scholarly journals Heavy Ion Acceleration by Double-cyclotron Absorption: Some Analytic Approximations

1989 ◽  
Vol 42 (5) ◽  
pp. 493 ◽  
Author(s):  
Lewis T Ball
Keyword(s):  
Heavy Ions ◽  
Heavy Ion ◽  
Simple Approximation ◽  
Ion Acceleration ◽  
Analytic Approximations ◽  
Simple Analytic Expression ◽  
Cyclotron Absorption ◽  
Analytic Expression ◽  
The Waves ◽  
Special Case

possible to accelerate heavy ions in a magnetised plasma via a process where an ion simultaneously absorbs two gyromagnetic waves whose frequencies sum to the ion gyrofrequency. Analytic approximations to the probability of such double-cyclotron absorption are derived. A particularly simple approximation is presented for the special case where the waves all have frequencies very close to half the ion gyrofrequency. The rate of perpendicular acceleration of the ions due to double-cyclotron absorption is considered, and a simple analytic expression is derived for the case here the waves have the quasimonochromatic distribution mentioned above. One possible application of these proximatio.ns is to investigate the proposal that perpendicular acceleration of oxygen (0+) ions in the Earth's magnetosphere, due to double-cyclotron absorption, may give rise to O+-conic distributions

scholarly journals Laser-driven acceleration of heavy ions at ultra-relativistic laser intensity

2018 ◽  
Vol 36 (4) ◽  
pp. 507-512 ◽  
Author(s):  
J. Domański ◽  
J. Badziak ◽  
M. Marchwiany
Keyword(s):  
Laser Pulse ◽  
Heavy Ions ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Energy ◽  
Target Thickness ◽  
High Energy Density ◽  
Ion Acceleration ◽  
Acceleration Process ◽  
Particle In Cell

AbstractThis paper presents the results of numerical investigations into the acceleration of heavy ions by a multi-PW laser pulse of ultra-relativistic intensity, to be available with the Extreme Light Infrastructure lasers currently being built in Europe. In the numerical simulations, performed with the use of a multi-dimensional (2D3V) particle-in-cell code, the thorium target with a thickness of 50 or 200 nm was irradiated by a circularly polarized 20 fs laser pulse with an energy of ~150 J and an intensity of 1023 W/cm2. It was found that the detailed run of the ion acceleration process depends on the target thickness, though in both considered cases the radiation pressure acceleration (RPA) stage of ion acceleration is followed by a sheath acceleration stage, with a significant role in the post-RPA stage being played by the ballistic movement of ions. This hybrid acceleration mechanism leads to the production of an ultra-short (sub-picosecond) multi-GeV ion beam with a wide energy spectrum and an extremely high intensity (>1021 W/cm2) and ion fluence (>1017 cm−2). Heavy ion beams of such extreme parameters are hardly achievable in conventional RF-driven ion accelerators, so they could open the avenues to new areas of research in nuclear and high energy density physics, and possibly in other scientific domains.

scholarly journals Dynamics of laser-driven heavy-ion acceleration clarified by ion charge states

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
M. Nishiuchi ◽  
N. P. Dover ◽  
M. Hata ◽  
H. Sakaki ◽  
Ko. Kondo ◽  
...  
Keyword(s):  
Heavy Ion ◽  
Ion Acceleration ◽  
Charge States

scholarly journals Terrestrial aurora: astrophysical laboratory for anomalous abundances in stellar systems

2014 ◽  
Vol 32 (2) ◽  
pp. 77-82 ◽  
Author(s):  
I. Roth
Keyword(s):  
Solar Flares ◽  
Heavy Ions ◽  
Electromagnetic Waves ◽  
Stellar System ◽  
Decay Product ◽  
Early Solar System ◽  
Physical Processes ◽  
In Situ Observations ◽  
The Waves

Abstract. The unique magnetic structure of the terrestrial aurora as a conduit of information between the ionosphere and magnetosphere can be utilized as a laboratory for physical processes at similar magnetic configurations and applied to various evolutionary phases of the solar (stellar) system. The most spectacular heliospheric abundance enhancement involves the 3He isotope and selective heavy elements in impulsive solar flares. In situ observations of electromagnetic waves on active aurora are extrapolated to flaring corona in an analysis of solar acceleration processes of 3He, the only element that may resonate strongly with the waves, as well as heavy ions with specific charge-to-mass ratios, which may resonate weaker via their higher gyroharmonics. These results are applied to two observed anomalous astrophysical abundances: (1) enhanced abundance of 3He and possibly 13C in the late stellar evolutionary stages of planetary nebulae; and (2) enhanced abundance of the observed fossil element 26Mg in meteorites as a decay product of radioactive 26Al isotope due to interaction with the flare-energized 3He in the early solar system.

scholarly journals Heavy-ion acceleration and self-generated waves in coronal shocks

2011 ◽  
Vol 535 ◽  
pp. A34 ◽  
Author(s):  
M. Battarbee ◽  
T. Laitinen ◽  
R. Vainio
Keyword(s):  
Heavy Ion ◽  
Ion Acceleration

scholarly journals UV core dimming in coronal streamer belt and the projection effects

2019 ◽  
Vol 623 ◽  
pp. A95 ◽  
Author(s):  
L. Abbo ◽  
S. Giordano ◽  
L. Ofman
Keyword(s):  
Magnetic Structure ◽  
Heavy Ions ◽  
Solar Minimum ◽  
Heavy Ion ◽  
Spectral Lines ◽  
Slow Solar Wind ◽  
Physical Parameters ◽  
Streamer Belt ◽  
Coronal Streamer ◽  
Tilted Dipole

During solar minimum activity, the coronal structure is dominated by a tilted streamer belt, associated with the sources of the slow solar wind. It is known that some UV coronal spectral observations show a quite evident core dimming in heavy ions emission in quiescent streamers. In this paper, our purpose is to investigate this phenomenon by comparing observed and simulated UV coronal ion spectral line intensities. First, we computed the emissivities and the intensities of HI Lyα and OVI spectral lines starting from the physical parameters of a time-dependent 3D three-fluid MHD model of the coronal streamer belt. The model is applied to a tilted dipole (10°) solar minimum magnetic structure. Next, we compared the results obtained from the model in the extended corona (from 1.5 to 4 R⊙) to the UV spectroscopic data from the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO during the minimum of solar activity (1996). We investigate the line-of-sight integration and projection effects in the UV spectroscopic observations, disentangled by the 3D multifluid model. The results demonstrate that the core dimming in heavy ions is produced by the physical processes included in the model (i.e., combination of the effects of heavy ion gravitational settling, and energy exchange of the preferentially heated heavy ions through the interaction with electrons and protons) but it is visible only in some cases where the magnetic structure is simple, such as a (tilted) dipole.

scholarly journals Stopping power of heavy ions in strongly coupled plasmas

1995 ◽  
Vol 13 (2) ◽  
pp. 311-319 ◽  
Author(s):  
G. Zwicknagel ◽  
C. Toepffer ◽  
P.-G. Reinhard
Keyword(s):  
Heavy Ions ◽  
Weak Coupling ◽  
Heavy Ion ◽  
Stopping Power ◽  
Electron Cooling ◽  
Strongly Coupled ◽  
Electron Plasmas ◽  
Coupling Behavior ◽  
Ion Storage ◽  
Coupled Plasmas

We investigate the stopping power of heavy ions in strongly coupled electron plasmas by performing molecular dynamics (MD) computer simulations. A comparison with conventional weak coupling theories shows that these fail in describing the stopping power at low ion velocities and strong coupling. Then nonlinear screening effects become important and this causes a change in the dependence of the stopping power on the ion charge Zp at low ion velocities. From the MD simulation, we find the stopping power to behave like ZP1.43 instead of the weak coupling behavior Zp2 ln(const/Zp). Similar results were recently obtained by experiments in connection with electron cooling at heavy ion storage rings.

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