The level structure of104Rh deduced from the103Rh(n, γ)104Rh reaction

A sensitive, high resolution study of the¹⁰³Rh(n, γ)¹⁰⁴Rh reaction has revealed the presence of 516 transitions in the energy range 3,700 to 7,000 keV. These results have been used to interpret the reaction in terms of a statistical model in which a constant temperature level density is assumed. Previous work which revealed a much simpler level structure is quantitatively explained in terms of resolution and sensitivity. The average reduced radiative width is significantly lower than that reported for nuclides in theA=100 mass region and the width shows an indication of an energy dependence somewhat greater thanE _γ ³ . The neutron separation energy of the reaction is found to be 6,999.0±0.1 keV.     

Nonlinear volterra equations with infinite delay

This paper is concerned with the existence and stability of nonlinear Volterra equations which have infinite delay and are of the form: $$x (\varphi ) (t) = W (t, \tau ) \varphi (0) + \int\limits_\tau ^t {W (t, s)} F(s,x_s (\varphi )) ds, x_\tau (\varphi ) = \varphi \in C_u .$$ Here,X denotes a Banach space;W(t, s) is a linear evolution operator mappingX toX; C _u is the space of uniformly continuous functions endowed with the supremum norm; andF(·,·) is a continuous mapping ofR×C _u toX. The autonomous version of the preceding equation is also considered. A nonlinear semigroup is associated with its solutions and the infinitesimal generator of the semigroup is characterized. The generator is then used to represent and approximate solutions to the autonomous equation.     

Reciprocity principles associated with the general linear gravity wave problem

Summary Reziprocity principles are presented which hold for the general problem of small amplitude wave motion on the surface of an incompressible liquid. The effects of viscosity, surface tension, irrotationality, free surface sources and solid boundary geometry at liquid-solid intersections are discussed.

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Zusammenfassung Reziprozitätsprinzipien, die für das allgemeine Problem der Wellenbewegung mit kleinen Amplituden auf der Oberfläche einer inkompressiblem Flüssigkeit gelten, werden angegeben. Die Einflüsse von Viskosität, Oberflächenspannung, Wirbelfreiheit, Quellen an der freien Oberfläche un die Geometrie fester Ränder bei flüssig-festen Übergängen werden diskutiert.

     

Causal logic of Minkowski space

It is shown that double-orthogonal sets (diamonds) in Minkowski space form an orthomodular complete lattice. Connection with empirical logic of Randall and Foulis is discussed.     

Magnetic moments and the high field susceptibilities of MnFe2O4

An extended version of the noncollinear spin model bySawatzky et al. is developed to derive a dependence of the differential high field susceptibility on the degree of inversion of the ferrite MnFe₂O₄. Using the available data on the main molecular field coefficients it is shown that the present model imposes restrictions on values of. Determination of from the measurements of the field dependence of the saturated moments at low temperatures on samples with varying degrees of inversion reveals good quantitative agreement with the present model.     

Rigorous information-theoretic derivation of quantum-statistical thermodynamics. II

Part I of the present work outlined the rigorous application of information theory to a quantum mechanical system in a thermodynamic equilibrium state. The general formula developed there for the best-guess density operator \(\hat \rho\) was indeterminate because it involved in an essential way an unspecified prior probability distribution over the continuumD _H of strong equilibrium density operators. In Part II mathematical evaluation of \(\hat \rho\) is completed after an epistemological analysis which leads first to the discretization ofD _H and then to the adoption of a suitable indifference axiom to delimit the set of admissible prior distributions. Finally, quantal formulas for information-theoretic and thermodynamic entropies are contrasted, and the entire work is summarized.     

Nuclear orientation of106Rh in iron

The anisotropy of -rays from the decay of oriented¹⁰⁶Rh nuclei was studied at temperatures between 14 and 100 mK. The ground state magnetic moment was determined to be |(1⁺)|=3.07(9) n.m. Incomplete orientation was observed which is assumed to result from relaxation during the 43 s lifetime of the decaying nucleus.     

General alloy analogs of itinerant magnetic systems

Magnetically disordered, strong correlated itinerant electron systems are studied within the Hubbard model. Following an alloy analogy, the approximated system hamiltonian contains local vectoral magnetic fields at the atomic sites, which can be oriented into all space directions. The statistical system of the localized magnetic moments (due to the fields) is treated by the aid of a generalized CPA-technique. Supposing a macroscopic magnetic structure of sublattice antiferromagnetism, the formation of incomplete antiferromagnetic ordering of the localized moments is examined. The results show, that the electron density plays an essential roll for the question, whether or not it is possible to go beyond the pure (itinerant) antiferromagnetic state. Including the results of earlier papers for homogeneous macroscopic magnetic structure, on the whole scale of electron densities it is summed up (at zero temperature), where the different states (without-, with incomplete- or with complete magnetic order) are able to exist. It is shown, for fixed density respectively, which different phases are passed through on changing the coupling constant.Work supported by the Deutsche Forschungsgemeinschaft     

Hyperfine structure investigations of some odd levels of Co I by level crossing and optical methods

Using the level crossing technique the ratios and absolute values of the hyperfine structure (hfs) constants of the levelsz ⁴F_9/2 andz ⁴F_7/2 of the configuration 3d ⁷4s4p of Co I were measured:z ⁴ F _9/2: ¦A¦=(811±12)MHz; ¦B¦=(48±93) MHz;B/A=?0.06±0.11 A>0; B<0z ⁴ F _7/2: ¦A¦ = (659 ±11)MHz; ¦B¦=(33±84)MHz;B/A=?0.05±0.13 A>0; B<0. In addition the hfs constants of three other excited levels of Co I could be determined by optical methods:z ⁴ F _9/2:A=525±26 MHz;B=200 MHzy ⁴ F _9/2:A=300±30 MHz;B=?500 MHzy ⁴ G _11/2:A=315±20 MHz;B=400 MHz. The experimental results are compared with known experimental and also with theoretical values which where calculated using the parametric potential method.     

Measurement of theg-factor of the 4 1 + -state of202Pb

Theg-factor of the 4 ₁ ⁺ -state of²⁰²Pb was investigated by the IPAC-technique. Inspite of the long half-life, which was measured as:T _1/2(4 ₁ ⁺ -state)=1.97(2)ns and the strong applied external magnetic field of 95.0 kG no rotation of the 787 keV-(422keV)-961 keVγ-γ angular correlation could be observed. Theg-factor must therefore be very small. A computer fit gave the limits:g(4 ₁ ⁺ -state)=+0.002(4). This smallg-factor can be understood by the assumption of an accidental cancellation of a positive contribution by the main [f _5/2 ² ]₄-configuration and several negative contributions by admixtures of all other possible two neutron configurations.