The present status of the field of fluorescence yields, radiationless (Auger and Coster-Kronig) and radiative transition probabilities is summarized. Tables of experimental and theoretical results are included, and tables of "best values" of important quantities are presented.

X-Ray Fluorescence Yields, Auger, and Coster-Kronig Transition Probabilities

Energy levels of A = 21−44 nuclei (V)

The theory of nuclear electron capture is reviewed in the light of current understanding of weak interactions. Experimental methods and results regarding capture probabilities, capture ratios, and EC/Beta(+) ratios are summarized. Radiative electron capture is discussed, including both theory and experiment. Atomic wave function overlap and electron exchange effects are covered, as are atomic transitions that accompany nuclear electron capture. Tables are provided to assist the reader in determining quantities of interest for specific cases.

Orbital electron capture by the nucleus

Publisher Summary The type of radiationless reorganization of the electronic shells of an atom that has come to be known as the Auger effect plays an important role in very many areas of physics, including atomic, nuclear, elementary particle, solid state, and surface physics, and a number of reviews are available covering either the whole subject. A parameter that contains much of the information of interest in applications of the Auger effect is the fluorescence yield. The reorganization of atoms, initially ionized in a specified inner sub shell, is generally independent of the mode of primary ionization. The application of intermediate coupling theory, first without configuration interaction, gave stimulus to experimentalists to look for the fine structure of Auger spectra. For intermediate atomic numbers, the relative intensities of the different lines agreed satisfactorily with theory. For higher shells, the possibility of transfer of vacancies between sub shells leads to even more complicated relations.

The Auger Effect

Calculated response of intrinsic germanium detectors to narrow beams of photons with energies up to ∼300 keV☆

TheK-shell fluorescence yield of germanium has been determined asωK=0.570±0.003 by the modified proportional counter technique using a special wall-less proportional counter filled with methane and small admixture of germanium hydride GeH4. The required ratio of the total photoabsorption to the absorption in theK-shell has been obtained from the separate study of the energy dependence of the X-ray absorption in germanium.

The K -shell fluorescence yield of germanium

TheK-shell fluorescence yield of gallium has been determined asω K =0.529± 0.002 from the study of theK-capture in germanium 71 by the use of GeH4 as gaseous source in a multiwire proportional counter system.

The K-shell fluorescence yield of gallium

TheK-capture of the naturally radioactive isotope potassium 40 has been studied using a special large proportional counter whose cathode made of thin metallized polyester foil was common to a ring of surrounding proportional counting units connected in anticoincidence. As source potassium cyanide has been employed evaporated in vacuum on the cathode and covered by antimony. From the measured spectrum ofK X-radiation of argon the specific activity of potassium due toK-capture has been determined as 2,25±0,25 disintegrations per sec per gram of natural potassium. This result yields for the ratio ofK and (L+Mu ...) electron capture probabilities the value 0,44±0,9.

J. Pahor

Papers

The K -shell fluorescence yield of germanium

The K-shell fluorescence yield of gallium

Electron capture in potassium 40