Ion acceleration and abundance enhancements by electron beam instabilities in impulsive solar flares

1993 ◽  
Vol 412 ◽  
pp. 386 ◽  
Author(s):  
James A. Miller ◽  
Adolfo F. Vinas
Keyword(s):  
Electron Beam ◽  
Solar Flares ◽  
Ion Acceleration ◽  
Beam Instabilities

scholarly journals Response of chromospheric lines to different periodic non-thermal electron beams

2015 ◽  
Vol 11 (S320) ◽  
pp. 239-242
Author(s):  
Jianxia Cheng ◽  
Mingde Ding
Keyword(s):  
Electron Beam ◽  
Solar Flares ◽  
Local Thermodynamic Equilibrium ◽  
Response Times ◽  
Electron Beams ◽  
Lower Atmosphere ◽  
Mass Motion ◽  
Thermal Electron ◽  
Hydrodynamic Simulations ◽  
Beam Injection

AbstractSolar flares produce radiations in very broad wavelengths. Spectra can supply us abundant information about the local plasma, such as temperature, density, mass motion and so on. Strong chromospheric lines, like the most studied Hα and Ca II 8542 Å lines are formed under conditions of departures from local thermodynamic equilibrium in the lower atmosphere subject to flare heating. Understanding how these lines are formed is very useful for us to correctly interpret the observations. In this paper, we try to figure out the response of chromospheric lines heated by different periodic non-thermal electron beams. Our results are based on radiative hydrodynamic simulations. We vary the periods of electron beam injection from 1.25 s to 20 s. We compare the response times to different heating parameters. Possible explanations are discussed.

scholarly journals Вольт-амперные характеристики начальной стадии дугового разряда в высоковольтном вакуумном диоде

2019 ◽  
Vol 45 (12) ◽  
pp. 33
Author(s):  
С.Г. Давыдов ◽  
А.Н. Долгов ◽  
А.В. Корнеев ◽  
Р.Х. Якубов
Keyword(s):  
Electron Beam ◽  
High Voltage ◽  
Arc Discharge ◽  
Ion Beam ◽  
Vacuum Diode ◽  
Vacuum Arc ◽  
Ion Acceleration ◽  
Plasma Cloud ◽  
Initial Stage ◽  
Instability Development

AbstractThe process of electron instability development and propagation of a cathode electron beam and anomalous ion beam, followed by outburst of current in the initial stage of arc discharge was observed in rarefied plasma cloud of high-voltage vacuum diode. These events are consistent with the model of anomalous ion acceleration in interelectrode plasma at the spark stage of vacuum arc discharge.

scholarly journals Electron beam instabilities in gyrotron beam tunnels

1998 ◽  
Vol 5 (6) ◽  
pp. 2421-2430 ◽  
Author(s):  
M. Pedrozzi ◽  
S. Alberti ◽  
J. P. Hogge ◽  
M. Q. Tran ◽  
T. M. Tran
Keyword(s):  
Electron Beam ◽  
Beam Instabilities

Ion acceleration in impulsive solar flares

1993 ◽  
Vol 415 ◽  
pp. 342 ◽  
Author(s):  
Jurgen Steinacker ◽  
Uwe Jaekel ◽  
Reinhard Schlickeiser
Keyword(s):  
Solar Flares ◽  
Ion Acceleration

scholarly journals Electron Beam as Origin of White-Light Solar Flares

1989 ◽  
Vol 104 (1) ◽  
pp. 19-30
Author(s):  
J. Aboudarham ◽  
J. C. Henoux
Keyword(s):  
Electron Beam ◽  
White Light ◽  
Solar Flares ◽  
Light Emission ◽  
Continuum Emission ◽  
Continuum Radiation ◽  
Photospheric Level ◽  
Hydrogen Ionization ◽  
Semi Empirical ◽  
Flare Model

AbstractWe study the effect of chromospheric bombardment by an electron beam during solar flares. Using a semi-empirical flare model, we investigate energy balance at temperature minimum level and in the upper photosphere. We show that non-thermal hydrogen ionization (i.e., due to the electrons of the beam) leads to an increase of chromospheric hydrogen continuum emission, H− population, and absorption of photo-spheric and chromospheric continuum radiation. So, the upper photosphere is radiatively heated by chromospheric continuum radiation produced by the beam. The effect of hydrogen ionization is an enhanced white-light emission both at chromospheric and photospheric level, due to Paschen and H− continua emission, respectively. We then obtain white-light contrasts compatible with observations, obviously showing the link between white-light flares and atmospheric bombardment by electron beams.

X-Rays at the SIAM Photon Source

2005 ◽  
Vol 107 ◽  
pp. 1-6 ◽  
Author(s):  
R. Apiwatwaja ◽  
S. Chunjarean ◽  
K. Hass ◽  
G. Hoyes ◽  
C. Kaewprasert ◽  
...  
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Photon Beam ◽  
Electron Beam Energy ◽  
X Rays ◽  
Vacuum Chambers ◽  
Wavelength Shifter ◽  
Insertion Device ◽  
Beam Instabilities ◽  
Photon Source

In this note, we describe the upgrade effort to convert the SIAM Photon source into an Xray synchrotron radiation facility with photon energies up to some 15 keV. This conversion of SIAM Photon into a third generation light source can be achieved through an increase of the electron beam energy and the addition of recently available superconducting wavelength shifter and multipole wiggler magnets. A gradual retrofit of vacuum chambers aiming at a reduction of electron beam instabilities as well as a modification of the focusing structure are expected to greatly increase the brightness of the photon beam. These upgrades will be implemented gradually over a few years to minimize the interruption of ongoing experimental activities. As an ultimate upgrade, a study has been started which shows the feasibility to implement a 2 GeV storage ring replacing the present ring in the same foot print. This new ring is configured to provide double the number of insertion device photon beam lines.

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