Efficiency enhancement of anomalous-Doppler electron cyclotron masers with tapered magnetic field

2014 ◽  
Vol 21 (2) ◽  
pp. 023117 ◽  
Author(s):  
Chao-Ran Xie ◽  
Ling-Bao Kong ◽  
Pu-Kun Liu ◽  
Chao-Hai Du ◽  
Zhi-Ling Hou ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Cyclotron ◽  
Efficiency Enhancement ◽  
Electron Cyclotron Masers ◽  
Tapered Magnetic Field

Dependence of the a-Si:H Defect Density of States on the Magnetic Field Profile of an Electron Cyclotron Resonance Microwave Plasma

1992 ◽  
Vol 258 ◽  
Author(s):  
F.S. Pool ◽  
J.M. Essick ◽  
Y.H. Shing ◽  
R.T. Mather
Keyword(s):  
Magnetic Field ◽  
Density Of States ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Defect Density ◽  
Electron Cyclotron ◽  
Field Profile ◽  
Magnetic Field Profile ◽  
The Magnetic Field

ABSTRACTThe magnetic field profile of an electron cyclotron resonance (ECR) microwave plasma was systematically altered to determine subsequent effects on a-Si:H film quality. Films of a-Si:H were deposited at pressures of 0.7 mTorr and 5 mTorr with a H2/SiH4 ratio of approximately three. The mobility gap density of states ND, deposition rate and light to dark conductivity were determined for the a-Si:H films. This data was correlated to the magnetic field profile of the plasma, which was characterized by Langmuir probe measurements of the ion current density. By variation of the magnetic field profile ND could be altered by more than an order of magnitude, from 1×1016 to 1×1017 at 0.7 mTorr and 1×1016 to 5×1017 at 5 mTorr. Two deposition regimes were found to occur for the conditions of this study. Highly divergent magnetic fields resulted in poor quality a-Si:H, while for magnetic field profiles defining a more highly confined plasma, the a-Si:H was of device quality and relatively independent of the magnetic field configuration.

The Kinematics of Cyclotron Emission for Quantized Electrons

1982 ◽  
Vol 4 (4) ◽  
pp. 359-362 ◽  
Author(s):  
D.B. Melrose ◽  
R.G. Hewitt ◽  
A.J. Parle
Keyword(s):  
Magnetic Field ◽  
Classical Theory ◽  
Major Axis ◽  
Lorentz Factor ◽  
Geometric Interpretation ◽  
Semi Major Axis ◽  
Electron Cyclotron Masers ◽  
Recent Developments ◽  
Cyclotron Emission ◽  
The Magnetic Field

Since the work of Wu and Lee (1979) there has been renewed interest in the classical theory of electron cyclotron masers (Lee and Wu 1980, Lee et al. 1980, Wu et al. 1981, 1982, Hewitt et al. 1981, 1982, Melrose et al. 1982, Omidi and Gurnett 1982, Melrose and Dulk 1982). A useful idea in these recent developments of the classical theory concerns a geometric interpretation of the classical gyroresonance conditionwhere Ωe, is the nonrelativistic gyrofrequency, s = 0, ± 1, ± 2,… is the harmonic number, is the Lorentz factor and ║ and ┴ denote components parallel and perpendicular to the magnetic field. In v┴ − v║ space (1) represents an ellipse with centre v║ = vc, v┴ = 0, eccentricity e0 and semi-major axis V parallel to the v┴ axis, with

scholarly journals Cyclotron lines in highly magnetized neutron stars

2019 ◽  
Vol 622 ◽  
pp. A61 ◽  
Author(s):  
R. Staubert ◽  
J. Trümper ◽  
E. Kendziorra ◽  
D. Klochkov ◽  
K. Postnov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Direct Measurement ◽  
Resonant Scattering ◽  
Electron Cyclotron ◽  
X Ray ◽  
Cyclotron Line ◽  
The Magnetic Field ◽  
Proton Cyclotron

Cyclotron lines, also called cyclotron resonant scattering features are spectral features, generally appearing in absorption, in the X-ray spectra of objects containing highly magnetized neutron stars, allowing the direct measurement of the magnetic field strength in these objects. Cyclotron features are thought to be due to resonant scattering of photons by electrons in the strong magnetic fields. The main content of this contribution focusses on electron cyclotron lines as found in accreting X-ray binary pulsars (XRBP) with magnetic fields on the order of several 1012Gauss. Also, possible proton cyclotron lines from single neutron stars with even stronger magnetic fields are briefly discussed. With regard to electron cyclotron lines, we present an updated list of XRBPs that show evidence of such absorption lines. The first such line was discovered in a 1976 balloon observation of the accreting binary pulsar Hercules X-1, it is considered to be the first direct measurement of the magnetic field of a neutron star. As of today (end 2018), we list 35 XRBPs showing evidence of one ore more electron cyclotron absorption line(s). A few have been measured only once and must be confirmed (several more objects are listed as candidates). In addition to the Tables of objects, we summarize the evidence of variability of the cyclotron line as a function of various parameters (especially pulse phase, luminosity and time), and add a discussion of the different observed phenomena and associated attempts of theoretical modeling. We also discuss our understanding of the underlying physics of accretion onto highly magnetized neutron stars. For proton cyclotron lines, we present tables with seven neutron stars and discuss their nature and the physics in these objects.

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