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.

V.—Dissymmetrical Separations in the Zeeman Effect in Tungsten and Molybdenum

1909 ◽  
Vol 29 ◽  
pp. 75-83 ◽  
Author(s):  
Robert Jack
Keyword(s):  
Magnetic Field ◽  
Wave Length ◽  
Zeeman Effect ◽  
Normal Type ◽  
Single Spectrum ◽  
Large Numbers ◽  
Middle Component ◽  
The Absolute ◽  
The Difference ◽  
The Magnetic Field

It has been mentioned by Professor Voigt of Göttingen in his newly published book and by Professor Zeeman of Amsterdam in the Physikalische Zeitschrift, that I have found examples of strongly marked dissymmetry in studying the Zeeman Effect in tungsten and molybdenum. Professor Zeeman has also discovered and published such cases of dissymmetry in other elements. Not only have many examples of normal dissymmetry been found, but almost as many cases of abnormal dissymmetry. To explain those terms, normal and abnormal, let us consider that the single spectrum line is broken up, when the light is in the magnetic field, into the three components, 1, 2, 3, where the numbers begin from the component which has the shortest wave-length. In the normal dissymmetrical triplet the middle component is nearer the component on the red side than that on the violet one, i.e. for the normal type the interval 1–2 is greater than the interval 2–3, but in the abnormal dissymmetrical triplet 2 is nearer to 1 than to 3. These observations of Professor Zeeman and myself, which were made at the same time in the Universities of Amsterdam and Göttingen, having been communicated to Professor Voigt, he wrote and published in the above-mentioned book an extension to his and Professor H. A. Lorentz's theories of the Zeeman Effect. In his original theory Professor Voigt had shown that, considering the electrons as uncoupled, cases of normal dissymmetry might arise among the Zeeman triplets, this dissymmetry being accompanied by a greater intensity of the red component than the violet one. He pointed out also that the ‘absolute’ dissymmetry or the difference between the absolute displacements of the red and violet components should be independent of the magnetic field strength used to produce the Zeeman Effect. To explain the large numbers of complicated types of Zeeman Effect which have been found —in the study of the Zeeman Effect in tungsten I discovered lines with no fewer than 17 to 19 components, the largest numbers hitherto found—Professors Voigt and Lorentz made use in their theories of couplings between electrons of the same vibration frequencies.

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.

scholarly journals A re-investigation of the β-ray spectrum of radium B and radium C

1924 ◽  
Vol 105 (730) ◽  
pp. 165-184 ◽  
Keyword(s):  
Strong Evidence ◽  
Detailed Examination ◽  
Point Of View ◽  
General Point ◽  
Quantum Equation ◽  
Absorption Energy ◽  
Γ Rays ◽  
Γ Ray ◽  
Improved Technique

An interpretation of the β-ray spectrum of radium B has already been given by one of us. It was shown that there is strong evidence for supposing that many of the β-ray groups are due to the ejection of electrons from the K, L... levels of the radium B atom by the action of the various homogeneous γ-rays emitted by the disintegrating atoms, the energy of the ejected electron being given by the quantum equation E = hv — w 0 , where v is the frequency of the γ-ray and w 0 the absorption energy of the level. L. Meitner has arrived at similar results from a study of the thorium bodies, and the general point of view would appear to be therefore correct. All the work on the radium B spectrum was based on the original measurements of Rutherford and Robinson carried out nine years ago, and it was to be anticipated that a more detailed examination with the improved technique would bring out many new points.

scholarly journals β-ray spectra and their meaning

1922 ◽  
Vol 101 (708) ◽  
pp. 1-17 ◽  
Keyword(s):  
Wave Length ◽  
X Rays ◽  
Ernest Rutherford ◽  
Active Atom ◽  
Magnetic Spectrum ◽  
Γ Rays

In a previous paper, I described some measurements of the magnetic spectrum of the β-ravs ejected from various metals by the γ-rays of radium B. These experiments showed that the conversion of monochromatic γ-rays into β-rays was described by the same quantum relation that holds for X-rays and light, and using this knowledge it was found possible to give a complete explanation of the natural β-ray spectrum of radium B. Sir Ernest Rutherford had already shown that the lines in the β-ray spectrum were due in some way to the conversion of monochromatic γ-rays in the same radio active atom that emitted them, and these experiments on the excited spectra now proved that the strong lines were due to the conversion of the γ-rays in the K ring, and the weaker lines to conversion in the L 3 ring. This explanation of the line β-ray spectrum is, by itself, of considerable interest, but of far greater importance is the fact that these experiments give a method of finding the wave-lengths of γ-rays. The shortest wave-length that has been measured by the crystal method is 0·07 Å. U., and at present it seems almost impossible to extend this range much further by this method. Since many radio-active bodies emit γ-rays of shorter wave-length than this any method by which these wave-lengths may be found is important

scholarly journals The incidence of light upon a transparent sphere of dimensions comparable with the wave-length

1910 ◽  
Vol 84 (567) ◽  
pp. 25-46 ◽  
Keyword(s):  
Magnetic Field ◽  
Maxwell's Equations ◽  
Wave Length ◽  
Plane Waves ◽  
Scattered Wave ◽  
Great Distance ◽  
Primary Wave ◽  
Electro Magnetic Field ◽  
The Difference ◽  
Electro Magnetic

In a paper, now nearly thirty years old, I applied Maxwell’s equations of the electro-magnetic field to investigate the disturbance produced by an obstacle upon plane waves of light which travel through a medium otherwise uniform, giving particular attention to the case where the properties of the obstacle differ but little from those of its surroundings. The difference may consist in a variation of K — the specific inductive capacity, or of μ — the magnetic capacity, or of both; but it was shown that the last supposition leads to results inconsistent with observation, and that the evidence favours the view that μ is to be treated as invariable. Denoting electric displacements by f, g, h , the primary wave was taken to be h 0 = e int e ikx , (23) so that the direction of propagation is along x (negatively), and that of vibration parallel to z . ∆ μ being omitted, the electric displacements ( f 1 , g 1 , h 1 ) in the scattered wave, so far as they depend upon the first power of ∆K, have at a great distance the values f 1 , g 1 , h 1 = k 2 KP/4 πr ( αγ / r 2 , βγ / r 2 , – α 2 + β 2 / r 2 ), (35, 37, 38) in which P = ∭ h 0 ∆K -1 e -ikr dx dy dz . (36)

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.

scholarly journals The absolute intensities and internal conversion coefficients of the y-rays of radium B and radium C

1930 ◽  
Vol 129 (809) ◽  
pp. 180-207 ◽  
Keyword(s):  
Electronic Structure ◽  
Internal Conversion ◽  
Photoelectric Absorption ◽  
Homogeneous Groups ◽  
Absolute Intensities ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Γ Rays ◽  
Γ Ray ◽  
Parent Atom

It is well known that with many radioactive bodies the departure of the disintegration particle is followed by the emission of γ-rays. In addition to γ-rays of frequencies v 1 , v 2 , ..., it is observed that there is an electronic emission consisting of several homogeneous groups whose energies can be written The energies of these groups are identical with those that would be produced by photoelectric absorption in the parent atom of the γ-rays emitted from the nucleus, and this phenomenon is frequently described as the internal conversion of γ-rays. By this is meant that in every case when the nucleus emits energy E this occurs in the form of radiation of frequency E/ h , but that this does not always escape as such from the atom. In a fraction a of the cases the radiation is absorbed in the electronic structure and gives rise to a photoelectron, in the remaining fraction (1 — α) the γ-ray is emitted clear of the atom. The quantity a is termed the coefficient of internal conversion. Smekal* and others have pointed out that there is no need and even no justification to consider the γ-ray ever to be emitted in the case of those atoms which give photoelectrons. All that can be truly inferred from the experimental facts is that the atom as a whole is capable of emitting energy E, and this it may do either in the form of a quantum of radiation hv = E, or in the form of an electron of energy E — K, or E — L, etc., followed by the appropriate excited K-, L-, X-radiations. The greater portion of this energy E is certainly resident in the nucleus, so that this second standpoint implies some type of what may be termed collision interaction between the nucleus and the electronic structure of the atom.

Radioactive Pollution

2002 ◽  
Keyword(s):  
Atomic Number ◽  
Electromagnetic Waves ◽  
Neutron Radiation ◽  
Atomic Weight ◽  
Atomic Mass Unit ◽  
X Rays ◽  
Orbital Electron ◽  
Γ Rays ◽  
The Difference ◽  
A Charge

Radiation that, on passage through matter, produces ions by knocking electrons out of their orbits is called ionizing radiation. This radiation is produced through decomposition of unstable, naturally occurring or synthetic elements referred to as radionuclides. The four types of radiation are ∝-particles, β-particles, γ-rays, and neutrons. The ∝-particles have a mass of two protons and two neutrons and a charge of +2; β -particles are electrons with a mass of 0.00055 atomic mass unit (amu) and a charge of –1; γ -rays and X-rays are high-frequency electromagnetic waves with no mass and no charge. The difference between γ -rays and X-rays is that γ -rays occur naturally, whereas X-rays are generated. In addition, γ -rays are of higher frequency than X-rays. Release of an ∝ -particle leads to the formation of a daughter element with an atomic number 2 units lower and an atomic weight 4 units lower than that of the parent nuclide. Similarly, release of a β -particle from the nucleus causes conversion of a neutron to a proton, producing a daughter element with the same atomic weight as the parent nuclide but with its atomic number increased by 1 unit. Neutron radiation does not occur naturally and is released only from synthetic radionuclides. Neutrons, which have no charge, are formed from protons. This conversion is accompanied by the release of an orbital electron from the atom. Neutrons produce ions indirectly, by collisions with hydrogen atoms. The impact knocks out protons, which in turn produce ions on passage through matter. Capture of a neutron forms an isotope of the parent nuclide with its atomic weight increased by 1 unit. The mode of action of particles (∝ and β ) varies from that of photons (γ - and X-rays). When ∝- or β -particles travel through matter, their electric charges (positive or negative) cause ionization of the atoms in the matter. This is called a direct effect. Whereas the track of ∝- particles is short and straight, β -particles scatter, frequently producing a wavy track. Gamma- and X-rays act indirectly.

scholarly journals Extension of the Radio Spectrum of AE Aqr to the Sub-millimetric Range

1995 ◽  
Vol 151 ◽  
pp. 268-271
Author(s):  
Meil Abada-Simon ◽  
Tim S. Bastian ◽  
Jay A. Bookbinder ◽  
Monique Aubier ◽  
Gordon Bromage ◽  
...  
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Ultra Violet ◽  
Radio Spectrum ◽  
Cataclysmic Variable ◽  
X Rays ◽  
Dipole Axis ◽  
Γ Rays ◽  
Γ Ray ◽  
Magnetic Poles

AE Aquarii is a magnetic cataclysmic variable containing a white dwarf and a K3-K7 star which lies slightly above the main sequence. The white dwarf is the most rapidly rotating known (Prot ≃ 33.08 s, Patterson 1979), and it is the most strongly asynchronous with its revolution (Porb = 9.88 hr). The white dwarf accretes matter from the K star, which approximately fills the Roche lobe. AE Aqr exhibits flares in the soft X-rays, the ultra-violet, and almost continuously in the visible and the radio regimes. Rapid optical and TeV γ-ray bursts have also been discovered, which are modulated with the period of the white dwarf and at half of this period (de Jager & Meintjes 1993). This modulation, also found in X-rays, is interpreted as the accretion of matter onto the white dwarf’s magnetic poles. The strength of the white dwarf’s magnetic field is not well-determined, it is estimated to be ∼ 6.104 - 105 G (Lamb & Patterson 1983, Cropper 1986) at the white dwarf’s surface. Eracleous et al. (1994) recently suggested that the magnetic dipole axis lies close to the equatorial plane (∼ 20°). De Jager et al. (1994) discovered a rapid spin down of the white dwarf leading to a spin down power which exceeds the accretion power. They suggest that a significant fraction of the spin down power may be converted to the acceleration of particles, which may explain the radio and the γ-ray emissions. Both the characteristics of the optical flares and the existence of TeV γ-rays suggest a relation with the non-thermal radio flares.

Sign in / Sign up

Export Citation Format

Share Document