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Simulation of electron acceleration at collisionless plasma shocksLowe, Robert Edward January 2002 (has links)
No description available.
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Turbulent transport of space charge in the atmospheric surface layerBarlow, Janet F. January 1999 (has links)
No description available.
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The optimization of the FADC readout system for the Zeus central tracking detectorCussans, David George January 1993 (has links)
No description available.
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Analytical and numerical investigation of energetic particles interacting with turbulent magnetic fieldsHeusen, Martin H. 24 January 2017 (has links)
A fundamental problem in astrophysics is the interaction between space plasmas and energetic particles. Plasmas form the vast majority of space and can be found in any astrophysical environment, from the plasma of the solar wind to the interstellar medium for example. When plasmas stream through space, they give rise to turbulent magnetic fields. In addition, space is populated by energetic particles whose origins could be interplanetary, such as solar energetic particles generated by explosions on the surface of the Sun, or Galactic, such as cosmic rays generated by supernova remnants. As these particles propagate through interplanetary or interstellar space, they experience scattering due to magnetic turbulence. Describing these scattering effects, through the calculation of diffusion coefficients, is crucial to understanding several important processes in astrophysics. Such processes include particle acceleration at interplanetary shocks, solar modulation and space weather studies, and the motion of cosmic rays through galaxies. A test-particle code is developed to simulate the interaction of charged particles with turbulent magnetic fields. Diffusion coefficients along and across the mean magnetic field are calculated and compared with analytical theories and space mission measurements. Turbulence models with reduced dimensionality and full three-dimensional corresponding to different space settings are considered, including reproducing the magnetic turbulence in the solar wind and the interstellar medium. Wave propagation, dynamical effects, and unique turbulence setups such as noisy hydrodynamic models are also considered. We show that the influence of turbulence properties and various space regimes on transport parameters is minor and not as strong as originally thought. This points toward a universal transport behaviour of charged particles which motivates the employment of a comprehensive diffusion formula for different space settings. In addition, we were able for the first time to accurately describe the interaction between Galactic cosmic rays and dynamical solar wind turbulence to reproduce observational results of mean free paths. The validity of certain asymptotic limits for the parallel and perpendicular diffusion coefficients are examined. It is shown that only two parameters control those limits, namely the fundamental length scale of magnetic turbulence and the ratio of turbulence strength to the mean field. / February 2017
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Removal of charged aerosolsTripathi, Sachchida Nand January 2000 (has links)
No description available.
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Studies of Particles and Wave Propagation in Periodic and Quasiperiodic Nonlinear MediaSun, Ning, 1963- 05 1900 (has links)
This thesis examines the properties of transmission and transport of light and charged particles in periodic or quasiperiodic systems of solid state and optics, especially the nonlinear and external field effects and the dynamic properties of these systems.
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Modelování magnetohydrodynamických jevů / Modeling of magnetohydrodynamic phenomenaMačák, Martin January 2018 (has links)
Theoretical part of this thesis is dedicated to the theoretical basis of electric conduction phenomena in fluids and method of calculation of magnetohydrodynamic phenomena. In the experimental part, computational modules have been developed to complement and augment the use of commercial simulation programs for simulation in the field of magnetohydrodynamics. On practical examples of mass spectrometer simulation, Einzel lens, electron movement and electric circuit breaker, the functionality of the computational models and the correctness of the obtained results were documented. Created computational modules can be used to design and optimize products using magnetohydrodynamic phenomena.
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Strangeness Photoproduction in the {gamma}p {yields} K{sup 0} {Sigma}{sup +} ReactionBrian Carnahan January 2003 (has links)
Thesis (Ph.D.); Submitted to the Catholic Univ. of America, Washington, DC (US); 1 May 2003. / Published through the Information Bridge: DOE Scientific and Technical Information. "JLAB-PHY-03-40" "DOE/ER/40150-2764" Brian Carnahan. 05/01/2003. Report is also available in paper and microfiche from NTIS.
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Probes of new physics at the intensity and energy frontiersMagill, Gabriel 23 November 2018 (has links)
In this thesis, we review the basics of phenomenology in particle physics at neutrino beam dump experiments and hadron colliders. We then consider the phenomenology of various new particles, with masses between 1 MeV and 1 TeV, at the intensity and energy frontiers. We perform sensitivity analyses for physics beyond the standard model at particle colliders (LEP and LHC) and a number of past and future neutrino beam dump experiments (SHiP, DUNE, LSND, MicroBooNE, MiniBooNE and SBND). In particular, we motivate searches for new heavy neutral leptons in single photon events at neutrino and collider experiments (and also via supernova cooling), millicharged particles in single electron events at neutrino experiments, lepton flavor violating scalars via standard model induced mixed flavor neutrino trident production at neutrino experiments, and colored scalar doublets at colliders in events with many jets, soft leptons and low missing energy. In the process, we set novel new bounds on the parameters of these theories and propose powerful new searches that can be performed. We also motivate the construction of a new detector at the LHC called milliQan, and perform a full Geant4 simulation to calculate its projected sensitivity for millicharged particles. The milliQan experiment has since been approved and is currently undergoing construction. / Thesis / Doctor of Philosophy (PhD) / In this thesis, we review the basics of particle physics at neutrino experiments and particle colliders. We then motivate and develop key searches that can be performed to look for new particles at a series of existing and future experiments. We focus on new particles with masses between the electron mass and 1000 times the proton mass. The many searches we consider involve looking for processes that produce a single ray of light, a single electron, a pair of oppositely charged "electron-like" events, new collider signatures, and/or modifications of star explosions. In the process, we set novel new bounds on many theories. We also motivate the construction of a new detector at the Large Hadron Collider called milliQan, and perform a full simulation to assess its future performance. The milliQan experiment has since been approved and is currently undergoing construction.
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Transverse Collective Flow and Emission Order of Mid-Rapidity Fragments in Fermi Energy Heavy Ion CollisionsKohley, Zachary Wayne 2010 August 1900 (has links)
The Equation of State (EoS) of asymmetric nuclear matter has been explored through the study of mid-rapidity fragment dynamics from the 35 MeV/u $^{70}$Zn $^{70}$Zn, $^{64}$Zn $^{64}$Zn, and $^{64}$Ni $^{64}$Ni systems. The experimental data was collected at the Texas A and M Cyclotron Institute using the 4 NIMROD-ISiS array, which provided both
event characterization and excellent isotopic resolution of charged particles.
The transverse collective flow was extracted for proton, deuteron, triton, 3He,
alpha, and 6He particles. Isotopic and isobaric effects were observed in the transverse
flow of the fragments. In both cases, the transverse flow was shown to decrease
with an increasing neutron content in the fragments. The (N/Z)sys dependence of
the transverse flow and the difference betwen the triton and 3He flow were shown to
be sensitive to the density dependence of the symmetry energy using the stochastic
mean-field model. A stiff parameterization of Esym(p) was found to provide better
agreement with the experimental data.
The transverse flow for intermediate mass fragments (IMFs) was investigated,
providing a new probe to study the nuclear EoS. A transition from the IMF flow
strongly depending on the mass of the system, in the most violent collisions, to a
dependence on the charge of the system, for the peripheral reactions, was observed.
Theoretical simulations were used to show that the relative differences in the IMF flow
are sensitive to the density dependence of the symmetry energy. The best agreement
between the experiment and theory was achieved with a stiff Esym(p).
A new method was developed in which correlations between the projectile-like
and mid-rapidity fragments were examined using a scaled flow. Theoretical simulations
were used to show that the scaled flow of the particles was connected to their
average order of emission. The experimental results suggest that the mid-rapidity
region is preferentially populated with neutron-rich light charged particles and the
Z=3-4 IMFs at a relatively early stage in the collision.
This work presents additional constraints on the nuclear EoS and insight into
the mid-rapidity dynamics observed in Fermi energy heavy-ion collisions.
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