scholarly journals Inferred charge states of high energy solar particles from the solar isotope spectrometer on ACE

1999 ◽  
Vol 26 (2) ◽  
pp. 149-152 ◽  
Author(s):  
C. M. S. Cohen ◽  
A. C. Cummings ◽  
R. A. Leske ◽  
R. A. Mewaldt ◽  
E. C. Stone ◽  
...  
Keyword(s):  
High Energy ◽  
Solar Particles ◽  
Charge States

scholarly journals Common overabundance of $\mathsf{^3}$He in high-energy solar particles

2003 ◽  
Vol 408 (1) ◽  
pp. L1-L4 ◽  
Author(s):  
J. Torsti ◽  
J. Laivola ◽  
L. Kocharov
Keyword(s):  
High Energy ◽  
Solar Particles

Neutron monitor observations of high-energy solar particles during the new cycle

Solar Physics ◽  
1967 ◽  
Vol 2 (4) ◽  
Author(s):  
G.A. Baird ◽  
G.G. Bell ◽  
S.P. Duggal ◽  
M.A. Pomerantz
Keyword(s):  
Neutron Monitor ◽  
High Energy ◽  
Solar Particles

scholarly journals Selective Effects in Cosmic Rays Induced by Coulombian Interactions with Finite Temperature Plasmas

1981 ◽  
Vol 94 ◽  
pp. 365-366
Author(s):  
J. Pérez-Peraza ◽  
S. S. Trivedi
Keyword(s):  
Cosmic Rays ◽  
Energy Levels ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Losses ◽  
Deceleration Rate ◽  
Acceleration Rate ◽  
Charge States ◽  
High Energy Particles

The role of Coulombian energy losses in cosmic ray physics is generally over simplified by using the Bethe-Block formulation which does not depend explicitly on the temperature of the medium. The role of low energy particles is usually neglected, as a result of the over estimation of losses when the temperature of the medium is ignored. A deep analysis of Coulombian losses may raise the importance of these particles in the dynamics of the Galaxy. In fact, the deceleration of these particles is determined by charge interchange processes with the target ions and electrons, which energy dependence is roughly the inverse of ionisation losses. Even high energy particles may be subject to this kind of deceleration if the temperature is very high. The consideration of Coulombian losses through all energy ranges with explicit dependence on the temperature has been discussed by Perez and Lara (1979): a fully ionized medium of hydrogen has been assumed to prevail in most of cosmic ray sources. One kind of the implications is the determination of particle composition. It is claimed that a given kind of ion is preferentially accelerated or depleted depending on whether the acceleration is higher or lower than the deceleration rate at the beginning of the acceleration of thermal material. Species which undergo depletion are accelerated only if their energy is higher than that for which both rates are equated (Ec,E′c and E′c′) in such a way that only those of the hot tails of their thermal distributions are effectively accelerated. These will appear depleted relative to other species which are free accelerated because their deceleration rates at low energies are lower than the acceleration rate. It can be noted in the next figures, that if both rates would not intersect at the beginning of the acceleration, they would not join at higher energies because the acceleration rate grows faster with energy than the deceleration rate. Three arbitrary acceleration rates are used for illustration: Fermi-2nd order (αβW), Betatron or adiabatic heating (αβ2W) and shock wave acceleration (αW), where α, β and W are the efficiency, the particles velocity and the total energy per nucleon respectively. In Fig. 1 it can be seen that this selective acceleration relative to Coulombian losses is defined at different energy levels depending on the kind of acceleration involved. Since the main effect of the temperature on the losses at the beginning of the acceleration is through the local charge states of the ions, the sequence of energy losses among different species is highly assorted. This is translated in a great amount of possibilities of particle enhancements and depletions according to the temperature of the source and the kind of acceleration operating therein. If particles under go acceleration in a fully stripped state, the sequence of losses at all energy levels is such that the heavy elements are depleted in relation with the lighter ones; same is the situation, what-ever the initial charge state, for high energy particles in the range of ionisation. It may be concluded, on basis to the observational enhancement of heavy cosmic rays, that hot regions are not likely sources, and that acceleration initiates from thermal energies. On Fig. 2 it is illustrated the enhancement of Fe over 0 in solar flare conditions, on basis to the charge states as given by Jordan (1969). If α < 2.71 s−1 both elements would be depleted, whereas if α>3.45 s−1 both would be preferentially accelerated.

High-energy solar particles and human exploration

Space Weather ◽  
2005 ◽  
Vol 3 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Louis J. Lanzerotti
Keyword(s):  
High Energy ◽  
Solar Particles ◽  
Human Exploration

scholarly journals PAMELA’S MEASUREMENTS OF MAGNETOSPHERIC EFFECTS ON HIGH-ENERGY SOLAR PARTICLES

2015 ◽  
Vol 801 (1) ◽  
pp. L3 ◽  
Author(s):  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
M. Boezio ◽  
...  
Keyword(s):  
High Energy ◽  
Solar Particles

scholarly journals Mean High-Energy Ionic Charge States during the September 2017 Solar Energetic Particle Events Observed by ACE and STEREO

2019 ◽  
Author(s):  
Allan Labrador ◽  
Luke Sollitt ◽  
Christina Cohen ◽  
Eric Christian ◽  
Alan C. Cummings ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
High Energy ◽  
Ionic Charge ◽  
Solar Energetic Particle Events ◽  
Charge States

scholarly journals Visible-Light Activation of Photocatalytic for Reduction of Nitrogen to Ammonia by Introducing Impurity Defect Levels into Nanocrystalline Diamond

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4559
Author(s):  
Rui Su ◽  
Zhangcheng Liu ◽  
Haris Naeem Abbasi ◽  
Jinjia Wei ◽  
Hongxing Wang
Keyword(s):  
Visible Light ◽  
Wavelength Region ◽  
Average Diameter ◽  
High Energy ◽  
Nitrogen Vacancy ◽  
Energy Conditions ◽  
Nitrogen Doped ◽  
Single Crystal Diamond ◽  
Defect Levels ◽  
Charge States

Nitrogen impurity has been introduced in diamond film to produce a nitrogen vacancy center (NV center) toward the solvated electron-initiated reduction of N2 to NH3 in liquids, giving rise to extend the wavelength region beyond the diamond’s band. Scanning electron microscopy and X-ray diffraction demonstrate the formation of the nanocrystalline nitrogen-doped diamond with an average diameter of ten nanometers. Raman spectroscopy and PhotoLuminescence (PL) spectrum show characteristics of the NV0 and NV− charge states. Measurements of photocatalytic activity using supraband (λ < 225 nm) gap and sub-band gap (λ > 225 nm) excitation show the nitrogen-doped diamond significantly enhanced the ability to reduce N2 to NH3 compared to the polycrystalline diamond and single crystal diamond (SCD). Our results suggest an important process of internal photoemission, in which electrons are excited from negative charge states into conduction band edges, presenting remarkable photoinitiated electrons under ultraviolet and visible light. Other factors, including transitions between defect levels and processes of reaction, are also discussed. This approach can be especially advantageous to such as N2 and CO2 that bind only weakly to most surfaces and high energy conditions.

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