Coster-Kronig transition

In addition, whenever the Auger process occurs in a doubly ionized atom, satellite peaks resulting either from shake-off in the primary ionization or from Coster-Kronig transitions from 1 vacancies ) canbe observed . 

McMaster et al. (1969). Fluorescence yields (including Auger and Coster-Kronig transitions) are from Bambynek et al. (1972). Sample thickness corrections use the formula of Compton (1929). 

Baker DR (2002) The Hard X-ray Microprobe. In Synchrotron Radiation Earth, Environmental, and Material Sciences Applications. Short Course Series Vol. 30. Henderson GS and Baker DR (eds) Mineralogical Society of Canada, Ottawa, Canada, p 99-130 Bambynek W, Crasemann B, Fink RW, Freund HU, Mark H, Swift CD, Price RE, Rao PV (1972) X-ray fluorescence yields, Auger and Coster-Kronig transition probabilities. Rev Mod Phys 44 716-813 Bearden JA (1964) X-ray wavelengths. U. S. Atomic Energy Commission Report NY0-10586 Bearden JA (1967) X-ray wavelengths. Rev Mod Phys 39 78-124... 

Fluorescence yield (tUx) of an atomic shell/subshell is defined as the probability that a vacancy in that shell/subshell is filled through radiative transitions. Since the vacancy can also be filled by nonradiative processes (Auger electrons and Coster-Kronig transitions), the fluorescence yield (cuk or cul) = Radiative yield/Total yield. The fluorescence yield values have been given by Bambynek et al. (1972) and Krause (1979). 

The fluorescence yield values (tu ) of the L-subshell and the Coster-Kronig transition probabilities (/y) are listed by Krause (1979). The relative radiative transition probabilities Fij) of the ith subshell contributing to the jth peak can be taken from Cohen (1990). The ionization cross-sections can be theoretically calculated using the ECPSSR theory (see Sect. 1.11.3 for different theories on ion-atom collision). 

Coster-Kronig decay Tliis decay process is a special Auger decay in which the original vacancy is transferred to a higher subshell of the same shell. Auger and Coster-Kronig transitions are (essentially) two-electron processes and cause the emission of electrons with characteristic energies. 

Comprehensive theoretical calculations of radiative transition rates as well as Auger and Coster-Kronig transition rates are available. However, uncertainties are large for Coster-Kronig transitions with small excess energy due to the strong influence of several effects (i) many-body interactions in the initial and final atomic systems, (ii) relaxation in the final ionic state, and (iii) exchange interaction between the continuum electron and the final bound-state electrons. For an experimental determination of decay rates, various techniques have been employed, e.g., the use of radioactive sources or coincidence techniques. Most techniques... 

Figure 6b (bottom) reproduces the Mm (3p3/2- 5d) spectrum of y-Ce. As the Lm spectrum (top) the Mm absorption exhibits the characteristic absorption line of lanthanide p - d transitions. In Mm absorption Coster-Kronig transitions strongly increase the total lifetime broadening of the final states. Therefore mixed valent states can be only qualitatively traced from M, spectra (Kaindl et al. 1984). 

Also available are the results of relativistic relaxed-orbital ab initio calculations of L-shell Coster-Kronig transition energies for all possible transitions in berkelium atoms [75], relativistic relaxed-orbital Hartree-Fock-Slater calculations of the neutral-atom electron binding energies in berkelium [76], and... 

Figure 4 Energy diagram for LLM Coster-Kronig transition.

Figure 5 Energy diagram for MMM super Coster-Kronig transition.

When radiationless transitions occur between subshells of the same shell, they are called Coster-Kronig transitions because Coster and Kronig [2] suggested the existence of radiationless transitions between subshells having the same principal quantum number in order to explain various phenomena, essentially specific satellites in L spectra. 

For X = K (no subshell) the number of X-ray photons emitted is given by Nk=N(Dk where N is the total number of K holes involved. Here N is equal to the sum of radiative and radiationless transitions. To a first approximation, K radiationless transition probability is nearly independent of Z, while radiative electric-dipole probability is proportional to Z. It justifies useful semiempirical laws based on q)kOcZ /(Z +c), c=constant. They are discussed in [4] which also gives many references on Auger and related processes up to 1971. Due to Coster-Kronig transitions, experimental and theoretical problems are more complicated for X = L, M,. .. Experimental data depend on the primary vacancy distribution which must remain unaltered before the vacancies are filled. Literature provides either total X-shell data(X = L, M,. ..) or partial Xj-subshelldata (Xj = L., Lg, L3,. ..). Definitions... 

Other references relating to Auger and Coster-Kronig transitions may be found In the section on fluorescence yields , p. 220. 

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