Synthesis of poly (vinylpyrrolidone)/Fe 3 O 4 @SiO 2 nanoporous catalyst by γ ‐rays and evaluation their sono‐photo‐Fenton degradation of toluidine blue under magnetic field

2021 ◽  
Author(s):  
Mohamed Mohamady Ghobashy ◽  
Ahmed M. Elbarbary ◽  
Dalia E. Hegazy
Keyword(s):  
Magnetic Field ◽  
Toluidine Blue ◽  
Γ Rays

scholarly journals The internal conversion of gamma-rays.—Part II

1928 ◽  
Vol 121 (787) ◽  
pp. 447-456
Keyword(s):  
Magnetic Field ◽  
Quantum Mechanics ◽  
Wave Equation ◽  
Gamma Rays ◽  
Internal Conversion ◽  
Scalar Potential ◽  
X Ray ◽  
Electro Magnetic Field ◽  
Γ Rays ◽  
Electro Magnetic

In a previous paper the absorption of γ-rays in the K-X-ray levels of the atom in which they are emitted was calculated according to the Quantum Mechanics, supposing the γ-rays to be emitted from a doublet of moment f ( t ) at the centre of the atom. The non-relativity wave equation derived from the relativity wave equation for an electron of charge — ε moving in an electro-magnetic field of vector potential K and scalar potential V is h 2 ∇ 2 ϕ + 2μ ( ih ∂/∂ t + εV + ih ε/μ c (K. grad)) ϕ = 0. (1) Suppose, however, that K involves the space co-ordinates. Then, (K. grad) ϕ ≠ (grad . K) ϕ , and the expression (K . grad) ϕ is not Hermitic. Equation (1) cannot therefore be the correct non-relativity wave equation for a single electron in an electron agnetic field, and we must substitute h 2 ∇ 2 ϕ + 2μ ( ih ∂/∂ t + εV) ϕ + ih ε/ c ((K. grad) ϕ + (grad. K) ϕ ) = 0. (2)

scholarly journals The Milky Way Disk Warp

1989 ◽  
Vol 120 ◽  
pp. 537-537 ◽  
Author(s):  
E. Florido ◽  
E. Battaner ◽  
E. Alfaro ◽  
M.L. Sanchez-Saavedra
Keyword(s):  
Magnetic Field ◽  
Milky Way ◽  
Magellanic Clouds ◽  
Open Clusters ◽  
Late Type ◽  
Tidal Interaction ◽  
Different Ages ◽  
Γ Rays ◽  
Intergalactic Magnetic Field

A warped disk in our own galaxy is evident by means of HI, HII, γ-rays and dust observations, but unexistent when star distributions are considered, specially those of late type stars. This fact is in disagreement with the theories which assume a gravitational origin of warps, for instance a tidal interaction with the Magellanic Clouds. We tried to find the z-distribution of open clusters of different ages, for which a warp distribution was neither found nor rejected. Assuming an intergalactic magnetic field origin of the warp, we obtain a direction of the field in the Milky Way neighborhood given by (b,1) = (45°, 74°).

THE LOW-TEMPERATURE ORDERED STATE OF CERIUM MAGNESIUM NITRATE AND ITS INFLUENCE ON NUCLEAR ORIENTATION

1964 ◽  
Vol 42 (8) ◽  
pp. 1469-1480 ◽  
Author(s):  
J. M. Daniels ◽  
J. Felsteiner
Keyword(s):  
Magnetic Field ◽  
Nuclear Orientation ◽  
Dipole Interaction ◽  
Magnesium Nitrate ◽  
Divalent Ions ◽  
Antiferromagnetic Ordering ◽  
Γ Rays ◽  
Γ Ray ◽  
The Magnetic Field ◽  
Ordered State

The method of Luttinger and Tisza for minimizing the dipole–dipole interaction energy is applied to cerium magnesium nitrate, and an antiferromagnetic ordering of the cerium spins at 0 °K is found. Using this configuration, the magnetic field at the divalent ions is calculated. Next, the anisotropy of γ rays from Co60 aligned in this salt is calculated for temperatures below 0.003 °K. Qualitative agreement is found between these calculations and measurements of γ-ray anisotropy reported in the literature.

The magnetic field at chromium nuclei in iron and nickel

1976 ◽  
Vol 54 (8) ◽  
pp. 827-829 ◽  
Author(s):  
S. A. Wender ◽  
L. Keszthelyi ◽  
J. A. Cameron
Keyword(s):  
Magnetic Field ◽  
Angular Distribution ◽  
Magnetic Fields ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Γ Rays ◽  
The Magnetic Field

The integral rotation of the angular distribution of γ rays from the 749 keV level of 51 Cr excited by the (α,n) reaction in Ti5Fe95 and Ti5Ni95 targets has been used to measure the hyperfine magnetic fields at Cr nuclei in these alloys at liquid nitrogen temperature. The values are[Formula: see text]

scholarly journals The absolute energies of the groups in magnetic β-ray spectra

1924 ◽  
Vol 105 (729) ◽  
pp. 60-69 ◽  
Keyword(s):  
Magnetic Field ◽  
Wave Length ◽  
X Rays ◽  
Homogeneous Groups ◽  
Absorption Energy ◽  
Length Measurements ◽  
Γ Rays ◽  
Γ Ray ◽  
The Absolute ◽  
The Difference

Most β-ray bodies emit several homogeneous groups of β-rays, and the energies of the electrons forming these groups may be found from the deflection they suffer in a magnetic field. Various experiments have shown that these groups are due to the conversion, according to the quantum relation, of γ-rays in the different electronic levels of the atom. In fact, the energy of any group is of the form E 1 = hv — (absorption energy of level). Two β-ray groups due to the conversion of a γ-ray of definite frequency in the K and L levels of the atom will differ in energy by the difference in energy between the K and L absorption energies. Both in testing this equation, and in using it to deduce frequencies of the γ-rays, it is necessary to compare energies of β-rays determined in terms of a magnetic field, with absorption energies deduced from wave-length measurements of X-rays. It is thus important to obtain values of the absolute β-ray energies as accurate as possible. The most accurate previous values were those of Rutherford and Robinson.

scholarly journals Evolution and observational signatures of the cosmic ray electron spectrum in SN 1006

2020 ◽  
Vol 499 (2) ◽  
pp. 2785-2802
Author(s):  
Georg Winner ◽  
Christoph Pfrommer ◽  
Philipp Girichidis ◽  
Maria Werhahn ◽  
Matteo Pais
Keyword(s):  
Magnetic Field ◽  
Electron Spectrum ◽  
Supernova Remnants ◽  
Cosmic Ray ◽  
Electron Acceleration ◽  
Galactic Cosmic Rays ◽  
Shock Acceleration ◽  
X Rays ◽  
Γ Rays ◽  
Γ Ray

ABSTRACT Supernova remnants (SNRs) are believed to be the source of Galactic cosmic rays (CRs). SNR shocks accelerate CR protons and electrons which reveal key insights into the non-thermal physics by means of their synchrotron and γ-ray emission. The remnant SN 1006 is an ideal particle acceleration laboratory because it is observed across all electromagnetic wavelengths from radio to γ-rays. We perform 3D magnetohydrodynamics (MHD) simulations where we include CR protons and follow the CR electron spectrum. By matching the observed morphology and non-thermal spectrum of SN 1006 in radio, X-rays, and γ-rays, we gain new insight into CR electron acceleration and magnetic field amplification. (1) We show that a mixed leptonic–hadronic model is responsible for the γ-ray radiation: while leptonic inverse-Compton emission and hadronic pion-decay emission contribute equally at GeV energies observed by Fermi, TeV energies observed by imaging air Cherenkov telescopes are hadronically dominated. (2) We show that quasi-parallel acceleration (i.e. when the shock propagates at a narrow angle to the upstream magnetic field) is preferred for CR electrons and that the electron acceleration efficiency of radio-emitting GeV electrons at quasi-perpendicular shocks is suppressed at least by a factor ten. This precludes extrapolation of current 1D plasma particle-in-cell simulations of shock acceleration to realistic SNR conditions. (3) To match the radial emission profiles and the γ-ray spectrum, we require a volume-filling, turbulently amplified magnetic field and that the Bell-amplified magnetic field is damped in the immediate post-shock region. Our work connects microscale plasma physics simulations to the scale of SNRs.

A COMPTON-ELECTRON γ-SPECTROMETER WITH TWO-DIRECTIONAL FOCUSING

1960 ◽  
Vol 38 (6) ◽  
pp. 720-750 ◽  
Author(s):  
G. E. Lee-Whiting
Keyword(s):  
Magnetic Field ◽  
Line Width ◽  
Cylindrical Symmetry ◽  
Maximum Efficiency ◽  
Electron Spectrometer ◽  
Γ Rays ◽  
Γ Ray ◽  
Compton Electron ◽  
Γ Spectrometer ◽  
The Magnetic Field

Improvements in the design of one type of Compton-electron spectrometer for γ-rays are proposed. The design requires a magnetic field of cylindrical symmetry and of slow radial variation, a simply curved radiator, and a system of apertures. Electrons are accepted only if they are ejected from the radiator with small components of momentum in two orthogonal directions perpendicular to the incident γ-ray. Since the magnetic field can also be used to measure the momentum of the selected electrons, the instrument can function as a γ-ray spectrometer. Higher-order aberrations are discussed, and a method of calculating the values of the various spectrometer parameters corresponding to maximum efficiency is given. Calculations of the intrinsic line-width, caused by the motion of the electron within the atom before collision with the photon, are carried out.

scholarly journals Particle acceleration and magnetic field amplification in massive young stellar object jets

2021 ◽  
Author(s):  
Anabella T Araudo ◽  
Marco Padovani ◽  
Alexandre Marcowith
Keyword(s):  
Magnetic Field ◽  
Cosmic Ray ◽  
Maximum Energy ◽  
Shock Acceleration ◽  
Relativistic Electrons ◽  
Diffusive Shock Acceleration ◽  
Field Amplification ◽  
Protostellar Jets ◽  
Γ Rays ◽  
The Magnetic Field

Abstract Synchrotron radio emission from non-relativistic jets powered by massive protostars has been reported, indicating the presence of relativistic electrons and magnetic fields of strength ∼0.3 −5 mG. We study diffusive shock acceleration and magnetic field amplification in protostellar jets with speeds between 300 and 1500 km s−1. We show that the magnetic field in the synchrotron emitter can be amplified by the non-resonant hybrid (Bell) instability excited by the cosmic-ray streaming. By combining the synchrotron data with basic theory of Bell instability we estimate the magnetic field in the synchrotron emitter and the maximum energy of protons. Protons can achieve maximum energies in the range 0.04 − 0.65 TeV and emit γ rays in their interaction with matter fields. We predict detectable levels of γ rays in IRAS 16547-5247 and IRAS 16848-4603. The γ ray flux can be significantly enhanced by the gas mixing due to Rayleigh-Taylor instability. The detection of this radiation by the Fermi satellite in the GeV domain and the forthcoming Cherenkov Telescope Array at higher energies may open a new window to study the formation of massive stars, as well as diffusive acceleration and magnetic field amplification in shocks with velocities of about 1000 km s−1.

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