[en] Preliminary work on L₁-subshell x-ray fluorescence and Coster--Kronig yields, and measurements of mean L-fluorescence yields from double vacancy states in indium is reported

[en] Calculated values of the coefficients of internal conversion of gamma rays in the K shell and L₁, L₂, L₃ subshells from published tabulations by Band and Trzhaskovskaya and by Roesel et al. at Data Nucl. Data Tables, 21, 92-514(1978) are compared with values obtained by computer interpolation among tabulated values of Hager and Seltzer Nucl. Data, A4, 1-235(1968). In some cases, agreement among the three calculations is remarkably good, and differences are generally less than 5%. In a few cases, there are differences as large as 20 to 50%, corresponding to the threshold effect described by Roesel et al. The Z-dependent resonance minimum described by Roesel et al. is also observed in the comparison of E1-E4 conversion in the L₁ subshell. In several cases (notably M1-M4 conversion in the K shell and L₁ subshell), the Band and Roesel calculations show dramatically different dependence on gamma energy and atomic number. For Z = 100, the Band calculation for E4 conversion in the L₃ subshell shows irregular behavior at energies below the K-shell binding energy. A few high-quality measurements of internal conversion coefficients (+-5%) would help greatly to establish a basis for choice among the theoretical calculations. 32 figures

[en] The 100 keV transition in ¹⁸²W was studied in order to check the L₁/L₂ and L₂/L₃ ratios of the internal conversion coefficients (ICC). The ¹⁸²Ta source was produced by reactor irradiation of ¹⁸¹Ta layer sprayed on an aluminium foil. The π√2 type β-spectrometer was used. The form of the L₃-line and for the first time the fraction of Lsub(3)Nsub(1-5)-lines of the double internal conversion respectively to the conversion of L₃ subshells were measured. 12 measurements of L₁/L₂ and L₂/L₃ ratios in the corresponding points of the spectrum were performed in order to determine the ratios of ICC in L-subshells. The results of all the measurements were in good agreements within the limits of statistical errors. The mean weighted values of the.ratios of the lines intensities of equal L₁/L₂ = 0.0823+-0.0013 and L₂/L₃ = 1.126+-0.010 at the errors +-0.0006 and +-0.009 respectively. The theoretical values of these ratios were determined by the graphical intarpolation of the ICC ratios using the ICC tabulated values

[en] K and L X-ray yields and p-state absorption probability for plutonium formed in liquid hydrogen and in gas are given

No abstract available

[en] We discuss asymmetry of the shape of β-lines of the Tm atom emitted in knockout of an electron from L and M shells in a nuclear transition. (These lines are used for calibration of the spectrometer in the experiment performed at the Institute of Theoretical and Experimental Physics on the search for a nonzero neutrino mass.) The asymmetry arises as the result of excitation of outer electrons to the discrete and continuous spectra. The ''shake-up'' mechanism is dominant up to excitation energies around 150 eV, and its probability is calculated with the Hartree-Fock method

[en] Most widely used Internal Conversion Coefficients (ICCs) data tables are those of Hager and Seltzer, Rosel et al and Band and Trzhaskovskaya. Although theoretical ICCs differ as a consequence of the model adopted by the authors, details of the physical assumptions, inadequate knowledge of some quantities involved in the computations and approximations made in the code, agreement among the calculated data can be remarkably good, varying by less than a few percent and generally less than 5%. Various analysts, Campbell and Martin, Raman et al. have pointed out the differences between equivalent tabulations and between calculated and experimental ICC values. Whatever deviations that have been reported earlier have been brought down by the theoretical calculations of BRICC. No systematic deviations could be found in terms of transition energy, atomic number etc. We confidently recommend the BRICC tables for theoretical ICCs using BRICC code for interpolation. BRICC are the best theoretical ICC calculations. Now with the new theoretical calculation of BRICC, it has become possible to explain the systematic discrepancy problem raised by many authors over the years. If at all discrepancies exist in some case they are not systematic but can be attributed to multipole mixing

No abstract available

[en] Two applications of the method of directional correlations are described. The first part deals with gamma-gamma directional correlations measurements. A total of 27 cascades have been studied in ⁹⁷Tc, ²⁰⁶Pb and ²⁰⁶Bi. Information is obtained on the angular momenta of levels, multipolarities of electromagnetic transitions and further, reduced transition probabilities. The later part of this thesis describes a determination of anisotropic directional correlation between gamma-rays and LX-rays in ¹⁶⁰Dy. To the authors' knowledge this is the first observation of an anisotropic correlation between gamma rays and X-rays following internal conversion. (Auth.)

[en] A total of 69 conversion coefficients, which include 29 K-, 22 L- and 18 M - conversion coefficients for 36 transitions in the decay of ^177mLu have been determined for the first time. A detailed study of the level scheme of ¹⁷⁷Hf for comparison with unified model predictions has been carried out