A5064301744- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Radiation Therapy and Dosimetry
- Solar Radiation and Photovoltaics
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Atomic and Subatomic Physics Research
- Earthquake Detection and Analysis
- Neutrino Physics Research
- Magnetic confinement fusion research
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Fluid Dynamics and Turbulent Flows
- Atmospheric Ozone and Climate
- Characterization and Applications of Magnetic Nanoparticles
- Chalcogenide Semiconductor Thin Films
Mahidol University
2016-2025
Shinshu University
2021-2023
Rajamangala University of Technology
2021-2023
University of Delaware
2017-2023
Chonnam National University
2021-2023
National Astronomical Research Institute of Thailand
2016-2023
Chiang Mai University
2021-2023
South College
2023
Chinese Academy of Sciences
2023
University of Wisconsin–River Falls
2021-2023
view Abstract Citations (189) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Effect of Adiabatic Deceleration on the Focused Transport Solar Cosmic Rays Ruffolo, D. In framework focused transport theory, adiabatic deceleration arises from focusing in solar wind frame and differential convection. An explicit formula is given for individual particles as a function pitch angle. other first-order effects wind, including convection, are...
Since the science white paper of Large High Altitude Air Shower Observatory (LHAASO) published on arXiv in 2019 [e-Print: 1905.02773 (astro-ph.HE)], LHAASO has completed transition from a project to an operational gamma-ray astronomical observatory is new generation multi-component facility located Daocheng, Sichuan province China, at altitude 4410 meters. It aims measuring with unprecedented sensitivity spectrum, composition, and anisotropy cosmic rays energy range between 10$^{12}$...
Abstract Modelling the transport of cosmic rays (CRs) in heliosphere represents a global challenge field heliophysics, that such study, if it were to be performed from first principles, requires careful modelling both large scale heliospheric plasma quantities (such as structure heliosphere, or magnetic field) and small various turbulence-related quantities). Here, recent advances our understanding galactic are reviewed, with an emphasis on new developments pertaining their coefficients,...
Data from nine high-latitude neutron monitors are used to deduce the intensity-time and anisotropy-time profiles pitch-angle distributions of energetic protons near Earth during major solar event on 2000 July 14 (also known as Bastille Day event). In addition, particle magnetic field measurements Wind, Advanced Composition Explorer, Solar Heliospheric Observatory (SOHO) in analysis. The observations fitted with good agreement between two independent numerical models interplanetary transport....
Two-dimensional (2D) models of magnetic field fluctuations and turbulence are widely used in space, astrophysical, laboratory contexts. Here we discuss some general properties such their observable power spectra. While the line random walk a one-dimensional (slab) model is determined by correlation scale, for 2D models, it characterized different length ultrascale. We scales ultrascales present technique determining an ultrascale from observations at single spacecraft, demonstrating its...
Direct evidence of an inertial-range turbulent energy cascade has been provided by spacecraft observations in heliospheric plasmas. In the solar wind, average value derived heating rate near 1 au is $\sim 10^{3}\, \mathrm{J\,kg^{-1}\,s^{-1}}$, amount sufficient to account for observed departures from adiabatic expansion. Parker Solar Probe (PSP), even during its first encounter, offers opportunity compute, a similar fashion, fluid-scale decay rate, much closer corona than any prior in-situ...
The solar wind shows periods of highly Alfvénic activity, where velocity fluctuations and magnetic are aligned or antialigned with each other. It is generally agreed that plasma field observed by the Parker Solar Probe (PSP) during first encounter mostly Alfvénic. However, quantitative measures Alfvénicity needed to understand how characterization these compares standard from prior missions in inner outer heliosphere, fast slow wind, at high low latitudes. To investigate this issue, we...
ABSTRACT The transition from subAlfvénic to superAlfvénic flow in the solar atmosphere is examined by means of Parker Solar Probe (PSP) measurements during encounters 8 14. Around 220 periods with a duration ≥10 min are identified. distribution their durations, heliocentric distances, and Alfvén Mach number analysed compared global magnetohydrodynamic model corona wind which includes turbulence effects. results consistent patchy fragmented morphology, suggestive turbulent zone within occurs...
The largest relativistic (~1 GeV) solar proton event of the current activity cycle occurred on Easter 2001 (April 15). This was first such to be observed by Spaceship Earth, an 11-station network neutron monitors optimized for measuring angular distribution cosmic rays. We derive particle density and anisotropy as functions time model these with numerical solutions Boltzmann equation. conclude that transport in interplanetary medium diffusive this event, a radial mean free path 0.17 AU. high...
Nonlinear guiding center (NLGC) theory has been used to explain the asymptotic perpendicular diffusion coefficient κ⊥ of energetic charged particles in a turbulent magnetic field, which can be applied better understand cosmic ray transport. Here we re-derive NLGC, replacing assumption diffusive decorrelation with random ballistic (RBD), yields an explicit formula for κ⊥. We note that scattering processes cause reversal motion along field line, i.e., "backtracking," leading partial...
Various mechanisms have been proposed to explain observed suprathermal particle populations in the solar wind, including direct acceleration at flares, stochastic acceleration, shock and by random compression or reconnection sites. Using magnetic field data from Advanced Composition Explorer (ACE), we identify coherent structures interplanetary shocks, analyze temporal association of energetic fluxes with these structures. Coherent having a range intensities are identified using Partial...
We use a three-dimensional magnetohydrodynamic simulation of the solar wind to calculate cosmic ray diffusion coefficients throughout inner heliosphere ($2~R_\odot - 3$ AU). The resolves large-scale flow, which is coupled small-scale fluctuations through turbulence model. Simulation results specify background fields and parameters, are used compute study their behavior in heliosphere. parallel mean free path evaluated using quasi-linear theory, while perpendicular determined by non-linear...
The transport of energetic particles perpendicular to the mean magnetic field in space plasmas has long been viewed as a diffusive process. However, there is an apparent conflict between recent observations solar (SEPs): (1) Impulsive flares can exhibit "dropouts" which SEP intensity near Earth repeatedly disappears and reappears, indicating filamentary distribution SEPs little diffusion across these boundaries. (2) Observations by IMP-8 Ulysses spacecraft, while they were on opposite sides...
The solar cosmic ray event associated with the X17.2 class flare of 28 October 2003 was unusual in several respects: (1) Several high‐latitude neutron monitors observed a large, highly anisotropic spike at onset. (2) earliest onset detected by stations viewing towards anti‐Sunward hemisphere. (3) displayed an extremely slow, protracted decay. (4) near‐equatorial monitor Tsumeb, Africa recorded small increase consistent ≈7 minutes prior to high latitudes. We analyze these signals and infer...
The problem of the separation random magnetic field lines in collisionless astrophysical plasmas is closely related to line walk and highly relevant transport charged particles turbulent plasmas. In order generalize treatments based on quasi-linear theory, here we examine nearby by employing a nonperturbative technique Corrsin independence hypothesis. Specifically, consider case two-component turbulence which fluctuations are mixture one-dimensional (slab) two-dimensional ingredients, as...
A ground level enhancement (GLE) is a solar event that accelerates ions (mostly protons) to GeV range energies in such great numbers ground-based detectors, as neutron monitors, observe their showers Earth's atmosphere above the Galactic cosmic ray background. GLEs are of practical interest because an enhanced relativistic ion flux poses hazard astronauts, air crews, and aircraft electronics, provides earliest direct indication impending space radiation storm. The giant GLE 2005 January 20...
Abstract Neutron monitors are the premier instruments for precisely tracking time variations in Galactic cosmic ray flux at GeV‐range energies above geomagnetic cutoff location of measurement. Recently, a new capability has been developed to record and analyze neutron delay distribution (related multiplicity) infer spectrum as well. In particular, from histograms we can determine leader fraction L , defined neutrons that did not follow previous detection same tube atmospheric secondary...
We present a theory and numerical evidence for the existence of previously unexplored in-plane electric field in collisionless asymmetric magnetic reconnection. This field, dubbed ``Larmor field,'' is associated with finite Larmor radius effects distinct from known Hall field. Potentially, it could be an important indicator upcoming Magnetospheric Multiscale mission to locate reconnection sites as we expect appear on magnetospheric side, pointing earthward, at dayside magnetopause site.
ABSTRACT Neutron monitors (NMs) are ground-based detectors of cosmic-ray showers that widely used for high-precision monitoring changes in the Galactic (GCR) flux due to solar storms and wind variations. In present work, we show a single neutron monitor station can also short-term GCR spectrum, avoiding systematic uncertainties comparing data from different stations, by means NM time-delay histograms. Using 2007–2014 Princess Sirindhorn Monitor , at Doi Inthanon, Thailand, with world’s...
The Galactic cosmic ray spectrum exhibits subtle variations over the 22 yr solar magnetic cycle in addition to more dramatic 11 sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of flux at top atmosphere above detector. At any given location field Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as cutoff rigidity, which can be accurately calculated using detailed models geomagnetic field. By carrying...
Abstract Neutron monitors (NMs) are ground‐based detectors that measure variations of the Galactic cosmic ray flux at GV range rigidities. Differences in configuration, electronics, surroundings, and location induce systematic effects on calculation yield functions NMs worldwide. Different estimates NM can differ by a factor 2 or more. In this work, we present new Monte Carlo simulations to calculate perform an absolute (not relative) comparison with count rate Princess Sirindhorn Monitor...
We study the enhancement of accuracy high-order lattice Boltzmann method (LBM) in both order equilibrium-distribution expansion and degree precision Gauss–Hermite quadrature. Furthermore, we investigate regularization. utilize two-dimensional Kolmogorov flow Taylor–Green vortex over a wide range Knudsen numbers (Kn) as benchmark. The quadrature is assessed up to 33, 14, regularization 10. compare results direct simulation Monte Carlo (DSMC) method. indicate an improvement from increasing but...
Abstract Neutron monitors are a standard tool for high-precision monitoring of changes in the Galactic cosmic ray (GCR) flux that occur as result variations heliospheric conditions and solar storms. In Thailand, we have developed mobile neutron monitor named “Changvan” based on 3NM64 design, except middle counter lacks lead producer rings, so call it semileaded monitor. From 2021 April to 2023 April, Changvan operated at Science Technology Park, Mae Hia, Chiang Mai, an altitude about 340 m...
Ground-based observations of cosmic rays by neutron monitors and muon detectors have found precursor anisotropies before the arrival an interplanetary shock subsequent Forbush decrease, possibly providing advance warning space weather effects on impact at Earth's magnetosphere. Surprisingly, observe precursors with a greater lead time than monitors. Here, we explain both loss cone reflection in common mathematical framework perform time-dependent numerical simulations cosmic-ray transport...