Large frequency shifts of absorption profiles due to the combination of optical pumping, light shift, and magnetic fields in sodium vapor

1994 ◽  
Vol 50 (3) ◽  
pp. 2434-2437 ◽  
Author(s):  
B. Röhricht ◽  
P. Eschle ◽  
C. Wigger ◽  
S. Dangel ◽  
R. Holzner ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Optical Pumping ◽  
Light Shift ◽  
Sodium Vapor ◽  
Frequency Shifts ◽  
Large Frequency

scholarly journals Sensitivity of low-degree solar p modes to active and ephemeral regions: frequency shifts back to the Maunder minimum

2019 ◽  
Vol 489 (1) ◽  
pp. L86-L90 ◽  
Author(s):  
William J Chaplin ◽  
Rachel Howe ◽  
Sarbani Basu ◽  
Yvonne Elsworth ◽  
Timothy W Milbourne ◽  
...  
Keyword(s):  
Active Region ◽  
Magnetic Fields ◽  
Spatial Scales ◽  
Active Regions ◽  
Activity Cycle ◽  
Maunder Minimum ◽  
Field Frequency ◽  
Frequency Shifts ◽  
Near Surface ◽  
Low Degree

ABSTRACT We explore the sensitivity of the frequencies of low-degree solar p modes to near-surface magnetic flux on different spatial scales and strengths, specifically to active regions with strong magnetic fields and ephemeral regions with weak magnetic fields. We also use model reconstructions from the literature to calculate average frequency offsets back to the end of the Maunder minimum. We find that the p-mode frequencies are at least 3 times less sensitive (at 95  per cent confidence) to the ephemeral-region field than they are to the active-region field. Frequency shifts between activity cycle minima and maxima are controlled predominantly by the change of active region flux. Frequency shifts at cycle minima (with respect to a magnetically quiet Sun) are determined largely by the ephemeral flux, and are estimated to have been $0.1\, \rm \mu Hz$ or less over the last few minima. We conclude that at epochs of cycle minimum, frequency shifts due to near-surface magnetic activity are negligible compared to the offsets between observed and model frequencies that arise from inaccurate modelling of the near-surface layers (the so-called surface term). The implication is that this will be the case for other Sun-like stars with similar activity, which has implications for asteroseismic modelling of stars.

SABRE Hyperpolarization of Bipyridine Stabilized Ir-Complex at High, Low and Ultralow Magnetic Fields

2017 ◽  
Vol 231 (3) ◽  
Author(s):  
Andrey N. Pravdivtsev
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Dynamic Nuclear Polarization ◽  
Signal Amplification ◽  
Nuclear Polarization ◽  
Optical Pumping ◽  
Spin Exchange ◽  
Spin Exchange Optical Pumping ◽  
Wide Range

AbstractA strong limitation of nuclear magnetic resonance is its low inherent sensitivity that can be overcome by using an appropriate hyperpolarization technique. Presently, dynamic nuclear polarization and spin-exchange optical pumping are the only hyperpolarization techniques that are used in applied medicine. However, both are relatively complex in use and expensive. Here we present a modification of the signal amplification by reversible exchange (SABRE) hyperpolarization method – SABRE on stabilized Ir-complexes. A stabilized Ir-complex (here we used bipyridine for stabilization) can be hyperpolarized in a wide range of magnetic fields from a few μT upto 10 T with

Magnetic coupling of waves and oscillations in the lower solar atmosphere: can the tail wag the dog?

2005 ◽  
Vol 364 (1839) ◽  
pp. 351-381 ◽  
Author(s):  
Robert Erdélyi
Keyword(s):  
Magnetic Fields ◽  
Solar Atmosphere ◽  
Acoustic Waves ◽  
Large Scale ◽  
Magnetic Coupling ◽  
Small Scale ◽  
Coupling Mechanism ◽  
Frequency Shifts ◽  
Characteristic Features ◽  
Lower Solar Atmosphere

Can the ubiquitously magnetic solar atmosphere have any effect on solar global oscillations? Traditionally, solar atmospheric magnetic fields are considered to be somewhat less important for the existence and characteristic features of solar global oscillations ( p , f and the not-yet-observed g -modes). In this paper, I demonstrate the importance of the presence of magnetism and plasma dynamics for global resonant oscillations in the solar atmosphere. In particular, in the lower part of the solar atmosphere there are both coherent and random components of magnetic fields and velocity fields, each of which contribute on its own to the line widths and frequency variations of solar global acoustic waves. Changes in the coherent large-scale atmospheric magnetic fields cause frequency shifts of global oscillations over a solar cycle. The random character of the continuously emerging, more localized, magnetic carpet (i.e. small-scale, possibly even sub-resolution, loops) gives rise to additional frequency shifts. On the other hand, random and organized surface and sub-surface flows, like surface granulation, meridional flows or differential rotation, also affect the coupling mechanism of global oscillations to the lower magnetic atmosphere. The competition between magnetic fields and flows is inevitable. Finally, I shall discuss how solar global oscillations can resonantly interact with the overlaying inhomogeneous lower solar atmosphere embedded in a magnetic carpet. Line width broadening and distorsion of global acoustic modes will be discussed. The latter is suggested to be tested and measured by using ring-analysis techniques.

Outstanding Stellar Microwave Flares in 1986

1987 ◽  
Vol 7 (1) ◽  
pp. 55-59 ◽  
Author(s):  
O. B. Slee ◽  
G. J. Nelson ◽  
R. T. Stewart ◽  
Alan E. Wright ◽  
David L. Jauncey ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Main Sequence ◽  
Relativistic Electrons ◽  
Spectral Indices ◽  
Frequency Range ◽  
High Brightness ◽  
Brightness Temperatures ◽  
Simultaneous Measurements ◽  
Gyrosynchrotron Emission ◽  
Large Frequency

AbstractWe describe bright microwave events that were first detected with the Parkes 64-m telescope at 8.4 or 22 GHz from six active-chromosphere stars. In some flares spectral data were obtained over a large frequency range from simultaneous measurements with the Parkes reflector (8.4 or 22 GHz), the Tidbinbilla interferometer (8.4 and 2.29 GHz), the Fleurs synthesis telescope (1.42 GHz) and the Molonglo Observatory synthesis telescope (0.843 GHz). Data on circular polarization were obtained from the Parkes observations at 8.4 GHz.The stars were in a wide variety of evolutionary states, ranging from a single pre-main-sequence star (HD 36705), two RS CVn binaries (HD 127535, HD 128171), an Algol (HD 132742) and two apparently single K giants (HD 32918 and HD 196818). Their high brightness temperatures, positive spectral indices and low polarization are consistent with optically thick gyrosynchrotron emission from mildly relativistic electrons with average energies 0.5 to 3 MeV gyrating in inhomogeneous magnetic fields of 5 to 100 G.

Optical pumping of cesium in high magnetic fields

1971 ◽  
Vol 36 (1) ◽  
pp. 31-32 ◽  
Author(s):  
F.A. Franz ◽  
T.R. Marshall ◽  
J.A. Munarin
Keyword(s):  
Magnetic Fields ◽  
Optical Pumping ◽  
High Magnetic Fields

SELECTIVE AMPLIFICATION OF NARROW RESONANCE FORMED IN TRANSMISSION SPECTRUM OF Rb NANO-CELL IN MAGNETIC FIELD

2012 ◽  
Vol 15 ◽  
pp. 9-15
Author(s):  
A. SARGSYAN ◽  
G. HAKHUMYAN ◽  
R. MIRZOYAN ◽  
A. PAPOYAN ◽  
D. SARKISYAN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Transmission Spectrum ◽  
Optical Pumping ◽  
Atomic Transition ◽  
New Method ◽  
Narrow Resonance ◽  
Selective Amplification ◽  
Resonant Transmission

Recently it was shown that "λ-Zeeman Technique" (λ-ZT) is a convenient tool to study individual transitions between the Zeeman sublevels of hyperfine levels in an external magnetic field. λ-ZT is based on resonant transmission spectrum of nanometric thin cell (NTC) of thickness L = λ, where λ is the resonant wavelength 794 nm for Rb D1 line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field. Examination of VSOP resonances allows one to identify and investigate an atomic transition in the range of magnetic fields 10 - 5000 G. Here we present a new method for selective addressing of VSOP resonance amplification (more than 10 times).

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