflow filter. In order to produce materials suitable for column deployment several approaches were examined. First, attempts were made to coat zirconium oxide microspheres (196 µm) with a layer of MST. This proved largely unsuccessful. An alternate approach was then taken synthesizing a porous monolith of MST which could be used as a column. Several parameters were tested, and conditions were found that were able to produce a continuous structure versus an agglomeration of particles. This monolith material showed Sr uptake comparable to that of previously evaluated samples of engineered MST in batch contact testing.

  1. Particle physics and cosmology

    International Nuclear Information System (INIS)

    This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs

  2. Big Bang Day: 5 Particles - 3. The Anti-particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

  3. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H2 for 12 hours with no visible reaction or weight loss

  4. New particle data

    CERN Multimedia

    2002-01-01

    The 2002 edition of the Review of Particle Physics has been published. It appears in the July 1st edition of Physical Review D with the reference: K. Hagiwara et al., Physical Review D66, 010001 (2002). The printing of the Particle Physics Booklets is planned to be finished at the end of August, so copies are expected to arrive at CERN for distribution by mid-September. The full data are available at the Berkeley site, as well as at various other mirrors around the world. As for copies of the full Review, for which CERN is responsible for the distribution outside the Americas, the Far East and Australasia, the quantity has been reduced by 60% compared to the 2000 edition. It will thus no longer be possible for all individuals to have their personal copy. Priority will be given to ensure that copies are sent to all groups and institutes engaged in particle physics research.

  5. On particle track detectors

    Science.gov (United States)

    Benton, E. V.; Gruhn, T. A.; Andrus, C. H.

    1973-01-01

    Aqueous sodium hydroxide is widely used to develop charged particle tracks in polycarbonate film, particularly Lexan. The chemical nature of the etching process for this system has been determined. A method employing ultra-violet absorbance was developed for monitoring the concentration of the etch products in solution. Using this method it was possible to study the formation of the etching solution saturated in etch products. It was found that the system super-saturates to a significant extent before precipitation occurs. It was also learned that the system approaches its equilibrium state rather slowly. It is felt that both these phenomena may be due to the presence of surfactant in the solution. In light of these findings, suggestions are given regarding the preparation and maintenance of the saturated etch solution. Two additional research projects, involving automated techniques for particle track analysis and particle identification using AgCl crystals, are briefly summarized.

  6. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  7. Nuclear and particle physics

    CERN Document Server

    Amsler, Claude

    2015-01-01

    Nuclear and Particle Physics provides an introductory course on nuclear and particle physics for undergraduate and early-graduate students, which the author has taught for several years at the University of Zurich. It contains fundamentals on both nuclear and particle physics, giving emphasis to the discovery and history of developments in the field, and is experimentally/phenomenologically oriented. It contains detailed derivations of formulae such as 2–3 body phase space, the Weinberg-Salam model, and neutrino scattering. Originally published in German as Kern- und Teilchenphysik, several sections have been added to this new English version to cover modern topics, including updates on neutrinos, the Higgs boson, the top quark and bottom quark physics.

  8. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2015-01-01

    This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

  9. The particle zoo

    CERN Document Server

    Hesketh, Gavin

    2016-01-01

    What is everything really made of? If we split matter down into smaller and infinitesimally smaller pieces, where do we arrive? At the Particle Zoo - the extraordinary subatomic world of antimatter, neutrinos, strange-flavoured quarks and yetis, gravitons, ghosts and glueballs, mindboggling eleven-dimensional strings and the elusive Higgs boson itself. Be guided around this strangest of zoos by Gavin Hesketh, experimental particle physicist at humanity's greatest experiment, the Large Hadron Collider. Concisely and with a rare clarity, he demystifies how we are uncovering the inner workings of the universe and heading towards the next scientific revolution. Why are atoms so small? How did the Higgs boson save the universe? And is there a theory of everything? The Particle Zoo answers these and many other profound questions, and explains the big ideas of Quantum Physics, String Theory, The Big Bang and Dark Matter...and, ultimately, what we know about the true, fundamental nature of reality.

  10. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  11. MICE Particle Identification Systems

    CERN Document Server

    Sanders, D A

    2009-01-01

    The international Muon Ionization Cooling Experiment (MICE) is being built, at the Rutherford Appleton Laboratory (RAL), to demonstrate the feasibility of ionization cooling of muon beams. This is one of the major technological steps needed in the development of a muon collider and a neutrino factory based on muon decays in a storage ring. MICE will use particle detectors to measure the cooling effect with high precision, achieving a precision on the measurement of emittance of 0.1% or better. The particle i.d. detectors and trackers must work in harsh environmental conditions due to high magnetic fringe fields and RF noise. We will briefly describe the MICE particle i.d. detector systems, and show some current performance measurements of these detectors.

  12. Supertwistors and massive particles

    CERN Document Server

    Mezincescu, Luca; Townsend, Paul K

    2013-01-01

    In the (super)twistor formulation of massless particle mechanics, the mass-shell constraint is replaced by a "spin-shell" constraint from which the spin content can be read off. We extend this formalism to {\\it massive} particles in three and four space-time dimensions, explaining how the spin-shell constraints are related to Poincar\\'e Casimirs. We further extend the formalism (in these spacetime dimensions) to a supertwistor form of the generic N-extended superparticle action, which we use to prove equivalence of the massive N=1 and BPS-saturated N=2 superparticle actions. We also find (again in three and four spacetime dimensions) the supertwistor form of the action for massless and massive "spinning particles" with N-extended worldline supersymmetry, and we show how it simplifies special features of the N=2 case.

  13. WORKSHOP: Stable particle motion

    International Nuclear Information System (INIS)

    Full text: Particle beam stability is crucial to any accelerator or collider, particularly big ones, such as Brookhaven's RHIC heavy ion collider and the larger SSC and LHC proton collider schemes. A workshop on the Stability of Particle Motion in Storage Rings held at Brookhaven in October dealt with the important issue of determining the short- and long-term stability of single particle motion in hadron storage rings and colliders, and explored new methods for ensuring it. In the quest for realistic environments, the imperfections of superconducting magnets and the effects of field modulation and noise were taken into account. The workshop was divided into three study groups: Short-Term Stability in storage rings, including chromatic and geometric effects and correction strategies; Long-Term Stability, including modulation and random noise effects and slow varying effects; and Methods for determining the stability of particle motion. The first two were run in parallel, but the third was attended by everyone. Each group considered analytical, computational and experimental methods, reviewing work done so far, comparing results and approaches and underlining outstanding issues. By resolving conflicts, it was possible to identify problems of common interest. The workshop reaffirmed the validity of methods proposed several years ago. Major breakthroughs have been in the rapid improvement of computer capacity and speed, in the development of more sophisticated mathematical packages, and in the introduction of more powerful analytic approaches. In a typical storage ring, a particle may be required to circulate for about a billion revolutions. While ten years ago it was only possible to predict accurately stability over about a thousand revolutions, it is now possible to predict over as many as one million turns. If this trend continues, in ten years it could become feasible to predict particle stability over the entire storage period. About ninety participants

  14. Multiswarm Particle Swarm Optimization with Transfer of the Best Particle

    OpenAIRE

    Xiao-peng Wei; Jian-xia Zhang; Dong-sheng Zhou; Qiang Zhang

    2015-01-01

    We propose an improved algorithm, for a multiswarm particle swarm optimization with transfer of the best particle called BMPSO. In the proposed algorithm, we introduce parasitism into the standard particle swarm algorithm (PSO) in order to balance exploration and exploitation, as well as enhancing the capacity for global search to solve nonlinear optimization problems. First, the best particle guides other particles to prevent them from being trapped by local optima. We provide a detailed des...

  15. Collection of particles

    International Nuclear Information System (INIS)

    Apparatus and a method for collecting particles formed by vaporisation during a high temperature treatment of steel (eg cutting or welding) are described in which gas is drawn from the area in which the treatment is taking place through a collector in which the particles are separated magnetically. The air may be drawn by an air ejector from a hood around the treatment area. The invention has particular application where the high temperature treatment is the laser cutting of the stainless steel wrapper around a nuclear fuel sub-assembly. (author)

  16. Composite magnetic particles

    International Nuclear Information System (INIS)

    This patent claim on behalf of I.C.I. Ltd., relates to the preparation and use of composite magnetic particles, comprising a low density core, and having a magnetic coating over at least a proportion of the surface. The density of such particles can be chosen to suit a range of applications, e.g. in affinity chromatography, in radioimmunoassay, in the transport of the associated component, such as a drug or enzyme, to a specific site in a living organism. (U.K.)

  17. Particle and nuclear physics

    CERN Document Server

    Faessler, Amand

    2013-01-01

    Progress in Particle and Nuclear Physics, Volume 26 covers the significant advances in understanding the fundamentals of particle and nuclear physics. This volume is divided into four chapters, and begins with a brief overview of the various possible ideas beyond the standard model, the problem they address and their experimental tests. The next chapter deals with the basic physics of neutrino mass based on from a gauge theoretic point of view. This chapter considers the various extensions of the standard electroweak theory, along with their implications for neutrino physics. The discussio

  18. Review of Particle Physics

    Science.gov (United States)

    Olive, K. A.; Particle Data Group

    2014-08-01

    The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on: Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov. Contents Abstract, Contributors, Highlights and Table of ContentsAcrobat PDF (4.4 MB) IntroductionAcrobat PDF (595 KB) Particle Physics Summary Tables Gauge and Higgs bosonsAcrobat PDF (204 KB) LeptonsAcrobat PDF (167 KB) QuarksAcrobat PDF (115 KB) MesonsAcrobat PDF (976 KB) BaryonsAcrobat PDF (384 KB) Searches (Supersymmetry, Compositeness, etc.)Acrobat PDF (120 KB) Tests of conservation lawsAcrobat PDF (383 KB) Reviews, Tables, and Plots Detailed contents for this sectionAcrobat PDF (73 KB) Constants, Units, Atomic and Nuclear PropertiesAcrobat PDF (395 KB) Standard Model and Related TopicsAcrobat PDF (8.37 MB) Astrophysics and CosmologyAcrobat PDF (3.79 MB) Experimental Methods and CollidersAcrobat PDF (3.82 MB) Mathematical Tools of Statistics, Monte Carlo, Group Theory Acrobat

  19. Incompressible smoothed particle hydrodynamics

    International Nuclear Information System (INIS)

    We present a smoothed particle hydrodynamic model for incompressible fluids. As opposed to solving a pressure Poisson equation in order to get a divergence-free velocity field, here incompressibility is achieved by requiring as a kinematic constraint that the volume of the fluid particles is constant. We use Lagrangian multipliers to enforce this restriction. These Lagrange multipliers play the role of non-thermodynamic pressures whose actual values are fixed through the kinematic restriction. We use the SHAKE methodology familiar in constrained molecular dynamics as an efficient method for finding the non-thermodynamic pressure satisfying the constraints. The model is tested for several flow configurations

  20. The particle accelerator

    International Nuclear Information System (INIS)

    As the Palais de la Decouverte (in Paris) is the sole scientific vulgarization establishment in the world to operate an actual particle accelerator able to provoke different types of nuclear reactions, the author recalls some historical aspects of the concerned department since the creation of the 'Radioactivity - Atom synthesis' department in 1937. He recalls the experiments which were then performed, the installation of the particle accelerator in 1964 and its renewal. He describes what's going on in this accelerator. He gives an overview of the difficulties faced after it has been decided to move it, of the works which had to be performed, and of radiation protection measures

  1. Alpha particles in fusion research

    International Nuclear Information System (INIS)

    This collection of 39 (mostly view graph) presentations addresses various aspects of alpha particle physics in thermonuclear fusion research, including energy balance and alpha particle losses, transport, the influence of alpha particles on plasma stability, helium ash, the transition to and sustainment of a burning fusion plasma, as well as alpha particle diagnostics. Refs, figs and tabs

  2. Particle sizes from sectional data

    DEFF Research Database (Denmark)

    Pawlas, Zbynek; Nyengaard, Jens Randel; Jensen, Eva Bjørn Vedel

    2009-01-01

    We propose a new statistical method for obtaining information about particle size distributions from sectional data without specific assumptions about particle shape. The method utilizes recent advances in local stereology. We show how to estimate separately from sectional data the variance due to...... the local stereological estimation procedure and the variance due to the variability of particle sizes in the population. Methods for judging the difference between the distribution of estimated particle sizes and the distribution of true particle sizes are also provided....

  3. Supertwistors and massive particles

    Energy Technology Data Exchange (ETDEWEB)

    Mezincescu, Luca, E-mail: mezincescu@server.physics.miami.edu [Department of Physics, University of Miami, Coral Gables, FL 33124 (United States); Routh, Alasdair J., E-mail: a.j.routh@damtp.cam.ac.uk [DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Townsend, Paul K., E-mail: p.k.townsend@damtp.cam.ac.uk [DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2014-07-15

    In the (super)twistor formulation of massless (super)particle mechanics, the mass-shell constraint is replaced by a “spin-shell” constraint from which the spin content can be read off. We extend this formalism to massive (super)particles (with N-extended space–time supersymmetry) in three and four space–time dimensions, explaining how the spin-shell constraints are related to spin, and we use it to prove equivalence of the massive N=1 and BPS-saturated N=2 superparticle actions. We also find the supertwistor form of the action for “spinning particles” with N-extended worldline supersymmetry, massless in four dimensions and massive in three dimensions, and we show how this simplifies special features of the N=2 case. -- Highlights: •Spin-shell constraints are related to Poincaré Casimirs. •Twistor form of 4D spinning particle for spin N/2. •Twistor proof of scalar/antisymmetric tensor equivalence for 4D spin 0. •Twistor form of 3D particle with arbitrary spin. •Proof of equivalence of N=1 and N=2 BPS massive 4D superparticles.

  4. Charged particle beams

    CERN Document Server

    Humphries, Stanley

    2013-01-01

    Detailed enough for a text and sufficiently comprehensive for a reference, this volume addresses topics vital to understanding high-power accelerators and high-brightness-charged particle beams. Subjects include stochastic cooling, high-brightness injectors, and the free electron laser. Humphries provides students with the critical skills necessary for the problem-solving insights unique to collective physics problems. 1990 edition.

  5. Two beautiful new particles

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    In beautiful agreement with the Standard Model, two new excited states (see below) of the Λb beauty particle have just been observed by the LHCb Collaboration. Similarly to protons and neutrons, Λb is composed of three quarks. In the Λb’s case, these are up, down and… beauty.   Although discovering new particles is increasingly looking like a routine exercise for the LHC experiments (see previous features), it is far from being an obvious performance, particularly when the mass of the particles is high. Created in the high-energy proton-proton collisions produced by the LHC, these new excited states of the Λb particle have been found to have a mass of, respectively, 5912 MeV/c2 and 5920 MeV/c2. In other words, they are over five times heavier than the proton or the neutron. Physicists only declare a discovery when data significantly show the relevant signal. In order to do that, they often have to analyse large samples of data. To ...

  6. Technicolour particles at LEP

    International Nuclear Information System (INIS)

    After an introduction into the technicolour theories the light colourless and electrically neutral pseudoscalars with masses between 350 MeV and 3 GeV are considered which might be detected at LEP via radiative toponium decays. Furthermore, the pair production of such particles in e+e--annihilations is discussed. Then the prospects for studying coloured pseudoscalars are considered. (HSI)

  7. Introduction to particle physics

    International Nuclear Information System (INIS)

    This book gives a presentation of particles (leptons, photons, hadrons, quarks, bosons) and of their static properties and conservation laws. A description of their interaction follows. Then, the symmetries and the standard model are presented with their implications for future research and cosmology. (J.S.)

  8. Energetic solar particles

    International Nuclear Information System (INIS)

    In this review, some of the important aspects of energetic solar particles and their relation to solar physics are discussed. The major aspects of solar cosmic ray studies currently under investigation are identified and attention is focussed on the problems of the physical processes in the sun which may be responsible for these phenomena. The studies of the composition and energy spectra of solar cosmic ray nuclei are related to the basic problem of particle acceleration process in sun and to the composition of elements in solar atmosphere. The composition of higher energy (>20 MeV/amu) multiply charged nuclei of He, C, N, O, Ne, Mg, Si and Fe give information on the abundance of elements in the solar atmosphere. At lower energies (approximately 1-10 MeV/amu), the abundances of these elements show enhancements relative to solar abundances and these enhancements are believed to be due to particle acceleration mechanisms operative in the sun which are not fully understood at present. Studies of the relative abundances of H2, H3 and He3 isotopes and Li, Be, B nuclei in the solar cosmic rays can also be studied. The question of the relationship of the accelerated particles in the sun to the optical flare phenomena is discussed. Further studies of different aspects of these phenomena may give important clues to a wide ranging phenomena in the active sun. The observational methods employed for these studies are mentioned. (A.K.)

  9. Particle physics and cosmology

    International Nuclear Information System (INIS)

    The authors describe the connection between cosmology and particle physics in an introductory way. In this connection the big bang theory and unified gauge models of strong, electromagnetic, and weak interactions are considered. Furthermore cosmological nucleosynthesis is discussed in this framework, and the problem of cosmic neutrinos is considered with special regards to its rest mass. (HSI).

  10. Lord of the particles

    CERN Multimedia

    Loll, Anna-Cathrin

    2009-01-01

    "Rolf-Dieter Heuer is the new director general of the world's largest particle physics research center. Though the German physicist never expected to gain this influential position in Switzerland, it seems a natural step in his career trajectory" (1.5 pages)

  11. Particle physics experiments 1992

    International Nuclear Information System (INIS)

    The research programs described here were carried out in 1992 at Rutherford Appleton Laboratory and funded by the United Kingdom Science and Engineering Research Council. The area covered in these experiments is particle physics. Unedited contributions from over forty experimental programs are included. Experiments are listed according to their current status, the accelerator used and its years of operation. (UK)

  12. Multiscale Simulations Using Particles

    DEFF Research Database (Denmark)

    Walther, Jens Honore

    vortex methods for problems in continuum fluid dynamics, dissipative particle dynamics for flow at the meso scale, and atomistic molecular dynamics simulations of nanofluidic systems. We employ multiscale techniques to breach the atomistic and continuum scales to study fundamental problems in fluid...

  13. Fuel particle coating data

    International Nuclear Information System (INIS)

    Development of coating on nuclear fuel particles for the High-Temperature Fuels Technology program at the Los Alamos Scientific Laboratory included process studies for low-density porous and high-density isotropic carbon coats, and for ZrC and ''alloy'' C/ZrC coats. This report documents the data generated by these studies

  14. Charged Particle Optics Theory

    Czech Academy of Sciences Publication Activity Database

    Hawkes, P. W.; Lencová, Bohumila

    -, č. 6 (2006), s. 6-8 Grant ostatní: EC 5RP(XE) G5RD-CT-2000-00344 Institutional research plan: CEZ:AV0Z20650511 Keywords : optics of charged particles * design of ion lithography system * spot profile * the finite element method Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering www.phantomsnet.net

  15. Particle physics experiments 1988

    International Nuclear Information System (INIS)

    This report describes work carried out in 1988 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. More than forty projects at different accelerators (SPS, ISIS, PETRA, LAMPF, LEP, HERA, BNL, ILL, LEAR) are listed. Different organisations collaborate on different projects. A brief progress report is given. References to published articles are given. (author)

  16. Particle physics experiments 1982

    International Nuclear Information System (INIS)

    Work carried out in 1982 on 52 experiments approved by the Particle Physics Experiments Selection Panel is described. Each experiment is listed under title, collaboration, technique, accelerator, year of running, status and spokesman. Unedited contributions are given from each experiment. (U.K.)

  17. Bullish on particles

    CERN Multimedia

    Turner, Michael Stanley

    2005-01-01

    Particle physics was, until recently, the flagship of U.S. physics. if not U.S. science. With ever larger "atom smasher" and such charismatic figures as J.R. Oppenheimer and Richard Feynamn, the field attracted the best and the brightest (1 page)

  18. Parzen Particle Filters

    DEFF Research Database (Denmark)

    Lehn-Schiøler, Tue; Erdogmus, Deniz; Principe, Jose C.

    Using a Parzen density estimator any distribution can be approximated arbitrarily close by a sum of kernels. In particle filtering this fact is utilized to estimate a probability density function with Dirac delta kernels; when the distribution is discretized it becomes possible to solve an...

  19. 'God' particle proves elusive

    CERN Multimedia

    Radford, T

    2001-01-01

    For more than a decade, scientists at CERN have been hoping that a key theoretical particle called the Higgs boson, would turn up in a subatomic collision. Some of them are now though beginning to wonder if it has ever existed.

  20. Particles and Fields

    Science.gov (United States)

    Georgi, Howard; Wilczek, Frank; Tinyakov, Peter; Tytgat, Michel

    2013-03-01

    2011 marked the hundredth anniversary both of the famous Solvay conferences, and of the Geiger-Marsden experiment that launched the modern understanding of subatomic structure. I was asked to survey the status and prospects of particle physics for the anniversary Solvay conference, with appropriate perspective. This is my attempt.

  1. Matter: the fundamental particles

    CERN Multimedia

    Landua, Rolf

    2007-01-01

    "The largest particle physics centre in the world is located in Europe. It straddles the Franco-Swiss border, near Geneva. At CERN - the European Organisation for Nuclear Research , which is focused on the science of nuclear matter rather than on the exploitation of atomic energy - there are over 6 500 scientists." (1 page)

  2. Lunar Soil Particle Separator

    Science.gov (United States)

    Berggren, Mark

    2010-01-01

    The Lunar Soil Particle Separator (LSPS) beneficiates soil prior to in situ resource utilization (ISRU). It can improve ISRU oxygen yield by boosting the concentration of ilmenite, or other iron-oxide-bearing materials found in lunar soils, which can substantially reduce hydrogen reduction reactor size, as well as drastically decreasing the power input required for soil heating

  3. Particle Physics and Cosmology

    CERN Document Server

    Pralavorio, P

    2015-01-01

    Today, both particle physics and cosmology are described by few parameter Standard Models, i.e. it is possible to deduce consequence of particle physics in cosmology and vice verse. The former is examined in this lecture, in light of the recent systematic exploration of the electroweak scale by the LHC experiments. The two main results of the first phase of the LHC, the discovery of a Higgs-like particle and the absence so far of new particles predicted by "natural" theories beyond the Standard Model (supersymmetry, extra-dimension and composite Higgs) are put in a historical context to enlighten their importance and then presented extensively. To be complete, a short review from the neutrino physics, which can not be probed at LHC, is also given. The ability of all these results to resolve the 3 fundamental questions of cosmology about the nature of dark energy and dark matter as well as the origin of matter-antimatter asymmetry is discussed in each case.

  4. Particle Swarm Optimization Toolbox

    Science.gov (United States)

    Grant, Michael J.

    2010-01-01

    The Particle Swarm Optimization Toolbox is a library of evolutionary optimization tools developed in the MATLAB environment. The algorithms contained in the library include a genetic algorithm (GA), a single-objective particle swarm optimizer (SOPSO), and a multi-objective particle swarm optimizer (MOPSO). Development focused on both the SOPSO and MOPSO. A GA was included mainly for comparison purposes, and the particle swarm optimizers appeared to perform better for a wide variety of optimization problems. All algorithms are capable of performing unconstrained and constrained optimization. The particle swarm optimizers are capable of performing single and multi-objective optimization. The SOPSO and MOPSO algorithms are based on swarming theory and bird-flocking patterns to search the trade space for the optimal solution or optimal trade in competing objectives. The MOPSO generates Pareto fronts for objectives that are in competition. A GA, based on Darwin evolutionary theory, is also included in the library. The GA consists of individuals that form a population in the design space. The population mates to form offspring at new locations in the design space. These offspring contain traits from both of the parents. The algorithm is based on this combination of traits from parents to hopefully provide an improved solution than either of the original parents. As the algorithm progresses, individuals that hold these optimal traits will emerge as the optimal solutions. Due to the generic design of all optimization algorithms, each algorithm interfaces with a user-supplied objective function. This function serves as a "black-box" to the optimizers in which the only purpose of this function is to evaluate solutions provided by the optimizers. Hence, the user-supplied function can be numerical simulations, analytical functions, etc., since the specific detail of this function is of no concern to the optimizer. These algorithms were originally developed to support entry

  5. Elementary particle physics: Experimental

    International Nuclear Information System (INIS)

    We are carrying out a research program in high energy experimental particle physics. Studies of high energy hadronic interactions and leptoproduction processes continue using several experimental techniques. Progress has been made on the study of multiparticle production processes in nuclei. Ultra-high energy cosmic ray nucleus-nucleus interactions have been investigated by the Japanese American Cosmic Emulsion Experiment (JACEE) using balloon-borne emulsion chamber detectors. In the area of particle astrophysics, our studies of cosmic ray nuclear interactions have enabled use to make the world's most accurate determination of the comparison of the cosmic rays above 1013eV. We have only the detector that can observe interaction vertices and identify particles at energies up to 10**15 eV. Our observations are getting close to placing limits on the acceleration mechanisms postulated for pulsars in which the spin and magnetic moment axes are at different angles. In June, 1989 approval was given by NASA for our participation in the Space Station program. The SCINATT experiment will make use of emulsion chamber detectors, similar to the planned JACEE hybrid balloon flight detectors. These detector will permit precise determination of secondary particle charges, momenta and rapidities, and the accumulation of data will be at least a factor of 10 to 100 greater than in balloon experiments. Emulsion chamber techniques ate also employed in an experiment using accelerator heavy ion beams at CERN and Brookhaven National Laboratory to investigate particle production processes in central collisions of nuclei in the energy range 15 -- 200A GeV. Our study of hadroproduction in lepton interactions is continuing with approval of another 8 months run for deep inelastic muon scattering experiment E665 at Fermilab

  6. Particle physics in your pocket!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    CERN physicists, take out your smartphones! Two new particle physics applications for Android phones have been developed by a physicist from the University of Bern: “Particle Properties” and “Particle Physics Booklet 2010”.   “When I'm on shift, I enjoy looking at the online event displays,” says Igor Kreslo from the Laboratory for High Energy Physics at the University of Bern, the physicist who has developed the two particle physics applications for Android. “Sometimes very beautiful events appear, with many different particles. I like to discuss these displays with my students, just to develop their ability to identify particles. We try to find out which particle is which and how it might decay… I think that's the best way to teach students the phenomenology of particle physics.” When scientists study particle physics, they require some vital information, such as the decay branching ...

  7. Experimental Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfeld, Carl [Univ of South Carolina; Mishra, Sanjib R. [Univ of South Carolina; Petti, Roberto [Univ of South Carolina; Purohit, Milind V. [Univ of South Carolina

    2014-08-31

    The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the Ba

  8. A palette of particles

    CERN Document Server

    Bernstein, Jeremy

    2013-01-01

    From molecules to stars, much of the cosmic canvas can be painted in brushstrokes of primary color: the protons, neutrons, and electrons we know so well. But for meticulous detail, we have to dip into exotic hues - leptons, mesons, hadrons, quarks. Bringing particle physics to life as few authors can, Jeremy Bernstein here unveils nature in all its subatomic splendor. In this graceful account, Bernstein guides us through high-energy physics from the early twentieth century to the present, including such highlights as the newly discovered Higgs boson. Beginning with Ernest Rutherford's 1911 explanation of the nucleus, a model of atomic structure emerged that sufficed until the 1930s, when new particles began to be theorized and experimentally confirmed. In the postwar period, the subatomic world exploded in a blaze of unexpected findings leading to the theory of the quark, in all its strange and charmed variations. An eyewitness to developments at Harvard University and the Institute for Advanced Study in Prin...

  9. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    The present collection of letters from JINR, Dubna, contains seven separate records on the integral representation for structure functions and target mass effects, multiscale properties of DNA primary structure including cross-scale correlations, dissipative evolution of the elementary act, the fine structure of the MT=1 Gamow-Teller resonance in 147gTb→147Gd β+/EC decay, the behaviour of the TVO temperature sensors in the magnetic fields, a fast method for searching for tracks in multilayer drift chambers of HADES spectrometer, a novel approach to particle track etching including surfactant enhanced control of pore morphology, azimuthal correlations of secondary particles in 32S induced interactions with Ag(Br) nuclei at 4.5 GeV/ c/ nucleon

  10. Optics of Biological Particles

    CERN Document Server

    Hoekstra, Alfons; Videen, Gorden

    2007-01-01

    This book covers the optics of single biological particles, both theory and experiment, with emphasis on Elastic Light Scattering and Fluorescence. It deals with the optics of bacteria (bio-aerosols), marine particles (selected phytoplankton communities) and red and white blood cells. Moreover, there are dedicated chapters on a general theory for scattering by a cell, and modelling and simulation of scattering by inhomogeneous biological cells. Finally, one chapter is dedicated to astro-biological signatures, discussing the possibilities for detecting non-terrestrial biological material. The volume has up-to-date discussions on new experimental and numerical techniques, and many examples of applications of these techniques in real-life systems, as used to detect and characterize e.g. biological warfare agents or human blood cells.

  11. Ultralight particle dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2013-10-15

    We review the physics case for very weakly coupled ultralight particles beyond the Standard Model, in particular for axions and axion-like particles (ALPs): (i) the axionic solution of the strong CP problem and its embedding in well motivated extensions of the Standard Model; (ii) the possibility that the cold dark matter in the Universe is comprised of axions and ALPs; (iii) the ALP explanation of the anomalous transparency of the Universe for TeV photons; and (iv) the axion or ALP explanation of the anomalous energy loss of white dwarfs. Moreover, we present an overview of ongoing and near-future laboratory experiments searching for axions and ALPs: haloscopes, helioscopes, and light-shining-through-a-wall experiments.

  12. Research in particle physics

    International Nuclear Information System (INIS)

    This proposal presents the research accomplishments and ongoing activities of Boston University researchers in high energy physics. Some changes have been made in the structure of the program from the previous arrangement of tasks. Task B, Accelerator Design Physics, is being submitted as a separate proposal for an independent grant; this will be consistent with the nature of the research and the source of funding. We are active in seven principal areas which will be discussed in this report: Colliding Beams - physics of e+e- and bar pp collisions; MACRO Experiment - search for magnetic monopoles and study of cosmic rays; Proton Decay - search for nucleon instability and study of neutrino interactions; Particle Theory - theoretical high energy particle physics, including two Outstanding Junior Investigator awards; Muon G-2 - measurement of the anomalous magnetic moment of the muon; SSCintcal - calorimetry for the GEM Experiment; and Muon detectors for the GEM Experiment

  13. The first elementary particle

    International Nuclear Information System (INIS)

    A historical aspect of electron discovery by J.J. Thomson through standard model is given and entitled only to say that the quarks and gluons as well as the photon, W+, W-,Z0, and the electron and other leptons are more elementary than nucleons and pions, because their fields appear in a theory, the Standard Model , that applies over a much wider range of energies than the effective field theory that describes nucleon and pions at low energy. Any final conclusion about the elementarily of the quarks and gluons or even the electrons themselves cannot reached. When we have such a theory we may find that the elementary structures of physics are not particles at all. It is probable that since obtaining a final theory for matter and force, a response to this question that which particle is elementary can not been given

  14. The paradox particle

    International Nuclear Information System (INIS)

    As well as being a leading physics writer, Christine Sutton of Oxford is also a particle physicist, currently working on the Zeus experiment at DESY's HERA electron-proton collider. Her latest book ''Spaceship Neutrino'' Cambridge University Press ISBN 0 521 36404 3 [hardback] or 0 521 36703 4 [paperback]) is a fascinating account of the emergence of the neutrino on the stage of science. In sixty years, the neutrino has been transformed from an apologetic idea its originator dared not publish to one of the main experimental tools of modern high energy research, while cosmologists have realized that this bizarre particle could play a major role in the Universe

  15. Research in particle physics

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This proposal presents the research accomplishments and ongoing activities of Boston University researchers in high energy physics. Some changes have been made in the structure of the program from the previous arrangement of tasks. Task B, Accelerator Design Physics, is being submitted as a separate proposal for an independent grant; this will be consistent with the nature of the research and the source of funding. We are active in seven principal areas which will be discussed in this report: Colliding Beams - physics of e{sup +}e{sup {minus}} and {bar p}p collisions; MACRO Experiment - search for magnetic monopoles and study of cosmic rays; Proton Decay - search for nucleon instability and study of neutrino interactions; Particle Theory - theoretical high energy particle physics, including two Outstanding Junior Investigator awards; Muon G-2 - measurement of the anomalous magnetic moment of the muon; SSCintcal - calorimetry for the GEM Experiment; and Muon detectors for the GEM Experiment.

  16. Cosmology and particle physics

    Science.gov (United States)

    Turner, Michael S.

    1988-01-01

    The interplay between cosmology and elementary particle physics is discussed. The standard cosmology is reviewed, concentrating on primordial nucleosynthesis and discussing how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is discussed, showing how a scenario in which the B-, C-, and CP-violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and for the present baryon-to-photon ratio. It is shown how the very early dynamical evolution of a very weakly coupled scalar field which is initially displaced from the minimum of its potential may explain a handful of very fundamental cosmological facts which are not explained by the standard cosmology.

  17. Fundamentals of gas particle flow

    CERN Document Server

    Rudinger, G

    1980-01-01

    Fundamentals of Gas-Particle Flow is an edited, updated, and expanded version of a number of lectures presented on the "Gas-Solid Suspensions” course organized by the von Karman Institute for Fluid Dynamics. Materials presented in this book are mostly analytical in nature, but some experimental techniques are included. The book focuses on relaxation processes, including the viscous drag of single particles, drag in gas-particles flow, gas-particle heat transfer, equilibrium, and frozen flow. It also discusses the dynamics of single particles, such as particles in an arbitrary flow, in a r

  18. Effective particle magnetic moment of multi-core particles

    Energy Technology Data Exchange (ETDEWEB)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

    2015-04-15

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  19. Effective particle magnetic moment of multi-core particles

    Science.gov (United States)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; van IJzendoorn, Leo J.; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-04-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems - BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm - and one single-core particle system - SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  20. Relaxation from particle production

    CERN Document Server

    Hook, Anson

    2016-01-01

    We consider using particle production as a friction force by which to implement a "Relaxion" solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.

  1. Supersymmetry in particle physics

    International Nuclear Information System (INIS)

    This paper discusses explicit models of the standard matter interactions with broken supersymmetry, the common feature of which is the appearance of the full spectrum of superpartners of all known particles in the 100 Gev-1 Tev region. The author states that although the details of this spectrum are in general model dependent, ways to search for these superparticles exist and can be considered according to the various options presented

  2. Cosmology and particle physics

    International Nuclear Information System (INIS)

    This paper comprises the contents of four lectures in which the author illustrates the two-way nature of the interplay between the fields of cosmology and particle physics by focusing on several specifics: a review of the standard cosmology, concentrating on primordial nucleosynthesis; baryogenesis; monopoles; and the case in which a very early first-order phase transition associated with spontaneous symmetry breaking has the potential to explain some very fundamental cosmological facts

  3. Radiation in Particle Simulations

    Energy Technology Data Exchange (ETDEWEB)

    More, R; Graziani, F; Glosli, J; Surh, M

    2010-11-19

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle

  4. Supersymmetric particles at LEP

    International Nuclear Information System (INIS)

    The authors examine whether the supersymmetrization of nature at a mass scale up to 100 GeV can be confirmed or excluded by experiments with LEP. They review the qualitative features of the spectroscopy suggested by supersymmetric theories. Then they discuss possible production rates and means of detection of these particles at LEP. In this framework they make some remarks about other projects for future high energy physics machines which can be used for the study of supersymmetric phenomena. (HSI)

  5. Ergodicity of particle systems

    CERN Document Server

    Dzhin Ven Chen

    2002-01-01

    The ergodicity relative to shifts, the mixing and related problems on the invariant measures for the interacting particles systems, such as the Ising ferromagnetic stochastic models, the contact processes, the systems with exception, the selector systems with three possible stochastically preconceived opinions or with many possible opinions, etc. are studied. The obtained results provide for the answers to certain questions, related to these models. The applied methods are based on duality

  6. PARTICLE BEAM TRACKING CIRCUIT

    Science.gov (United States)

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  7. Dynamic radioactive particle source

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  8. Particle transfer in multiregion

    International Nuclear Information System (INIS)

    Asymptotic calculations for reflection and transmission coefficients for particle incident on an inhomogeneous plane parallel medium are performed. The medium is assumed to consist of several different optically thick homogeneous layers. Functional relations between the reflection and transmission coefficients for the sub-layers are obtained. The invariant embedding concepts are used to calculate the albedo for sub-layers. Numerical calculations and comparisons are performed. (author)

  9. Particle physics experiments 1980

    International Nuclear Information System (INIS)

    This report describes work carried out in 1980 on experiments approved by the Particle Physics Ezperiments Selection Panel. A table of contents giving, title and collaboration, technique, accelerator used, year of running, status as at December 1980, the spokesman and experimental code, is followed by unedited contributions from each of the 54 experiments included in this annual review including lists of submitted publications. (U.K.)

  10. Resampling in particle filters

    OpenAIRE

    Hol, Jeroen D.

    2004-01-01

    In this report a comparison is made between four frequently encountered resampling algorithms for particle filters. A theoretical framework is introduced to be able to understand and explain the differences between the resampling algorithms. This facilitates a comparison of the algorithms based on resampling quality and on computational complexity. Using extensive Monte Carlo simulations the theoretical results are verified. It is found that systematic resampling is favourable, both in resamp...

  11. Advanced coated particle fuels

    International Nuclear Information System (INIS)

    The coated particle fuel (cpf) has been developed for use in high-temperature gas-cooled reactors, but it may find applications in other types of reactors. In JAERI, besides the development of cpf for High Temperature Engineering Test Reactor, conceptual studies of the cpf applications in actinide burner reactors and space reactors have been made. The conceptual design studies as well as the research and development of advanced coatings, ZrC and TiN, are reviewed. (author)

  12. Particles, fluids and vortices

    OpenAIRE

    J.W. van Holten

    2001-01-01

    Classical particle mechanics on curved spaces is related to the flow of ideal fluids, by a dual interpretation of the Hamilton-Jacobi equation. As in second quantization, the procedure relates the description of a system with a finite number of degrees of freedom to one with infinitely many degrees of freedom. In some two-dimensional fluid mechanics models a duality transformation between the velocity potential and the stream function can be performed relating sources and sinks in one model t...

  13. Particle simulations of BWO

    International Nuclear Information System (INIS)

    The electromagnetic particle code MAGIC is used to study the operation of the relativistic backward-wave oscillator. The two main parameter regimes of interest are those for the Sandia experiments (shallow ripples), and those for the recently published Soviet experiment (deep ripples). We discuss basic BWO operation, some of the main trends as parameters are varied, and show comparisons between MAGIC and the linear theories of Swegle and Bromborsky

  14. Unusual Subatomic Particle Discovered

    OpenAIRE

    Trulove, Susan

    2003-01-01

    Sookyung Choi of Gyeongsang University, Korea, and Stephen Olsen, professor of physics at the University of Hawaii, members of an international team of researchers at the High Energy Accelerator Organization (KEK) in Tsukuba, Japan, have announced the discovery of a new and unusual sub-atomic particle. One member of that team is Leo Piilonen of Blacksburg, professor of physics in the College of Science at Virginia Tech.

  15. Forecasting report. Particle physics

    International Nuclear Information System (INIS)

    The present status of particle and antiparticle physics is examined. As for electromagnetic interactions, the quantum electrodynamics theory is briefly reviewed and the various types of hadronic electromagnetic interactions classified. The theoretical approaches of strong interactions are outlined with hadron spectroscopy. Dynamical models and high energy phenomena are presented. The theoretical problems of weak interaction physics are examined with some experimental aspects. Experimental investigations of the hadron internal structure are briefly surveyed

  16. A Characteristic Particle Length

    CERN Document Server

    Roberts, Mark D

    2015-01-01

    It is argued that there are characteristic intervals associated with any particle that can be derived without reference to the speed of light $c$. Such intervals are inferred from zeros of wavefunctions which are solutions to the Schr\\"odinger equation. The characteristic length is $\\ell=\\beta^2\\hbar^2/(8Gm^3)$, where $\\beta=3.8\\dots$; this length might lead to observational effects on objects the size of a virus.

  17. Particle Identification with BELLE

    CERN Document Server

    Satpathy, A

    1999-01-01

    The working principle and performance of the BELLE particle identification device (PID), based on a hybrid system consisting of an array of high precision scintillator Time of Flight and silica Aerogel Counters, is discussed. The performances achieved in the beam tests are satisfactory and Monte Carlo tests of meeting physics objectives of BELLE are promising. Prior to the real experiment which is expected to commence in spring 1999, the BELLE PID is taking cosmic ray data for calibration and fine tuning.

  18. MICE Particle Identification Systems

    OpenAIRE

    Sanders, D. A.

    2009-01-01

    The international Muon Ionization Cooling Experiment (MICE) is being built, at the Rutherford Appleton Laboratory (RAL), to demonstrate the feasibility of ionization cooling of muon beams. This is one of the major technological steps needed in the development of a muon collider and a neutrino factory based on muon decays in a storage ring. MICE will use particle detectors to measure the cooling effect with high precision, achieving a precision on the measurement of emittance of 0.1% or better...

  19. Particle Velocity Measuring System

    Science.gov (United States)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

    1998-01-01

    Method and apparatus are provided for determining the velocity of individual food particles within a liquid/solid food mixture that is cooked by an aseptic cooking method whereby the food mixture is heated as it flows through a flowline. At least one upstream and at least one downstream microwave transducer are provided to determine the minimum possible travel time of the fastest food particle through the flowline. In one embodiment, the upstream detector is not required. In another embodiment, a plurality of small dipole antenna markers are secured to a plurality of food particles to provide a plurality of signals as the markers pass the upstream and downstream transducers. The dipole antenna markers may also include a non-linear element to reradiate a harmonic frequency of a transmitter frequency. Upstream and downstream transducers include dipole antennas that are matched to the impedance of the food slurry and a signal transmission cable by various impedance matching means including unbalanced feed to the antennas.

  20. Particle ID in LHCb

    International Nuclear Information System (INIS)

    Particle identification (PID) is a fundamental requirement for LHCb and is provided by CALO, MUON and RICH sub-detectors. The Calorimeters provide identification of electrons, photons and hadrons in addition to the measurement of their energies and positions. As well as being part of the LHCb trigger, the MUON system provides identification of muons to a very high level of purity, essential for many CP-sensitive measurements that have J/ψ's in their final states. Hadron identification, in particular the ability to distinguish kaons and pions, is crucial to many LHCB analyses, particularly where the final states of interest are purely hadronic. The LHCb RICH system provides this, covering a momentum range between 1 and 100 GeV/c. To maintain the integrity of the LHCb physics performance, it is essential to measure and monitor the particle identification efficiency and mis-identification fraction over time. This can be done by using specific decays, such as K-shorts, φ's, Λ's, J/ψ's and D*'s, for which pure samples can be isolated using only kinematic quantities, due to their unique decay topologies. This allows for clean samples of known particle types to be selected, which can then be used to calibrate and monitor the PID performance from data. The procedures for performing this will be presented, together with preliminary results from the 2009 and 2010 LHC runs. (author)

  1. The particle suppliers

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Particles are supplied to the LHC by six accelerators inter-connected by several kilometres of transfer lines. This represents yet another complex chain of processes whereby particles are produced, bunched, synchronised and injected into the LHC at the precise moment it's ready to receive them. In other words, for collisions to be produced at the end of the chain, all the injectors must be in perfect working order.   Among all the questions asked by the many visitors to CERN, one in particular comes up time and time again: "Why don't you just connect the LHC directly to the proton source?" In other words, why do you need this whole chain of accelerators acting as an "injector" for the LHC? Before colliding inside the LHC, particles first have to pass through no fewer than six different accelerators: the 90 keV duoplasmatron source, the 750 keV RFQ, the 50 MeV Linac 2, the 1.4 GeV synchrotron injector ("PS Booster" or PSB), the 25 GeV Proton Sy...

  2. Alpha Particle Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Ray, K.

    2009-05-13

    The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

  3. Particle motion in fluidised beds

    International Nuclear Information System (INIS)

    Gas fluidised beds are important components in many process industries, e.g. coal combustors and granulators, but not much is known about the movement of the solids. Positron Emission Particle Tracking (PEPT) enables the movement of a single, radioactive tracer particle to be followed rapidly and faithfully. Experiments were carried out in columns sized between 70 and 240mm. diameter, operating in the bubbling regime at ambient process conditions using particles of group B and D (Geldart Classification). Particle motion was tracked and the data applied to models for particle movement at the gas distributor as well as close to other surfaces and to models for particle circulation in beds of cohesive particles. In the light of these data, models for particle and bubble interaction, particle circulation, segregation, attrition, erosion, heat transfer and fluidised bed scale-up rules were reassessed. Particle motion is directly caused by bubble motion, and their velocities were found to be equal for particles travelling in a bubble. PEPT enables particle circulation to be measured, giving a more accurate correlation for future predictions. Particle motion follows the scale-up rules based on similarities of the bubble motion in the bed. A new group of parameters was identified controlling the amount of attrition in fluidised beds and a new model to predict attrition is proposed. (author)

  4. Particles and cosmology

    International Nuclear Information System (INIS)

    When the common ground between particle physics, astrophysics and cosmology started to become a developing area, the Institute for Nuclear Research (INR) of the Russian Academy of Sciences had the foresight in 1981 to institute the Baksan Schools on Particles and Cosmology. This now traditional event, held biannually in the Baksan Valley, has gone on to attract international participation. The site is close to the INR Baksan Neutrino Observatory with its underground and surface installations, including the SAGE gallium solar neutrino detector, the Underground Scintillation Telescope, and the 'Carpet' extensive air shower array. Participation is mainly from experimentalists working in non accelerator particle physics and particle astrophysics. The most recent School, held from April 21 to 28, began with an opening address by INR Director V. A. Matveev. J.Frieman reviewed standard big bang cosmology, emphasizing how the recent COBE results and the observations of large scale galaxy clustering fit into a standard cosmology framework. For inflationary cosmology, he showed how different models may be tested through their predictions for large-scale galactic structure and for cosmic microwave background anisotropy. A.Stebbins presented details of the large scale distribution of galaxies which, combined with velocity information and microwave background anisotropy data, provide strong constraints on theories of the origin of primordial inhomogeneities. Inflation requires, and theories of the large scale structure strongly favour the critical value for the cosmic mass density, while, as D.Seckel explained in his lecture on nucleosynthesis and abundances of the light elements, the baryon contribution to this density has to be tens of times smaller. A general review on the observational evidence for dark matter, dark matter particle candidates and the strategy of dark matter searches was given by I. Tkachev, who stressed the gravitational microlensing MACHO

  5. Particle Theory & Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Shafi, Qaisar [Univ. of Delaware, Newark, DE (United States); Barr, Steven [Univ. of Delaware, Newark, DE (United States); Gaisser, Thomas [Univ. of Delaware, Newark, DE (United States); Stanev, Todor [Univ. of Delaware, Newark, DE (United States)

    2015-03-31

    1. Executive Summary (April 1, 2012 - March 31, 2015) Title: Particle Theory, Particle Astrophysics and Cosmology Qaisar Shafi University of Delaware (Principal Investigator) Stephen M. Barr, University of Delaware (Co-Principal Investigator) Thomas K. Gaisser, University of Delaware (Co-Principal Investigator) Todor Stanev, University of Delaware (Co-Principal Investigator) The proposed research was carried out at the Bartol Research included Professors Qaisar Shafi Stephen Barr, Thomas K. Gaisser, and Todor Stanev, two postdoctoral fellows (Ilia Gogoladze and Liucheng Wang), and several graduate students. Five students of Qaisar Shafi completed their PhD during the period August 2011 - August 2014. Measures of the group’s high caliber performance during the 2012-2015 funding cycle included pub- lications in excellent refereed journals, contributions to working groups as well as white papers, and conference activities, which together provide an exceptional record of both individual performance as well as overall strength. Another important indicator of success is the outstanding quality of the past and current cohort of graduate students. The PhD students under our supervision regularly win the top departmental and university awards, and their publications records show excellence both in terms of quality and quantity. The topics covered under this grant cover the frontline research areas in today’s High Energy Theory & Phenomenology. For Professors Shafi and Barr they include LHC related topics including supersymmetry, collider physics, fl vor physics, dark matter physics, Higgs boson and seesaw physics, grand unifi and neutrino physics. The LHC two years ago discovered the Standard Model Higgs boson, thereby at least partially unlocking the secrets behind electroweak symmetry breaking. We remain optimistic that new and exciting physics will be found at LHC 14, which explain our focus on physics beyond the Standard Model. Professors Shafi continued his

  6. Fundamental principles of particle detectors

    International Nuclear Information System (INIS)

    This paper goes through the fundamental physics of particles-matter interactions which is necessary for the detection of these particles with detectors. A listing of 41 concepts and detector principles are given. 14 refs., 11 figs

  7. Particle accelerator; the Universe machine

    CERN Multimedia

    Yurkewicz, Katie

    2008-01-01

    "In summer 2008, scientists will switch on one of the largest machines in the world to search for the smallest of particle. CERN's Large Hadron Collider particle accelerator has the potential to chagne our understanding of the Universe."

  8. Amps particle accelerator definition study

    Science.gov (United States)

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  9. On collisions of Brownian particles

    OpenAIRE

    Ichiba, Tomoyuki; Karatzas, Ioannis

    2010-01-01

    We examine the behavior of $n$ Brownian particles diffusing on the real line with bounded, measurable drift and bounded, piecewise continuous diffusion coefficients that depend on the current configuration of particles. Sufficient conditions are established for the absence and for the presence of triple collisions among the particles. As an application to the Atlas model for equity markets, we study a special construction of such systems of diffusing particles using Brownian motions with refl...

  10. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich

    1965-01-01

    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  11. Charge of dust particles in a particle chain

    CERN Document Server

    Yousefi, Razieh; Matthews, Lorin Swint; Hyde, Truell W

    2016-01-01

    Charged dust particles form structures which are extended in the vertical direction in the electrode sheath of a rf discharge when confined within a glass box. The charge on each particle as a function of height varies due to the changing plasma conditions and the wakefield of upstream particles. Here an analysis of the equilibrium state of chains of varying number of particles is analyzed to determine the charge on each particle within a vertically extended chain as well as the magnitude of the positive wakefield charge.

  12. Random packing of digitized particles

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.

    2012-01-01

    The random packing of regularly and irregularly shaped particles has been studied extensively. Within this paper, packing is studied from the perspective of digitized particles. These digitized particles are developed for and used in cellular automata systems, which are employed for the simple mathe

  13. Planck Particles and Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Crothers S. J.

    2006-07-01

    Full Text Available The alleged existence of so-called Planck particles is examined. The various methods for deriving the properties of these "particles" are examined and it is shown that their existence as genuine physical particles is based on a number of conceptual fl aws which serve to render the concept invalid.

  14. Signals of Particle Dark Matter

    OpenAIRE

    Lin, Tongyan

    2012-01-01

    This thesis explores methods of detecting dark matter particles, with some emphasis on several dark matter models of current interest. Detection in this context means observation of an experimental signature correlated with dark matter interactions with Standard Model particles. This includes recoils of nuclei or electrons from dark matter scattering events, and direct or indirect observation of particles produced by dark matter annihilation.

  15. Particle splitting in smoothed particle hydrodynamics based on Voronoi diagram

    CERN Document Server

    Chiaki, Gen

    2015-01-01

    We present a novel method for particle splitting in smoothed particle hydrodynamics simulations. Our method utilizes the Voronoi diagram for a given particle set to determine the position of fine daughter particles. We perform several test simulations to compare our method with a conventional splitting method in which the daughter particles are placed isotropically over the local smoothing length. We show that, with our method, the density deviation after splitting is reduced by a factor of about two compared with the conventional method. Splitting would smooth out the anisotropic density structure if the daughters are distributed isotropically, but our scheme allows the daughter particles to trace the original density distribution with length scales of the mean separation of their parent. We apply the particle splitting to simulations of the primordial gas cloud collapse. The thermal evolution is accurately followed to the hydrogen number density of 10^12 /cc. With the effective mass resolution of ~10^-4 Msu...

  16. Apparatus for separating particles utilizing engineered acoustic contrast capture particles

    Energy Technology Data Exchange (ETDEWEB)

    Kaduchak, Gregory; Ward, Michael D

    2016-05-17

    An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

  17. Apparatus for separating particles utilizing engineered acoustic contrast capture particles

    Science.gov (United States)

    Kaduchak, Gregory; Ward, Michael D.

    2011-12-27

    An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

  18. Radiation in Particle Simulations

    Energy Technology Data Exchange (ETDEWEB)

    More, R M; Graziani, F R; Glosli, J; Surh, M

    2009-06-15

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known (section 3). The second method expands the electromagnetic field in normal modes (plane-waves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion (section 4). The third method is a hybrid MD/MC (molecular dynamics/Monte Carlo) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions (section 5). The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc.(section 6). This approach is inspired by the Virial expansion method of equilibrium statistical mechanics.

  19. Hadron particle theory

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J.R.

    1995-05-01

    Radiation therapy with ``hadrons`` (protons, neutrons, pions, ions) has accrued a 55-year track record, with by now over 30,000 patients having received treatments with one of these particles. Very good, and in some cases spectacular results are leading to growth in the field in specific well-defined directions. The most noted contributor to success has been the ability to better define and control the radiation field produced with these particles, to increase the dose delivered to the treatment volume while achieving a high degree of sparing of normal tissue. An additional benefit is the highly-ionizing, character of certain beams, leading to creater cell-killing potential for tumor lines that have historically been very resistant to radiation treatments. Until recently these treatments have been delivered in laboratories and research centers whose primary, or original mission was physics research. With maturity in the field has come both the desire to provide beam facilities more accessible to the clinical setting, of a hospital, as well as achieving, highly-efficient, reliable and economical accelerator and beam-delivery systems that can make maximum advantage of the physical characteristics of these particle beams. Considerable work in technology development is now leading, to the implementation of many of these ideas, and a new generation of clinically-oriented facilities is beginning to appear. We will discuss both the physical, clinical and technological considerations that are driving these designs, as well as highlighting, specific examples of new facilities that are either now treating, patients or that will be doing so in the near future.

  20. Hadron particle theory

    International Nuclear Information System (INIS)

    Radiation therapy with ''hadrons'' (protons, neutrons, pions, ions) has accrued a 55-year track record, with by now over 30,000 patients having received treatments with one of these particles. Very good, and in some cases spectacular results are leading to growth in the field in specific well-defined directions. The most noted contributor to success has been the ability to better define and control the radiation field produced with these particles, to increase the dose delivered to the treatment volume while achieving a high degree of sparing of normal tissue. An additional benefit is the highly-ionizing, character of certain beams, leading to creater cell-killing potential for tumor lines that have historically been very resistant to radiation treatments. Until recently these treatments have been delivered in laboratories and research centers whose primary, or original mission was physics research. With maturity in the field has come both the desire to provide beam facilities more accessible to the clinical setting, of a hospital, as well as achieving, highly-efficient, reliable and economical accelerator and beam-delivery systems that can make maximum advantage of the physical characteristics of these particle beams. Considerable work in technology development is now leading, to the implementation of many of these ideas, and a new generation of clinically-oriented facilities is beginning to appear. We will discuss both the physical, clinical and technological considerations that are driving these designs, as well as highlighting, specific examples of new facilities that are either now treating, patients or that will be doing so in the near future

  1. Particle Dark Matter Candidates

    CERN Document Server

    Scopel, Stefano

    2007-01-01

    I give a short overview on some of the favorite particle Cold Dark Matter candidates today, focusing on those having detectable interactions: the axion, the KK-photon in Universal Extra Dimensions, the heavy photon in Little Higgs and the neutralino in Supersymmetry. The neutralino is still the most popular, and today is available in different flavours: SUGRA, nuSUGRA, sub-GUT, Mirage mediation, NMSSM, effective MSSM, scenarios with CP violation. Some of these scenarios are already at the level of present sensitivities for direct DM searches.

  2. Cosmology and particle physics

    International Nuclear Information System (INIS)

    The author reviews the standard cosmology, focusing on primordial nucleosynthesis, and discusses how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is examined in which the B, C, CP violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and the present baryon-to-baryon ratio. Monoposes, cosmology and astrophysics are reviewed. The author also discusses supersymmetry/supergravity and cosmology, superstrings and cosmology in extra dimensions, and axions, astrophics, and cosmology

  3. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  4. Where was the particle?

    OpenAIRE

    Wechsler, Sofia

    2003-01-01

    The hypothesis of empty/full waves considers that a click in a detector is triggered by a property carried by the wave-packet that impinges on that detector. Different authors call this property particle, but according to the terminology of this hypothesis, the term full wave is used in this text. The present article discusses the validity of the empty/full waves hypothesis. It is shown that the energy conservation principle imposes for a full wave a continuous trajectory from the source to t...

  5. Fluid and particle mechanics

    CERN Document Server

    Michell, S J

    2013-01-01

    Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

  6. Lectures in particle physics

    CERN Document Server

    Green, Dan

    1994-01-01

    The aim of this book on particle physics is to present the theory in a simple way. The style and organization of the material is unique in that intuition is employed, not formal theory or the Monte Carlo method. This volume attempts to be more physical and less abstract than other texts without degenerating into a presentation of data without interpretation.This book is based on four courses of lectures conducted at Fermilab. It should prove very useful to advanced undergraduates and graduate students.

  7. Biomimetic folding particle chains

    International Nuclear Information System (INIS)

    Full text: The sequence of the amino acids in proteins dictates their folded 3-D structure. We have recently by simulations shown that this principle can be applied to flexible strings of isotropically interacting particles with at least one attractive patchy interaction, allowing the design of new materials and structures. Our goal is now to realize this directed self-folding on a colloidal size scale to study the folding in real time in real space. We discuss our use of polymer brushes, depletion interactions and liquid-interface scaffold chemistry to realize the goal. (author)

  8. Suspended particle interactions

    International Nuclear Information System (INIS)

    The objectives of the study are to determine the factors influencing the extent of Pu deposition from airborne effluents onto foliage, the potential for the resuspension of Pu from the leaf surface and the extent of Pu uptake and translocation by the plant. Using a low-wind-speed aerosol plant-exposure chamber, polydispersed aerosols were generated, particles characterized with respect to AMAD and GSD, and parameters such as deposition rate and deposition velocity evaluated for the plant canopy. The fate of surface deposited Pu compounds with respect to chemical modification and leachability was evaluated by leaching with synthetic ''rainwater'' and 0.1 percent HNO3 solutions

  9. Physics of windblown particles

    Science.gov (United States)

    Greeley, Ronald; Leach, Rodman; Marshall, John R.; White, Bruce; Iversen, James D.; Nickling, William G.; Gillette, Dale; Sorensen, Michael

    1987-01-01

    A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program.

  10. MICE Particle Identification System

    CERN Document Server

    Bogomilov, M

    2010-01-01

    The Muon Ionization Cooling Experiment, MICE, at the ISIS accelerator lo- cated at the Rutherford Appleton Laboratory, UK, will be the first experiment to study muon cooling at high precision. Demonstration of muon ionization cooling is an essential step towards the construction of a neutrino factory or a muon collider. Muons are produced by pion decay in a superconducting solenoid and reach MICE with a range of emittances and momenta. The purity of the muon beam is ensured by a system of particle detectors we will briefly describe here.

  11. Capture of soft particles on electrostatically heterogeneous collectors: brushy particles.

    Science.gov (United States)

    Wen, Yicun; Guo, Xuhong; Kalasin, Surachate; Santore, Maria M

    2014-03-01

    This work investigated how particle softness can influence the initial adhesive capture of submicrometer colloidal particles from flow onto collecting surfaces. The study focused on the case dominated by potential attractions at the particle periphery (rather than, for instance, steric stabilization, requiring entropically costly deformations to access shorter-range van der Waals attractions.) The particles, "spherical polyelectrolyte brushes" with diameters in the range of 150-200 nm depending on the ionic strength, consisted of a polystyrene core and a corona of grafted poly(acrylic acid) chains, producing a relatively thick (20-40 nm) negative brushy layer. The adhesion of these particles was studied on electrostatically heterogeneous collecting surfaces: negatively charged substrates carrying flat polycationic patches made by irreversibly adsorbing the poly-l-lysine (PLL) polyelectrolyte. Variation in the amount of adsorbed PLL changed the net collector charge from completely negatively charged (repulsive) to positively charged (attractive). Adjustments in ionic strength varied the range of the electrostatic interactions. Comparing capture kinetics of soft brushy particles to those of similarly sized and similarly charged silica particles revealed nearly identical particle capture kinetics over the full range of collecting surface compositions at high ionic strengths. Even though the brushy particles contained an average of 5 vol % PAA in the brushy shell, with the rest being water under these conditions, their capture was indistinguishable from that of similarly charged rigid spheres. The brushy particles were, however, considerably less adherent at low ionic strengths where the brush was more extended, suggesting an influence of particle deformability or reduced interfacial charge. These findings, that the short time adhesion of brushy particles can resemble that of rigid particles, suggest that for bacteria and cell capture, modeling the cells as rigid

  12. Particle size influence on effective permittivity of particle-gas mixture with particle clusters

    Institute of Scientific and Technical Information of China (English)

    Lijun Xu; Chang Liu; Zhang Cao; Xiaomin Li

    2013-01-01

    The influence of particle size on the effective permittivity of a particle-gas mixture in the presence of particle clusters was studied using numerical analysis involving the three-dimensional finite element method.The effective permittivity of the mixture was obtained by calculating the electrostatic energy generated in the computation domain.Numerical results show that for fixed volume fraction of particles in the mixture,the effective permittivity of the mixture increases with decreasing particle size.Static experiments were carried out by using a differential capacitance sensor with parallel plates.The variation of the effective permittivity with particle size is shown by experimental data to agree with the numerical results.The methodology described and the results obtained in this paper may be used to help modify the measurement of particles volume fraction in the presence of particle clusters when a capacitance sensor is used.

  13. Fluid particle dynamics: a synthesis of dissipative particle dynamics and smoothed particle dynamics

    OpenAIRE

    Español, Pep

    1997-01-01

    We present a generalization of dissipative particle dynamics that includes shear forces between particles. The new algorithm has the same structure as the (isothermal) smoothed particle dynamics algorithm, except that it conserves angular momentum and includes thermal fluctuations consistently with the principles of equilibrium statistical mechanics. This clarifies the connection of dissipative particle dynamics with numerical resolution algorithms of the macroscopic Navier-Stokes equations.

  14. Synthesis of Biofunctional Janus Particles.

    Science.gov (United States)

    Li, Binghui; Wang, Man; Chen, Kui; Cheng, Zhifeng; Chen, Gaojian; Zhang, Zexin

    2015-06-01

    Janus particles with anisotropic biofunctionalities are perfect models to mimic anisotropic architectures and directional interactions that occur in nature. It is therefore highly desirable to develop reliable and efficient methods to synthesize biofunctional Janus particles. Herein, a facile method combining seeded-emulsion polymerization and thiol-click chemistry has been developed to synthesize Janus particles with glucose moieties on one side. These biofunctional Janus particles show region-selective binding of protein, which represents a big step toward biomimicry, and demonstrates the potential of the bioJanus particles for targeted drug delivery and binding. PMID:25858757

  15. Dusty-Plasma Particle Accelerator

    Science.gov (United States)

    Foster, John E.

    2005-01-01

    A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the

  16. Particle acceleration in modified shocks

    International Nuclear Information System (INIS)

    Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed. (author)

  17. Particle characterization for geothermal operations

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, O.J.; Kandarpa, V.

    1981-01-06

    A detailed summary of an ongoing evaluation of existing particle measuring methodology with emphasis on (a) adapting of existing methods in geothermal operations and (b) further development of existing instrumentation for field use is presented. The various instruments and methods used and/or suggested for particle characterization are described in detail. Theoretical and practical aspects of particle characterizations are outlined. A plan for further laboratory and field experiments is outlined. The instrumentations to be selected after some additional lab and field tests will be used in the studies on (a) formation damage through particle invasion and (b) characterizing and monitoring of particle suspensions in geothermal operations.

  18. Chicago particle accelerator conference

    International Nuclear Information System (INIS)

    Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed

  19. Particle physics -- Future directions

    International Nuclear Information System (INIS)

    Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the physics opportunities offered by a linear collider and a (muon storage ring) neutrino factory. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment. I describe some of the great questions before us and the challenges of providing the instruments that will be needed to define them more fully and eventually to answer them

  20. Particle physics experiments, 1991

    International Nuclear Information System (INIS)

    Data taking for this experiment was completed in December 1983. The samples include approximately 19,000 (ν) and 11,000 (ν-bar) charged current events. These constitute the largest data set of interactions on free protons. Work published to date includes studies of inclusive structure functions and final state properties, exclusive final states, neutral current cross sections and production of strange and charmed particles. During the past year results have been published on the production of f2 (1270) and ν0 (770) mesons in ρp and ρ-barp charged current interactions. In the case of the f2 this represents the first observation of such production. It is found that the multiplicities are 0.047±0.017 in ρp and 0.17±0.018 in ρ-barp. The f2 mesons are mostly produced at large hadronic invariant mass W and in the forward hemisphere. The production of ν0 mesons can be observed with high statistics in both ρp and ρ-barp interactions and the differential cross section studied. The observations are compared with LUND Monte Carlo predictions, which are generally found to be too high. However qualitative features of the data are reproduced. Work continues on a precise determination of the neutral current/charged current ratio, on the study of charged and neutral current structure functions and on the production of strange particles. (author)

  1. Intermittency in particle physics

    International Nuclear Information System (INIS)

    This thesis presents an analysis of intermittency as it appears in high energy multiparticle production. Momentum space particle distributions are scale invariant and fluctuate from events to events. This phenomenon originates from Hydrodynamics. Some results about hydrodynamics intermittency are by the way deduced using random diffusion processes and the Landau-Ginzburg equation. A phenomenological approach utilizing random cascading models is used to describe the morphology and intermittent features of particle distributions. Along these lines, a thorough study of random cascades is performed. The origin of intermittent fluctuation is to be found within the Framework of Quantum Field Theory. Indeed intermittency is intimately linked to the perturbative cascade of Quantum Chromodynamics. The long distance behaviour of perturbative QCD is intermittent at the leading collinear logarithm approximation. Moreover fluctuations of matter density along the rapidity axis suggest that the gluon cascade undergoes a phase transition towards a valley landscape where gluons are prone to get clumped within small regions. This is compatible with the so-called preconfinement

  2. Particle physics---Experimental

    International Nuclear Information System (INIS)

    We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density ∼ 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams

  3. Stalking the ultimate particle

    CERN Multimedia

    2003-01-01

    If you missed the ARTE programme entitled "L'Ultime Particule" broadcast in February, you have another chance to catch it in CERN's Main Auditorium on 13 March. "L'Ultime Particule" is a documentary by the French director Michel Andrieu that seeks to explain particle physics through a contemplative quest for the research physicists of matter of today and yesteryear. Invariably kitted out in a red parka and a soft hat, the programme's investigator scours the planet and the archives in search of the research physicists who are stalking the ultimate particle, the Higgs boson, in their quest to understand the structure of matter. Naturally enough, CERN is an important stage of his journey where Michel Andrieu and his team spent several days last year. Both from the physics and metaphysical points of view, "L'Ultime Particule" is worth seeing. The film's director, Michel Andrieu, will introduce his documentary and answer questions from the audience after the documentary has been shown. L'Ultime Particule by Mic...

  4. On Particles and Primes

    CERN Document Server

    Knill, Oliver

    2016-01-01

    Primes in the two complete associative normed division algebras C and H have affinities with structures seen in the standard model of particle physics. On the integers in the two algebras, there are two equivalence relations: a strong one, related to a U(1) and SU(3) symmetry allowing to permute and switch signs of the coordinates of the integers, as well as a weak relation with origins from units U(1),SU(2) in the algebra. Weak equivalence classes within the strong equivalence classes of odd primes in C case relate to leptons, the inert ones being neutrino like, and the split ones resembling electron-positron pairs. In the H case, for odd primes, the equivalence classes come in groups of two or three, leading to a caricature of hadrons featuring either mesons built by a quark pair or then baryons obtained by quark triplets. We can now list for every rational prime p all these particles and attach fractional charges to its constituents.

  5. Particle therapy for noncancer diseases

    Energy Technology Data Exchange (ETDEWEB)

    Bert, Christoph; Engenhart-Cabillic, Rita; Durante, Marco [GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Philipps-University Marburg, Center for Radiology, Department of Radiation Therapy, Baldinger Strasse, 35043 Marburg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Biophysics Department, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universitaet Darmstadt, Institut fuer Festkoerperphysik, Hochschulstrasse 3, 64289 Darmstadt (Germany) and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany)

    2012-04-15

    Radiation therapy using high-energy charged particles is generally acknowledged as a powerful new technique in cancer treatment. However, particle therapy in oncology is still controversial, specifically because it is unclear whether the putative clinical advantages justify the high additional costs. However, particle therapy can find important applications in the management of noncancer diseases, especially in radiosurgery. Extension to other diseases and targets (both cranial and extracranial) may widen the applications of the technique and decrease the cost/benefit ratio of the accelerator facilities. Future challenges in this field include the use of different particles and energies, motion management in particle body radiotherapy and extension to new targets currently treated by catheter ablation (atrial fibrillation and renal denervation) or stereotactic radiation therapy (trigeminal neuralgia, epilepsy, and macular degeneration). Particle body radiosurgery could be a future key application of accelerator-based particle therapy facilities in 10 years from today.

  6. Particle therapy for noncancer diseases

    International Nuclear Information System (INIS)

    Radiation therapy using high-energy charged particles is generally acknowledged as a powerful new technique in cancer treatment. However, particle therapy in oncology is still controversial, specifically because it is unclear whether the putative clinical advantages justify the high additional costs. However, particle therapy can find important applications in the management of noncancer diseases, especially in radiosurgery. Extension to other diseases and targets (both cranial and extracranial) may widen the applications of the technique and decrease the cost/benefit ratio of the accelerator facilities. Future challenges in this field include the use of different particles and energies, motion management in particle body radiotherapy and extension to new targets currently treated by catheter ablation (atrial fibrillation and renal denervation) or stereotactic radiation therapy (trigeminal neuralgia, epilepsy, and macular degeneration). Particle body radiosurgery could be a future key application of accelerator-based particle therapy facilities in 10 years from today.

  7. Particle transport and deposition: basic physics of particle kinetics

    OpenAIRE

    Tsuda, Akira; Henry, Frank S.; Butler, James P.

    2013-01-01

    The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. Whereas the particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic, this interaction can be beneficial for disease treatment if the inhaled particles are therapeu...

  8. Anomalous particle pinch in Tokamaks

    International Nuclear Information System (INIS)

    The diffusion coefficient in phase space usually varies with the particle energy. A consequence is the dependence of the fluid particle flux on the temperature gradient. If the diffusion coefficient in phase space decreases with the energy in the bulk of the thermal distribution function, the particle thermodiffusion coefficient which links the particle flux to the temperature gradient is negative. This is a possible explanation for the inward particle pinch that is observed in tokamaks. A quasilinear theory shows that such a thermodiffusion is generic for a tokamak electrostatic turbulence at low frequency. This effect adds to the particle flux associated with the radial gradient of magnetic field. This behavior is illustrated with a perturbed electric potential, for which the trajectories of charged particle guiding centers are calculated. The diffusion coefficient of particles is computed and compared to the quasilinear theory, which predicts a divergence at low velocity. It is shown that at low velocity, the actual diffusion coefficient increases, but remains lower than the quasilinear value. Nevertheless, this differential diffusion between cold and fast particles leads to an inward flux of particles. (author)

  9. Anomalous dispersions of `hedgehog' particles

    Science.gov (United States)

    Bahng, Joong Hwan; Yeom, Bongjun; Wang, Yichun; Tung, Siu On; Hoff, J. Damon; Kotov, Nicholas

    2015-01-01

    Hydrophobic particles in water and hydrophilic particles in oil aggregate, but can form colloidal dispersions if their surfaces are chemically camouflaged with surfactants, organic tethers, adsorbed polymers or other particles that impart affinity for the solvent and increase interparticle repulsion. A different strategy for modulating the interaction between a solid and a liquid uses surface corrugation, which gives rise to unique wetting behaviour. Here we show that this topographical effect can also be used to disperse particles in a wide range of solvents without recourse to chemicals to camouflage the particles' surfaces: we produce micrometre-sized particles that are coated with stiff, nanoscale spikes and exhibit long-term colloidal stability in both hydrophilic and hydrophobic media. We find that these `hedgehog' particles do not interpenetrate each other with their spikes, which markedly decreases the contact area between the particles and, therefore, the attractive forces between them. The trapping of air in aqueous dispersions, solvent autoionization at highly developed interfaces, and long-range electrostatic repulsion in organic media also contribute to the colloidal stability of our particles. The unusual dispersion behaviour of our hedgehog particles, overturning the notion that like dissolves like, might help to mitigate adverse environmental effects of the use of surfactants and volatile organic solvents, and deepens our understanding of interparticle interactions and nanoscale colloidal chemistry.

  10. Formation of Bidisperse Particle Clouds

    Science.gov (United States)

    Er, Jenn Wei; Zhao, Bing; Law, Adrian W. K.; Adams, E. Eric

    2014-11-01

    When a group of dense particles is released instantaneously into water, their motion has been conceptualized as a circulating particle thermal (Ruggerber 2000). However, Wen and Nacamuli (1996) observed the formation of particle clumps characterized by a narrow, fast moving core shedding particles into wakes. They observed the clump formation even for particles in the non-cohesive range as long as the source Rayleigh number was large (Ra > 1E3) or equivalently the source cloud number (Nc) was small (Nc < 3.2E2). This physical phenomenon has been investigated by Zhao et al. (2014) through physical experiments. They proposed the theoretical support for Nc dependence and categorized the formation processes into cloud formation, transitional regime and clump formation. Previous works focused mainly on the behavior of monodisperse particles. The present study further extends the experimental investigation to the formation process of bidisperse particles. Experiments are conducted in a glass tank with a water depth of 90 cm. Finite amounts of sediments with various weight proportions between coarser and finer particles are released from a cylindrical tube. The Nc being tested ranges from 6E-3 to 9.9E-2, which covers all the three formation regimes. The experimental results showed that the introduction of coarse particles promotes cloud formation and reduce the losses of finer particles into the wake. More quantitative descriptions of the effects of source conditions on the formation processes will be presented during the conference.

  11. Nano-particles

    International Nuclear Information System (INIS)

    Nano-particles (N.P.) are structures comprising from some hundred to some thousand atoms. Owing to their size (1 to 100 nanometers), the physical and chemical properties of these nano-objects differ from those of classical materials. They cover a wide development area, which includes medical research: they can be classified into two major groups, organic N.P. (liposomes, polymers N.P., carbon nano tubes, fullerenes) and inorganic N.P. (quantum dots, magnetic N.P., Raman probes). N.P. can be conceived to act as a drug delivery system (therapeutic), imaging probe (diagnostic) or both (theranostic). We report recent data from scientific literature and describe main N.P. within medical area, their state of development, and the limited knowledge of their toxicity in human being. (author)

  12. Research in particle physics

    International Nuclear Information System (INIS)

    Research accomplishments and current activities of Boston University researchers in high energy physics are presented. Principal areas of activity include the following: detectors for studies of electron endash positron annihilation in colliding beams; advanced accelerator component design, including the superconducting beam inflector, electrostatic quadrupoles, and the ''electrostatic muon kicker''; the detector for the MACRO (Monopole, Astrophysics, and Cosmic Ray Observatory) experiment; neutrino astrophysics and the search for proton decay; theoretical particle physics (electroweak and flavor symmetry breaking, hadron collider phenomenology, cosmology and astrophysics, new field-theoretic models, nonperturbative investigations of quantum field theories, electroweak interactions); measurement of the anomalous magnetic moment of the muon; calorimetry for the GEM experiment; and muon detectors for the GEM experiment at the Superconducting Super Collider

  13. Overview of particle physics

    International Nuclear Information System (INIS)

    An overview of the situation of particle physics at the end of 1985 is given. It includes the following topics: ideas which have been tested or will soon be tested such as the standard model based on the symmetry group SUsub(C)(3)xSUsub(L)(2)xU(1), light Higgs and preons; theoretical ideas whose time has not yet come (basically because no accelerators are being constructed to test them) such as N=1 supersymmetry and N=1 supergravity right-handed weak currents, extended supergravities and superstring models; ideas for which non-accelerator and passive experiments have been mounted such as proton decay, nn-bar oscillations, neutrino masses and oscillations, monopoles and dark matter

  14. Ultrafine particles in cities.

    Science.gov (United States)

    Kumar, Prashant; Morawska, Lidia; Birmili, Wolfram; Paasonen, Pauli; Hu, Min; Kulmala, Markku; Harrison, Roy M; Norford, Leslie; Britter, Rex

    2014-05-01

    Ultrafine particles (UFPs; diameter less than 100 nm) are ubiquitous in urban air, and an acknowledged risk to human health. Globally, the major source for urban outdoor UFP concentrations is motor traffic. Ongoing trends towards urbanisation and expansion of road traffic are anticipated to further increase population exposure to UFPs. Numerous experimental studies have characterised UFPs in individual cities, but an integrated evaluation of emissions and population exposure is still lacking. Our analysis suggests that the average exposure to outdoor UFPs in Asian cities is about four-times larger than that in European cities but impacts on human health are largely unknown. This article reviews some fundamental drivers of UFP emissions and dispersion, and highlights unresolved challenges, as well as recommendations to ensure sustainable urban development whilst minimising any possible adverse health impacts. PMID:24503484

  15. A particle identification system

    International Nuclear Information System (INIS)

    Particles of different charge Z and mass M resulting from a nuclear reaction can be distinguished by a measurement of the differential energy loss Δ E and the energy E. The product Δ E x E is proportional to Z2M times, a logarithmic term which contains M, Z and E. It is possible to construct a function based on the expression of the product, which does not depend on energy. The reaction products can be identified by analysing the output of an analogue circuit, which forms an approximation of the desired function. Such a circuit is presented here. Two logarithmic pulse amplifiers, two adding circuits and two attenuators are the essential parts of the system. The logarithmic behaviour of the two amplifiers is determined by the forward current characteristic of a diode. (author)

  16. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    The present collection of letters from JINR, Dubna, contains nine separate letters on data on elastic (p,n) charge exchange: compilation, the potentialities of δ-electron control of luminosity in experiments with internal targets at the Nuclotron, pion broadening and low-mass dilepton production, fluctuation of electromagnetic cascade axis in dense amorphous segmented media, the forward detector of the ANKE spectrometer. Tracking system and its use in data analysis, quantum field theory with three-dimensional vector time, curvature decomposition and the Einstein-Yang-Mills equations, an integral equation for the spinor amplitude of a massive neutral Dirac particle in a curved space time with arbitrary geometry and surprising resonances in 147Sm(nα)144Nd reaction

  17. Particles and Nuclei, Letters

    International Nuclear Information System (INIS)

    The present collection of letters from JINR, Dubna, contains eight separate letters on analysis of experimental data on relativistic nuclear collisions in the Lobachevski space, relativistic contribution of the final-state interaction to deuteron photodisintegration, on the charge asymmetry of the like-sign lepton pairs induced by B - B bar - production asymmetry, limits on the νe → νe neutrino oscillation parameters from an experiment at the IHEP-JINR neutrino detector, excitation of high spin isomers in photonuclear reactions, study of product formation in proton-nuclear reactions on the 129I target induced by 660-MeV protons, application of jet pumps in the cryogenic system of the Nuclotron - superconducting accelerator of relativistic particles and study of the silicon drift detector performance with inclined tracks

  18. The hot particle problem

    International Nuclear Information System (INIS)

    The evaluation of the hazard posed to the skin by very small radioactive sources (diameter 2 at a depth of about 100-150 μm which would prevent the occurrence of even superficial transient ulceration. The NCRP have used primarily US pig skin data and have produced a criterion which is aimed to prevent the occurrence of a more severe response of acute deep ulceration. The NCRP suggested exposure limit, which is given in terms of a total beta particle exposure of 1010, is less restrictive than that suggested by the ICRP task group by a factor of about 5. The disparity reflects the different levels of acceptable damage and possibly some differences in dose estimates used in the animal studies on which the threshold criteria are based. (author)

  19. Experimental particle physics

    International Nuclear Information System (INIS)

    The goals of this research are the experimental testing of fundamental theories of physics beyond the standard model and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large-area underground detector to search fore grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low- and high-energy neutrinos; the Chooz experiment to search for reactor neutrino oscillations at a distance of 1 km from the source; a new proposal (the Perry experiment) to construct a one-kiloton liquid scintillator in the Fairport, Ohio underground facility IMB to study neutrino oscillations with a 13 km baseline; and development of technology for improved liquid scintillators and for very-low-background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments

  20. Particles and quantum fields

    CERN Document Server

    Kleinert, Hagen

    2016-01-01

    This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordin...

  1. Charged-particle coating

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W.L.; Crane, J.K.; Hendricks, C.D.

    1980-08-29

    Advanced target designs require thicker (approx. 300 ..mu..m) coatings and better surface finishes that can be produced with current coating techniques. An advanced coating technique is proposed to provide maximum control of the coating flux and optimum manipulation of the shell during processing. In this scheme a small beam of ions or particles of known incident energy are collided with a levitated spherical mandrel. Precise control of the incident energy and angle of the deposition flux optimizes the control of the coating morphology while controlled rotation and noncontact support of the shell minimizes the possibility of particulate or damage generated defects. Almost infinite variability of the incident energy and material in this process provides increased flexibility of the target designs which can be physically realized.

  2. C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 �- 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  3. C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 - 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  4. Developments in Particle Detection

    CERN Document Server

    Virdee, Tejinder S

    2001-01-01

    From the many recent developments in particle detectors we select some of the major and challenging ones. The selected developments are primarily those necessitated by the harsh environment of the LHC. The presentations made in the parallel sessions of this conference are mostly placed in the context of these developments. This includes those connected with two new experiments concepts which were presented namely: TESLA and BTeV. From the inner tracking we look at pixel detectors, silicon microstrip detectors and microstrip gas detectors; from calorimetry we consider PbWO4 scintillating crystals and the 'accordion' liquid argon calorimeter; from the muon systems we consider monitored drift tubes (MDTs), thin-gap chambers (TGCs) and resistive plate chambers (RPCs). Another subject covered, and much reported in the parallel sessions, is that of photodetectors including avalanche photodiode s (APDs), vacuum phototriodes (VPTs), hybrid photodiodes (HPDs) and visible light photon detectors (VLPCs). Finally the imp...

  5. Theoretical Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Kamionkowski, Marc

    2013-08-07

    Abstract: Theoretical Particle Astrophysics The research carried out under this grant encompassed work on the early Universe, dark matter, and dark energy. We developed CMB probes for primordial baryon inhomogeneities, primordial non-Gaussianity, cosmic birefringence, gravitational lensing by density perturbations and gravitational waves, and departures from statistical isotropy. We studied the detectability of wiggles in the inflation potential in string-inspired inflation models. We studied novel dark-matter candidates and their phenomenology. This work helped advance the DoE's Cosmic Frontier (and also Energy and Intensity Frontiers) by finding synergies between a variety of different experimental efforts, by developing new searches, science targets, and analyses for existing/forthcoming experiments, and by generating ideas for new next-generation experiments.

  6. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    The present collection of letters from JINR, Dubna, contains nine separate records on thermal multifragmentation, nuclear fog and critical temperature for the liquid-gas phase transition, topological and nontopological solutions for the chiral bag model with constituent quarks, comparison of ATLAS tilecal module No. 8 high-precision metrology measurement results obtained by laser (JINR) and photogrammetric (CERN) methods, calibration of the beam polarimeter at the JINR synchrophasotron, anomalous A-, t-dependence and the phase behaviour of partial wave of coherent production of radial state π (1300), about some inverse problems of nuclear physics, the nuclear matter modification at intermediate energies, experimental research of the NN scattering with polarized particles at the VdG accelerator of Charles university. Project 'NN interactions' and the forward detector of the ANKE spectrometer. Scintillation and Cherenkov hodoscopes

  7. Charged-particle coating

    International Nuclear Information System (INIS)

    Advanced target designs require thicker (approx. 300 μm) coatings and better surface finishes that can be produced with current coating techniques. An advanced coating technique is proposed to provide maximum control of the coating flux and optimum manipulation of the shell during processing. In this scheme a small beam of ions or particles of known incident energy are collided with a levitated spherical mandrel. Precise control of the incident energy and angle of the deposition flux optimizes the control of the coating morphology while controlled rotation and noncontact support of the shell minimizes the possibility of particulate or damage generated defects. Almost infinite variability of the incident energy and material in this process provides increased flexibility of the target designs which can be physically realized

  8. [Medium energy particle physics

    International Nuclear Information System (INIS)

    Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of 3H, 3He, 4He; Detailed Balance in pd right reversible γ3H; Interaction Dynamics); and Search for the Rare Decay Μ+ → e+ + γ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects

  9. Particles: glueballs detected

    International Nuclear Information System (INIS)

    For about twenty years, the glueballs, hypothetical particles predicted by the quantum chromodynamics (QCD) theory, have never been detected with certainty. Thanks to extraordinary complex computer calculations, Donald Weingarten's team from the IBM research center of Yorktown Heights new New York (USA), have claimed that they are now able to define glueballs. According to their calculations, glueballs have been detected several times in the debris from the collision experiments carried out at the SLAC, the CERN or the Pekin Institute for High Energy Physics. A critical commentary of these affirmations is given by Pierre Fayet from the ENS (Ecole Normale Superieure of Paris, France). This short paper gives also a short recall of the gluon model and of glueballs properties according to QCD theory. (J.S.). 1 fig., 1 photo

  10. Particle processing technology

    Science.gov (United States)

    Yoshio, Sakka

    2014-02-01

    In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing [1-3]. This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si3N4-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also

  11. Particle acceleration by pulsars

    International Nuclear Information System (INIS)

    The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed. The relation of the favored models to cosmic rays is discussed. It is pointed out that the pairs made by the models may have observable consequences for observation of positrons in the local cosmic ray flux and for observations of the 511 keV line from the interstellar medium. Another new point is that asymmetry of plasma supply from at least one of the models may qualitatively explain the gross asymmetry of the X-ray emission from the Crab nebula. It is also argued that acceleration of cosmic ray nuclei by pulsars, while energetically possible, can occur only at the boundary of the bubbles blown by the pulsars, if the cosmic ray composition is to be anything like that of the known source spectrum

  12. Nanodosimetry of charged particles

    International Nuclear Information System (INIS)

    In last year's annual report, the authors described the development of an ultra-miniature counter (UMC), described some of its physical characteristics, and presented some first measurements with this counter of microdosimetric spectra for neutrons (15 MeV) and photons (137Cs). It remains to investigate in more detail the operational characteristics of the UMC and if possible, to make a comparison of relevant physical parameters such as gain and multiplication radius with the Segur theory. In order to accomplish these objectives, it is necessary to build a wall-less version of the UMC, which will be amenable to calibration and investigation with collimated beams of charged particles. The design of such a counter has been worked out in principle. Investigations into the optimal design of electrode structures and dimensions are being carried out at present. The main problem occurs with the design of the grid structure which is required to define the outer boundary of the collecting volume. Our initial attempts would make it appear at present that a counter of 1 to 1.5 mm diameter is feasible. This should be more than adequate to provide an appropriately wall-less counter within a reasonable size cavity. It will probably be about a year before a working counter can be produced. In the interim, it is possible to make some initial efforts into the investigation of operational characteristics of a wall-less UMC by making use of similar design, but at a somewhat larger size. These first attempts at measurement of charged particle microdosimetric spectra at nanometer site provide added evidence that these counters can yield useful microdosimetric data at far smaller site sizes than heretofore attempted. They also provide added incentive and encouragement for development of wall-less UMC

  13. Associated particle imaging (API)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    Associated Particle Imaging (API) is an active neutron probe technique that provides a 3-D image with elemental composition of the material under interrogation, and so occupies a unique niche in the interrogation of unknown objects. The highly penetrating nature of neutrons enables API to provide detailed information about targets of interest that are hidden from view. Due to the isotropic nature of the induced reactions, radiation detectors can be set on the same side of the object as the neutron source, so that the object can be interrogated from a single side. At the heat of the system is a small generator that produces a continuous, monoenergetic flux of neutrons. By measuring the trajectory of coincident alpha particles that are produced as part of the process, the trajectory of the neutron can be inferred. Interactions between a neutron and the material in its path often produce a gamma ray whose energy is characteristic of that material. When the gamma ray is detected, its energy is measured and combined with the trajectory information to produce a 3-D image of the composition of the object being interrogated. During the course of API development, a number of improvements have been made. A new, more rugged sealed Tube Neutron Generator (STNG) has been designed and fabricated that is less susceptible to radiation damage and better able to withstand the rigors of fielding than earlier designs. A specialized high-voltage power supply for the STNG has also been designed and built. A complete package of software has been written for the tasks of system calibration, diagnostics and data acquisition and analysis. A portable system has been built and field tested, proving that API can be taken out of the lab and into real-world situations, and that its performance in the field is equal to that in the lab.

  14. Polarization particle drift and quasi-particle invariants

    International Nuclear Information System (INIS)

    The second-order approximation in quasi-particle description of magnetized plasmas is studied. Reduced particle and guiding-centre velocities are derived taking account of the second-order renormalization and polarization drift modified owing to finite-Larmor-radius effects. The second-order adiabatic invariant of quasi-particle motion is found. Global adiabatic invariants for the magnetized plasma are revealed, and their possible role in energy exchange between particles and fields, nonlinear mode cascades and global plasma stability is shown. 49 refs

  15. Drag Coefficient of Hexadecane Particles

    Science.gov (United States)

    Nakao, Yoshinobu; Hishida, Makoto; Kajimoto, Sadaaki; Tanaka, Gaku

    This paper deals with the drag coefficient of solidified hexadecane particles and their free rising velocity in liquid. The drag coefficient was experimentally investigated in Reynolds number range of about 40-300. The present experimental results are summarized in the following; (1) the drag coefficient of solidified hexadecane particles formed in liquid coolant by direct contact cooling is higher than that of a smooth surface sphere, this high drag coefficient seems to be attributed to the non-smooth surface of the solidified hexadecane particles, (2) experimental correlation for the drag coefficient of the solidified hexadecane particles was proposed, (3 ) the measured rising velocity of the solidified hexadecane particle agrees well with the calculated one, (4) the drag coefficients of hexadecane particles that were made by pouring hexadecane liquid into a solid hollow sphere agreed well with the drag coefficient of smooth surface sphere.

  16. Fuzzy logic particle tracking velocimetry

    Science.gov (United States)

    Wernet, Mark P.

    1993-01-01

    Fuzzy logic has proven to be a simple and robust method for process control. Instead of requiring a complex model of the system, a user defined rule base is used to control the process. In this paper the principles of fuzzy logic control are applied to Particle Tracking Velocimetry (PTV). Two frames of digitally recorded, single exposure particle imagery are used as input. The fuzzy processor uses the local particle displacement information to determine the correct particle tracks. Fuzzy PTV is an improvement over traditional PTV techniques which typically require a sequence (greater than 2) of image frames for accurately tracking particles. The fuzzy processor executes in software on a PC without the use of specialized array or fuzzy logic processors. A pair of sample input images with roughly 300 particle images each, results in more than 200 velocity vectors in under 8 seconds of processing time.

  17. Ensemble Equivalence for Distinguishable Particles

    Directory of Open Access Journals (Sweden)

    Antonio Fernández-Peralta

    2016-07-01

    Full Text Available Statistics of distinguishable particles has become relevant in systems of colloidal particles and in the context of applications of statistical mechanics to complex networks. In this paper, we present evidence that a commonly used expression for the partition function of a system of distinguishable particles leads to huge fluctuations of the number of particles in the grand canonical ensemble and, consequently, to nonequivalence of statistical ensembles. We will show that the alternative definition of the partition function including, naturally, Boltzmann’s correct counting factor for distinguishable particles solves the problem and restores ensemble equivalence. Finally, we also show that this choice for the partition function does not produce any inconsistency for a system of distinguishable localized particles, where the monoparticular partition function is not extensive.

  18. Particle Acceleration in Astrophysical Sources

    CERN Document Server

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

  19. Classical Models of Subatomic Particles

    OpenAIRE

    Mann, R. B.; Morris, M. S.

    1993-01-01

    We look at the program of modelling a subatomic particle---one having mass, charge, and angular momentum---as an interior solution joined to a classical general-relativistic Kerr-Newman exterior spacetime. We find that the assumption of stationarity upon which the validity of the Kerr-Newman exterior solution depends is in fact violated quantum mechanically for all known subatomic particles. We conclude that the appropriate stationary spacetime matched to any known subatomic particle is flat ...

  20. Particle Acceleration in Astrophysical Sources

    OpenAIRE

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macros...

  1. Classical models of subatomic particles

    International Nuclear Information System (INIS)

    We look at the program of modelling a subatomic particle - one having mass, charge, and angular momentum - as an interior solution joined to a classical general-relativistic Kerr-Newman exterior spacetime. We find that the assumption of stationarity upon which the validity of the Kerr-Newman exterior solution depends is in fact violated quantum mechanically for all known subatomic particles. We conclude that the appropriate stationary spacetime matched to any known subatomic particle is flat space. (orig.)

  2. Optical trapping of absorbing particles

    CERN Document Server

    Rubinsztein-Dunlop, H; Friese, M E J; Heckenberg, N R

    1998-01-01

    Radiation pressure forces in a focussed laser beam can be used to trap microscopic absorbing particles against a substrate. Calculations based on momentum transfer considerations show that stable trapping occurs before the beam waist, and that trapping is more effective with doughnut beams. Such doughnut beams can transfer angular momentum leading to rotation of the trapped particles. Energy is also transferred, which can result in heating of the particles to temperatures above the boiling point of the surrounding medium.

  3. The CMS Particle Flow Algorithm

    OpenAIRE

    Beaudette, Florian

    2014-01-01

    A particle flow event-reconstruction algorithm has been successfully deployed in the CMS experiment and is nowadays used by most of the analyses. It aims at identifying and reconstructing individually each particle arising from the LHC proton-proton collision, by combining the information from all the subdetectors. The resulting particle-flow event reconstruction leads to an improved performance for the reconstruction of jets and MET, and for the identification of electrons, muons, and taus. ...

  4. Particle plasmons: Why shape matters

    Science.gov (United States)

    Barnes, William L.

    2016-08-01

    Simple analytic expressions for the polarizability of metallic nanoparticles are in wide use in the field of plasmonics, but their origins are not obvious. In this article, expressions for the polarizability of a particle are derived in the quasistatic limit in a manner that allows the physical origin of the terms to be clearly seen. The discussion is tutorial in nature, with particular attention given to the role of particle shape since this is a controlling factor in particle plasmon resonances.

  5. Amorphous silicon based particle detectors

    OpenAIRE

    Wyrsch, N; Franco, A; Riesen, Y.; Despeisse, M; S. Dunand; Powolny, F; Jarron, P.; Ballif, C.

    2012-01-01

    Radiation hard monolithic particle sensors can be fabricated by a vertical integration of amorphous silicon particle sensors on top of CMOS readout chip. Two types of such particle sensors are presented here using either thick diodes or microchannel plates. The first type based on amorphous silicon diodes exhibits high spatial resolution due to the short lateral carrier collection. Combination of an amorphous silicon thick diode with microstrip detector geometries permits to achieve micromete...

  6. Particle decay in inflationary cosmology

    OpenAIRE

    Boyanovsky, D.; de Vega, H. J.

    2004-01-01

    We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a prelude to a more general scenario, the method is applied here to study the decay of a particle in de Sitter inflation via a trilinear coupling to massless conformally coupled particles, both for wavelengths much larger and much smaller than the Hubble radius. F...

  7. Quark matter or new particles?

    Science.gov (United States)

    Michel, F. Curtis

    1988-01-01

    It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).

  8. Cooperative Transport of Brownian Particles

    OpenAIRE

    Derenyi, Imre; Vicsek, Tamas

    1998-01-01

    We consider the collective motion of finite-sized, overdamped Brownian particles (e.g., motor proteins) in a periodic potential. Simulations of our model have revealed a number of novel cooperative transport phenomena, including (i) the reversal of direction of the net current as the particle density is increased and (ii) a very strong and complex dependence of the average velocity on both the size and the average distance of the particles.

  9. Optical trapping of absorbing particles

    OpenAIRE

    Rubinsztein-Dunlop, H.; Nieminen, T. A.; Friese, M. E. J.; Heckenberg, N R

    2003-01-01

    Radiation pressure forces in a focussed laser beam can be used to trap microscopic absorbing particles against a substrate. Calculations based on momentum transfer considerations show that stable trapping occurs before the beam waist, and that trapping is more effective with doughnut beams. Such doughnut beams can transfer angular momentum leading to rotation of the trapped particles. Energy is also transferred, which can result in heating of the particles to temperatures above the boiling po...

  10. Particle plasmons: Why shape matters

    CERN Document Server

    Barnes, William L

    2016-01-01

    Simple analytic expressions for the polarizability of metallic nanoparticles are in wide use in the field of plasmonics, but their origins are not obvious. In this article, expressions for the polarizability of a particle are derived in the quasistatic limit in a manner that allows the physical origin of the terms to be clearly seen. The discussion is tutorial in nature, with particular attention given to the role of particle shape since this is a controlling factor in particle plasmon resonances.

  11. Aspects of experimental particle physics

    International Nuclear Information System (INIS)

    The paper contains three lectures on Experimental Particle Physics which were given at the 16th British Universities Summer School for Theoretical and Elementary Particle Physics, Durham, 1986. The first lecture briefly reviews the physics which underpins all particle detectors, and the second lecture describes how this physics influences a modern detector. The last lecture is concerned with the topics of beams and computers, and includes the physics of stochastic cooling and the Halting theorem. (U.K.)

  12. Trajectory dependent particle response for anisotropic mono domain particles in magnetic particle imaging

    Science.gov (United States)

    Graeser, M.; Bente, K.; Neumann, A.; Buzug, T. M.

    2016-02-01

    In magnetic particle imaging, scanners use different spatial sampling techniques to cover the field of view (FOV). As spatial encoding is realized by a selective low field region (a field-free-point, or field-free-line), this region has to be moved through the FOV on specific sampling trajectories. To achieve these trajectories complex time dependent magnetic fields are necessary. Due to the superposition of the selection field and the homogeneous time dependent fields, particles at different spatial positions experience different field sequences. As a result, the dynamic behaviour of those particles can be strongly spatially dependent. So far, simulation studies that determined the trajectory quality have used the Langevin function to model the particle response. This however, neglects the dynamic relaxation of the particles, which is highly affected by magnetic anisotropy. More sophisticated models based on stochastic differential equations that include these effects were only used for one dimensional excitation. In this work, a model based on stochastic differential equations is applied to two-dimensional trajectory field sequences, and the effects of these field sequences on the particle response are investigated. The results show that the signal of anisotropic particles is not based on particle parameters such as size and shape alone, but is also determined by the field sequence that a particle ensemble experiences at its spatial position. It is concluded, that the particle parameters can be optimized in terms of the used trajectory.

  13. Trajectory dependent particle response for anisotropic mono domain particles in magnetic particle imaging

    International Nuclear Information System (INIS)

    In magnetic particle imaging, scanners use different spatial sampling techniques to cover the field of view (FOV). As spatial encoding is realized by a selective low field region (a field-free-point, or field-free-line), this region has to be moved through the FOV on specific sampling trajectories. To achieve these trajectories complex time dependent magnetic fields are necessary. Due to the superposition of the selection field and the homogeneous time dependent fields, particles at different spatial positions experience different field sequences. As a result, the dynamic behaviour of those particles can be strongly spatially dependent. So far, simulation studies that determined the trajectory quality have used the Langevin function to model the particle response. This however, neglects the dynamic relaxation of the particles, which is highly affected by magnetic anisotropy. More sophisticated models based on stochastic differential equations that include these effects were only used for one dimensional excitation. In this work, a model based on stochastic differential equations is applied to two-dimensional trajectory field sequences, and the effects of these field sequences on the particle response are investigated. The results show that the signal of anisotropic particles is not based on particle parameters such as size and shape alone, but is also determined by the field sequence that a particle ensemble experiences at its spatial position. It is concluded, that the particle parameters can be optimized in terms of the used trajectory. (paper)

  14. Particles Emission from Gasoline Vehicles

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-fang; GE Yun-shan; TAN Jian-wei; HE Chao; YOU Ke-wei; YOU Qiu-wen

    2009-01-01

    Number concentration and size distribution from gasoline cars are investigated at transient modes on the chassis dynamometers,which are measured using electrical low pressure impactor (ELPI) for the ECE15 and EUDC cycles.Results indicate that,during cold start,particle number emission is higher than that under hot start.It is found that the number of particles increases with the vehicle speeds.Furthermore,particles with diameter smaller than 200 nm constitute the predominant part of total emission in the entire cycle.In addition,the tentative information about composition of emitted particles is also discussed.

  15. Particle detectors and black holes

    International Nuclear Information System (INIS)

    The author recalls the elevator experiment which ultimately led Einstein to his formulation of General Relativity. In addition to the classical falling weights, flashlights, etc, the author suggests the experimenter also take along a particle detector. This detector will be a particularly simple detector consisting of a Schroedinger particle of mass m in a box with walls impermeable to the detector particle. From the equivalence principle, the detector particle in the accelerated elevator will be in an effective potential maz where z is the coordinate in the direction of the acceleration a, measured from let's say, the center of the detector. The author gives a derivation of the detection process. (Auth.)

  16. Aging fingerprints in combustion particles

    Directory of Open Access Journals (Sweden)

    V. Zelenay

    2011-05-01

    Full Text Available Soot particles can significantly influence the Earth's climate by absorbing and scattering solar radiation as well as by acting as cloud condensation nuclei. However, despite their environmental (as well as economic and political importance, the way these properties are affected by atmospheric processing is still a subject of discussion. In this work, soot particles emitted from two different cars, a EURO 2 transporter, a EURO 3 passenger vehicle, and a wood stove were investigated on a single-particle basis. The emitted exhaust, including the particulate and the gas phase, was processed in a smog chamber with artificial solar radiation. Single particle specimens of both unprocessed and aged soot were characterized using x-ray absorption spectroscopy and scanning electron microscopy. Comparison of the spectra from the unprocessed and aged soot particles revealed changes in the carbon functional group content, such as that of carboxylic carbon, which can be ascribed to both the condensation of secondary organic compounds on the soot particles and oxidation of primary soot particles upon photochemical aging. Changes in the morphology and size of the single soot particles were also observed upon aging. Furthermore, we show that the soot particles take up water in humid environments and that their water uptake capacity increases with photochemical aging.

  17. Fluctuation interactions of colloidal particles

    International Nuclear Information System (INIS)

    For like-charged colloidal particles, two mechanisms of attraction between them survive when the interparticle distance is larger than the Debye screening length. One of them is the conventional van der Waals attraction and the second is the attraction mechanism mediated by thermal fluctuations of particle position. The latter is related to the effective variable mass (Euler mass) of the particles produced by the fluid motion. The strongest attraction potential (up to the value of the temperature T) corresponds to the case of uncharged particles and a relatively large Debye screening length. In this case, the third attraction mechanism is involved. It is mediated by thermal fluctuations of the fluid density.

  18. Multi-Particle Universal Processes

    Directory of Open Access Journals (Sweden)

    J. Novotný

    2005-01-01

    Full Text Available We generalize bipartite universal processes to the subclass of multi-particle universal processes from one to N particles. We show how the general statement for a multi-particle universal process can be constructed. The one-parameter family of processes generating totally anti-symmetric states has been generalized to a multi-particle regime and its entanglement properties have been studied. A view is given on the complete positivity and the possible physical realization of universal processes. 

  19. Particles matter: Transformation of suspended particles in constructed wetlands

    OpenAIRE

    Mulling, B.T.M.

    2013-01-01

    This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator bacteria and viruses, while in situ production generates suspended particles including bacterial consortia that closely resemble that of natural shallow water systems. This transformation is driven ...

  20. Particles formation and particle design using supercritical fluids

    OpenAIRE

    Knez, Željko; Weidner, Eckhard

    2012-01-01

    Major recent advances. Particle formation and design of solid particles and powdery composites with unique properties is at the moment a major developmentof supercritical fluids (synonymsČ dense gasses, dense fluids, highpressure) applications. This review will focus on recent advances and on fundamentals of these processes and their applications.

  1. Particle-accelerator decommissioning

    International Nuclear Information System (INIS)

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  2. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's 50th anniversary celebrations. Fifty candles for CERN, an international laboratory renowned for fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting exhibitions of plastic arts and performances entitled: Accelerated Particles. Several works will be exhibited and performed in two 'salons'. Salon des matières: An exhibition of plastic arts From Tues 12 October to Wed 3 November 2004 Tuesdays to Fridays: 16:00 to 19:00 Saturdays: 14:00 to 18:00 Exhibition open late on performance nights, entrance free Salon des particules: Musical and visual performances Tues 12 and Mon 25 October from 20:00 to 23:00 Preview evening for both events: Tues 12 October from 18:...

  3. Playing with particles

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Could the principles of particle physics ever be explained by a game? Could a deck of cards ever teach the Standard Model the way Monopoly teaches economics? According to players of the Quark Matter card game, the answer is an easy “yes!”.   Csaba Török and Judit Csörgő (second and third from left) at the award ceremony for the Eötvös University Innovation Contest. When he was only 17 years old, Hungarian student Csaba Török came up with the idea for the Quark Matter cards. “I wanted people to think of the Standard Model as fun – not just a serious, scientific theory,” says Csaba. “The cards can turn everyone into a pseudo-physicist.” He shared the idea with his friend Judit Csörgő and her physicist father, Tamás Csörgő, and together they went on to develop Quark Matter into the game it is today. Csaba and Judit were both members o...

  4. EXHIBITION: Accelerated Particles

    CERN Multimedia

    2004-01-01

    http://www.cern.ch/cern50/ An exhibition of plastic arts and two evenings of performances by sound and visual artists as part of CERN's fiftieth anniversary celebrations. The fiftieth anniversary of a world famous organization like CERN, an international laboratory specializing in fundamental research, is a cause for celebration. Since March this year, Geneva and neighbouring parts of France have been the venues for a wealth of small and large-scale events, which will continue until November. Given CERN's location in the commune of Meyrin, the ForuMeyrin is hosting two "salons" consisting of an exhibition of plastic arts and evenings of music and visual arts performances with the collective title of "Accelerated Particles". Several works will be exhibited and performed. Salon des matières: An exhibition of plastic arts Until Wednesday 3 November 2004. Tuesdays to Fridays: 4.00 p.m. to 7.00 p.m. Saturdays: 2.00 p.m. to 6.00 p.m. Doors open late on the evening of the performances. Salon des ...

  5. Astrophysical Smooth Particle Hydrodynamics

    CERN Document Server

    Rosswog, Stephan

    2009-01-01

    In this review the basic principles of smooth particle hydrodynamics (SPH) are outlined in a pedagogical fashion. To start, a basic set of SPH equations that is used in many codes throughout the astrophysics community is derived explicitly. Much of SPH's success relies on its excellent conservation properties and therefore the numerical conservation of physical invariants receives much attention throughout this review. The self-consistent derivation of the SPH equations from the Lagrangian of an ideal fluid is the common theme of the remainder of the text. Such a variational approach is applied to derive a modern SPH version of Newtonian hydrodynamics. It accounts for gradients in the local resolution lengths which result in corrective, so-called "grad-h-terms". This strategy naturally carries over to the special-relativistic case for which we derive the corresponding grad-h set of equations. This approach is further generalized to the case of a fluid that evolves on a curved, but fixed background space-time.

  6. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  7. The Particle--Motion Problem.

    Science.gov (United States)

    Demana, Franklin; Waits, Bert K.

    1993-01-01

    Discusses solutions to real-world linear particle-motion problems using graphing calculators to simulate the motion and traditional analytic methods of calculus. Applications include (1) changing circular or curvilinear motion into linear motion and (2) linear particle accelerators in physics. (MDH)

  8. Lagrangian multi-particle statistics

    DEFF Research Database (Denmark)

    Lüthi, Beat; Berg, Jacob; Ott, Søren;

    2007-01-01

    Combined measurements of the Lagrangian evolution of particle constellations and the coarse-grained velocity derivative tensor. partial derivative(u) over tilde (i) /partial derivative x(j) are presented. The data are obtained from three-dimensional particle tracking measurements in a quasi isotr...

  9. Dust particle charging in sheath

    International Nuclear Information System (INIS)

    The charging and the screening of spherical dust particles in sheaths near the wall were studied using computer simulation. The three-dimensional PIC/MCC method and molecular dynamics method were applied to describe plasma particles motion and interaction with macroscopic dust grain. Calculations were carried out at different neutral gas pressures and wall potentials. Values of the charge of the dust particles and spatial distributions of plasma parameters are obtained by modelling. The results have shown that the charge of the dust particles in the sheath, as well as the spatial distribution of the ions and electrons near the dust particles, depend strongly on the wall potential. It is shown that for large negative values of the wall potential the negative charge of a dust particle decreases due to the decline of the electron density in its vicinity. In addition, the flow of energy of the ions on the surface of dust particles is increased due to better focusing effect of the dust particle field on ions.

  10. Monte Carlo Particle Lists: MCPL

    CERN Document Server

    Kittelmann, Thomas; Knudsen, Erik B; Willendrup, Peter; Cai, Xiao Xiao; Kanaki, Kalliopi

    2016-01-01

    A binary format with lists of particle state information, for interchanging particles between various Monte Carlo simulation applications, is presented. Portable C code for file manipulation is made available to the scientific community, along with converters and plugins for several popular simulation packages.

  11. Planck Particles and Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Crothers S. J.

    2006-07-01

    Full Text Available The alleged existence of so-called Planck particles is examined. The various methods for deriving the properties of these “particles” are examined and it is shown that their existence as genuine physical particles is based on a number of conceptual flaws which serve to render the concept invalid.

  12. Alpha Particle Emission in Fission

    International Nuclear Information System (INIS)

    Soon after it was discovered that alpha particles are occasionally emitted in fission, it was concluded, on the basis of the energy and angular distributions of these particles, that they are emitted from the space between the fragments at times close to that of the snapping of the neck that connects them. It is shown that, independent of any (still unknown) dynamic features of the alpha-particle ejection process, the energy required to emit alpha particles from between the fragments at the indicated time is barely available. Presumably the rareness of alpha particles in fission, and the apparent absence of still heavier ''third'' particles, is associated with the marginal energy supply at the time of actual fragment division. The fact that the total kinetic energy release in so-called ternary fission is roughly equal to that in normal binary fission instead of being about 20 MeV larger is shown to imply that the mean fragment separation at the division time is larger in ternary fission. This is interpreted to indicate that alpha particles are emitted with greatest probability n those fissions where ample energy happens to be provided through the stretching of an abnormally long neck between the fragments before they actually divide. It is suggested that the release of the alpha particles is a sudden rather than adiabatic process. (author)

  13. Build Your Own Particle Sensor

    Science.gov (United States)

    This is an information packet explaining an educational outreach activity, where the participant does some simple electronics with low cost components to build a particle sensor that can turn one to three small lights on based upon the detected concentration of particles.

  14. Largest particle detector nearing completion

    CERN Multimedia

    2006-01-01

    "Construction of another part of the Large Hadron Collider (LHC), the worl's largest particle accelerator at CERN in Switzerland, is nearing completion. The Compact Muon Solenoid (CMS) is oner of the LHC project's four large particle detectors. (1/2 page)

  15. A Many Particle Adiabatic Invariant

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    For a system of N charged particles moving in a homogeneous, sufficiently strong magnetic field, a many-particle adiabatic invariant constrains the collisional exchange of energy between the degrees of freedom perpendicular to and parallel to the magnetic field. A description of the phenomenon in...

  16. Particle Production in Ekpyrotic Scenarios

    CERN Document Server

    Hipolito-Ricaldi, W S; Ferreira, Elisa G M; Graef, L L

    2016-01-01

    We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction is sufficient to lead to a hot state of matter after the bounce. Hence, no separate reheating mechanism is necessary.

  17. Computer Algebra in Particle Physics

    OpenAIRE

    Weinzierl, Stefan

    2002-01-01

    These lectures given to graduate students in theoretical particle physics, provide an introduction to the ``inner workings'' of computer algebra systems. Computer algebra has become an indispensable tool for precision calculations in particle physics. A good knowledge of the basics of computer algebra systems allows one to exploit these systems more efficiently.

  18. Entanglement entropy in particle decay

    CERN Document Server

    Lello, Louis; Holman, Richard

    2013-01-01

    The decay of a parent particle into two or more daughter particles results in an entangled quantum state, as a consequence of conservation laws in the decay process. We use the Wigner-Weisskopf formalism to construct an approximation to this state that evolves in time in a {\\em manifestly unitary} way. We then construct the entanglement entropy for one of the daughter particles by use of the reduced density matrix obtained by tracing out the unobserved states and follow its time evolution. We find that it grows over a time scale determined by the lifetime of the parent particle to a maximum, which when the width of the parent particle is narrow, describes the phase space distribution of maximally entangled Bell-like states.

  19. Optomechanics of Levitated Dielectric Particles

    CERN Document Server

    Yin, Zhang-qi; Li, Tongcang

    2013-01-01

    We review recent works on optomechanics of optically trapped microspheres and nanoparticles in vacuum, which provide an ideal system for studying macroscopic quantum mechanics and ultrasensitive force detection. An optically trapped particle in vacuum has an ultrahigh mechanical quality factor as it is well-isolated from the thermal environment. Its oscillation frequency can be tuned in real time by changing the power of the trapping laser. Furthermore, an optically trapped particle in vacuum may rotate freely, a unique property that does not exist in clamped mechanical oscillators. In this review, we will introduce the current status of optical trapping of dielectric particles in air and vacuum, Brownian motion of an optically trapped particle at room temperature, Feedback cooling and cavity cooling of the Brownian motion. We will also discuss about using optically trapped dielectric particles for studying macroscopic quantum mechanics and ultrasensitive force detection. Applications range from creating macr...

  20. Health effects of exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Pihlava, T.; Uuppo, M.; Niemi, S.

    2013-11-01

    This report introduces general information about diesel particles and their health effects. The purpose of this report is to introduce particulate matter pollution and present some recent studies made regarding the health effects of particulate matter. The aim is not to go very deeply into the science, but instead to keep the text understandable for the average layman. Particulate matter is a complex mixture of extremely small particles and liquid droplets. These small particles are made up of a number of components that include for example acids, such as nitrates and sulphates, as well as organic chemicals, metals and dust particles from the soil. Particulate matter comes from several sources, such as transportation emissions, industrial emissions, forest fires, cigarette smoke, volcanic ash and climate variations. Particles are divided into coarse particles with diameters less than 10 ..m, fine particles with diameters smaller than 2.5 ..m and ultra-fine particles with diameters less than 0.1 ..m. The particulate matter in diesel exhaust gas is a highly complex mixture of organic, inorganic, solid, volatile and partly volatile compounds. Many of these particles do not form until they reach the air. Many carcinogenic compounds have been found in diesel exhaust gas and it is considered carcinogenic to humans. Particulate matter can cause several health effects, such as premature death in persons with heart or lung disease, cancer, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and an increase in respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. It is estimated that in Finland about 1300 people die prematurely due to particles and the economic loss in the EU due to the health effects of particles can be calculated in the billions. Ultra-fine particles are considered to be the most harmful to human health. Ultrafine particles usually make the most of their quantity and surface area

  1. Method to detect biological particles

    International Nuclear Information System (INIS)

    A medical-diagnostic method to detect immunological as well as other specific reactions is described. According to the invention, first reactive particles (e.g. antibodies) are adsorbed on the surface of a solid, non-reactive substrate. The coated substrate is subjected to a solution which one assumes to contain the second biological particles (e.g. antigens) which are specific to the first and form complexes with these. A preferential radioactive labelling (e.g. with iodine 125) of the second biological particle is then directly or indirectly carried out. Clearage follows labelling in order to separate the second biological particles from the first ones. A specific splitting agent can selectively break the bond of both types of particle. The splitting agent solution is finally separated off and its content is investigated for the presence of labelling. (VJ)

  2. Heavy charged particle therapy

    International Nuclear Information System (INIS)

    A pilot study of heavy charged particles with heavy ion medical accelerator in Chiba (HIMAC) for advanced H and N cancer has been carried out from June 1994 at National Institute of Radiological Sciences (NIRS). As of the beginning of August 1994, three patients were treated by 290 MeV carbon ions. The patients had adenocarcinoma of the cheek mucosa, squamous cell carcinoma of the ethmoid sinus and adenoid cystic carcinoma of the sublingual gland. Patients were immobilized by individual head coach and thermosplint facial shell. Individual collimators and bolus were also prepared for each ports. Dose fractionation for the initial pilot study group was 16.2 GyE/18 fractions/6 weeks, which would be equivalent to standard fractionation of 60.0 Gy/30 fractions/6 weeks with photons. This dose fractionation was considered to be 20% lesser than 75 GyE/37.5 fractions/7.5 weeks, which is estimated to be maximum tolerance dose for advanced H and N cancers. HIMAC worked well and there was no major trouble causing any treatment delay. Acute skin reactions of 3 patients were 2 cases of bright erythema with patchy moist desquamation and one of dull erythema, which were evaluated as equivalent reaction with irradiated dose. Acute mucosa reactions appeared to have lesser reaction than predicted mucositis. Tumor reactions of three patients were partial reaction (PR) at the end of treatment and nearly complete remission (CR) after 6 months of treatment. From October 1994, we started to treat patients with advanced H and N cancer with 10% high dose than previous dose. And new candidates of pilot study with non small cell lung cancer, brain tumor and carcinoma of the tongue were entered into pilot study. At the end of February 1995, a total of 21 patients were treated by carbon ions. (J.P.N.)

  3. Numerical analysis of microstructure formation of magnetic particles and nonmagnetic particles in MR fluids

    International Nuclear Information System (INIS)

    Microstructure formation of magnetic particles and nonmagnetic particles in MR fluids is investigated using the particle method simulation. Nonmagnetic sphere particles are rearranged in the field direction due to the chain-like cluster formation of magnetic particles. In the contrast, the nonmagnetic spherocylinder particles are not sufficiently rearranged in the field direction by using the cluster formation of sphere magnetic particles.

  4. Alpha particle physics for ITER

    International Nuclear Information System (INIS)

    The paper is devoted to the analysis of a variety of physical processes which, in the ITER EDA configuration, determine the nature of alpha particle heating in the plasma interior and alpha particle losses to the first wall. The paper consists of results from the alpha particle toroidal field (TF) ripple loss calculations and an analysis of alpha particle collective effects including Alfven modes, sawtooth stabilization, etc. It is shown that the ripple loss in the present ITER configuration is only a few per cent, which cannot directly affect the achievement of ignition. In spite of the up-down asymmetry, the loss fraction does not strongly depend on the toroidal drift direction. However, the heat load is highly localized and can be as high as 1 MW/m2 on the top of the protective limiters. Preliminary calculations of toroidicity induced Alfven eigenmode (TAE) stability indicate that high n numbers may be unstable, but the computational tools, needed for reliable quantitative predictions, are still in a state of development. The likelihood of appreciable alpha particle loss will depend on whether TAE modes produce stochastic alpha particle diffusion or not. The effect of fast particles on the m = 1 mode is also discussed. (author). 15 refs, 2 figs, 1 tab

  5. Primary particles in ship emissions

    Science.gov (United States)

    Fridell, Erik; Steen, Erica; Peterson, Kjell

    There is not much data available regarding particle emissions from ships. In this study the size distributions of particles in ship exhaust from three different ships in normal operational conditions were studied using a cascade impactor. The ships were equipped with slow- or medium-speed main engines and medium-speed auxiliary engines. The fuel was residual oil except for the auxiliary engines on one ship which used marine diesel. Large emissions and a dependence of the sulfur content in the fuel were observed. High amounts of relatively large particles (around 8 μm) were observed. These are attributed to re-entrained soot particles from walls in the engine systems. A strong variation between different ships was observed for the particle-size distribution and for the dependence on engine load. The particle emissions were found to be reduced to about half, over the whole size range, by an SCR system. The total particle emission, measured after dilution, varied between 0.3 and 3 g kW h -1 depending on load, fuel and engine.

  6. Particles matter: Transformation of suspended particles in constructed wetlands

    NARCIS (Netherlands)

    B.T.M. Mulling

    2013-01-01

    This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator b

  7. Particle interferometry, binary sources and oscillations in two- particle correlations

    CERN Document Server

    Csörgö, T

    2001-01-01

    The basics and the formalism of Bose-Einstein correlations is briefly reviewed. The invariant Buda-Lund form is summarized. Tools are presented that can be utilized in a model-independent search for non- Gaussian structures in the two-particle Bose-Einstein correlation functions. The binary source formalism of particle interferometry is presented and related to oscillations in the two-particle Bose- Einstein and Fermi-Dirac correlation functions. The frequency of the observed oscillations in the NA49 two-proton correlation function in Pb+Pb collisions at CERN SPS energies is explained with the help of the reconstructed space-time picture of particle production and the binary nature of the proton source in this reaction. (44 refs).

  8. Quark and particle helicities in hadronic charmed particle decays

    International Nuclear Information System (INIS)

    We investigate possibilities of obtaining information on the chirality of the charm-changing current (antics) by measuring the helicities of hadrons with spin in exclusive hadronic charmed particle decays. (orig.)

  9. Pressure control and particle`s motion in ALPHA

    CERN Document Server

    Rudakov, Kirill

    2013-01-01

    The first project was a system to control the pressure of water and gas. The second project was the calculation of tracks of particles. The third project was to make an estimation of mutual inductance.

  10. Hot particles - a hot topic

    International Nuclear Information System (INIS)

    The health effects of hot particles have remained largely unknown. The nuclear power plant accident in Chernobyl spread hot particles into the environment, and findings by a Finnish research team show that their health effects have generally been underestimated. The essential feature from the point of view of health effect is that hot particles cause a very high radiation dose in a very small area in the surrounding organ or tissue. Up to now it has generally been thought that a dose limited within a small area would be even less dangerous than the same dose distributed throughout the body. Hot particles, however, are very effective in causing malignant changes in cells. Beta radiation emitted by hot particles causes permanent mutations in the genetic constitution, or the DNA molecule, of cells. At the same time they effectively stimulate the multiplication of cells by first causing the death of cells in their vicinity. When this results in a chronic wound around the hot particle, cells that are further away from the particle try to heal the wound by dividing rapidly. These cells have received high radiation doses but managed to survive. The mutated cell is thus able to build a malignant clone, which can develop further into cancer. Exposure to hot particles takes place mostly through the skin and, in particular, through the respiratory tract Most of the particles that were carried to Finland from Chernobyl were small in both size and activity. They became deposited onto the ground within a few days, and thus disappeared quickly from breathing air (orig.)

  11. DNA Gel Particles: Particle Preparation and Release Characteristics

    OpenAIRE

    Morán, M. Carmen; Miguel, M. Graça; Lindman, Björn

    2007-01-01

    Aqueous mixtures of oppositely charged polyelectrolytes undergo associative phase separation, resulting in coacervation, gelation, or precipitation. This phenomenon has been exploited here to form DNA gel particles by interfacial diffusion. We report the formation of DNA gel particles by mixing solutions of DNA (either single-stranded (ssDNA) or double-stranded (dsDNA)) with solutions of cationic surfactant CTAB and solutions of the protein lysozyme. Swelling, surface morphology, and DNA rele...

  12. Basset history force for the particle-particle collision

    Czech Academy of Sciences Publication Activity Database

    Lukerchenko, Nikolay

    Moskva: MAI-PRINT, 2010, s. 82-83. ISBN 978-5-7035-2184-7. [Meždunarodnaja konferencia po neravnovesnym processam v soplach i strujach (NPNJ'2010) /8./. Alušta (RU), 25.05.2010-31.05.2010] R&D Projects: GA ČR GA103/09/1718 Institutional research plan: CEZ:AV0Z20600510 Keywords : basset force * particle collision * numerical model * fluid flow with solid particles Subject RIV: BK - Fluid Dynamics

  13. Ultrafine particles in the atmosphere

    CERN Document Server

    Brown, L M; Harrison, R M; Maynard, A D; Maynard, R L

    2003-01-01

    Following the recognition that airborne particulate matter, even at quite modest concentrations, has an adverse effect on human health, there has been an intense research effort to understand the mechanisms and quantify the effects. One feature that has shone through is the important role of ultrafine particles as a contributor to the adverse effects of airborne particles. In this volume, many of the most distinguished researchers in the field provide a state-of-the-art overview of the scientific and medical research on ultrafine particles. Contents: Measurements of Number, Mass and Size Distr

  14. Particle tracking around surface nanobubbles

    CERN Document Server

    Dietrich, Erik; Lohse, Detlef; Seddon, James R T

    2016-01-01

    The exceptionally long lifetime of surface nanobubbles remains one of the biggest questions in the field. One of the proposed mechanisms for the stability is the \\emph{dynamic equilibrium} model, which describes a constant flux of gas in and out of the bubble. Here, we describe results from particle tracking experiments to measure this flow. The results are analysed by measuring the Vorono\\"i cell size distribution, the diffusion, and speed of the tracer particles. We show that there is no detectable difference in the movement of particles above nanobubble-laden surfaces, as compared to nanobubble-free surfaces.

  15. Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3772 CPC is a compact, rugged, and full-featured instrument that detects airborne particles down to 10 nm in diameter, at an aerosol flow rate of 1.0 lpm, over a concentration range from 0 to 1x104 #/cc. This CPC is ideally suited for applications without high concentration measurements, such as basic aerosol research, filter and air-cleaner testing, particle counter calibrations, environmental monitoring, mobile aerosol studies, particle shedding and component testing, and atmospheric and climate studies.

  16. Particle Tracking of Fluorescent Microspheres

    Science.gov (United States)

    Kaminski, Zofia; Mueller, Joachim; Berk, Serkan

    2010-10-01

    In this research, the diffusion coefficients of the fluorescent microspheres and the relation of those coefficients to particle radius were investigated. An additional focus was to see how well the measured radius of the microspheres compared to the radius as reported by the manufacturer and to measure the distribution of radii in a sample. This study further developed the critical process of ensuring particle movement within the sample volume and made preliminary sample measurements.The methods developed for tracking microspheres will later be used to determine the radii of virus like particles (VLPs), which are a non-infectious model system of the HIV virus. Results from our measurements will be reported.

  17. Monitoring of particle swarm optimization

    Institute of Scientific and Technical Information of China (English)

    Yuhui SHI; Russ EBERHART

    2009-01-01

    In this paper, several diversity measurements will be discussed and defined. As in other evolutionary algorithms, first the population position diversity will be discussed followed by the discussion and definition of population velocity diversity which is different from that in other evolutionary algorithms since only PSO has the velocity parameter. Furthermore, a diversity measurement called cognitive diversity is discussed and defined, which can reveal clustering information about where the current population of particles intends to move towards. The diversity of the current population of particles and the cognitive diversity together tell what the convergence/divergence stage the current population of particles is at and which stage it moves towards.

  18. Coulomb interactions in particle beams

    International Nuclear Information System (INIS)

    This book develops analytical and computer models for beams in which Coulomb interactions are important. The research into the different phenomena of Coulomb interactions in particle beams is stimulated by developments in the field of electron beam lithography for VLSI electronics. The standard theory of charged particle optics breaks down for intense beams in which interactions between particles are significant. This monograph is devoted to the theory of these intense beams, which are not only used in VLSI electronics but also in scanning electron microscopes. The theory is also applicable to focused ion beams, which are used in VLSI mask repair

  19. "Buddha's Light" of Cumulative Particles

    CERN Document Server

    Kopeliovich, Vladimir B; Potashnikova, Irina K

    2014-01-01

    We show analytically that in the cumulative particles production off nuclei multiple interactions lead to a glory-like backward focusing effect. Employing the small phase space method we arrived at a characteristic angular dependence of the production cross section $d\\sigma \\sim 1/ \\sqrt {\\pi - \\theta}$ near the strictly backward direction. This effect takes place for any number $n\\geq 3 $ of interactions of rescattered particle, either elastic or inelastic (with resonance excitations in intermediate states), when the final particle is produced near corresponding kinematical boundary. Such a behaviour of the cross section near the backward direction is in qualitative agreement with some of available data.

  20. Superparamagnetic relaxation of weakly interacting particles

    DEFF Research Database (Denmark)

    Mørup, Steen; Tronc, Elisabeth

    1994-01-01

    The influence of particle interactions on the superparamagnetic relaxation time has been studied by Mossbauer spectroscopy in samples of maghemite (gamma-Fe2O3) particles with different particle sizes and particle separations. It is found that the relaxation time decreases with decreasing particl...

  1. Inclusive Focus Particles in English and Korean

    Science.gov (United States)

    Kang, Sang-gu

    2011-01-01

    When discussing focus particles, it has been common practice to rely on the dichotomy of inclusive vs. exclusive particles, "a la" Konig (1991). Inclusive focus particles are often further divided into scalar particles, such as "also", "too", and "either", and non-scalar particles, such as "even". In this thesis, I advance a comparative analysis…

  2. Matter and Interactions: A Particle Physics Perspective

    Science.gov (United States)

    Organtini, Giovanni

    2011-01-01

    In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

  3. Pion production and particle correlations

    International Nuclear Information System (INIS)

    Intermediate energy heavy ion collisions have been studied using the carbon-beam produced at the CERN SC-accelerator. Cross-sections for π+ and π- have been measured over a wide range of large angles at 60, 75 and 86 MeV/nucleon. The yields and shapes are compared to a nucleon-nucleon scattering approach, which underestimates the yields by orders of magnitude. The π-/π+-ratio observed is close to unity for 12C + 12C, but the enhancement for 12C + 208Pb is much larger than expected from the neutron excess in 208Pb. Large-angle light-particle correlations for 86 MeV/nucleon carbon induced reactions on different targets (C, Al, Cu, Au) have been studied. An excess of correlations is observed in the particle-particle scattering plane. The strength of this effect increases with observed particle mass and decreases with target mass. (author)

  4. Magnetic guidance of charged particles

    CERN Document Server

    Dubbers, Dirk

    2015-01-01

    Many experiments and devices in physics use static magnetic fields to guide charged particles from a source onto a detector, and we ask the innocent question: What is the distribution of particle intensity over the detector surface? One should think that the solution to this seemingly simple problem is well known. We show that, even for uniform guide fields, this is not the case and present analytical point spread functions (PSF) for magnetic transport that deviate strongly from previous results. The "magnetic" PSF shows unexpected singularities, which were recently also observed experimentally, and which make detector response very sensitive to minute changes of position, field amplitude, or particle energy. In the field of low-energy particle physics, these singularities may become a source of error in modern high precision experiments, or may be used for instrument tests, for instance in neutrino mass retardation spectrometers.

  5. Particles trajectories in magnetic filaments

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain)

    2015-07-15

    The motion of a particle in a spatially harmonic magnetic field is a basic problem involved, for example, in the mechanism of formation of a collisionless shock. In such settings, it is generally reasoned that particles entering a Weibel generated turbulence are trapped inside it, provided their Larmor radius in the peak field is smaller than the field coherence length. The goal of this work is to put this heuristic conclusion on firm ground by studying, both analytically and numerically, such motion. A toy model is analyzed, consisting of a relativistic particle entering a region of space occupied by a spatially harmonic field. The particle penetrates the magnetic structure in a direction aligned with the magnetic filaments. Although the conclusions are not trivial, the main result is confirmed.

  6. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS can improve ISRU oxygen...

  7. Exotic Long-lived Particles

    DEFF Research Database (Denmark)

    Jørgensen, Morten Dam

    A search for hadronising long-lived massive particles at the Large Hadron Collider is conducted with the ATLAS detector. No excess events are found. Based on statistical analysis, upper limits on the production cross section are observed to be between 0.01 pb and 0.006 pb for colour octet particl...... addition, two neutrino flavour detection algorithms are developed which allow separation of charge-current muon events from other neutrino events.......A search for hadronising long-lived massive particles at the Large Hadron Collider is conducted with the ATLAS detector. No excess events are found. Based on statistical analysis, upper limits on the production cross section are observed to be between 0.01 pb and 0.006 pb for colour octet particles...

  8. Experimental entanglement of four particles

    Science.gov (United States)

    Sackett; Kielpinski; King; Langer; Meyer; Myatt; Rowe; Turchette; Itano; Wineland; Monroe

    2000-03-16

    Quantum mechanics allows for many-particle wavefunctions that cannot be factorized into a product of single-particle wavefunctions, even when the constituent particles are entirely distinct. Such 'entangled' states explicitly demonstrate the non-local character of quantum theory, having potential applications in high-precision spectroscopy, quantum communication, cryptography and computation. In general, the more particles that can be entangled, the more clearly nonclassical effects are exhibited--and the more useful the states are for quantum applications. Here we implement a recently proposed entanglement technique to generate entangled states of two and four trapped ions. Coupling between the ions is provided through their collective motional degrees of freedom, but actual motional excitation is minimized. Entanglement is achieved using a single laser pulse, and the method can in principle be applied to any number of ions. PMID:10749201

  9. Kinetic interfaces of patchy particles

    Science.gov (United States)

    Araújo, N. A. M.; Dias, C. S.; Telo da Gama, M. M.

    2015-05-01

    We study the irreversible adsorption of patchy particles on substrates in the limit of advective mass transport. Recent numerical results show that the interface roughening depends strongly on the particle attributes, such as, patch-patch correlations, bond flexibility and strength of the interactions, uncovering new absorbing phase transitions. Here, we revisit these results and discuss in detail the transitions. In particular, we present new evidence that the tricritical point, observed in systems of particles with flexible patches, is in the tricritical directed percolation universality class. A scaling analysis of the time evolution of the correlation length for the aggregation of patchy particles with distinct bonding energies confirms that the critical regime is in the Kardar-Parisi-Zhang with quenched disorder universality class.

  10. Particles trajectories in magnetic filaments

    CERN Document Server

    Bret, Antoine

    2015-01-01

    The motion of a particle in a spatially harmonic magnetic field is a basic problem involved, for example, in the mechanism of formation of a collisionless shock. In such settings, it is generally reasoned that particles entering a Weibel generated turbulence are trapped inside it, provided their Larmor radius in the peak field is smaller than the field coherence length. The goal of this work is to put this heuristic conclusion on firm ground by studying, both analytically and numerically, such motion. A toy model is analyzed, consisting of a relativistic particle entering a region of space occupied by a spatially harmonic field. The particle penetrates the magnetic structure in a direction aligned with the magnetic filaments. Although the conclusions are not trivial, the main result is confirmed.

  11. Contact interactions between particle worldlines

    Science.gov (United States)

    Edwards, James P.

    2016-01-01

    We construct contact interactions for bosonic and fermionic point particles. We first relate the resulting theories to classical electrostatics by taking functional averages over worldlines whose endpoints are fixed to charged particles. Counting those paths which pass through a space-time point x μ gives the static electric field at that point, provided we take the limit where the length measured along the worldlines is large. We also investigate corrections to the classical field that arise beyond leading order in this limit before constructing a theory of point particles that interact when their worldlines intersect. We quantise this theory and show that the partition function contains propagator couplings between the endpoints of the particles before discussing how this is related to the worldline formalism of quantum field theory and general action at a distance theories.

  12. Particle-vortex symmetric liquid

    CERN Document Server

    Mulligan, Michael

    2016-01-01

    We introduce an effective theory with manifest particle-vortex symmetry for disordered thin films undergoing a magnetic field-tuned superconductor-insulator transition. The theory may enable one to access both the critical properties of the strong-disorder limit, which has recently been confirmed [Breznay et al., PNAS 113, 280 (2016)] to exhibit particle-vortex symmetric electrical response, and the metallic phase discovered earlier [Mason and Kapitulnik, Phys. Rev. Lett. 82, 5341 (1999)] in less disordered samples. Within the effective theory, the Cooper-pair and field-induced vortex degrees of freedom are simultaneously incorporated into an electrically-neutral Dirac fermion minimally coupled to an (emergent) Chern-Simons gauge field. A derivation of the theory follows upon mapping the superconductor-insulator transition to the integer quantum Hall plateau transition and the subsequent use of Son's particle-hole symmetric composite Fermi liquid. Remarkably, particle-vortex symmetric response does not requir...

  13. Practical Statistics for Particle Physicists

    CERN Document Server

    Prosper, Harrison B

    2015-01-01

    These lectures introduce the basic ideas and practices of statistical analysis for particle physicists, using a real-world example to illustrate how the abstractions on which statistics is based are translated into practical application.

  14. Elementary Particles A New Approach

    Directory of Open Access Journals (Sweden)

    FranciscoMartnezFlores.

    2015-07-01

    Full Text Available ABSTRACT It is shown the inexistence of neutrinos to define precisely the concept of relativistics mass under this scheme to elementarys particles as electron and interactions particles like photons correspond an electromagnetic and virtual mass. Nucleons protons and neutrons have real or inertial mass for being composite particles since inertia needs structure it is provided by an interactive network originated by strong and weak forces. This mass is building up atoms and all the material world under Classical Physics and Chemistrys laws.These actual masses may be considered as electromagnetic and virtual one thanks to its charge in order to establish the high energies level needed to obtain all particles physics elementary or not which are governed by the laws of Quantum Physics. With all this one may set up amore reasonable and understandable new Standard Model which being projected into Cosmological Model can get rid of some inconsistencies and concepts difficult to be admitted.

  15. Study of heavy flavored particles

    International Nuclear Information System (INIS)

    This report discusses progress on the following topics: time-of- flight system; charmed baryon production and decays; D decays to baryons; measurement of sigma plus particles magnetic moments; and strong interaction coupling

  16. Virtual effects of Higgs particles

    Science.gov (United States)

    McWilliams, Bruce; Li, Ling-Fong

    1981-02-01

    The possibility of observing Higgs particles through virtual effects is considered in detail for a general gauge theory. The effect of charged Higgs particles on low-energy weak interaction processes, like muon decay, tau decay, nuclear beta decay, pion decay, and some higher-order processes is analyzed. The effect of flavor-changing neutral Higgs particles on rare decay modes of the muon and kaon, μe conversion, K o- overlineKo and D o- overlineDo mixing is also studied. We discuss constraints on possible extensions of the Weinberg-Salam model and experiments sensitive to their Higgs particles. In particular, we analyze the neutral Higgs which couple to fermions in the minimal SU(2) L×SU(2) R×U(1) model and find that they probably have mass greater than 100 GeV.

  17. Fundamental particles and their interactions

    OpenAIRE

    Ananthanarayan, B.

    2005-01-01

    In this article the current understanding of fundamental particles and their interactions is presented for the interested non-specialist, by adopting a semi-historical path. A discussion on the unresolved problems is also presented.

  18. Magnetic guidance of charged particles

    Directory of Open Access Journals (Sweden)

    Dirk Dubbers

    2015-09-01

    Full Text Available Many experiments and devices in physics use static magnetic fields to guide charged particles from a source onto a detector, and we ask the innocent question: What is the distribution of particle intensity over the detector surface? One should think that the solution to this seemingly simple problem is well known. We show that, even for uniform guide fields, this is not the case, and we present analytical point spread functions (PSF for magnetic transport that deviate strongly from previous results. The “magnetic” PSF shows unexpected singularities, which were recently also observed experimentally, and which make detector response very sensitive to minute changes of position, field amplitude, or particle energy. In the field of low-energy particle physics, these singularities may become a source of error in modern high precision experiments, or may be used for instrument tests.

  19. Particle Physics: a Progress Report

    OpenAIRE

    Altarelli, Guido

    2006-01-01

    We present a concise review of where we stand in particle physics today. First we discuss QCD, then the electroweak sector and finally the motivations and the avenues for new physics beyond the Standard Model.

  20. Particle identification by silicon detectors

    International Nuclear Information System (INIS)

    A method is developed for the evaluation of the energy loss, dE/dx, of a charged particle traversing a silicon strip detector. The method is applied to the DELPHI microvertex detector leading to diagrams of dE/dx versus momentum for different particles. The specific case of pions and protons is treated and the most probable value of dE/dx and the width of the dE/dx distribution for those particles in the momentum range of 0.2 GeV/c to 1.5 GeV/c, are obtained. The resolution found is 13.4 % for particles with momentum higher than 2 GeV/c and the separation power is 2.9 for 1.0 GeV/c pions and protons. (author)

  1. Lunar Soil Particle Separator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Soil Particle Separator (LSPS) is an innovative method to beneficiate soil prior to in-situ resource utilization (ISRU). The LSPS improves ISRU oxygen...

  2. Particle accelerators and scientific culture

    International Nuclear Information System (INIS)

    A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how our description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

  3. Particle accelerators and scientific culture

    International Nuclear Information System (INIS)

    A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how the description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

  4. The Marginalized Auxiliary Particle Filter

    OpenAIRE

    Fritsche, Carsten; Schön, Thomas; Klein, Anja

    2010-01-01

    In this paper we are concerned with nonlinear systems subject to a conditionally linear, Gaussian sub-structure. This structure is often exploited in high-dimensional state estimation problems using the marginalized (aka Rao-Blackwellized) particle filter. The main contribution in the present work is to show how an efficient filter can be derived by exploiting this structure within the auxiliary particle filter. Based on a multisensor aircraft tracking example, the superior performance of the...

  5. Particle-vortex symmetric liquid

    OpenAIRE

    Mulligan, Michael

    2016-01-01

    We introduce an effective theory with manifest particle-vortex symmetry for disordered thin films undergoing a magnetic field-tuned superconductor-insulator transition. The theory may enable one to access both the critical properties of the strong-disorder limit, which has recently been confirmed [Breznay et al., PNAS 113, 280 (2016)] to exhibit particle-vortex symmetric electrical response, and the metallic phase discovered earlier [Mason and Kapitulnik, Phys. Rev. Lett. 82, 5341 (1999)] in ...

  6. Particle Emission from Dark Matter

    International Nuclear Information System (INIS)

    When some kinds of symmetry breaking occur at the cosmological phase transition, the production of topological and/or non-topological defects can be expected. Here we consider the interaction of the defects within which the condensation of various fields may be realized at the core with dark matter particles, for example, axions or neutralinos. The astrophysical limits on the particle physics model are discussed

  7. New particle searches at PEP

    International Nuclear Information System (INIS)

    The new particles that could be produced at PEP are discussed in terms of their specific signatures and production rates. We find that a small number of general signatures characterize these particles. Backgrounds associated with the general signatures are considered and necessary rejection rates are calculated. We describe several typical detectors and tabulate the requirements they place on the PEP machine and the experimental areas. 10 figs., 2 tabs

  8. Electromagnetic deflection of spinning particles

    International Nuclear Information System (INIS)

    Many applications use uniform magnetic fields to deflect charged particles into accurately known orbits. It is shown that particles with a magnetic dipole moment will also suffer an anomalous deflection in such fields if their energy is higher than a certain threshold. The closeness of the electron's g-factor to 2 leads to a sizeable decrease in its threshold energy, to such an extent that the effect could play a significant role in current high-energy accelerators. 18 refs

  9. Hybrid particles and associated methods

    Science.gov (United States)

    Fox, Robert V; Rodriguez, Rene; Pak, Joshua J; Sun, Chivin

    2015-02-10

    Hybrid particles that comprise a coating surrounding a chalcopyrite material, the coating comprising a metal, a semiconductive material, or a polymer; a core comprising a chalcopyrite material and a shell comprising a functionalized chalcopyrite material, the shell enveloping the core; or a reaction product of a chalcopyrite material and at least one of a reagent, heat, and radiation. Methods of forming the hybrid particles are also disclosed.

  10. Theories of particle dark matter

    International Nuclear Information System (INIS)

    This brief review outlines some of the most attractive theoretical motivations for particle dark matter, and illustrates how they fit into the bigger context of physics beyond the Standard Model. Particular emphasis is given to the generic properties of theories of dark matter, and how the mechanism by which it interacts with the Standard Model particles influences its phenomenology. Brief descriptions of the most popular models, including supersymmetric theories and theories with universal extra dimensions are discussed. (authors)

  11. Blind Analysis in Particle Physics

    OpenAIRE

    Roodman, Aaron

    2003-01-01

    A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of "experimenter's bias" and the advantages of a blind analysis are described. Three distinct kinds of blind analysis in particle physics are presented in detail. Finally, the BABAR collaboration's experience with the blind analysis technique is discussed.

  12. CHEMICAL REACTIONS AT NANOMETAL PARTICLES

    OpenAIRE

    GALO CÁRDENAS-TRIVIÑO

    2005-01-01

    The concept of nanochemistry and the reactions involved are discussed. The work is focused on nanoparticles obtained from colloidal dispersions. The colloidal particles by transmission electron microscopy of low and high resolution were analyzed. The high resolution electron miscroscopy (HRTEM) allow us to classify the nanostructure of the metal particles in some polyhedral models: cubooctahedron, truncated octahedron, tetracai decahedron and icosahedron. Some HRTEM of Pd-2 propanol and Ge-2-...

  13. Boson/Fermion Janus Particles

    CERN Document Server

    Tsekov, R

    2016-01-01

    Thermodynamically, bosons and fermions differ by their statistics only. A general entropy functional is proposed by superposition of entropic terms, typical for different quantum gases. The statistical properties of the corresponding Janus particles are derived by variation of the weight of the boson/fermion fraction. It is shown that di-bosons and anti-fermions separate in gas and liquid phases, while three-phase equilibrium appears for poly-boson/fermion Janus particles.

  14. Microfluidics - Sorting particles with light

    DEFF Research Database (Denmark)

    Glückstad, J.

    2004-01-01

    Microfluidic systems have great potential to perform complex chemical and biological processing and analysis on a single disposable chip. That goal is now a step closer with the demonstration of an efficient all-optical particle sorter.......Microfluidic systems have great potential to perform complex chemical and biological processing and analysis on a single disposable chip. That goal is now a step closer with the demonstration of an efficient all-optical particle sorter....

  15. The universe and elementary particles

    International Nuclear Information System (INIS)

    This article draws a parallel between particle physics and the evolution of the knowledge about the universe. The standard model of cosmology is a consistent theory that involves the general theory of relativity and reproduces most experimental results of particle physics. The standard model used in particle physics gathers all the knowledge about particles and their mutual interactions, this model is based on the restricted theory of relativity and on quantum mechanics. Progress in the luminosity and resolution of ground-based telescopes have been huge during the last century, now space telescopes such as Hubble and space probes can examine the universe through all the wavelengths. Some observations in cosmology could find explanations in the framework of particle physics, it is the case for the apparent absence of anti-matter in the universe or for the missing mass. Physicists try to reproduce on earth the conditions in which was the matter just after the big-bang. At that moment matter was a plasma in which quarks and gluons were freely moving. In order to reach this state physicists have to focus a great deal of energy on a small volume. They do so by accelerating heavy ions and making them collide on heavy atom target. The discovery of the Higgs boson would shed light on the process that gives mass to particles. (A.C.)

  16. Surgical smoke and ultrafine particles

    Directory of Open Access Journals (Sweden)

    Nowak Dennis

    2008-12-01

    Full Text Available Abstract Background Electrocautery, laser tissue ablation, and ultrasonic scalpel tissue dissection all generate a 'surgical smoke' containing ultrafine ( Methods To measure the amount of generated particulates in 'surgical smoke' during different surgical procedures and to quantify the particle number concentration for operation room personnel a condensation particle counter (CPC, model 3007, TSI Inc. was applied. Results Electro-cauterization and argon plasma tissue coagulation induced the production of very high number concentration (> 100000 cm-3 of particles in the diameter range of 10 nm to 1 μm. The peak concentration was confined to the immediate local surrounding of the production side. In the presence of a very efficient air conditioning system the increment and decrement of ultrafine particle occurrence was a matter of seconds, with accumulation of lower particle number concentrations in the operation room for only a few minutes. Conclusion Our investigation showed a short term very high exposure to ultrafine particles for surgeons and close assisting operating personnel – alternating with longer periods of low exposure.

  17. Plasma physics via particle simulation

    International Nuclear Information System (INIS)

    Plasmas are studied by following the motion of many particles in applied and self fields, analytically, experimentally and computationally. Plasmas for magnetic fusion energy devices are very hot, nearly collisionless and magnetized, with scale lengths of many ion gyroradii and Debye lengths. The analytic studies of such plasmas are very difficult as the plasma is nonuniform, anisotropic and nonlinear. The experimental studies have become very expensive in time and money, as the size, density and temperature approach fusion reactor values. Computational studies using many particles and/or fluids have complemented both theories and experiments for many years and have progressed to fully three dimensional electromagnetic models, albeit with hours of running times on the fastest largest computers. Particle simulation methods are presented in some detail, showing particle advance from acceleration to velocity to position, followed by calculation of the fields from charge and current densities and then further particle advance, and so on. Limitations due to the time stepping and use of a spatial grid are given, to avoid inaccuracies and instabilities. Examples are given for an electrostatic program in one dimension of an orbit averaging program, and for a three dimensional electromagnetic program. Applications of particle simulations of plasmas in magnetic and inertial fusion devices continue to grow, as well as to plasmas and beams in peripheral devices, such as sources, accelerators, and converters. (orig.)

  18. Measuring momentum for charged particle tomography

    Science.gov (United States)

    Morris, Christopher; Fraser, Andrew Mcleod; Schultz, Larry Joe; Borozdin, Konstantin N.; Klimenko, Alexei Vasilievich; Sossong, Michael James; Blanpied, Gary

    2010-11-23

    Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.

  19. Few interacting particles in a random potential

    OpenAIRE

    Shepelyansky, D. L.; Sushkov, O. P.

    1996-01-01

    We study the localization length of few interacting particles in a random potential. Concentrating on the case of three particles we show that their localization length is strongly enhanced comparing to the enhancement for two interacting particles.

  20. Open statistical issues in particle physics

    OpenAIRE

    Lyons, Louis

    2008-01-01

    Many statistical issues arise in the analysis of Particle Physics experiments. We give a brief introduction to Particle Physics, before describing the techniques used by Particle Physicists for dealing with statistical problems, and also some of the open statistical questions.

  1. Particle entrapment as a feedback effect

    CERN Document Server

    Shklyaev, Sergey V

    2008-01-01

    We consider a suspension of polarizable particles under the action of traveling wave dielectrophoresis (DEP) and focus on particle induced effects. In a situation where the particles are driven by the DEP force, but no external forces are exerted on the fluid, the joint motion of the particles can induce a steady fluid flow, which leads to particle entrapment. This feedback effect is proven to be non-negligible even for small volume concentration of particles.

  2. Detection of High-Energy Particles

    OpenAIRE

    Lohse, Thomas

    2006-01-01

    In spite of quantum field theoretical and philosophical problems to define the concept of elementary particles and to understand their localizability, particles become intuitively apparent by the traces they leave in particle detectors. Today, experimental particle physicists have reached a high degree of perfection in measuring and visualizing particles up to highest energies using a variety of high technology detection devices and sophisticated, powerful particle accel...

  3. Particle entrapment as a feedback effect

    OpenAIRE

    Shklyaev, Sergey V.; Straube, Arthur V.

    2007-01-01

    We consider a suspension of polarizable particles under the action of traveling wave dielectrophoresis (DEP) and focus on particle induced effects. In a situation where the particles are driven by the DEP force, but no external forces are exerted on the fluid, the joint motion of the particles can induce a steady fluid flow, which leads to particle entrapment. This feedback effect is proven to be non-negligible even for small volume concentration of particles.

  4. Fractal aggregation and breakup of fine particles

    Directory of Open Access Journals (Sweden)

    Li Bingru

    2016-01-01

    Full Text Available Breakup may exert a controlling influence on particle size distributions and particles either are fractured or are eroded particle-by-particle through shear. The shear-induced breakage of fine particles in turbulent conditions is investigated using Taylor-expansion moment method. Their equations have been derived in continuous form in terms of the number density function with particle volume. It suitable for future implementation in computational fluid dynamics modeling.

  5. Particles in water properties and processes

    CERN Document Server

    Gregory, John

    2005-01-01

    INTRODUCTION Particles in the Aquatic Environment Colloidal Aspects PARTICLE SIZE AND RELATED PROPERTIES Particle Size and Shape Particle Size Distributions Particle Transport Light Scattering and Turbidity Measurement of Particle Size SURFACE CHARGE Origin of Surface Charge The Electrical Double Layer Electrokinetic Phenomena COLLOID INTERACTIONS AND COLLOID STABILITY Colloid Interactions - General Concepts van der Waals Interaction Electrical Double Layer Interaction Combined Interaction - DLVO Theory Non-DLVO Interactions AGGREGATION KINETICS Collision Frequency - Smoluchow

  6. Particle-hole and particle-particle correlations in neodymium isotopes

    International Nuclear Information System (INIS)

    Excited states in 140,142,144,146Nd nuclei, up to an excitation energy of about 5 MeV, were investigated by (p,t) experiments performed with a good energy resolution. These data, together with proton and deuteron scattering data from a previous experiment, are compared with Quasi-Particle Phonon Model evaluations, in which the competition between particle-hole and particle-particle residual interactions is considered. The B(Eλ) distributions are satisfactorily reproduced. The 146,148Nd(p,t) reaction data are well accounted for, while difficulties are found in reproducing those for 142,144Nd(p,t). Limitations and improvements of the model are discussed. (orig.)

  7. Particle Emissions from Biomass Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Szpila, Aneta; Bohgard, Mats [Lund Inst. of Technology (Sweden). Div. of Ergonomics and Aerosol Technology; Strand, Michael; Lillieblad, Lena; Sanati, Mehri [Vaexjoe Univ. (Sweden). Div. of Bioenergy Technology; Pagels, Joakim; Rissler, Jenny; Swietlicki, Erik; Gharibi, Arash [Lund Univ. (Sweden). Div. of Nuclear Physics

    2003-05-01

    We have shown that high concentrations of fine particles of the order of 2-7x10{sup -7} particles per cm{sup 3} are being formed in all the combustion units studied. There was a higher difference between the units in terms of particle mass concentrations. While the largest differences was found for gas-phase constituents (CO and THC) and polyaromatic hydrocarbons. In 5 out of 7 studied units, multi-cyclones were the only measure for flue-gas separation. The multicyclones had negligible effect on the particle number concentration and a small effect on the mass of particles smaller than 5 {mu}m. The separation efficiency was much higher for the electrostatic precipitators. The boiler load had a dramatic influence on the coarse mode concentration during combustion of forest residue. PM0.8-6 increased from below 5 mg/m{sup 3} to above 50 mg/m{sup 3} even at a moderate change in boiler load from medium to high. A similar but less pronounced trend was found during combustion of dry wood. PM0.8-PM6 increased from 12 to 23 mg/m{sup 3} when the load was changed from low to high. When increasing the load, the primary airflow taken through the grate is increased; this itself may lead to a higher potential of the air stream to carry coarse particles away from the combustion zone. Measurements with APS-instrument with higher time-resolution showed a corresponding increase in coarse mode number concentration with load. Additional factor influencing observed higher concentration of coarse mode during combustion of forest residues, could be relatively high ash content in this type of fuel (2.2 %) in comparison to dry wood (0.3 %) and pellets (0.5 %). With increasing load we also found a decrease in PM1 during combustion of forest residue. Whether this is caused by scavenging of volatilized material by the high coarse mode concentration or a result of a different amount of volatilized material available for formation of fine particles needs to be shown in future studies. The

  8. Coulomb interactions in particle beams

    International Nuclear Information System (INIS)

    This thesis presents a theoretical description of the Coulomb interaction between identical charged particles (electrons or ions) in focussed beam. The charge-density effects as well as the various statistical interaction effects, known as the Boersch effect and the 'trajectory displacement effect', are treated. An introductory literature survey is presented from which the large differences in theoretical approach appear. Subsequently the methods are investigated which are used in studies of comparable problems in plasma physics and stellar dynamics. These turn out to be applicable to particle beams only for certain extreme conditions. The approach finally chosen in this study is twofold. On the one hand use is made of a semi-analytical model in which the statistical and dynamical aspects of the N-particle problem are reduced to two-particle problem. This model results in a number of explicit equations in the experimental parameters, with ties of the beam can be determined directly. On the other hand use has been made of a purely numerical Monte Carlo model in which the kinematical equations of an ensemble interacting particles with 'at random' chosen starting conditions are solved exactly. This model does not lead to general expressions, but yields a specific numerical prediction for each simulated experimental situation. The results of both models appear to agree well mutually. This yields a consistent theory which complements the existing knowledge of particle optics and which allow the description of systems in which the interaction between particles can not be neglected. The predictions of this theory are qualitatively and quantitatively compared with those from some other models, recently reported in literature. (author). 256 refs.; 114 figs.; 1180 schemes; 5 tabs

  9. Schwarzschild black hole as particle accelerator of spinning particles

    CERN Document Server

    Zaslavskii, O B

    2016-01-01

    It is shown that in the Schwarzschild background there exists direct counterpart of the Ba\\~{n}ados-Silk-West effect for spinning particles. This means that if two particles collide near the black hole horizon, their energy in the centre of mass frame can grow unbound. In doing so, the crucial role is played by so-called near-critical trajectories when particle's parameters are almost fine-tuned. Direct scenario of the collision under discussion is possible with restriction on the energy-to-mass ratio \\thinspace $E/m<\\frac{1}{2\\sqrt{3}}$ only. However, if one takes into account multiple scattering, this becomes possible for $E\\geq m$ as well.

  10. Laser and Particle Guiding Micro-Elements for Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Plettner, T.; Gaume, R.; Wisdom, J.; /Stanford U., Phys. Dept.; Spencer, J.; /SLAC

    2005-06-07

    Laser driven particle accelerators require sub-micron control of the laser field as well as precise electron-beam guiding so fabrication techniques that allow integrating both elements into an accelerator-on-chip format become critical for the success of such next generation machines. Micromachining technology for silicon has been shown to be one such feasible technology in PAC2003[1] but with a variety of complications on the laser side. However, fabrication of transparent ceramics has become an interesting technology that could be applied for laser-particle accelerators in several ways. We discuss the advantages such as the range of materials available and ways to implement them followed by some different test examples we been considered. One important goal is an integrated system that avoids having to inject either laser or particle pulses into these structures.

  11. Isolation of technogenic magnetic particles

    Energy Technology Data Exchange (ETDEWEB)

    Catinon, Mickaël, E-mail: mickael.catinon@gmail.com [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France); Ayrault, Sophie, E-mail: sophie.ayrault@lsce.ispl.fr [Laboratoire des Sciences du Climat et de l' Environnement, UMR 8212, CEA-CNRS-UVSQ/IPSL, 91198 Gif-sur-Yvette (France); Boudouma, Omar, E-mail: boudouma@ccr.jussieu.fr [Service du MEB, UFR928, Université Pierre et Marie Curie, 75252 Paris VI (France); Bordier, Louise, E-mail: Louise.Bordier@lsce.ipsl.fr [Laboratoire des Sciences du Climat et de l' Environnement, UMR 8212, CEA-CNRS-UVSQ/IPSL, 91198 Gif-sur-Yvette (France); Agnello, Gregory, E-mail: contact@evinrude.fr [Evinrude, Espace St Germain, 38200 Vienne (France); Reynaud, Stéphane, E-mail: stephane.reynaud@ujf-grenoble.fr [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France); Tissut, Michel, E-mail: michel.tissut@ujf-grenoble.fr [Laboratoire LECA, UMR 5553, Equipe Pollution, Environnement, Ecotoxicologie et Ecoremédiation, Univ. J. Fourier, 38041 Grenoble (France)

    2014-03-01

    Technogenic magnetic particles (TMPs) emitted by various industrial sources, such as smelting plants, end up after atmospheric transfer on the soil surface. In the present study, we characterised the origin and composition of such particles emitted by a large iron smelting plant and deposited on particular substrates, namely tombstones, which act as a very interesting and appropriate matrix when compared to soil, tree bark, lichens or attic dust. The isolation and subsequent description of TMPs require a critical step of separation between different components of the sample and the magnetic particles; here, we described an efficient protocol that fulfils such a requirement: it resorts to water suspension, sonication, repeated magnetic extraction, sedimentation, sieving and organic matter destruction at 550 °C in some instances. The isolated TMPs displayed a noticeable crystalline shape with variable compositions: a) pure iron oxides, b) iron + Cr, Ni or Zn, and c) a complex structure containing Ca, Si, Mg, and Mn. Using Scanning Electron Microscope Energy Dispersive X-ray (SEM–EDX), we obtained profiles of various and distinct magnetic particles, which allowed us to identify the source of the TMPs. - Highlights: • The developed method offers a low-cost approach of large-scale dry deposition. • Tombstones are excellent supports for sampling these atmospheric deposits. • Smelted elements crystallise after cooling, giving typical technogenic magnetic particles (TMPs). • Coupling microscopic and bulk analyses allows identifying TMP origin. • Magnetic TMPs issued from steel industry were separated by a new technique.

  12. Isolation of technogenic magnetic particles

    International Nuclear Information System (INIS)

    Technogenic magnetic particles (TMPs) emitted by various industrial sources, such as smelting plants, end up after atmospheric transfer on the soil surface. In the present study, we characterised the origin and composition of such particles emitted by a large iron smelting plant and deposited on particular substrates, namely tombstones, which act as a very interesting and appropriate matrix when compared to soil, tree bark, lichens or attic dust. The isolation and subsequent description of TMPs require a critical step of separation between different components of the sample and the magnetic particles; here, we described an efficient protocol that fulfils such a requirement: it resorts to water suspension, sonication, repeated magnetic extraction, sedimentation, sieving and organic matter destruction at 550 °C in some instances. The isolated TMPs displayed a noticeable crystalline shape with variable compositions: a) pure iron oxides, b) iron + Cr, Ni or Zn, and c) a complex structure containing Ca, Si, Mg, and Mn. Using Scanning Electron Microscope Energy Dispersive X-ray (SEM–EDX), we obtained profiles of various and distinct magnetic particles, which allowed us to identify the source of the TMPs. - Highlights: • The developed method offers a low-cost approach of large-scale dry deposition. • Tombstones are excellent supports for sampling these atmospheric deposits. • Smelted elements crystallise after cooling, giving typical technogenic magnetic particles (TMPs). • Coupling microscopic and bulk analyses allows identifying TMP origin. • Magnetic TMPs issued from steel industry were separated by a new technique

  13. Cosmic censorship and test particles

    International Nuclear Information System (INIS)

    In this paper one unambiguous prediction of cosmic censorship is put to the test, namely that it should be impossible to destroy a black hole (i.e. eliminate its horizon) by injecting test particles into it. Several authors have treated this problem and have not found their conclusions in contradiction with the prediction. Here we prove that if a general charged spinning particle (with parameters very much smaller than the respective hole parameters) is injected in an arbitrary manner into an extreme Kerr-Newman black hole, then cosmic censorship is upheld. As a by-product of the analysis a natural proof is given of the Christodoulou-Ruffini conditions on the injection of a spinless particle which yield a reversible black-hole transformation. Finally we consider the injection of particles with parameters that are not small compared with those of the hole, for which cosmic censorship is apparently violated. By assuming the validity of cosmic censorship we are led to a few conjectures concerning the extent of the particle's interaction with the hole while approaching it

  14. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  15. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  16. Research in elementary particle physics

    International Nuclear Information System (INIS)

    Task A of this contract supports research in elementary particle physics using cryogenic particle detectors. We have developed superconducting aluminum tunnel-junction detectors sensitive to a variety of particle signals, and with potential application to a number of particle-physics problems. We have extended our range of technologies through a collaboration with Simon Labov, on niobium tri-layer junctions, and Jean-Paul Maneval, on high-Tc superconducting bolometers. We have new data on response to low-energy X-rays and to alpha-particle signals from large-volume detectors. The theoretical work under this contract (Task B) is a continued investigation of nonperturbative aspects of quantum gravity. A Monte Carlo calculation is proposed for Euclidian quantum gravity, based on the ''fifth-time action'' stabilization procedure. Results from the last year include a set of seven papers, summarized below, addressing various aspects of nonperturbative quantum gravity and QCD. Among the issues- addressed is the so-called ''problem of time'' in canonical quantum gravity

  17. Particle cosmology comes of age

    International Nuclear Information System (INIS)

    The application of modern ideas in particle physics to astrophysical and cosmological settings is a continuation of a fruitful tradition in astrophysics which began with the application of atomic physics, and then nuclear physics. In the past decade particle cosmology and particle astrophysics have been recognized as 'legitimate activities' by both particle physicists and astrophysicists and astronomers. During this time there has been a high level of theoretical activity producing much speculation about the earliest history of the Universe, as well as important and interesting astrophysical and cosmological constraints to particle physics theories. This period of intense theoretical activity has produced a number of ideas most worthy of careful consideration and scrutiny, and even more importantly, amenable to experimental/observational test. Among the ideas which are likely to be tested in the next decade are: the cosmological bound to the number of neutrino flavors, inflation, relic WIMPs as the dark matter, and MSW neutrino oscillations as a solution to the solar neutrino problems. 94 refs

  18. Particle cosmology comes of age

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S.

    1987-12-01

    The application of modern ideas in particle physics to astrophysical and cosmological settings is a continuation of a fruitful tradition in astrophysics which began with the application of atomic physics, and then nuclear physics. In the past decade particle cosmology and particle astrophysics have been recognized as 'legitimate activities' by both particle physicists and astrophysicists and astronomers. During this time there has been a high level of theoretical activity producing much speculation about the earliest history of the Universe, as well as important and interesting astrophysical and cosmological constraints to particle physics theories. This period of intense theoretical activity has produced a number of ideas most worthy of careful consideration and scrutiny, and even more importantly, amenable to experimental/observational test. Among the ideas which are likely to be tested in the next decade are: the cosmological bound to the number of neutrino flavors, inflation, relic WIMPs as the dark matter, and MSW neutrino oscillations as a solution to the solar neutrino problems. 94 refs.

  19. Engineered plant biomass feedstock particles

    Science.gov (United States)

    Dooley, James H.; Lanning, David N.; Broderick, Thomas F.

    2011-10-18

    A novel class of flowable biomass feedstock particles with unusually large surface areas that can be manufactured in remarkably uniform sizes using low-energy comminution techniques. The feedstock particles are roughly parallelepiped in shape and characterized by a length dimension (L) aligned substantially with the grain direction and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. The particles exhibit a disrupted grain structure with prominent end and surface checks that greatly enhances their skeletal surface area as compared to their envelope surface area. The L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers. The W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers. The L.times.W dimensions define a pair of substantially parallel top surfaces characterized by some surface checking between longitudinally arrayed fibers. At least 80% of the particles pass through a 1/4 inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. The feedstock particles are manufactured from a variety of plant biomass materials including wood, crop residues, plantation grasses, hemp, bagasse, and bamboo.

  20. Particle platforms for cancer immunotherapy

    Directory of Open Access Journals (Sweden)

    Serda RE

    2013-04-01

    Full Text Available Rita Elena Serda Department of Nanomedicine, The Methodist Hospital Research Institute, Houston, TX, USA Abstract: Elevated understanding and respect for the relevance of the immune system in cancer development and therapy has led to increased development of immunotherapeutic regimens that target existing cancer cells and provide long-term immune surveillance and protection from cancer recurrence. This review discusses using particles as immune adjuvants to create vaccines and to augment the anticancer effects of conventional chemotherapeutics. Several particle prototypes are presented, including liposomes, polymer nanoparticles, and porous silicon microparticles, the latter existing as either single- or multiparticle platforms. The benefits of using particles include immune-cell targeting, codelivery of antigens and immunomodulatory agents, and sustained release of the therapeutic payload. Nanotherapeutic-based activation of the immune system is dependent on both intrinsic particle characteristics and on the immunomodulatory cargo, which may include danger signals known as pathogen-associated molecular patterns and cytokines for effector-cell activation. Keywords: adjuvant, particle, immunotherapy, dendritic cell, cancer, vaccine

  1. Cocoa particles for food emulsion stabilisation.

    Science.gov (United States)

    Gould, Joanne; Vieira, Josélio; Wolf, Bettina

    2013-09-01

    Emulsifying properties of cocoa particles have been investigated in systems containing purified sunflower oil (PSO) and water at varying pH, concentration and source of cocoa particles including cocoa powders (CP), cocoa fibre (CF) and cocoa mass (CM). The effect of cocoa particle source, pH and cocoa particle concentration on emulsion stability was evaluated by following changes in characteristic droplet diameter. Size distributions acquired on the emulsions and aqueous cocoa particle suspensions overlapped. Based on cryo-SEM imaging of the emulsions, isolation of cocoa particle fines and a process of washing the cocoa particles to remove any water soluble molecules, it was concluded that the cocoa particle fines not captured by the small angle laser diffraction method employed for sizing, act as Pickering particles. This research has demonstrated a universal nature of a natural food particle to stabilise oil-in-water emulsions not requiring particle modification or adjusting of the solution properties of the emulsion phases. PMID:23851644

  2. Microscopic Simulation of Particle Detectors

    CERN Document Server

    Schindler, Heinrich

    Detailed computer simulations are indispensable tools for the development and optimization of modern particle detectors. The interaction of particles with the sensitive medium, giving rise to ionization or excitation of atoms, is stochastic by its nature. The transport of the resulting photons and charge carriers, which eventually generate the observed signal, is also subject to statistical fluctuations. Together with the readout electronics, these processes - which are ultimately governed by the atomic cross-sections for the respective interactions - pose a fundamental limit to the achievable detector performance. Conventional methods for calculating electron drift lines based on macroscopic transport coefficients used to provide an adequate description for traditional gas-based particle detectors such as wire chambers. However, they are not suitable for small-scale devices such as micropattern gas detectors, which have significantly gained importance in recent years. In this thesis, a novel approach, bas...

  3. Particle relabelling transformations in elastodynamics

    Science.gov (United States)

    Al-Attar, David; Crawford, Ophelia

    2016-04-01

    The motion of a self-gravitating hyperelastic body is described through a time-dependent mapping from a reference body into physical space, and its material properties are determined by a referential density and strain-energy function defined relative to the reference body. Points within the reference body do not have a direct physical meaning, but instead act as particle labels that could be assigned in different ways. We use Hamilton's principle to determine how the referential density and strain-energy functions transform when the particle labels are changed, and describe an associated `particle relabelling symmetry'. We apply these results to linearized elastic wave propagation and discuss their implications for seismological inverse problems. In particular, we show that the effects of boundary topography on elastic wave propagation can be mapped exactly into volumetric heterogeneity while preserving the form of the equations of motion. Several numerical calculations are presented to illustrate our results.

  4. Spectroscopy after the new particles

    International Nuclear Information System (INIS)

    Conventional spectroscopy is reexamined in a search for puzzles and paradoxes which have arisen in attempting to describe the properties of the known particles. These may offer clues to the missing elements necessary for the description of the new particles. The minimum number of elementary building blocks, charm and color, the colored quark model for saturation, spin splittings in the meson spectrum, three kinds of quarks, the Melosh transformation and the Jackson frame, beyond the single-quark transition--the Zweig rule mystery, new particles and old symmetries, the f--A2 interference, and tests of the Zweig rule by rho--ω and f--A2--f' interference are considered

  5. Dipsersion relations for unphysical particles

    CERN Document Server

    Siringo, Fabio

    2016-01-01

    Generalized dispersion relations are discussed for unphysical particles, e.g. confined degrees of freedom that are not present in the physical spectra but can give rise to observable bound states. While in general the propagator of the unphysical particles can have complex poles and cannot be reconstructed from the knowledge of the imaginary part, under reasonable assumptions the missing piece of information is shown to be in the rational function that contains the poles and must be added to the integral representation. For pure Yang-Mills theory, the rational part and the spectral term are identified in the explicit analytical expressions provided by the massive expansion of the gluon propagator. The multi particle spectral term turns out to be very small and the simple rational part provides, from first principles, an approximate propagator that is equivalent to the tree-level result of simple phenomenological models like the refined Gribov-Zwanziger model.

  6. Brownian motion of interacting particles

    Energy Technology Data Exchange (ETDEWEB)

    Ackerson, B.J.

    1976-01-01

    Guided by the descriptions which are used to describe noninteracting particles, it is argued that the generalized Smoluchowski equation, including the hydrodynamic interaction and corrections for ion cloud effects may be used to describe interacting particles for the temporal and spatial regimes probed by light beating spectroscopy. This equation is then used to find cumulants of decay of the intermediate scattering function. The generalized Smoluchowski equation is reduced to a simple diffusion equation. The resulting diffusion constant depends upon the interparticle forces and is reminiscent of some early descriptions for interacting systems. The generalized Smoluchowski equation is solved for the model system of a linear chain of colloidal particles interacting via nearest neighbor harmonic couplings. The results for the intermediate scattering function and the static structure factor are very reminiscent of corresponding measurements made for interacting colloidal systems. (GHT)

  7. Particle detection with drift chambers

    CERN Document Server

    Blum, Walter; Rolandi, Luigi

    2008-01-01

    This volume presents a thorough introduction to the theory and operation of drift chambers, one of the most important modern methods of elementary particle detection. The topics, presented in a text-book style with many illustrations, include the basics of gas ionization, by particles and by lasers, drift of electrons and ions in gases and signal creation and discuss in depth the fundamental limits of accuracy and the issue of particle identification. The book also surveys all types of drift chambers and the various drift-chamber gases in use. The calculation of the device parameters and physical processes are presented in some detail, as is all necessary background material. Thus the treatment, well beyond addressing the specialist in the field, is well suited to graduate physics students and nuclear engineers seeking a both thorough and pedagogical introduction to the field. The second edition presents a completely revised, updated and expanded version of this classic text. In particular, significantly more...

  8. Diffraction radiation from relativistic particles

    CERN Document Server

    Potylitsyn, Alexander Petrovich; Strikhanov, Mikhail Nikolaevich; Tishchenko, Alexey Alexandrovich

    2010-01-01

    This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results.

  9. Relativistic shocks and particle acceleration

    International Nuclear Information System (INIS)

    In this paper, we investigate the fluid dynamics of relativistic shock waves, and use the results to calculate the spectral index of particles accelerated by the Fermi process in such shocks. We have calculated the distributions of Fermi-accelerated particles at shocks propagating into cold proton-electron plasma and also cold electron-positron plasma. We have considered two different power spectra for the scattering waves, and find, in contrast to the non-relativistic case, that the spectral index of the accelerated particles depends on the wave power spectrum. On the assumption of thermal equilibrium both upstream and downstream, we present some useful fits for the compression ratio of shocks propagating at arbitrary speeds into gas of any temperature. (author)

  10. Particle production results from HELIOS

    International Nuclear Information System (INIS)

    This paper shows that global variables such as transverse energy and multiplicity can be used to characterize events according to impact parameter. E/sub t/ and multiplicity show a linear relationship, indicating that higher E/sub t/ arises from production of more particles rather than a large change in the particle spectra. The shapes of the distributions can be explained by superposition of nucleon-nucleon scattering. There is no large difference among the observed charged particle spectra from p + W, O + W, and S + W. We observe no sharp rise in vs E/sub t/, but it must be noted that the detected /sub pt/ spectrum is affected by the hadronization process and reflects conditions at the time of freezeout of hadrons. Also, an increase in the cross section for large pt is expected from hard scattering of partons and does not necessarily indicate more exotic processes. 10 refs., 6 figs

  11. Particle Systems and PDEs II

    CERN Document Server

    Soares, Ana

    2015-01-01

    This book focuses on mathematical problems concerning different applications in physics, engineering, chemistry and biology. It covers topics ranging from interacting particle systems to partial differential equations (PDEs), statistical mechanics and dynamical systems. The purpose of the second meeting on Particle Systems and PDEs was to bring together renowned researchers working actively in the respective fields, to discuss their topics of expertise and to present recent scientific results in both areas. Further, the meeting was intended to present the subject of interacting particle systems, its roots in and impacts on the field of physics, and its relation with PDEs to a vast and varied public, including young researchers. The book also includes the notes from two mini-courses presented at the conference, allowing readers who are less familiar with these areas of mathematics to more easily approach them. The contributions will be of interest to mathematicians, theoretical physicists and other researchers...

  12. Diffraction radiation from relativistic particles

    International Nuclear Information System (INIS)

    This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results. (orig.)

  13. Cosmic rays and particle physics

    CERN Document Server

    Gaisser, Thomas K; Resconi, Elisa

    2016-01-01

    Fully updated for the second edition, this book introduces the growing and dynamic field of particle astrophysics. It provides an overview of high-energy nuclei, photons and neutrinos, including their origins, their propagation in the cosmos, their detection on Earth and their relation to each other. Coverage is expanded to include new content on high energy physics, the propagation of protons and nuclei in cosmic background radiation, neutrino astronomy, high-energy and ultra-high-energy cosmic rays, sources and acceleration mechanisms, and atmospheric muons and neutrinos. Readers are able to master the fundamentals of particle astrophysics within the context of the most recent developments in the field. This book will benefit graduate students and established researchers alike, equipping them with the knowledge and tools needed to design and interpret their own experiments and, ultimately, to address a number of questions concerning the nature and origins of cosmic particles that have arisen in recent resea...

  14. An investigation of particles suspension using smoothed particle hydrodynamics

    Science.gov (United States)

    Pazouki, Arman; Negrut, Dan

    2013-11-01

    This contribution outlines a method for the direct numerical simulation of rigid body suspensions in a Lagrangian-Lagrangian framework using extended Smoothed Particle Hydrodynamics (XSPH) method. The dynamics of the arbitrarily shaped rigid bodies is fully resolved via Boundary Condition Enforcing (BCE) markers and updated according to the general Newton-Euler equations of motion. The simulation tool, refered to herien as Chrono::Fluid, relies on a parallel implementation that runs on Graphics Processing Unit (GPU) cards. The simulation results obtained for transient Poiseuille flow, migration of cylinder and sphere in Poiseuille flow, and distribution of particles at different cross sections of the laminar flow of dilute suspension were respectively within 0.1%, 1%, and 5% confidence interval of analytical and experimental results reported in the literature. It was shown that at low Reynolds number, Re = O(1), the radial migration (a) behaves non-monotonically as the particles relative distance (distance over diameter) increases from zero to two; and (b) decreases as the particle skewness and size increases. The scaling of Chrono::Fluid was demonstrated in conjunction with a suspension dynamics analysis in which the number of ellipsoids went up to 3e4. Financial support was provided in part by National Science Foundation grant NSF CMMI-084044.

  15. On the Possible Trajectories of Spinning Particles. I. Free Particles

    CERN Document Server

    Tarakanov, Alexander N

    2015-01-01

    By means of the method of moving Frenet-Serret frame the set of equations of motion is derived for spinning particle in an arbitrary external field, which is determined by potential depending from both position and the state of movement, as well as by two pseudo-vectors one of which is easily associated with external magnetic field, and another still remains undetermined. The equations give a possibility to describe the motion of both massive and massless particles with spin. All solutions of the equations of motion in the absence of external fields were found, and besides, we give more precise definition of a free object. It turns out that the massive particles always possess a longitudinal polarization. There are possible transversal motions of the following types: 1) oscillatory motion with proper frequency, 2) circular motion, and 3) complicated motion along rosette trajectories round the center of inertia with the velocity, varying in finite limits. Free massless particles can either fluctuate or move al...

  16. The Subatomic Particle Mass Spectrum

    OpenAIRE

    Oldershaw, R. L.

    2010-01-01

    Representative members of the subatomic particle mass spectrum in the 100 MeV to 7,000 MeV range are retrodicted to a first approximation using the Kerr solution of General Relativity. The particle masses appear to form a restricted set of quantized values of a Kerr-based angular momentum-mass relation: m = (sqrt n)(M), where values of n are a set of discrete integers and M is a revised Planck mass. A fractal paradigm manifesting global discrete self-similarity is critical to a proper determi...

  17. Superbackscattering from single dielectric particles

    Science.gov (United States)

    Liberal, Iñigo; Ederra, Iñigo; Gonzalo, Ramón; Ziolkowski, Richard W.

    2015-07-01

    We demonstrate that superbackscattering responses can be excited in subwavelength dielectric particles with simple geometries. The superbackscattering response arises from the simultaneous, coherent excitation of electric dipole and magnetic quadrupole resonances. Its signature is a superdirective scattering pattern simultaneously pointing towards both the forward and backward directions. The practical implementation of this effect with Tellurium particles operating in the thermal infrared is also addressed. The examples presented reveal that spherical resonators outperform array-based superbackscatterers in terms of the backscattering peak, compact size, robustness against losses and isotropic response.

  18. Tumour Therapy with Particle Beams

    OpenAIRE

    Grupen, C.

    2000-01-01

    Photons are exponentially attenuated in matter producing high doses close to the surface. Therefore they are not well suited for the treatment of deep seated tumours. Charged particles, in contrast, exhibit a sharp increase of ionisation density close to the end of their range, the so-called Bragg-peak. The depth of the Bragg-peak can be adjusted by varying the particle's energy. In parallel with the large energy deposit the increase in biological effectiveness for cell killing at the end of ...

  19. Mapping chaos in particle revolutions

    International Nuclear Information System (INIS)

    The relatively new technique of frequency map analysis has over the last 10 years turned out to be very effective for the analysis of numerical simulations in physical systems ranging even beyond the solar system to galaxies and back again to particle accelerators, particularly for systems with three or more degrees of freedom. More recently, with an eye towards revealing the dynamics of an actual particle beam, it has been applied for the first time to measured rather than simulated electron trajectories in a storage ring, in this case at the Advanced Light Source (ALS) at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab)

  20. Particles in Singular Magnetic Field

    CERN Document Server

    Marcinek, W

    1997-01-01

    An algebraic formalism for description of quantum states of charged particle with spin moving in two-dimensional space under influence of singular magnetic field is developed in terms of graded algebras. The fundamental assumption is that the particle is transformed into a composite system which consists quasiparticles, quasiholes and magnetic fluxes. Such system is endowed with generalized statistics determined by a grading group and a commutation factor on it. Composite systems corresponding to the quantum Hall effect and the electronic magnetotransport anomaly are described. The Fock space representation are also given.

  1. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  2. The wave-particle duality

    Science.gov (United States)

    Slavnov, D. A.

    2015-07-01

    The problem of wave-particle duality is considered within the framework of the algebraic approach. Contrary to the widespread belief, we demonstrate that wave-particle duality can be reconciled with the assumption that there exists some local physical reality determining the results of local measurements. A number of quantum experiments—double-slit electron scattering, Wheeler's delayed choice experiment, the past of photons passed through the interferometer—are discussed using the concept of locality. A clear physical interpretation of these experiments that does not contradict classical concepts is provided.

  3. Resonant particle production in branonium

    OpenAIRE

    Rosa, J. G.; March-Russell, John

    2007-01-01

    We study the mechanism of particle production in the world-volume of a probe anti D6-brane (or D6 with SUSY breaking) moving in the background created by a fixed stack of $D6$-branes. We show that this may occur in a regime of parametric resonance when the probe's motion is non-relativistic and it moves at large distances from the source branes in low eccentricity orbits. This leads to an exponential growth of the particle number in the probe's world-volume and constitutes an effective mechan...

  4. Particle creation in inhomogeneous spacetimes

    International Nuclear Information System (INIS)

    We study the creation of particles by inhomogeneous perturbations of spatially flat Friedmann-Robertson-Walker cosmologies. For massless scalar fields, the pair-creation probability can be expressed in terms of geometric quantities (curvature invariants). The results suggest that inhomogeneities on scales up to the particle horizon will be damped out near the Planck time. Perturbations on scales larger than the horizon are explicitly shown to yield no created pairs. The results generalize to inhomogeneous spacetimes several earlier studies of pair creation in homogeneous anisotropic cosmologies

  5. Chemical characterization of atmospheric particles

    International Nuclear Information System (INIS)

    In the characterisation of complex environmental materials such as atmospheric particulate matter, analytical specificity is required to account for the many dimensions of information present in the sample. These dimensions include size, morphology, elemental composition, inorganic and organic chemical speciation, all to be performed on either single particles or on the population (or bulk sample) basis. Various techniques were developed for such measurements, including a number of bulk analysis procedures, methodologies for microscopical analysis of individual particles, and a variety of procedures for organic/inorganic chemical speciation. (author)

  6. Spinning particles in General Relativity

    OpenAIRE

    Cianfrani, Francesco; Montani, Giovanni

    2007-01-01

    We analyze the behavior of a spinning particle in gravity, both from a quantum and a classical point of view. We infer that, since the interaction between the space-time curvature and a spinning test particle is expected, then the main features of such an interaction can get light on which degrees of freedom have physical meaning in a quantum gravity theory with fermions. Finally, the dimensional reduction of Papapetrou equations is performed in a 5-dimensional Kaluza-Klein background and Dix...

  7. Particle energy and Hawking temperature

    International Nuclear Information System (INIS)

    Some authors have recently found that the tunneling approach gives a different Hawking temperature for a Schwarzschild black hole in a different coordinate system. In this Letter, we find that to work out the Hawking temperature in a different coordinate system by the tunneling approach, we must use the correct definition of the energy of the radiating particles. By using a new definition of the particle energy, we obtain the correct Hawking temperature for a Schwarzschild black hole in two dynamic coordinate systems, the Kruskal-Szekers and dynamic Lemaitre coordinate systems.

  8. Trapped particles and harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, Jr, W E; DeGroot, J S

    1977-01-01

    A novel fluid-particle algorithm has been used to study the evolution of continuously generated ion acoustic waves numerically. The code permits the simultaneous analysis of the two nonlinearities involved: wave steepening or harmonic generation, a fluid effect; and wave damping and amplitude oscillations, a particle effect. For a temperature ratio 10 < T/sub e//T/sub i/ < 30, the behavior of low amplitude long wavelength waves is well described by a Korteweg-deVries equation augmented to include a time dependent damping term.

  9. Nuclear physics and particle therapy

    Science.gov (United States)

    Battistoni, G.

    2016-05-01

    The use of charged particles and nuclei in cancer therapy is one of the most successful cases of application of nuclear physics to medicine. The physical advantages in terms of precision and selectivity, combined with the biological properties of densely ionizing radiation, make charged particle approach an elective choice in a number of cases. Hadron therapy is in continuous development and nuclear physicists can give important contributions to this discipline. In this work some of the relevant aspects in nuclear physics will be reviewed, summarizing the most important directions of research and development.

  10. Particle transport in 3He-rich events: wave-particle interactions and particle anisotropy measurements

    Directory of Open Access Journals (Sweden)

    T. Hada

    Full Text Available Energetic particles and MHD waves are studied using simultaneous ISEE-3 data to investigate particle propagation and scattering between the source near the Sun and 1 AU. 3 He-rich events are of particular interest because they are typically low intensity "scatter-free" events. The largest solar proton events are of interest because they have been postulated to generate their own waves through beam instabilities. For 3 He-rich events, simultaneous interplanetary magnetic spectra are measured. The intensity of the interplanetary "fossil" turbulence through which the particles have traversed is found to be at the "quiet" to "intermediate" level of IMF activity. Pitch angle scattering rates and the corresponding particle mean free paths lW - P are calculated using the measured wave intensities, polarizations, and k directions. The values of lW - P are found to be ~ 5 times less than the value of lHe , the latter derived from He intensity and anisotropy time profiles. It is demonstrated by computer simulation that scattering rates through a 90° pitch angle are lower than that of other pitch angles, and that this is a possible explanation for the discrepancy between the lW - P and lHe values. At this time the scattering mechanism(s is unknown. We suggest a means where a direct comparison between the two l values could be made. Computer simulations indicate that although scattering through 90° is lower, it still occurs. Possibilities are either large pitch angle scattering through resonant interactions, or particle mirroring off of field compression regions. The largest solar proton events are analyzed to investigate the possibilities of local wave generation at 1 AU. In accordance with the results of a previous calculation (Gary et al., 1985 of beam stability, proton beams at 1 AU are found to be marginally stable. No evidence for substantial wave amplitude was found. Locally generated waves, if present, were less than 10-3 nT 2 Hz-1 at the leading

  11. Ultrafine Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  12. Low-enriched fuel particle performance review

    International Nuclear Information System (INIS)

    The available data on low-enriched (LEU) fuel particles were reviewed under the United States-Federal Republic of Germany Agreement. The most influential factors controlling the irradiation performance of LEU fuel particles were found to be plutonium transport, fission product transport, fuel particle mechanical performance and fuel particle chemical performande. (orig.)

  13. Low-enriched fuel particle performance review

    International Nuclear Information System (INIS)

    The available data on low-enriched uranium (LEU) fuel particles were reviewed under the United States-Federal Republic of Germany Agreement. The most influential factors controlling the irradiation performance of LEU fuel particles were found to be plutonium transport, fission product transport, fuel particle mechanical performance, and fuel particle chemical performance

  14. Particle astronomy and particle physics from the moon - The particle observatory

    Science.gov (United States)

    Wilson, Thomas L.

    1990-01-01

    Promising experiments from the moon using particle detectors are discussed, noting the advantage of the large flux collecting power Pc offered by the remote, stable environment of a lunar base. An observatory class of particle experiments is presented, based upon proposals at NASA's recent Stanford workshop. They vary from neutrino astronomy, particle astrophysics, and cosmic ray experiments to space physics and fundamental physics experiments such as proton decay and 'table-top' arrays. This research is background-limited on earth, and it is awkward and unrealistic in earth orbit, but is particularly suited for the moon where Pc can be quite large and the instrumentation is not subject to atmospheric erosion as it is (for large t) in low earth orbit.

  15. Hollow sphere ceramic particles for abradable coatings

    International Nuclear Information System (INIS)

    A hollow sphere ceramic flame spray powder is disclosed. The desired constituents are first formed into agglomerated particles in a spray drier. Then the agglomerated particles are introduced into a plasma flame which is adjusted so that the particles collected are substantially hollow. The hollow sphere ceramic particles are suitable for flame spraying a porous and abradable coating. The hollow particles may be selected from the group consisting of zirconium oxide and magnesium zirconate

  16. A Modified Particle Swarm Optimization Algorithm

    OpenAIRE

    Jie He; Hui Guo

    2013-01-01

    In optimizing the particle swarm optimization (PSO) that inevitable existence problem of prematurity and the local convergence, this paper base on this aspects is put forward a kind of modified particle swarm optimization algorithm, take the gradient descent method (BP algorithm) as a particle swarm operator embedded in particle swarm algorithm, and at the same time use to attenuation wall (Damping) approach to make fly off the search area of the particles of size remain unchanged and avoid t...

  17. Cellular structure in system of interacting particles

    OpenAIRE

    Lev, Bohdan

    2008-01-01

    The general description of formation the cellular structure in the system of interacting particles is proposed. Interactions between particles are presumably well-understood and the phase transition in which can be studied in the scale of particle resolution. We presented analytical results of possible cellular structures for suspension of colloidal particles, in system particles immersed in liquid crystal and gravitational system. We have shown that cellular structure formation can occur in ...

  18. Hygroscopic properties of Diesel engine soot particles

    Energy Technology Data Exchange (ETDEWEB)

    Weingartner, E.; Baltensperger, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Burtscher, H. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-11-01

    The hygroscopic properties of combustion particles, freshly emitted from a Diesel engine were investigated. It was found that these particles start to grow by water condensation at a relative humidity (RH)>80%. The hygroscopicity of these particles was enhanced when the sulfur content of the fuel was increased or when the particles were artificially aged (i.e. particles were subjected to an ozone or UV pre-treatment). (author) 2 figs., 5 refs.

  19. Introduction to Subatomic-Particle Spectrometers

    OpenAIRE

    Kaplan, Daniel M.; Lane, Charles E.; Nelson, Kenneth S.

    1998-01-01

    An introductory review, suitable for the beginning student of high-energy physics or professionals from other fields who may desire familiarity with subatomic-particle detection techniques. Subatomic-particle fundamentals and the basics of particle interactions with matter are summarized, after which we review particle detectors. We conclude with three examples that illustrate the variety of subatomic-particle spectrometers and exemplify the combined use of several detection techniques to cha...

  20. Turbulent pair dispersion of inertial particles

    OpenAIRE

    Bec, J; Biferale, L.; Lanotte, A.S.; Scagliarini, A; Toschi, F.

    2009-01-01

    The relative dispersion of pairs of inertial particles in incompressible, homogeneous, and isotropic turbulence is studied by means of direct numerical simulations at two values of the Taylor-scale Reynolds number $Re_{\\lambda} \\sim 200$ and 400. The evolution of both heavy and light particle pairs is analysed at varying the particle Stokes number and the fluid-to-particle density ratio. For heavy particles, it is found that turbulent dispersion is schematically governed by two temporal regim...

  1. Extrasensory perception of subatomic particles

    International Nuclear Information System (INIS)

    A century-old claim by two early leaders of the Theosophical Society to have used extra sensory perception (ESP) to describe subatomic particles is evaluated. Their observations are found to be consistent with facts of nuclear physics and with the quark model of particle physics provided that it is hypothesized that they described not atoms (as they assumed) but quasi compound nuclear systems formed prior to observation by an induced disintegration of two atomic nuclei and by the subsequent interactions of all their released constituents. The two Theosophists account of the force binding together the fundamental constituents of matter is shown to agree with the string model version of quantum chromodynamics. The physical implication of these remarkable correlations between ostensible, para normal observations of subatomic particles and facts and ideas of nuclear and particle physics is that quarks are not fundamental (as many physicists currently believe) but, instead, are bound states of three preons or subquarks. (author). 16 refs., 7 figs., 3 tabs

  2. Thomas-forbidden particle capture

    OpenAIRE

    Carter, John H.; Lieber, Michael

    2010-01-01

    At high energies, in particle-capture processes between ions and atoms, classical kinematic requirements show that generally double collision Thomas processes dominate. However, for certain mass-ratios these processes are kinematically forbidden. This paper explores the possibility of capture for such processes by triple or higher order collision processes.

  3. Standard model without Higgs particles

    International Nuclear Information System (INIS)

    A modification of the standard model of electroweak interactions with the nonlocal Higgs sector is proposed. Proper form of nonlocality makes Higgs particles unobservable after the electroweak symmetry breaking. They appear only as a virtual state because their propagator is an entire function. We discuss some specific consequences of this approach comparing it with the conventional standard model. 12 refs

  4. Standard model without Higgs particles

    International Nuclear Information System (INIS)

    A modification of the standard model of electroweak interactions with the nonlocal Higgs sector is proposed. Proper form of nonlocality makes Higgs particles unobservable after the electroweak symmetry breaking. They appear only as a virtual state because their propagator is an entire function. We discuss some specific consequences of this approach comparing it with the conventional standard model. (author). 12 refs

  5. Entanglement - From Particles to Consciousness

    Science.gov (United States)

    Teodorani, M.

    2007-06-01

    This book, which is entirely devoted to the description and discussion of the mechanism of quantum entanglement, is divided into three main parts: a) canonical entanglement in the realm of elementary particles; b) entanglement in the biological environment (DNA and microtubules); c) entanglement in the psychic realm. Cosmological entanglement and non-local SETI are discussed as well.

  6. Particle physics using nuclear targets

    Energy Technology Data Exchange (ETDEWEB)

    Ferbel, T.

    1978-01-01

    The use of nuclear targets in particle physics is discussed and some recent results obtained in studies of hadronic interactions on nuclei summarized. In particular experimental findings on inclusive production and on coherent dissociation of mesons and baryons at high energies are presented. 41 references.

  7. Fine Particle Scrubbing: A Proceedings

    Science.gov (United States)

    Journal of the Air Pollution Control Association, 1974

    1974-01-01

    These articles deal with the proceedings of a 1974 symposium on the use of wet scrubbers for the control of fine particle air pollutants. Various wet scrubbers, their engineering, performance, efficiency, and future are discussed. Tables, formulas, and models are included. (TK)

  8. Of people, particles and prejudice

    Science.gov (United States)

    Jackson, Penny; Greene, Anne; Mears, Matt; Spacecadet1; Green, Christian; Hunt, Devin J.; Berglyd Olsen, Veronica K.; Ilya, Komarov; Pierpont, Elaine; Gillman, Matthew

    2016-05-01

    In reply to Louise Mayor's feature article “Where people and particles collide”, about the experiences of researchers at CERN who are lesbian, gay, bisexual or transgender (LGBT), efforts to make LGBT CERN an officially recognized club, and incidents where posters advertising the club have been torn down or defaced (March pp31–36, http://ow.ly/YVP2Z).

  9. Pulmonary toxicology of respirable particles

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for the 44 papers presented in these proceedings that deal will radioactive particles. The last paper (Stannard) in the proceedings is an historical review of the field of inhalation toxicology and is not included in the analytics

  10. Research in elementary particle physics

    Science.gov (United States)

    Kirsch, L. E.; Schnitzer, H. J.

    Research in theoretical and experimental properties of elementary particles is described. This includes measurements made at the multiparticle spectrometer facility at Brookhaven, studies of baryonium production, inclusive hyperon production, and E(0) production. Theoretical work included extended field theories, subconstituent models, finite temperature quatum chromodynamics, grad unified theories, and calculational techniques in gauge theories.

  11. Particle Acceleration in Relativistic Outflows

    Science.gov (United States)

    Bykov, Andrei; Gehrels, Neil; Krawczynski, Henric; Lemoine, Martin; Pelletier, Guy; Pohl, Martin

    2012-01-01

    In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.

  12. Particle production at collider energies

    International Nuclear Information System (INIS)

    Key features of the SPS panti p Collider and the detectors of the UA-experiments involved are dealt with in chapter 2, which includes and accord to the ramping mode of the Collider, which allowed to raise the c.m. energy to 900 GeV in the UA5/2 experiment. The following chapters concentrate on physics results. Starting with a discussion of cross sections and diffraction dissociation in chapter 3 we then continue with a presentation of basic features of particle production such as rapidity and multiplicity distributions in chapter 4. There one of the unexpected findings at Collider energies, the breakdown of the so-called KNO-scaling, and new regularities potentially governing multiplicity distributions, are discussed. The findings about correlations among the final state particles, which may tell about the underlying dynamics of multi-particle production and be relevant to models thereof, are described in due detail in chapter 5. Transverse spectra and their trends with energy are shown in chapter 6. Results on identified particles are collected in a separate chapter in order to stress that this piece of information was an important outcome of the UA5 experiment. (orig./HSI)

  13. Weak decays of stable particles

    International Nuclear Information System (INIS)

    In this article we review recent advances in the field of weak decays and consider their implications for quantum chromodynamics (the theory of strong interactions) and electroweak theory (the combined theory of electromagnetic and weak interactions), which together form the ''Standard Model'' of elementary particles. (author)

  14. Particle physics using nuclear targets

    International Nuclear Information System (INIS)

    The use of nuclear targets in particle physics is discussed and some recent results obtained in studies of hadronic interactions on nuclei summarized. In particular experimental findings on inclusive production and on coherent dissociation of mesons and baryons at high energies are presented. 41 references

  15. Harmonic Oscillators and Elementary Particles

    CERN Document Server

    Sobouti, Y

    2016-01-01

    Two dynamical systems with same symmetry should have features in common, and as far as their shared symmetry is concerned, one may represent the other. The three light quark constituents of the hadrons, a) have an approximate flavor SU(3) symmetry, b) have an exact color SU(3) symmetry, and c) as spin 1/2 particles, have a Lorentz SO(3,1) symmetry. So does a 3D harmonic oscillator. a) Its Hamiltonian has the SU(3) symmetry, breakable if the 3 fundamental modes of oscillation are not identical. b) The 3 directions of oscillation have the permutation symmetry. This enables one to create three copies of unbreakable SU(3) symmetry for each mode of the oscillation, and mimic the color of the elementary particles. And c) The Lagrangian of the 3D oscillator has the SO(3,1) symmetry. This can be employed to accommodate the spin of the particles. In this paper we draw up a one-to-one correspondence between the eigen modes of the Poisson bracket operator of the 3D oscillator and the flavor multiplets of the particles, ...

  16. Bound states of 'dressed' particles

    International Nuclear Information System (INIS)

    A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)

  17. Cryogenic detectors for particle physics

    International Nuclear Information System (INIS)

    A comprehensive introduction to cryogenic detector developments for particle physics is presented, covering conventional detectors cooled to low temperature (scintillators and semiconductors), superconductive and thermal sensitive devices, as well as the basics of cold electronics. After giving a critical overview of current work, we elaborate on possible new ways for further improvements and briefly evaluate the feasibility of the main proposed applications

  18. Particle-induced thermonuclear fusion

    International Nuclear Information System (INIS)

    A nuclear fusion process for igniting a nuclear fusion pellet in a manner similar to that proposed for laser beams uses, an array of pulsed high energy combined particle beams, focused to bombard the pellet for isentropically compressing it to a Fermi-degenerate state by thermal blow-off and balanced beam momentum transfer. (author)

  19. Conformal invariant two particle processes

    International Nuclear Information System (INIS)

    For the conformal group (essentially the SO2(n,2)group) in n-dimensional Minkowsi-space homogeneous spaces are studied which can be interpreted as 2-particle configuration spaces, and 2-particle representations are induced (both participants are spin 0 particles). The eigensolutions of the Casimir-operator in momentum space are Clebsch-Gordan coefficients in momentum basis. The separation of a complete set of comuting operators from the Casimir eigenvalue equations results in all cases in differential equations with 2 variables (a direct consequence of the rank 2 of the homogen spaces), which can be classified as 'generalized hypergeometric differential operators in 2 variables' (this type, as the author supposes, has not been delt with in the literature so far). In the second part the classical conform invariant (relativistic) 2-particle problem, corresponding to the common quantum mechanical (or quantum field theoretical) problem, is presented and solved completely. It is shown for example that for participant momentums (reasonable in the classic sens) on the forward - or on the zero cone only scattering and no bound states are found. (orig./WBU)

  20. Build Your Own Particle Detector

    CERN Document Server

    Mehlhase, Sascha; The ATLAS collaboration

    2016-01-01

    To support the outreach activities of Atlas institutes and to grab people's attention in science exhibitions and during public events, we have created both a very detailed model of the experiment built entirely out of about Lego bricks as well as an outreach programme using Lego bricks to get people to think about particle detectors and involve them into a conversation about particle physics in general. A large Lego model, consisting of about 9500 pieces, has been 'exported' to more than 55 Atlas institutes and has been used in numerous exhibitions to explain the proportion and composition of the experiment to the public. As part of 'Build Your Own Particle Detector' programme (byopd.org) we conducted more than 15 events,either involving a competition to design and build the 'best' particle detector from a random pile of pieces or to take part in the construction of one of the large models, as part of a full day outreach event. Recently we've added miniature models of all four LHC experiments, that will be us...

  1. Direct charged particle imaging sensors

    International Nuclear Information System (INIS)

    CMOS image sensors optimized for charged particle imaging applications, such as electron microscopy and particle physics, have been designed and characterized. These directly image charged particles without reliance on performance-degrading hybrid technologies such as the use of scintillating materials. Based on standard CMOS active pixel sensor (APS) technology, the sensor arrays uses an 8-20 μm epitaxial layer that acts as a thicker sensitive region for the generation and collection of ionization electrons resulting from impinging high-energy particles. This results in a 100% fill factor and a far larger signal per incident electron than a standard CMOS photodiode could provide. A 512x550 pixels prototype has been fabricated and used extensively in an electron microscope, including having been used to take sample images. Temporal noise was measured to be 0.9 mV RMS, and the dynamic range was 60 dB. Power consumption at 70 frames/s is 20 mW. The full-width half-maximum of the collected ionization electron distribution was found to be 5.5 μm, yielding a spatial resolution of approximately 2.3 μm for individual incident electrons, and the modulation transfer function of the sensor at the Nyquist limit is to be 32%

  2. Pyrotechnic reaction residue particle analysis.

    Science.gov (United States)

    Kosanke, Kenneth L; Dujay, Richard C; Kosanke, Bonnie J

    2006-03-01

    Pyrotechnic reaction residue particle (PRRP) production, sampling and analysis are all very similar to that for primer gunshot residue. In both cases, the preferred method of analysis uses scanning electron microscopy to locate suspect particles and then uses energy dispersive x-ray spectroscopy to characterize the particle's constituent chemical elements. There are relatively few times when standard micro-analytical chemistry performed on pyrotechnic residues may not provide sufficient information for forensic investigators. However, on those occasions, PRRP analysis provides a greatly improved ability to discriminate between materials of pyrotechnic origin and other unrelated substances also present. The greater specificity of PRRP analysis is the result of its analyzing a large number of individual micron-sized particles, rather than producing only a single integrated result such as produced using standard micro-analytical chemistry. For example, PRRP analyses are used to demonstrate its ability to successfully (1) discriminate between pyrotechnic residues and unrelated background contamination, (2) identify that two different pyrotechnic compositions had previously been exploded within the same device, and (3) establish the chronology of an incident involving two separate and closely occurring explosions. PMID:16566762

  3. Research in elementary particle physics

    International Nuclear Information System (INIS)

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology

  4. Predicting the physics of particles

    International Nuclear Information System (INIS)

    A brief account is presented of the goals and methods of particle theorists, stressing the measurable quantities they would like to predict, the conventional starting points for such predictions, and some of the techniques used to arrive at a prediction. (author)

  5. Tomographic PIV: particles versus blobs

    International Nuclear Information System (INIS)

    We present an alternative approach to tomographic particle image velocimetry (tomo-PIV) that seeks to recover nearly single voxel particles rather than blobs of extended size. The baseline of our approach is a particle-based representation of image data. An appropriate discretization of this representation yields an original linear forward model with a weight matrix built with specific samples of the system’s point spread function (PSF). Such an approach requires only a few voxels to explain the image appearance, therefore it favors much more sparsely reconstructed volumes than classic tomo-PIV. The proposed forward model is general and flexible and can be embedded in a classical multiplicative algebraic reconstruction technique (MART) or a simultaneous multiplicative algebraic reconstruction technique (SMART) inversion procedure. We show, using synthetic PIV images and by way of a large exploration of the generating conditions and a variety of performance metrics, that the model leads to better results than the classical tomo-PIV approach, in particular in the case of seeding densities greater than 0.06 particles per pixel and of PSFs characterized by a standard deviation larger than 0.8 pixels. (paper)

  6. Massive particle accelerator revving up

    CERN Multimedia

    Kestenbaum, David S

    2007-01-01

    "This summer, physicists plan to throww the switch on what is arguably the largest and most complex science experiment ever conducted. An underground ring of superconducting magnets, reaching from Switzerland into France, will smash together subatomic particles at incredible force." (3 pages)

  7. Exotic Long-Lived Particles

    CERN Document Server

    Joergensen, Morten Dam

    A search for hadronising long-lived massive particles at the Large Hadron Collider is conducted with the ATLAS detector. No excess events are found. Based on statistical analysis, upper limits on the production cross section are observed to be between $0.01$ pb and $0.006$ pb for colour octet particles (gluinos) with masses ranging from $300 \\ \\mathrm{GeV/c}^2$ to $1400 \\ \\mathrm{GeV/c}^2$, and $0.01$ pb to $0.004$ pb for colour triplet particles (stops and sbottoms) with masses ranging from $200 \\ \\mathrm{GeV/c}^2$ to $900 \\ \\mathrm{GeV/c}^2$. In the context of Supersymmetry with decoupled sfermion and sboson sectors (Split-SUSY), this gives a lower limit on the gluino mass of $989 \\ \\mathrm{GeV/c}^2$, and $683 \\ \\mathrm{GeV/c}^2$ for the stop mass and $618 \\ \\mathrm{GeV/c}^2$ for the sbottom mass. In addition, a new method is presented that improves the speed ($\\beta$) estimation for long-lived particles in the ATLAS tile calorimeter with a factor of $7$ improvement in resolution at low-$\\beta$ and ...

  8. Lithography using quantum entangled particles

    Science.gov (United States)

    Williams, Colin (Inventor); Dowling, Jonathan (Inventor)

    2001-01-01

    A system of etching using quantum entangled particles to get shorter interference fringes. An interferometer is used to obtain an interference fringe. N entangled photons are input to the interferometer. This reduces the distance between interference fringes by n, where again n is the number of entangled photons.

  9. Particle physics prospects: August '81

    International Nuclear Information System (INIS)

    The author gives a review about symmetry breaking induced by scalar bosons. In this connection he discusses the electroweak symmetry breaking due to the Higgs mechanism, the CP-violation, and technicolor. Finally, he considers the connection between these particles and supersymmetry. (HSI)

  10. Alpha particle emitters in medicine

    International Nuclear Information System (INIS)

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 (211At) and natural bismuth-212 (212Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 (223Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs

  11. The future of particle physics

    OpenAIRE

    Mönig, K.

    2006-01-01

    After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.

  12. Deposition and Resuspension of Particles

    DEFF Research Database (Denmark)

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.;

    To investigate the physical process of deposition and resuspension of particles in the indoor environment, scale experiments are used and a sampling method is established. The influences of surface orientation and turbulence and velocity of the air on the dust load on a surface are analysed....

  13. Development of Particle Flow Calorimetry

    OpenAIRE

    Repond, Jose

    2011-01-01

    This talk reviews the development of imaging calorimeters for the purpose of applying Particle Flow Algorithms (PFAs) to the measurement of hadronic jets at a future lepton collider. After a short introduction, the current status of PFA developments is presented, followed by a review of the major developments in electromagnetic and hadronic calorimetry.

  14. Particle electric dipole-moments

    Energy Technology Data Exchange (ETDEWEB)

    Pendlebury, J.M. [Sussex Univ., Brighton (United Kingdom)

    1997-04-01

    The incentive to detect particle electric dipole-moments, as a window on time-reversal violation, remains undiminished. Efforts to improve the measurements for the neutron, the electron and some nuclei are still making rapid progress as more powerful experimental methods are brought to bear. A new measurement for the neutron at ILL is presented. (author). 7 refs.

  15. And then there were particles

    CERN Multimedia

    Landua, Rolf

    2007-01-01

    "The appearance of particles dates back to a period physicists find embarrassing, one when the amount of energy active in the Universe was so enormous that they simply cannot descrit it. It is, however, possible to imagine the birth of the elementary building blocks that make up matter and energy."(1 page)

  16. Elementary particles in curved spaces

    International Nuclear Information System (INIS)

    The theories in particle physics are developed currently, in Minkowski space-time starting from the Poincare group. A physical theory in flat space can be seen as the limit of a more general physical theory in a curved space. At the present time, a theory of particles in curved space does not exist, and thus the only possibility is to extend the existent theories in these spaces. A formidable obstacle to the extension of physical models is the absence of groups of motion in more general Riemann spaces. A space of constant curvature has a group of motion that, although differs from that of a flat space, has the same number of parameters and could permit some generalisations. In this contribution we try to investigate some physical implications of the presumable existence of elementary particles in curved space. In de Sitter space (dS) the invariant rest mass is a combination of the Poincare rest mass and the generalised angular momentum of a particle and it permits to establish a correlation with the vacuum energy and with the cosmological constant. The consequences are significant because in an experiment the local structure of space-time departs from the Minkowski space and becomes a dS or AdS space-time. Discrete symmetry characteristics of the dS/AdS group suggest some arguments for the possible existence of the 'mirror matter'. (author)

  17. Research in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    White, Andrew Paul [University of Texas at Arlington; De, Kaushik [University of Texas at Arlington; Brandt, Andrew [University of Texas at Arlington; Yu, Jaehoon [University of Texas at Arlington; Farbin, Amir [University of Texas at Arlington

    2015-02-02

    This report details the accomplishments and research results for the High Energy Physics Group at the University of Texas at Arlington at the Energy and Intensity Frontiers. For the Energy Frontier we have made fundamental contributions in the search for supersymmetric particles, proposed to explain the stabilization of the mass of the Higgs Boson – the agent giving mass to all known particles. We have also made major contributions to the search for additional Higgs Bosons and to the planning for future searches. This work has been carried out in the context of the ATLAS Experiment at CERN (European Nuclear Research Laboratory) and for which we have made major contributions to computing and data distribution and processing, and have worked to calibrate the detector and prepare upgraded electronics for the future. Our other contribution to the Energy Frontier has been to the International Linear Collider (ILC) project, potentially hosted by Japan, and to the Silicon Detector Concept (SiD) in particular. We have lead the development of the SiD Concept and have worked on a new form of precise energy measurement for particles from the high energy collisions of electrons and positrons at the ILC. For the Intensity Frontier, we have worked to develop the concept of Long Baseline Neutrino Experiment(s) (LBNE) at the Fermi National Accelerator Laboratory. Our contributions to detector development, neutrino beam studies, particle identification, software development will facilitate future studies of the oscillation of one type of neutrino into other type(s), establish the order of the neutrino masses, and, through an innovative new idea, allow us to create a beam of dark matter particles.

  18. Nanotechnology: Colourful Particles for Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.

    2015-07-01

    In 1857 Michael Faraday gave a well-attended lecture at the Royal Institution of Great Britain, in which he presented his pioneering experimental work that investigated the interaction of light with matter. Faraday’s study probed the fundamental properties of light as it was reflected and absorbed by progressively smaller particles. Very fine gold particles dispersed in liquid were shown to produce vivid colors not seen in larger particles. Faraday did not know he had created colloidal suspensions of quantum dots, but his insight correctly concluded that the distinct colors were somehow due to the minute size of the gold particles. This great experimental physicist had actually glimpsed a special condition where the particle’s quantum nature was expressed. This work set the future course for nanoscience and quantum theory, but it would take another 125 years before the physical basis of this phenomenon would be explained by quantum size effects. It is now known that when quantum dots are exposed to UV light, some of the electrons are excited as they gain energy, however they remain confined to discrete energy levels not observed in larger particles and solid materials. When the electrons relax and lose their energy, the quantum dot emits light at a specific color that varies with the size of the quantum dot. Bao and Bawendi have cleverly exploited the unique optical properties intrinsic to colloidal quantum dots to develop an innovative compact optical spectrometer that could be integrated with a smart phone camera or as a versatile miniature handheld sensing tool.

  19. Nuclear physics with polarized particles

    International Nuclear Information System (INIS)

    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory - a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear reactions. The book concludes with a brief review of modern applications in medicine and fusion energy research. For reasons of conciseness and of the pedagogical aims of this volume, examples are mainly taken from low-energy installations such as tandem Van de Graaff laboratories, although the emphasis of present research is shifting to medium- and high-energy nuclear physics. Consequently, this volume is restricted to describing non-relativistic processes and focuses on the energy range from astrophysical energies (a few keV) to tens of MeV. It is further restricted to polarimetry of hadronic particles. (orig.)

  20. Nuclear physics with polarized particles

    Energy Technology Data Exchange (ETDEWEB)

    Paetz gen. Schieck, Hans [Koeln Univ. (Germany). Inst. fuer Kernphysik

    2012-07-01

    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory - a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear reactions. The book concludes with a brief review of modern applications in medicine and fusion energy research. For reasons of conciseness and of the pedagogical aims of this volume, examples are mainly taken from low-energy installations such as tandem Van de Graaff laboratories, although the emphasis of present research is shifting to medium- and high-energy nuclear physics. Consequently, this volume is restricted to describing non-relativistic processes and focuses on the energy range from astrophysical energies (a few keV) to tens of MeV. It is further restricted to polarimetry of hadronic particles. (orig.)

  1. Multi-particle inspection using associated particle sources

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, Philip R.; Mihalczo, John T.; Mullens, James A.; McConchie, Seth M.; Hausladen, Paul A.

    2016-02-16

    Disclosed herein are representative embodiments of methods, apparatus, and systems for performing combined neutron and gamma ray radiography. For example, one exemplary system comprises: a neutron source; a set of alpha particle detectors configured to detect alpha particles associated with neutrons generated by the neutron source; neutron detectors positioned to detect at least some of the neutrons generated by the neutron source; a gamma ray source; a set of verification gamma ray detectors configured to detect verification gamma rays associated with gamma rays generated by the gamma ray source; a set of gamma ray detectors configured to detect gamma rays generated by the gamma ray source; and an interrogation region located between the neutron source, the gamma ray source, the neutron detectors, and the gamma ray detectors.

  2. On the kernel and particle consistency in smoothed particle hydrodynamics

    CERN Document Server

    Sigalotti, Leonardo Di G; Rendón, Otto; Vargas, Carlos A; Peña-Polo, Franklin

    2016-01-01

    The problem of consistency of smoothed particle hydrodynamics (SPH) has demanded considerable attention in the past few years due to the ever increasing number of applications of the method in many areas of science and engineering. A loss of consistency leads to an inevitable loss of approximation accuracy. In this paper, we revisit the issue of SPH kernel and particle consistency and demonstrate that SPH has a limiting second-order convergence rate. Numerical experiments with suitably chosen test functions validate this conclusion. In particular, we find that when using the root mean square error as a model evaluation statistics, well-known corrective SPH schemes, which were thought to converge to second, or even higher order, are actually first-order accurate, or at best close to second order. We also find that observing the joint limit when $N\\to\\infty$, $h\\to 0$, and $n\\to\\infty$, as was recently proposed by Zhu et al., where $N$ is the total number of particles, $h$ is the smoothing length, and $n$ is th...

  3. Turbulent pair dispersion of inertial particles

    CERN Document Server

    Bec, J; Lanotte, A S; Scagliarini, A; Toschi, F

    2009-01-01

    The relative dispersion of pairs of inertial particles in incompressible, homogeneous, and isotropic turbulence is studied by means of direct numerical simulations at two values of the Taylor-scale Reynolds number $Re_{\\lambda} \\sim 200$ and 400. The evolution of both heavy and light particle pairs is analysed at varying the particle Stokes number and the fluid-to-particle density ratio. For heavy particles, it is found that turbulent dispersion is schematically governed by two temporal regimes. The first is dominated by the presence, at large Stokes numbers, of small-scale caustics in the particle velocity statistics, and it lasts until heavy particle velocities have relaxed towards the underlying flow velocities. At such large scales, a second regime starts where heavy particles separate as tracers particles would do. As a consequence, at increasing inertia, a larger transient stage is observed, and the Richardson diffusion of simple tracers is recovered only at large times and large scales. These features ...

  4. CFD development for macro particle simulations

    Science.gov (United States)

    Zhao, Xiang; Glenn, Chance; Xiao, Zhigang; Zhang, Sijun

    2014-05-01

    Numerous industrial operations involve fluid-particle systems, in which both phases display very complex behaviour. Some examples include fluidisation technology in catalytic reactors, pneumatic transportation of grain or powder materials, carbon nanotube alignment in the nano-devices and circuit integration and so on. In this paper, a macro particle method is developed to model the fluid-particle flows. The macro particle is formed by a collection of micro-sized particles so that the number of macro particles to be tracked is much less than the number of smaller particles. Unlike the calculations of instantaneous point variables of fluid phase with moving discrete boundaries of the smaller particles with direct numerical simulation, the boundary of each macro particle is just dealt with the blocked-off approach. On the other hand, the flow fields based on the present method is solved by original Navier-Stokes, rather than the modified ones based on the locally averaged theorem. The flow fields are solved on the length scale of computational cells, while the resolutions of solid particles are the size of macro particle, which is determined as needed in specific applications. The macro particle method is validated by several selected cases, which demonstrate that the macro particle method could accurately resolve fluid-particle systems in an efficient, robust and flexible fashion.

  5. ELECTROSTATICALLY SUPPORTED MIXING OF FINE GRAINED PARTICLES

    Institute of Scientific and Technical Information of China (English)

    K.-E.; Wirth; M.; Linsenbühler

    2005-01-01

    The processing of fine-grained particles with diameters between 1 and 10 microns is difficult due to strong van-der-Waals attraction forces. In order to improve the handling properties, the fine-grained particles, i.e. host-particles,are coated with various nanoparticles, i.e. guest-particles. The mixing of fine-grained powders is influenced by particle-particle interactions. If these forces are distinctively used, both interactive and ordered mixtures can be produced.These particle mixtures consist of composite-particles that have new physical properties. These modified properties d epend strongly on the coating process, the diameter- and mass-relationship of the guest- and the host-particles. The properties of the composite-particles can systematically be adjusted to the requirements of industrial applications. For example, a laboratory bubbling fluidized bed can be used to describe the conveying behavior of the functionalized host-particles. Applications for the functionalized particles are in the pharmaceutical and the powder coating industries,e.g. enhanced dry powder inhalers and thin lacquer films. The present research compares three different mixing/coating processes. The composite-particles are characterized by TEM, SEM and with their fluidization characteristics. The coating process itself is monitored by the electrostatic charge of the particles.

  6. Selective particle capture by asynchronously beating cilia

    Science.gov (United States)

    Ding, Yang; Kanso, Eva

    2015-12-01

    Selective particle filtration is fundamental in many engineering and biological systems. For example, many aquatic microorganisms use filter feeding to capture food particles from the surrounding fluid, using motile cilia. One of the capture strategies is to use the same cilia to generate feeding currents and to intercept particles when the particles are on the downstream side of the cilia. Here, we develop a 3D computational model of ciliary bands interacting with flow suspended particles and calculate particle trajectories for a range of particle sizes. Consistent with experimental observations, we find optimal particle sizes that maximize capture rate. The optimal size depends nonlinearly on cilia spacing and cilia coordination, synchronous vs. asynchronous. These parameters affect the cilia-generated flow field, which in turn affects particle trajectories. The low capture rate of smaller particles is due to the particles' inability to cross the flow streamlines of neighboring cilia. Meanwhile, large particles have difficulty entering the sub-ciliary region once advected downstream, also resulting in low capture rates. The optimal range of particle sizes is enhanced when cilia beat asynchronously. These findings have potentially important implications on the design and use of biomimetic cilia in processes such as particle sorting in microfluidic devices.

  7. Fundamental physics in particle traps

    International Nuclear Information System (INIS)

    The individual topics are covered by leading experts in the respective fields of research. Provides readers with present theory and experiments in this field. A useful reference for researchers. This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

  8. Particle deposition in turbulent flow

    Energy Technology Data Exchange (ETDEWEB)

    Ranegger, G.; Schaflinger, U. [Technical Univ. Graz (Austria). CD-Lab. of Continuous Casting Processes

    2001-07-01

    During continuous casting processes impurities like deoxidation products in the melt deposit at the walls of the tundish nozzle and the stopper. This phenomenon, termed clogging, causes obstruction of the flow and decreases the quality of the casted metal. A knowledge of the flow pattern within the tundish nozzle-stopper region is very important for the design of the nozzle and the stopper. The transport of the particles will be calculated by using a Lagrangian approach. To simulate the turbulent fluctuations in the Lagrangian formulation, a stochastic procedure (Random Walk Model) will be employed. A new design for the nozzle and stopper region reduces turbulence, prevents recirculation and permits only a very limited lateral particle transport. (orig.)

  9. THOR Particle Processing Unit PPU

    Science.gov (United States)

    Federica Marcucci, Maria; Bruno, Roberto; Consolini, Giuseppe; D'Amicis, Raffaella; De Lauretis, Marcello; De Marco, Rossana; De Michelis, Paola; Francia, Patrizia; Laurenza, Monica; Materassi, Massimo; Vellante, Massimo; Valentini, Francesco

    2016-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. On board THOR, data collected by the Turbulent Electron Analyser, the Ion Mass Spectrum analyser and the Cold Solar Wind ion analyser instruments will be processed by a common digital processor unit, the Particle Processing Unit (PPU). PPU architecture will be based on the state of the art space flight processors and will be fully redundant, in order to efficiently and safely handle the data from the numerous sensors of the instruments suite. The approach of a common processing unit for particle instruments is very important for the enabling of an efficient management for correlative plasma measurements, also facilitating interoperation with other instruments on the spacecraft. Moreover, it permits technical and programmatic synergies giving the possibility to optimize and save spacecraft resources.

  10. Multiplication circuit for particle identification

    International Nuclear Information System (INIS)

    After having commented some characteristics of the particles present in a cyclotron, and their interactions, this report addresses the development and the implementation of a method and a device for selecting and counting particles. The author presents the principle and existing techniques of selection. In comparison with an existing device, the proportional counter and the scintillator are replaced by junctions: a surface barrier type junction (a silicon N layer with a very thin oxygen layer playing the role of the P layer), and lithium-based junction (a silicon P type layer made intrinsic by migration of lithium). The author then describes the developed circuit and assembly (background of the choice of a multiplication circuit), and their operation. In the next part, he presents the performed tests and discuses the obtained results. He finally outlines the benefits of the herein presented circuit

  11. Boron doping a semiconductor particle

    Science.gov (United States)

    Stevens, Gary Don; Reynolds, Jeffrey Scott; Brown, Louanne Kay

    1998-06-09

    A method (10,30) of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried (16), with the boron film then being driven (18) into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out (38) into piles and melted/fused (40) with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements.

  12. The Fermilab Particle Astrophysics Center

    Energy Technology Data Exchange (ETDEWEB)

    2004-11-01

    The Particle Astrophysics Center was established in fall of 2004. Fermilab director Michael S. Witherell has named Fermilab cosmologist Edward ''Rocky'' Kolb as its first director. The Center will function as an intellectual focus for particle astrophysics at Fermilab, bringing together the Theoretical and Experimental Astrophysics Groups. It also encompasses existing astrophysics projects, including the Sloan Digital Sky Survey, the Cryogenic Dark Matter Search, and the Pierre Auger Cosmic Ray Observatory, as well as proposed projects, including the SuperNova Acceleration Probe to study dark energy as part of the Joint Dark Energy Mission, and the ground-based Dark Energy Survey aimed at measuring the dark energy equation of state.

  13. Multivariate methods for particle identification

    CERN Document Server

    Visan, Cosmin

    2013-01-01

    The purpose of this project was to evaluate several MultiVariate methods in order to determine which one, if any, offers better results in Particle Identification (PID) than a simple n$\\sigma$ cut on the response of the ALICE PID detectors. The particles considered in the analysis were Pions, Kaons and Protons and the detectors used were TPC and TOF. When used with the same input n$\\sigma$ variables, the results show similar perfoance between the Rectangular Cuts Optimization method and the simple n$\\sigma$ cuts. The method MLP and BDT show poor results for certain ranges of momentum. The KNN method is the best performing, showing similar results for Pions and Protons as the Cuts method, and better results for Kaons. The extension of the methods to include additional input variables leads to poor results, related to instabilities still to be investigated.

  14. Fundamental physics in particle traps

    Energy Technology Data Exchange (ETDEWEB)

    Quint, Wolfgang; Vogel, Manuel (eds.) [GSI Helmholtz-Zentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2014-03-01

    The individual topics are covered by leading experts in the respective fields of research. Provides readers with present theory and experiments in this field. A useful reference for researchers. This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

  15. Non-accelerator particle physics

    International Nuclear Information System (INIS)

    The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are currently engaged in construction of the MACRO detector, an Italian-American collaborative research instrument with a total particle acceptance of 10,000 m2sr, which will perform a sensitive search for magnetic monopoles using excitation-ionization methods. Other major objective of the MACRO experiment are to search for astrophysical high energy neutrinos expected to be emitted by such objects as Vela X-1, LMC X-4 and SN-1987A and to search for low energy neutrino bursts from gravitational stellar collapse. We are also working on BOREX, a liquid scintillation solar neutrino experiment and GRANDE, a proposed very large area surface detector for astrophysical neutrinos, and on the development of new techniques for liquid scintillation detection

  16. Britain honours its particle physicists

    CERN Multimedia

    2004-01-01

    Theoretical and experimental particle physicists figure among the winners for 2004 of Britain's most prestigious prizes for physics, awarded by the Institute of Physics (IOP). The IOP's own Paul Dirac medal and prize, goes to this year to CERN's John Ellis for "his highly influential work on particle-physics phenomenology; in particular on the properties of gluons, the Higgs boson and the top quark". One of the institute's premier wards, it is made for outstanding contributions to theoretical (including mathematical and computational) physics. The Duddell medal and prize, in memory of William du Bois Duddell, the inventor of the electromagnetic oscillograph, is awarded for outstanding contributions to the advancement of knowledge through the application of physics, including the invention or design of scientific instruments or the discovery of materials used in their construction. It is shared this year by Geoff Hall, of Imperial College London, Alessandro Marchioro from CERN and Peter Sharp of the Rutherfor...

  17. Fundamental physics in particle traps

    CERN Document Server

    Vogel, Manuel

    2014-01-01

    This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

  18. Geometrical charged-particle optics

    CERN Document Server

    Rose, Harald

    2012-01-01

    This second edition is an extended version of the first edition of Geometrical Charged-Particle Optics. The updated reference monograph is intended as a guide for researchers and graduate students who are seeking a comprehensive treatment of the design of instruments and beam-guiding systems of charged particles and their propagation in electromagnetic fields. Wave aspects are included in this edition for explaining electron holography, the Aharanov-Bohm effect and the resolution of electron microscopes limited by diffraction. Several methods for calculating the electromagnetic field are presented and procedures are outlined for calculating the properties of systems with arbitrarily curved axis. Detailed methods are presented for designing and optimizing special components such as aberration correctors, spectrometers, energy filters monochromators, ion traps, electron mirrors and cathode lenses. In particular, the optics of rotationally symmetric lenses, quadrupoles, and systems composed of these elements are...

  19. Smoothed Particle Hydrodynamics in Astrophysics

    CERN Document Server

    Springel, Volker

    2011-01-01

    This review discusses Smoothed Particle Hydrodynamics (SPH) in the astrophysical context, with a focus on inviscid gas dynamics. The particle-based SPH technique allows an intuitive and simple formulation of hydrodynamics that has excellent conservation properties and can be coupled to self-gravity easily and highly accurately. The Lagrangian character of SPH allows it to automatically adjust its resolution to the clumping of matter, a property that makes the scheme ideal for many applications in astrophysics, where often a large dynamic range in density is encountered. We discuss the derivation of the basic SPH equations in their modern formulation, and give an overview about extensions of SPH developed to treat physics such as radiative transfer, thermal conduction, relativistic dynamics or magnetic fields. We also briefly describe some of the most important applications areas of SPH in astrophysical research. Finally, we provide a critical discussion of the accuracy of SPH for different hydrodynamical prob...

  20. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.