Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review

Effect of a Magnetic Field Upon the Polarization of Impact Radiation

W.H. McCorkle

Published Sep 15, 1935• 0 citations
Publisher

Abstract

Sodium $D$ line radiation excited by electrons moving parallel to a magnetic field of 300 gauss or more shows about 16 percent polarization, the major electric vibration being parallel to the direction of the exciting electron beam. In fields below 300 gauss the polarization is less, decreasing to zero in the absence of a field. That the polarization changes in a magnetic field must be due to the fact that the $3^{2}P_{\frac{3}{2}}$ level is a hyperfine multiplet which undergoes a Paschen-Back effect.

DOI
10.1103/physrev.48.532

Related papers

Polarization of Radiation Excited by Electron Impact

A. Ellett, Paul D. Foote, Fred L. Mohler

Polarized radiation following electron impact.---If a unidirectional beam of electrons, of velocity slightly in excess of the resonance potential, is projected through a vapor at a very low pressure so that effects due to atomic collision and resonance radiation are negligible, and in the absence of an applied field and resulting Larmor precession, there is reason to suspect that the radiation emitted perpendicular to the electron beam should be partially polarized, especially for lines corresponding to $\ensuremath{\Delta}j=1$.Polarization in mercury and sodium vapor.---Experiment showed a polarization of about 30 percent for $\ensuremath{\lambda}2537$ with the greatest intensity of the electrical vibration having a direction perpendicular to the electron beam. No polarization was detected for the unresolved sodium D-lines, confirming the recent observation of Kossel and Gerthsen.Polarization in mercury with field of 3 gauss.---A field parallel to the electron beam produced no effect. With the field perpendicular to the beam the radiation along the field was unpolarized while that perpendicular to the field was reduced in polarization to 13 percent. These results suggest that the atom radiates with the same distribution of polarization and intensity as in zero field but with the atom rotated through an angle determined by the time of excitation and the precessional velocity.

Physical Review•Jan 1, 1926•19 citations

Polarized Resonance Radiation in Weak Magnetic Fields

Robert Williams Wood, A. Ellett

Effect of a magnetic field on the polarization of resonance radiation of mercury and of sodium.---(1) Mercury $\ensuremath{\lambda}2536$. A beam of plane polarized monochromatic light was focussed on the bulb containing the vapor at low pressure (0\ifmmode^\circ\else\textdegree\fi{}C), and the polarization of the resonance radiation was determined photographically with the aid of a quartz wedge and a double image quartz prism. If the exciting beam is going east with the electric vector vertical, when the earth's field is carefully neutralized the polarization is 90 per cent in any horizontal direction and zero vertically; a field of only 2 gauss directed north reduces the polarization in its direction to nearly zero (the decrease with increasing field being exponential), changes the polarization east and also up to 60 percent, and increases the intensity directed upwards threefold. Similar effects are produced by fields in other directions. The polarization with zero field does not approach 100 per cent at low pressures, since 90 per cent was found also with the vapor at -50\ifmmode^\circ\else\textdegree\fi{}C, when the radiation first appeared. It was thought that the high value might be due to an orientation of the resonating atom by the field of the exciting light, but a beam of concentrated sunlight produced no effect. As found by Malinowski, a strong field of 10,000 gauss merely increased the intensity of the radiation about 10 per cent. This added light was found to be unpolarized. (2) Sodium $D$ line. In the case of sodium vapor the tube was heated to 185\ifmmode^\circ\else\textdegree\fi{}C, the observations were visual, and as a source of unreversed light, the glow on the surface of a sodium glass vacuum tube carrying a discharge, was used. The effects observed are similar to those for mercury, but differ for some directions; fields forty times stronger were required, and the polarization in zero field was only 6 per cent, probably due to traces of hydrogen. This was increased by the field in some directions to 30 per cent.Effect of magnetic field on fluorescent light of iodine vapor and on white scattered light from mercury and ether vapors.---The polarization was found not to be affected.

Physical Review•Sep 1, 1924•74 citations

Extension of a basic experiment: the polarisation of the white-light-excited spectrally resolved Na D lines and its relation to electron impact excitation

Bernhard Stumpf, Kurt Henry Becker, G. Schulz

The polarisation of spectrally resolved Na D lines excited by white, linearly polarised light in a homogeneous magnetic field up to 1000 G was measured by means of the crossed-beam technique. The axis of observation, the sodium beam and the direction of the magnetic field were mutually at right angles. The incoming light beam was directed along the magnetic field and linearly polarised either parallel to the axis of observation or perpendicular to it. A Lyot filter of high transmission and a sensitive photon-counting technique made it possible to detect the small intensities of the resolved Na D doublet excited by the light of a xenon arc lamp. The measured polarisations are found to be in excellent agreement with those calculated by means of Breit's theory and the ambiguities of earlier investigations are completely removed. The importance of our results for electron impact excitation in magnetic fields parallel to the beam is discussed. It is shown that the polarisation of the electron impact excited Na D lines is no longer perturbed by hyperfine structure if a magnetic field of 500 G parallel to the beam is applied.

Journal of Physics B Atomic and Molecular Physics•Nov 14, 1980•1 citation

Effect of Hyperfine Structure upon the Magnetic Rotation of the Plane of Maximum Polarization of Resonance Radiation

Bertrand J. Miller

An equation has been developed for the polarization, and the angle of maximum polarization of resonance radiation as observed along a magnetic field perpendicular to the electric vector and the direction of propagation of the incident beam. Explicit application has been made to the polarization and the angle for the line $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ for various values of the ratio of the hyperfine separation constant to the natural breadth of the levels, for a nuclear moment of \textonehalf{}. It was noted here that the form of the curves might differ widely from that to be expected from classical considerations. The polarization, and the angle of maximum polarization for the sodium D lines, for several values of the same ratio, were computed and compared with experimental observations. Thus a range of possible values of $A$ was determined, which is not in disagreement with previous figures, and a value for $\ensuremath{\tau}$ established which agrees well with that calculated from optical dispersion data.

Physical Review•Aug 1, 1940•0 citations

Magnetic Field Dependence of Polarized Scattering on Potassium

C. Thalmann, Jan Olof Stenflo, Alex J. Feller +1 more

The polarization that is generated by scattering of light on atoms depends on the atomic quantum number structure. According to standard scattering theory the sodium D1 (5896 A) and potassium D1 (7699 A) lines should be intrinsically unpolarizable. Since however the existence of D1 scattering polarization in the solar spectrum has been well documented but resisted theoretical explanations, we have carried out a laboratory experiment to find out if this is a problem of solar physics or of quantum physics. We find that the polarization matrix for scattering of the Stokes vector in the potassium D1 line exhibits a rich structure that changes dramatically when the field strength is varied in the sub-gauss regime. In contrast, standard scattering theory predicts zero polarization, even when optical pumping of the magnetic sub-levels of the hyperfine structure multiplet is accounted for.

•Jun 1, 2009•0 citations

Magnetically induced circular polarization

K.L. Stricklett, D. J. Burns, P. D. Burrow

Helium atoms excited to an aligned (1s3d${)}^{3}$D state are produced by electron impact parallel to a magnetic field. The initial alignment of the atomic state evolves into an orientation with finite angular momentum along the magnetic field direction and thus gives rise to a circularly polarized component in the (1s3d${)}^{3}$D\ensuremath{\rightarrow}(1s2p${)}^{3}$P radiation propagating parallel to the magnetic field. Circular-polarization fractions of a few percent are observed, in general agreement with theory. The measured polarization fraction is found to be pressure dependent, indicating that secondary excitation and cascade processes must be included for a complete description.

Physical Review A•Dec 1, 1987•2 citations
Sodium DDD line radiation excited by electrons moving parallel to a magnetic field of 300 gauss or more shows about 16 percent polarization, the major electric vibration being parallel to the direction of the exciting electron beam. In fields below 300 gauss the polarization is less, decreasing to zero in the absence of a field. That the polarization changes in a magnetic field must be due to the fact that the 32P323^{2}P_{\frac{3}{2}}32P23​​ level is a hyperfine multiplet which undergoes a Paschen-Back effect.
Polarized radiation following electron impact.---If a unidirectional beam of electrons, of velocity slightly in excess of the resonance potential, is projected through a vapor at a very low pressure so that effects due to atomic collision and resonance radiation are negligible, and in the absence of an applied field and resulting Larmor precession, there is reason to suspect that the radiation emitted perpendicular to the electron beam should be partially polarized, especially for lines corresponding to $\ensuremath{\Delta}j=1$.Polarization in mercury and sodium vapor.---Experiment showed a polarization of about 30 percent for $\ensuremath{\lambda}2537$ with the greatest intensity of the electrical vibration having a direction perpendicular to the electron beam. No polarization was detected for the unresolved sodium D-lines, confirming the recent observation of Kossel and Gerthsen.Polarization in mercury with field of 3 gauss.---A field parallel to the electron beam produced no effect. With the field perpendicular to the beam the radiation along the field was unpolarized while that perpendicular to the field was reduced in polarization to 13 percent. These results suggest that the atom radiates with the same distribution of polarization and intensity as in zero field but with the atom rotated through an angle determined by the time of excitation and the precessional velocity.
Effect of a magnetic field on the polarization of resonance radiation of mercury and of sodium.---(1) Mercury $\ensuremath{\lambda}2536$. A beam of plane polarized monochromatic light was focussed on the bulb containing the vapor at low pressure (0\ifmmode^\circ\else\textdegree\fi{}C), and the polarization of the resonance radiation was determined photographically with the aid of a quartz wedge and a double image quartz prism. If the exciting beam is going east with the electric vector vertical, when the earth's field is carefully neutralized the polarization is 90 per cent in any horizontal direction and zero vertically; a field of only 2 gauss directed north reduces the polarization in its direction to nearly zero (the decrease with increasing field being exponential), changes the polarization east and also up to 60 percent, and increases the intensity directed upwards threefold. Similar effects are produced by fields in other directions. The polarization with zero field does not approach 100 per cent at low pressures, since 90 per cent was found also with the vapor at -50\ifmmode^\circ\else\textdegree\fi{}C, when the radiation first appeared. It was thought that the high value might be due to an orientation of the resonating atom by the field of the exciting light, but a beam of concentrated sunlight produced no effect. As found by Malinowski, a strong field of 10,000 gauss merely increased the intensity of the radiation about 10 per cent. This added light was found to be unpolarized. (2) Sodium DDD line. In the case of sodium vapor the tube was heated to 185\ifmmode^\circ\else\textdegree\fi{}C, the observations were visual, and as a source of unreversed light, the glow on the surface of a sodium glass vacuum tube carrying a discharge, was used. The effects observed are similar to those for mercury, but differ for some directions; fields forty times stronger were required, and the polarization in zero field was only 6 per cent, probably due to traces of hydrogen. This was increased by the field in some directions to 30 per cent.Effect of magnetic field on fluorescent light of iodine vapor and on white scattered light from mercury and ether vapors.---The polarization was found not to be affected.
The polarisation of spectrally resolved Na D lines excited by white, linearly polarised light in a homogeneous magnetic field up to 1000 G was measured by means of the crossed-beam technique. The axis of observation, the sodium beam and the direction of the magnetic field were mutually at right angles. The incoming light beam was directed along the magnetic field and linearly polarised either parallel to the axis of observation or perpendicular to it. A Lyot filter of high transmission and a sensitive photon-counting technique made it possible to detect the small intensities of the resolved Na D doublet excited by the light of a xenon arc lamp. The measured polarisations are found to be in excellent agreement with those calculated by means of Breit's theory and the ambiguities of earlier investigations are completely removed. The importance of our results for electron impact excitation in magnetic fields parallel to the beam is discussed. It is shown that the polarisation of the electron impact excited Na D lines is no longer perturbed by hyperfine structure if a magnetic field of 500 G parallel to the beam is applied.
An equation has been developed for the polarization, and the angle of maximum polarization of resonance radiation as observed along a magnetic field perpendicular to the electric vector and the direction of propagation of the incident beam. Explicit application has been made to the polarization and the angle for the line $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ for various values of the ratio of the hyperfine separation constant to the natural breadth of the levels, for a nuclear moment of \textonehalf{}. It was noted here that the form of the curves might differ widely from that to be expected from classical considerations. The polarization, and the angle of maximum polarization for the sodium D lines, for several values of the same ratio, were computed and compared with experimental observations. Thus a range of possible values of AAA was determined, which is not in disagreement with previous figures, and a value for $\ensuremath{\tau}$ established which agrees well with that calculated from optical dispersion data.
The polarization that is generated by scattering of light on atoms depends on the atomic quantum number structure. According to standard scattering theory the sodium D1 (5896 A) and potassium D1 (7699 A) lines should be intrinsically unpolarizable. Since however the existence of D1 scattering polarization in the solar spectrum has been well documented but resisted theoretical explanations, we have carried out a laboratory experiment to find out if this is a problem of solar physics or of quantum physics. We find that the polarization matrix for scattering of the Stokes vector in the potassium D1 line exhibits a rich structure that changes dramatically when the field strength is varied in the sub-gauss regime. In contrast, standard scattering theory predicts zero polarization, even when optical pumping of the magnetic sub-levels of the hyperfine structure multiplet is accounted for.
Helium atoms excited to an aligned (1s3d)3{)}^{3})3D state are produced by electron impact parallel to a magnetic field. The initial alignment of the atomic state evolves into an orientation with finite angular momentum along the magnetic field direction and thus gives rise to a circularly polarized component in the (1s3d)3{)}^{3})3D\ensuremath{\rightarrow}(1s2p)3{)}^{3})3P radiation propagating parallel to the magnetic field. Circular-polarization fractions of a few percent are observed, in general agreement with theory. The measured polarization fraction is found to be pressure dependent, indicating that secondary excitation and cascade processes must be included for a complete description.