<i>Principles of Atomic Spectra</i>

Shore, Bruce W.; Menzel, Donald H.; Zipin, Richard B.

doi:10.1063/1.3035170

Cited by 142 publications

(65 citation statements)

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“…where (r, 0 ) are the spherical coordinates of the electron and where C:(R) is a tensor proportional to the spherical harmonic Yl,(8, 4) (Shore and Menzel 1968). In a n polarization transition q = 0 and hence the electron magnetic quantum number M does not change during the transition, that is AM = 0.…”

Section: Q : = Rc:(q)mentioning

confidence: 99%

Quasi-Landau spectrum of a hydrogen like atom in a high magnetic field

Starace

1973

J. Phys. B: At. Mol. Phys.

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A two dimensional semiclassical approximation is used to examine the σ polarization spectrum of a hydrogen like atom in a strong magnetic field. Resonances above the zero field ionization limit are found and their energy separations are computed over the region from the ionization limit to 40 ħω c above, where ω c is the cyclotron frequency, for magnetic fields of 10, 17, 25, 32, 40 and 47 kG. At the ionization limit the separation between resonances is found to be 1.500 ħω c , independent of magnetic field strength, which is in agreement with a separation of 1.5 ħω c observed experimentally by Garton and Tomkins (1969) in the sigma polarization spectrum of barium in a magnetic field of 24 kG. The energy separations are found to decrease above the ionization limit toward the value ħω c , which is characteristic of the levels of a free electron in a homogeneous magnetic field.

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Section: Q : = Rc:(q)mentioning

confidence: 99%

Quasi-Landau spectrum of a hydrogen like atom in a high magnetic field

Starace

1973

J. Phys. B: At. Mol. Phys.

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“…From Eq. 5.17 of reference (14), it is seen that the statistical weights of transitions to the substates of L", St are proportional to (2L" + 1) (2S" + 1). It is possible then, by knowing which (nTl') values are allowed by the symmetry of the transition operator, to predict the structure of the absorption spectrum by reference to atomic tables.…”

mentioning

confidence: 99%

“…The Is -S3d to Is ---4p intensity ratio is seven times larger in the tetrahedral coordination than in octahedral. The explanation given below shows how the in- [1s2s22p63s23p6]3dn,nz'1'(L",S), [1] KMfF3 |J (14). Furthermore, because the is hole is so close to the nucleus, as far as the energetics of the outer shells is concerned the final state of an ion having atomic number Z can be taken as that of an ion with atomic number Z + 1, but having a fully occupied is shell.…”

mentioning

confidence: 99%

Observations and interpretation of x-ray absorption edges in iron compounds and proteins.

Shulman¹,

Yafet²,

Eisenberger³

et al. 1976

Proc. Natl. Acad. Sci. U.S.A.

359

254

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X-ray absorption spectra near the Kx edge have been measured in various iron grou compounds using the intense synchrotron radiation available at the Stanford Synchrotron Research Project. In the cubic compounds KMF3 where M = Mn+2, Fe+2, Co+2, Ni+2, and Zn+2, well resolved lines were observed and assigned to the Is --.3d, Is -4s, and Is -4p transitions. The observed energies agreed rather well with the spectroscopic energy levels of the Z + 1 ion and the intensities are shown to agree with those expected on the basis of one electron transitions of the form Z ls2dn(LS) -. (Z + 1)Is2dnn'1(I",S). The energies of the intense Is-4p transition increase by about 5 V going from KFeF3 to K2NaFeF6, but only by about 1 V from K4Fe(CN)e to K3Fe(CNM. The transitions confirm that upon oxidation of the hexacyanides the iron electronic structure barely changes. In the iron sulfur protein rubredoxin, where the iron is bound to a tetrahedron of sulfurs, the Is-3d transition was about seven times more intense than the same transition in an octahedrally coordinated compound. These intensities parallel those observed in the d-d transitions of optical spectra,bcause in both types of spectra the intensities depend upon 4p admixture. In the heme protein cytochrome c, upon oxidation the Is-s4p transition shifts only about I V to higher energies, similar to the iron hexacyanides. These results are discussed in terms of covalent bonding. The absorption spectrum of x-rays near the K edge has traditionally been divided into a low energy region-the so-called absorption edge-in which the transitions are to bound states (1), and a higher energy region-the so-called extended x-ray absorption fine structure (EXAFS) spectrum-where the transitions are to free electron states (2-6). Recently, synchrotron sources of x-rays have become available whose intensities are about 105 times higher than were previously available. This results in improved signal to noise ratios, which allow meaningful measurements to be made on dilute systems (4-6).In this paper we present measurements, made with synchrotron radiation, of the x-ray absorption spectrum of iron proteins, and of some model compounds in the region of the absorption edge. (Fig. 1). We note that the first indications of absorption, in both compounds, are weak peaks which have been enlarged to facilitate comparison. The K2NaFeF6 peak is shifted about 1.3 V to higher energies from the analogous peak in KFeF3. The K2NaFeF6 peak stands by itself and is composed of a barely resolved doublet. The KFeF3 peak is less clearly separated from the base of the strong absorption, with the suggestion of a weaker peak about 2 V to higher energy.About 16 V to higher energies in the ferrous compound, and 19 V to higher energy in the ferric compound, there is an intense peak whose position depends upon the oxidation state of the iron. At somewhat lower energies, there are shoulders on this intense peak of varying degrees of resolution.We measured the absorption spectra of a series of perovskite cubic fluoride...

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“…For a line in the optical range, the region 100oBo1000 gauss is generally referred to as the Hanle-Zeeman regime. For Bo1 gauss, one has to pay attention to the interaction of electron with the magnetic and electric moments of the nucleus, which give rise to hyperfine splitting [28,29]. If the atom is exposed to an external electric quadrupole field either by itself or in combination with B, the splitting of the energy levels is not, in general, equally spaced [24,25,30,31] and in such scenarios, the atomic Hamiltonian in PAF is given by …”

Section: Energy Levels Of An Atom In Electric Quadrupole and Uniform mentioning

confidence: 99%

Scattering polarization in the presence of magnetic and electric fields

Sampoorna

Nagendra

et al. 2007

Journal of Quantitative Spectroscopy and Radiative Transfer

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The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Limiting cases of scattering under Zeeman effect, and Hanle effect in weak magnetic fields are discussed. The theory is general enough to handle scattering in intermediate magnetic fields (Hanle-Zeeman effect) and for arbitrary orientation of magnetic field. The quadrupolar electric field produces asymmetric line shifts, and causes interesting level-crossing phenomena either in the absence of an ambient magnetic field, or in its presence. It is shown that the quadrupolar electric field produces an additional depolarization in the Q=I profiles and rotation of the plane of polarization in the U=I profile over and above that arising from magnetic field itself. This characteristic may have a diagnostic potential to detect steady-state and time-varying electric fields that surround radiating atoms in solar atmospheric layers. r

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Principles of Atomic Spectra

Cited by 142 publications

References 0 publications

Quasi-Landau spectrum of a hydrogen like atom in a high magnetic field

Quasi-Landau spectrum of a hydrogen like atom in a high magnetic field

Observations and interpretation of x-ray absorption edges in iron compounds and proteins.

Scattering polarization in the presence of magnetic and electric fields

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