Structure of the Configurations of High Azimuthal Quantum Number in Cu II and the Rare Gases

1938 ◽  
Vol 54 (9) ◽  
pp. 749-753 ◽  
Author(s):  
George H. Shortley ◽  
Bernard Fried
1935 ◽  
Vol 31 (3) ◽  
pp. 407-415 ◽  
Author(s):  
H. M. Taylor

1. The purpose of this paper is to examine in detail the types of radiation emitted by a quantum mechanical system (representing a nucleus) when the radiating particle changes its azimuthal quantum number l by two, one, or nought. We assume that the radiating particle is spinless* and that it moves in a field possessing central symmetry, so that the particle may be described by a wave function ψn,l,m which factorizes into radial and angular parts,We assume secondly that the nucleus has a finite radius aN of the order of 10−12 cm., that is to say that π(r) = 0 for r > aN.


Many interesting features of the Stark-effect may be seen with unusual clearness in the arc spectra of helium, and these we shall mention very briefly before referring to the theory. The fact that an electric field applied to the source will bring out the combination lines 2 p — mp was discovered by Koch in 1915. Since that time many investigators have shown by Lo Surdo’s method that a moderate external field is sufficient to remove all restrictions with regard to changes in the azimuthal quantum number.


Rather more than a year ago it was announced that the bands which go down to the two 2 p 3 II ab levels had been found, but owing to the inclusion of a considerable number of wrong lines little progress in understanding them has been made until quite recently. The discovery of these bands is important for several reasons, of which we shall mention one at this stage. It proves that a system of triplet states analogous to the states of the orthohelium line spectrum really exists in the spectrum of H 2 and to that extent confirms the view we have taken of the structure of this spectrum. This follows since the singlet 2 p 1 II ab levels have now been firmly identified with the C level of Dieke and Hopfield; the final levels of the present band systems are undoubtedly 2 p II ab levels, and there is no room for any other 2 p II level in the singlet system. The notation here used is that proposed by Mulliken. It has been described by one of us in the 'Transactions of the Faraday Society,’ vol. 25, p. 628. It is assumed that in all the electronic states of H 2 with which these bands are concerned only one electron gets excited, the other being in an s state ( l = 0). Thus the resultant azimuthal quantum number L of the two electrons is equal to that of the azimuthal quantum number l of the excited electron. The magnitude of both these quantities is thus expressed by the letters s (for l = 0), p (for l == 1), d (for l ==2), etc., in such symbols as 2 p 3 II. In addition we have to specify A the resolved part of L about the molecular axis. This is indicated by the symbols Σ for Ʌ = 0, II for Ʌ = 1, Ʌ for Ʌ = 2. etc. The first number, such as 2 in 2 p 3 II ab , indicates the principal quantum number n and the second such as 3 shows that the level is believed to be a triplet level. The suffixes ab distinguish the double character of II, Δ, etc., levels which arise according to whether the value of Ʌ is positive or negative.


2002 ◽  
Vol 17 (06n07) ◽  
pp. 1045-1048 ◽  
Author(s):  
V. G. BAGROV ◽  
D. M. GITMAN ◽  
V. B. TLYACHEV

Aharonov-Bohm solenoid changes the energy spectrum of charge particles in pure magnetic field. In particular, the degeneracy with respect to azimuthal quantum number l is partially lifted. In turn, this complicates the radiation spectrum of a charged particle in magnetic field in the presence of the solenoid (Aharonov-Bohm effect). In particular, the degeneracy of the radiation intensity with respect to the azimuthal quantum number is lifted completely. In the present work we study l-dependence (induced by Aharonov-Bohm solenoid) of synchrotron radiation intensity in semiclassical approximation.


Many leading features in the Stark effect are best illustrated by studies in the spectra of the rare gases. In each spectrum at least one phase of the Stark effect stands out prominently. Thus in helium the Stark types for singlet lines are most clearly revealed, while in neon an analogue of the Paschen-Back effect makes its appearance, together with some departures from the normal Stark patterns for parhelium. The present experiments with xenon constitute evidence in support of a quantum-mechanical explanation of the origin of Stark displacements and reveal new features concerning the nature of Stark patterns. It was first observed in Stark displacements, in helium that sharp and principal series lines were displaced very little in comparison with diffuse series lines. The relatively small displacements received an early explanation on the grounds of an atomic model in which the s -and p -terms corresponded to electron orbits of high eccentricity which revolve rapidly in their planes. This action prevented the external field from producing an appreciable shift of the electrical centre from its normal position in the nucleus. Since the excess of the term in question over the hydrogen term of the same principal quantum number (the so-called hydrogen difference) measured the speed of revolution of the orbit, it seemed clear that hydrogen differences should serve as valuable guides to probable Stark displacements. Up to the present well organised data have appeared to support this view.


This paper derives the ordinary classification of multiplets, and the selection and summation rules, from Dirac's relativistic equation. The non-relativistic theory of the inner quantum number j and the magnetic quantum number u , and their selection rules, was worked out for an atom with any number of point-electrons by Born, Heisenberg and Jordan, using matrices, and by Dirac, using q -numbers. The two methods are equivalent, and depend principally upon the properties of the total angular momentum. 2 points out that the total angular momentum has the same properties in the new theory, so that the previous work can be taken over with scarcely any amendment. 3. deals with a selection rule that has received little theoretical attention. The azimuthal quantum number for a single electron is denoted by k , and Σ k is the sum for all the orbits involved in a given state. It is known empirically that Σ k always changes by an odd number. This is the basis of the distinction between S, P, D, ... and S', P', D', ... terms. The rule is proved rigorously in the absence of external fields. A practical consequence is that the O ++ lines of nebular spectra, if rightly identified, can occur only in electric or non-uniform magnetic fields, for they have ∆Σ k = 0.


1926 ◽  
Vol 23 (4) ◽  
pp. 403-411 ◽  
Author(s):  
Bertha Swirles

If it is assumed that the series electron of an atom polarises the core, then it has been shown by Born and Heisenberg that the polarisability α of the core in a given state may be calculated from the corresponding term value by means of the approximate formulae, where q is the quantum defect, δν is the difference between the term and the corresponding hydrogen term, R is the Rydberg constant in cm.−1, α1 is the radius of first hydrogen orbit, n is the principal quantum number, k is the azimuthal quantum number, For terms with small quantum defect either of the formulae (1) and may be used, but for terms with large quantum defect (1) gives a higher degree of accuracy.


Author(s):  
William Krakow

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.


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