scholarly journals Particle simulation for an axisymmetric pulsar magnetosphere

2012 ◽  
Vol 8 (S291) ◽  
pp. 537-539
Author(s):  
Tomohide Wada
Keyword(s):  
Gamma Ray ◽  
Particle Interaction ◽  
Mean Free Path ◽  
Pair Creation ◽  
Particle Simulation ◽  
Pulsar Magnetosphere ◽  
Simulation Code ◽  
Quadrupole Magnetic Field ◽  
Future Work ◽  
Magnetic Pair

AbstractWe developed a new particle simulation code which includes pair creation (magnetic pair creation and photon collision process), propagation of gamma-ray, inertia of particle, interaction of plasma and multi-pole stellar field for steady axisymmetric pulsar magnetosphere. The photon path is solved stochastically by an analytical solution of the mean free path of pair creation processes at the photon position. The superimposed quadrupole magnetic field forms asymmetric electrostatic clouds on tje poloidal plane and the accelerating region is different from the dipole case. Here, we demonstrate some results of a test run for our simulation. We will adopt the code for more complicated cases, such that all above-mentioned effects will be considered together in future work.

scholarly journals MAGNETIC PAIR CREATION TRANSPARENCY IN GAMMA-RAY PULSARS

2014 ◽  
Vol 790 (1) ◽  
pp. 61 ◽  
Author(s):  
Sarah A. Story ◽  
Matthew G. Baring
Keyword(s):  
Gamma Ray ◽  
Pair Creation ◽  
Magnetic Pair

scholarly journals Beam instabilities in a magnetized pair plasma

1999 ◽  
Vol 62 (1) ◽  
pp. 65-86 ◽  
Author(s):  
MAXIM LYUTIKOV
Keyword(s):  
Growth Rates ◽  
Particle Interaction ◽  
Kinetic Regime ◽  
Pulsar Magnetosphere ◽  
Pair Plasma ◽  
Electron Positron ◽  
Pulsar Radiation ◽  
Radiation Generation ◽  
Field Lines ◽  
Beam Instabilities

Beam instabilities in the strongly magnetized electron–positron plasma of a pulsar magnetosphere are considered. We analyse the resonance conditions and estimate the growth rates of the Cherenkov and cyclotron instabilities of the ordinary (O), extraordinary (X) and Alfvén modes in two limiting regimes: kinetic and hydrodynamic. The importance of the different instabilities as a source of coherent pulsar radiation generation is then estimated, taking into account the angular dependence of the growth rates and the limitations on the length of the coherent wave–particle interaction imposed by the curvature of the magnetic field lines. We conclude that in the pulsar magnetosphere, Cherenkov-type instabilities occur in the hydrodynamic regime, while cyclotron-type instabilities occur in the kinetic regime. We argue that electromagnetic cyclotron-type instabilities on the X, O and probably Alfvén waves are more likely to develop in the pulsar magnetosphere.

scholarly journals Gamma-rays from Solar Flares

2000 ◽  
Vol 195 ◽  
pp. 123-132 ◽  
Author(s):  
R. Ramaty ◽  
N. Mandzhavidze
Keyword(s):  
Energy Release ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Particle Interaction ◽  
Mass Motion ◽  
Relativistic Electrons ◽  
Total Energy Release ◽  
Flare Energy ◽  
Accelerated Particles

Gamma-ray emission is the most direct diagnostic of energetic ions and relativistic electrons in solar flares. Analysis of solar flare gamma-ray data has shown: (i) ion acceleration is a major consequence of flare energy release, as the total flare energy in accelerated particles appears to be equipartitioned between ≳ 1 MeV/nucleon ions and ≳ 20 keV electrons, and amounts to an important fraction of the total energy release; (ii) there are flares for which over 50% of the energy is in a particles and heavier ions; (iii) in both impulsive and gradual flares, the particles that interact at the Sun and produce gamma rays are essentially always accelerated by the same mechanism that operates in impulsive flares, probably stochastic acceleration through gyroresonant wave particle interaction; and (iv) gamma-ray spectroscopy can provide new information on solar abundances, for example the site of the FIP-bias onset and the photospheric 3He abundance. We propose a new technique for the investigation of mass motion and mixing in the solar atmosphere: the observations of gamma-ray lines from long-term radioactivity produced by flare accelerated particles.

scholarly journals A Comprehensive Study on Gamma Rays and Fast Neutron Sensing Properties of GAGOC and CMO Scintillators for Shielding Radiation Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shams A. M. Issa ◽  
M. I. Sayyed ◽  
M. H. M. Zaid ◽  
K. A. Matori
Keyword(s):  
Energy Range ◽  
Fast Neutron ◽  
Gamma Ray ◽  
Mean Free Path ◽  
Nuclear Radiation ◽  
Space Technology ◽  
Effective Electron ◽  
Geometrical Progression ◽  
Broad Energy Range ◽  
Removal Cross Section

The WinXCom program has been used to calculate the mass attenuation coefficients (μm), effective atomic numbers (Zeff), effective electron densities (Nel), half-value layer (HVL), and mean free path (MFP) in the energy range 1 keV–100 GeV for Gd3Al2Ga3O12Ce (GAGOC) and CaMoO4 (CMO) scintillator materials. The geometrical progression (G-P) method has been used to compute the exposure buildup factors (EBF) and gamma ray energy absorption (EABF) in the photon energy range 0.015–15 MeV and up to a 40 penetration depth (mfp). In addition, the values of the removal cross section for a fast neutron ∑R have been calculated. The computed data observes that GAGOC showed excellent γ-rays and neutrons sensing a response in the broad energy range. This work could be useful for nuclear radiation sensors, detectors, nuclear medicine applications (medical imaging and mammography), nuclear engineering, and space technology.

Development of Electromagnetic Particle Simulation Code in an Open System

2008 ◽  
pp. 329-343 ◽  
Author(s):  
Hiroaki Ohtani ◽  
Seiji Ishiguro ◽  
Ritoku Horiuchi ◽  
Yasuharu Hayashi ◽  
Nobutoshi Horiuchi
Keyword(s):  
Open System ◽  
Particle Simulation ◽  
Simulation Code

Three-dimensional parallelized fully-electromagnetic particle simulation code UNIPIC-3D

2010 ◽  
Vol 22 (9) ◽  
pp. 2103-2110
Author(s):  
陈再高 Chen Zaigao ◽  
王建国 Wang Jianguo ◽  
张殿辉 Zhang Dianhui ◽  
王玥 Wang Yue ◽  
刘纯亮 Liu Chunliang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Particle Simulation ◽  
Simulation Code

scholarly journals Modes of Energy Loss from Isolated Magnetized Neutron Star

1987 ◽  
Vol 125 ◽  
pp. 450-450
Author(s):  
S. Shibata
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Gamma Ray ◽  
Rotational Energy ◽  
Pair Creation ◽  
Dipole Radiation ◽  
Pair Plasma ◽  
Electron Positron ◽  
Closed Current ◽  
Electron Positron Pair

Pulsar may be regarded as a discharge tube by electron-positron pair creation. On this viewpoint we carry out two numerical calculations. The obtained magnetic field is consistent with the flow. We find that pulsars emit their rotational energy through three modes simultaneously. The three modes are (1)relativistic acceleration and following gamma-ray emission in the closed current circuit in the magnetosphere, (2)wind of the electron-positron pair plasma, and (3)dipole radiation.

scholarly journals A Three-dimensional Outer-magnetospheric Gap Model for Gamma-ray Pulsars: I. The Crab Pulsar

2000 ◽  
Vol 195 ◽  
pp. 223-232
Author(s):  
K. S. Cheng ◽  
M. Ruderman ◽  
L. Zhang
Keyword(s):  
Pair Production ◽  
Gamma Ray ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Crab Pulsar ◽  
Particle Flows ◽  
Consistent Model ◽  
Local Properties ◽  
Local Pair ◽  
Magnetic Pair

We use a three-dimensional pulsar magnetosphere model to study the geometry of outer-magnetospheric gaps. The vertical size of the “outer gap” is first determined by a self-consistent model in which the outer gap size is limited by pair production from collisions between (1) thermal photons produced from polar cap heating by backflow “outer gap” current, and (2) the curvature photons emitted by gap-accelerated charged particles. The transverse size of the outer gap is also determined by local pair production limits. In principle, there are two topologically disconnected outer gaps in the magnetosphere of a pulsar. Both incoming and outgoing particle flows are allowed. However, the emission morphologies produced by incoming particle flow is severely restricted by local pair production in the gap and the absorption of magnetic pair production near the star. Double-peaked light curves with strong bridges are most common. From the three-dimensional structure of the outer gap and its local properties, we calculate the emission morphologies and phase-resolved spectra of gamma-ray pulsars. Applications to the Crab pulsar illustrate the model.

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