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Total natural width

Generally, when studying autoionizing levels, we have to take into consideration both (radiative and radiationless) channels of their decay. The total natural width of the autoionizing level will be the sum of its autoionizing and radiative widths. [Pg.393]

It is interesting to consider a figure-of-merit, Qqed = 2 Eqed/ fi-r), where 2 Eqed is the total QED contribution to the transition energy and HE is the total natural width. This is plotted against Z for the four transitions in fig. 5. The potential experimental sensitivity to QED is much higher than for hydrogen-like ions, particularly for the 2 — 2 Pq, P2 transitions with Z > Q. Unfortunately... [Pg.191]

Fig, 5a. Calculated total natural widths F and partial natural widths F (inverse lifetime of the radiative decays), Ta (inverse lifetime of the Auger processes) and Fq (inverse lifetime of the Coster-Kronig processes) of K, Lj, Lji in, Mj and Mum levels for Z = 40-80 (from Keski-Rahkonen and Krause 1974). [Pg.466]

On the other hand, K absorption spectra are useful for an accurate determination of the Z dependence of the 1 s total natural widths, because the inverse core hole lifetime is much larger than the fine structure that has p symmetry above the... [Pg.469]

We recall that the total natural width F is the sum of radiative and nonradiative widths due to Auger and Coster-Kronig processes. [Pg.234]

In the following, we consider the shape and the width of the Mdssbauer velocity spectrum in more detail. We assume that the source is moving with velocity u, and the emission line is an unsplit Lorentzian according to (2.2) with natural width E. If we denote the total number of y-quanta emitted by the source per time unit toward the detector by Nq, the number N E)AE of recoU-free emitted y-rays with energy y in the range to -f dE is given by ([1] in Chap. 1)... [Pg.18]

The second factor involves the theory that defines the natural width of the lines. Radiations emitted by atoms are not totally monochromatic. With plasmas in particular, where the collision frequency is high (this greatly reduces the lifetime of the excited states), Heisenberg s uncertainty principle is fully operational (see Fig. 15.4). Moreover, elevated temperatures increase the speed of the atoms, enlarging line widths by the Doppler effect. The natural width of spectral lines at 6000 K is in the order of several picometres. [Pg.278]

The lifetime of a separate atom in its ground state is infinite, therefore the natural width of the ground level equals zero. Typical lifetimes of excited states with an inner vacancy are of the order 10-14 — 10 16 s, giving a natural width 0.1 — 10 eV. The closer the vacancy is to the nucleus, the more possibilities there are to occupy this vacancy and then the broader the level becomes. That is why T > Tl > Tm- Generally, the total linewidth T is the sum of radiative (Tr) and Auger (T ) widths, i.e. [Pg.402]

Before these partial quantities are discussed further, an important comment has to be made unlike the partial transition rates, the partial level widths have no direct physical meaning, because even for a selected decay branch it is always the total level width which determines the natural energy broadening. The partial level width is only a measure of the partial transition rate. Both aspects can be inferred from the Lorentzian distribution attached to a selected decay branch, e.g., Auger decay, which is given by... [Pg.58]

Here, as usual, ran = Vai — rai, final states of a system, i.e., the total level width is represented as sum of the partial contributions, connected with radiative decay into the concrete final states of a system. These contributions are proportional to the probabilities of the corresponding transitions. Naturally, the form of operator in (10) is determined by a gauge of the photon propagator (look discussion in Ref. [26]). In the zeroth approximation, the dependence f, on the nuclear and electron coordinates (/ n, l e(h)) is factorized ( eN). Therefore, the combined electron (hole)-nuclear one-photon transitions occur as each of the operators Tn and Te in (10) contains the combination of the nuclear and electron variables. After factorization and some transformations, the expression (10) can be presented in the following form ... [Pg.223]

The two processes are radically different in nature it would indeed be a remarkable coincidence if both these probabilities and their rates of change with energy, were to be so very similar. However, as we have seen in Sect. 8, it is not necessary to assume that the total probability of inelastic neutron emission increases very rapidly with energy. If, as is much more likely, the total neutron width is approximately independent of neutron energy, it follows that the average fission probability is also approximately independent of energy. [Pg.259]

It is probably useful to remark that the total natural line width is essentially 7-ray width below 6500... [Pg.170]

The experimental layout is presented in Fig. 14.5. A Co( Fe) isotope I with activity of lOmCi in a chromium matrix was used as a source of Mossbauer radiation. This source has a spectrum in the form of single line of natural width. The source is fixed in the Plexiglas disc and put in the center (/ = 2.5 cm) or near the edge (/ = I cm) of the resonant absorber 2, having a form of cylinder with diameter D = 2 cm and length L = 5 cm, made of Fe isotope (200 mg) in stainless steel (100 mg). The thickness of absorber 7 mg cm provides the requirement of total absorption of resonant radiation (for co - coeg < T/2) and almost full transparency for nonresonant radiation (for co - coeg > T/2). [Pg.309]

Here C denotes a constant, E the photon energy, q Ilie absorption limit and / the total natural core level width. [Pg.470]

The experimental linewidth and shape of the atomic absorption line in the gas clearly demonstrates the absence of many-body effects. The observed width (FWHM = 4.5 eV) is in good agreement with the calculated number for the total natural linewidth from Keski-Rahkonen (1974) ( = 3eV, cf fig. 5a) taking into account the E (Fano and Cooper 1968) dependence of the atomic spectral density. This observation clearly demonstrates that many-electron effects, which could also cause an asymmetric lineshape, do not contribute to the decay of the core... [Pg.480]

The following natural precursors have been selected for KOH activation coal (C), coal semi-coke (CS), pitch semi-coke (PS) and pitch mesophase (PM). An industrial activated carbon (AC) was also used. Activation was performed at 800°C in KOH with 4 1 (C KOH) weight ratio, for 5 hours, followed by a careful washing of the samples with 10% HC1 and distilled water. The activation process supplied highly microporous carbons with BET specific surface areas from 1900 to 3150 m2/g. The BET surface area together with the micro and the total pore volume of the KOH-activated carbons are presented in Table 1. The mean micropore width calculated from the Dubinin equation is designed as LD. [Pg.32]

The major requirement of the light source for atomic absorption is that it should emit the characteristic radiation (the spectrum) of the element to be determined at a half-width less than that of the absorption line. The natural absorption line width is about 10 4 (A), but due to broadening factors such as Doppler and collisional broadening, the real or total width for most elements at temperatures between 2000 ° and 3000 °K is typically 0.02 — 0.1 A. Hence, a high resolution monochromator is not required. [Pg.83]


See other pages where Total natural width is mentioned: [Pg.191]    [Pg.465]    [Pg.465]    [Pg.469]    [Pg.191]    [Pg.465]    [Pg.465]    [Pg.469]    [Pg.120]    [Pg.395]    [Pg.275]    [Pg.194]    [Pg.860]    [Pg.194]    [Pg.228]    [Pg.395]    [Pg.263]    [Pg.228]    [Pg.315]    [Pg.571]    [Pg.122]    [Pg.567]    [Pg.826]    [Pg.195]    [Pg.159]    [Pg.94]    [Pg.229]    [Pg.95]    [Pg.113]    [Pg.40]    [Pg.13]    [Pg.462]    [Pg.150]   
See also in sourсe #XX -- [ Pg.465 , Pg.466 , Pg.467 , Pg.468 ]




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