Diekll-Auger-Spektren von Eisen und Vanadium

The relative intensities of theKLL-Auger transitions of Fe (Z=26) und V (Z=23) were measured with an iron free, double focusing β-spectrometer. The results obtained are in good agreement with those measured bySokolowski andNordling forZ=29 andZ=32. This confirms the discrepancies between the nonrelativistically calculated intensities and the experimental values in the region of lowerZ. A summary is given about all known measurements of theKLL-Auger intensities. Also theKLL∶KLX-ratio of Fe was measured to be 1·0∶(0·19±0·01). The energy of the 14·4-keVγ-transition of Fe⁵⁷ was evaluated to be (14389±6) eV.     

DasKLL- Auger-Spektrum von Chlor

TheKLL Auger spectrum of chlorine in CCl₄ has been investigated with an electrostatic energy analyzer. The ionization in theK shell of chlorine was caused by electron impact. Absolute energies and relative intensities of transitionsKL ₁ L ₁(¹ S,KL ₁ L _2,3(¹ P),KL ₁ L _2,3(³ P) andKL _2,3 L _2,3(¹ D) have been determined. Via the width of theK level of chlorine also experimental values of absolute transition probabilities have been calculated. While the relative intensities deviate strongly from theoretical values, the absolute transition probabilities agree better with theoretical values, especially with those calculated byRubenstein. — In an appendix the natural line widths of theKLL components of argon have been calculated theoretically.     

Auger spectra for elements of low atomic number

KLL Auger spectra for the light elements sodium (Z=11) and magnesium (Z=12) have been studied. All five lines predicted by the extremeLS coupling theory are observed. A comparison is made with intensities predicted by the inter-configuration interaction theory ofAsaad. Agreement is obtained for the transition intensities to the three differentKLL configurations; however, theory does not give correct relative intensities within the 2s ² 2p ⁴ configuration. The measured Auger energies are compared with those calculated from the semi-empirical expression ofAsaad andBurhop and modified byHörnfeldt et al. Good agreement is obtained when we use electron binding energies measured by the ESCA method.     

TheL- andK- Auger spectra of tellurium

TheL- andK- Auger spectra of tellurium (Z=52) were studied from the electron capture decay of¹²⁵I. The measured relativeL- Auger transition intensities are not in agreement with the theoretical intensities of Asaad for silver (Z=47). The measured relativeKLL intensities are in agreement with those ofGraham et al. Relative intensities are given for theKL Y spectrum. TheKL Y/KLL ratio was measured to be 0.44 ± 0.02 in good agreement with the theoretical value given byWapstra.K/L andL subshell conversion ratios are given for the 35 keV nuclear transition in¹²⁵Te.     

Das KLL-Auger-Spektrum für 10≦Z≦36

The configuration interaction, applied very recently byAsaad to the calculations ofKLL-Auger spectra, could remove the large discrepancies which existed for lowZ between experimental and theoretical relative group intensities I(KL₁L_2,3)/I(KL₁L₁) and I(KL_2,3L_2,3)/I(KL₁L₁).Asaad's calculations, however, were based on binding energies E(L₁) and energies of the Coulomb and spin-orbit interaction, which were not very accurate. In the present calculations use has been made of more accurate binding energies E(L₁) and Coulomb and spin-orbit interaction energies. It is shown that the absolute error in the results of the new calculations is less than 10%. From this it follows that the remaining discrepancies between theoretical and experimental values of the group intensities for 10≦Z<25 may be solely attributed to the inadequacy of the calculated transition probabilities. This calls for calculations of transition amplitudes of the KLL-process with more accurate wave functions for Z<25, in particular for Z=10.     

TheK Auger spectrum of the free magnesium atom

TheK Auger spectrum of free Mg atoms has been investigated with an electrostatic energy analyzer at an energy resolution of 0.16%. The ionization in theK shell of the Mg vapour was caused by electron impact. Absolute energies and relative intensities of the normal Auger transitionsK-LL and of the most intense satellite lines have been determined. The experimental energies and relative group intensities of the normal lines agree well with theoretical values. The total intensity of special classes of satellites are compatible with calculations of the shake theory within the sudden approximation.     

The KLL and KLX auger electrons of arsenic from the 75Se decay

The KLL and KLX spectra for Auger electrons of arsenic (Z = 33) emitted during ⁷⁵Se decay were recorded, with an instrumental resolution of 11 eV, using a combined electrostatic spectrometer. The relative energies and intensities of nine KLL and ten KLX transitions were determined by computer analysis of the spectra. The margins of error were estimated to be 1–4 eV for energies and 2–50% for intensities. Except for the KL₁L₂ (¹P₁) transition, the measured relative intensities of the KLL transitions were found to agree, within 3 standard deviations (σ), with those calculated relativistically using the intermediate coupling approximation with configuration interaction. The discrepancy for the KL₁L₂ (¹P₁) transition amounted to 6σ. The KL₃M_2,3/KL₂M_2,3 transition intensity ratio agreed with the prediction based upon the intermediate coupling scheme but deviated by 7 σ from the value predicted by the jj coupling approximation.     

Auger- und Coster-Kronig-Übergänge der M-Schale von Krypton

The Auger spectra of theM ₂,M ₃,M ₄,M ₅ subshells of krypton and the Coster-Kronig spectra of theM ₁,M ₂,M ₃ subshells of krypton were measured with an electrostatical spectrometer. The ionization in theM shells was caused by electron impact. The use of a gaseous target made it possible to measure the Auger lines even at energies as low as 25 eV. The absolute energies and relative intensities of a great number of transitions were determined: 22 of theM _{4, 5} spectrum, 14 of theM _{2, 3} spectrum and 2 of theM ₁ spectrum. Only in the case of theM _{2, 3} spectrum a comparison between the relative intensities, determined experimentally, and those calculated byRubenstein forZ=47 was possible. The agreement is only qualitatively. Moreover, from the Auger electron energies measured, the following binding energies were calculated:E(M ₁)=(292,1±1,0) eV,E(M ₂)=(222,1±0,6) eV,E(M ₃)=(214,6±0,6)eV,E(N ₁ N ₁)=(62,81±0,05) eV.     

Excitation lines and multiple ionization in Auger spectra

Satellite lines of a new type and excessively large continuous distributions of energy degraded electrons are observed in theKLL Auger spectra of potassium, chlorine, and sulfur. The lines are tentatively interpreted as due to a process that is characteristic of the atom more than of the entire solid and the excessive number of electrons in the continuous distributions is interpreted as due to multiple ionization.     

Inelastic collision cross section of excited molecules

The (v′=6,J′=43) level in theB ¹Π _u electronic state of Na₂ has been selectively populated by excitation with the 4 880 Å line of the argon laser. Through collisions with He atoms energy is transferred to neighbouring rotational states in Na₂ and the density of these states is determined by observing fluorescence to electronic ground state. From previous measurement of the lifetime of theB ¹Π _u state and new measurements of the intensities of collision induced spectral lines as a function of He pressure, absolute collision cross sections for all rotational transitions up to ΔJ=±5 have been obtained. The total cross section for all rotational transitions observed is σ _rot ^total =65±15 Ų. Preliminary results about collision induced vibrational transitions are also presented.     

Conversion coefficients of transitions in111Cd by a new precision method

An electron-electron coincidence method for precise measurements of internal conversion probabilities is described. By usingK-Auger electrons the atom itself provides a unity standard in the same nuclear decay. The method is applied to the decay of¹¹¹In in which theK-conversion probability of the 245 keV transition is determined to be 0.0494±0.0011. Relative internal conversion intensities and transition energies are determined using a double focussing spectrometer. These data make it possible to calculate conversion coefficients for all electron shells.     

Search for correlation effects in theM 4, 5 N 4, 5 N 4, 5 Auger spectrum of xenon

TheM _{4, 5} N _{4, 5} N _{4, 5} Auger spectrum of xenon has been measured with high resolution. Theoretical line intensities and relative line energies for this spectrum have been calculated applyingjj coupling to the initial states and intermediate coupling and configuration interaction to the final states. Two facts indicate that correlation effects are only small in the present case: The application of configuration interaction gives only small changes in line intensities and the experimental line intensities are found to be in good agreement with theoretical results, calculated without configuration interaction.     

An electron spectroscopic determination of theL I energy in the elements Sodium (Z=11) to Copper (Z=29)

Energies of atomic electrons in theK andL shells of eighteen elements of low atomic numbers have been measured by electron spectroscopy. Tabulated values for theL _I energies are shown to be in need of considerable revision. AluminumKα radiation is shown to have high potentialities for ESCA studies.     

Messungen zu den Vibrations- und Zweiquasiteilchenzuständen in172Yb

The Coster-Kronig and Auger spectrum of theL ₁ shell of gaseous argon has been investigated with an electrostatical spectrometer. The ionization in theL ₁ shell of argon was caused by electron impact. Absolute energies and relative intensities of all the Coster-Kronig and Auger transitions have been determined. The relative intensities of transitions within the groupsL ₁ L _{2, 3} M ₁,L ₁ L _{2, 3} M _{2, 3} andL ₁ MM agree fairly well with the theoretical values, calculated byRubenstein for extreme Russel-Saunders coupling, if intermediate coupling theory is used properly. Via the widthγ(L ₁) of theL ₁ level of argon, found in this experiment to be (1.84±0.2) eV, the following absolute group transition probabilities were determined (in units of 10¹⁴ sec^?1):W(L₁ L _{2, 3} M ₁)=(5.5±1.0),W(L₁ L _{2, 3} M _{2, 3})=(20.8±2.8),W(L₁ MM)=(1.44±0.16). The theoretical values are 21.0, 20.4 and 1.27. The possible reason for the large discrepancy between the experimental and theoretical value ofW(L₁ L _{2, 3} M ₁) is the use of the incorrect value of 287 eV for the binding energyE(L₁) byRubenstein. From the energies of theL ₁ MM transitions this value has been determined to beE(L₁)=(326.5±0.5) eV. This is the first direct measurement ofE(L₁) of argon.     

Sulphur KLL auger spectra of gaseous sulphur compounds

Measurements of the diagram-line energies and intensities of sulphur KLL Auger spectra for the gaseous compounds H₂S, SO₂ and SF₆ are p     

Measurement of the Lamb shift 42S1/2-42P1/2 of the helium ion

Helium ions were produced in then=4 states by electron collisions with ground state atoms, resulting in simultaneous ionization and excitation. Dipole transitions between the Zeeman levels of the states 4² S _1/2 and 4² P _1/2 were induced by a microwave electric field. The intensity of the emitted Fowlerα line 4686 Å, corresponding to transitions from then=4 to then=3 states was then reduced by about 3%. From the measurements, a value of the Lamb shiftδ=1751±25 MHz was obtained, compared with the theoretical valueδ=1768.23±0.55 MHz, and the results ofLea, Leventhal andLamb ofδ=1765±20 MHz.     

Charge-transfer transitions and optical spectra of vanadates

Specific features of the charge-transfer states and O2p → V3d transitions in the (VO₆)^9? octahedral complex are studied using the cluster approach. The reduced matrix elements of the electric-dipole transition operator are calculated for many-electron wave functions corresponding to the initial and final states of a charge-transfer transition. Using a parameterization of the results, the relative intensities of the allowed charge-transfer transitions are calculated disregarding the mixing of different configurations of the same symmetry. The Tanabe-Sugano theory is used with inclusion of this mixing to calculate the energies of many-electron charge-transfer transitions and their actual intensities. Modeling of the optical spectrum of LaVO₃ reveals a complicated charge-transfer transition band consisting of 81 lines. The main maxima of the band are in the range 6.3–7.3 eV. There are also additional maxima in the regions of ≈3 and ≈8–9 eV. The bandwidth is ≈10 eV. The results of model calculations are in agreement with experiments and demonstrate the weakness of the widely used assumption that the spectrum of charge-transfer transitions has a simple structure.     

Der Zerfall des Gd151

The electron-capture decay of Gd¹⁵¹ was investigated by means ofγ- andγ-γ-coincidence spectrometry, using scintillation counters. Besides the knownγ-rays of 22 kev, 154 kev, 175 kev, 244 kev and 308 kev additionalγ-transitions with energies of 107 kev and 350 kev could be assigned to the decay of Gd¹⁵¹.γ-γ-coincidence measurements showed the following cascade transitions: (107 kev–244 kev), (154 kev–175 kev–22 kev) and (308 kev–22 kev). TheK-conversion-coefficients of several transitions were determined by comparing theγ-intensities and the previously known conversion electron-intensities, using a direct measurement of theK-conversion-coefficient of the 175 kev-transition by a delayed coincidence-experiment as a normalization of the relative intensities. With the available information a level-scheme for Eu¹⁵¹ is proposed.     

Phenomenological renormalization of free nucleon-nucleon interaction

Low-lying spectra of⁶Li,¹⁸F,¹⁸O,⁴²Sc,⁴²Ca,⁵⁸Ni and⁹²Zr are studied with Sussex matrix elements (SME) and their central, spin-orbit and tensor components. It is observed that major contribution to level energies comes from the central part, while the tensor part provides the finer details of spectra, particularly forT=0 levels. The spin-orbit part does not make any appreciable contribution to level energies. A phenomenological renormalization of the SME is carried out to improve the agreement with the experimental results. It turns out that some of the low-lyingT=0 levels can be satisfactorily described if the SME in the³S₁ relative state are made (1+α) times their bare interaction value, whereα is a constant to be determined from a comparison with experimental level energies. Similarly, forT=1 levels, better agreement with the experimental results is obtained if aδ-function-plus-quadrupole interaction is added to the SME.     

On the intensities ofK X rays following thermal neutron capture

Through the measurement of the absolute intensities of theK _α andK _β X rays following slow neutron capture in¹⁵⁵Gd,¹⁷⁶Lu and¹⁹⁹Hg and their comparison with the intensities of theK-conversion electron transitions from the same reaction it is shown that theK X rays are caused only by internal conversion.