Volume 21, Issue 8

The momentum spectrum of cosmic ray muons and the charge ratio at 5200 m above sea level have been measured. To separate the spectrum of muons from the total spectrum a lead absorber was used. From theoretical models the spectrum of muons is calculated. Good agreement is found between the calculated and measured muon spectrum.

Λ convergent self consistent field calculation for the OH 3 + ion is reported. The results indicate that the isolated ion is planar, with an OH distance of 1.9007 a. u. ( = 1.006 Å nearly), self consistent field energy of —76.3722 a. u., and force constants of k 1 = 6.84 × 10 5 dynes/cm and k Δ /l 2 =2.39 × 10 5 dynes/cm. The correlation contribution to the binding energy for several ten electron systems are analysed in the Appendix.

Es wurden die Molwärmen von 4 Magnesiumproben gemessen, die verschiedene Mengen an Wasserstoff und Silicium enthalten. Bei den drei Proben mit niedrigem Si-Gehalt treten im Temperaturbereich von 150°—300°K Exzeßmaxima auf, die verschwinden, wenn der Si-Gehalt vergrößert wird. Es wird daraus auf Valenzbindungen zwischen Wasserstoff und Silicium in festem Magnesium geschlossen. Die Ursache für das Auftreten der Exzeßmaxima bei den Proben mit niedrigem Si-Gehalt wird im Beweglichwerden von H-Atomen oder Protonen gesehen. Die genauere Verfolgung dieses Ansatzes führt zu der Anahme, daß die Protonen im Gitter teils auf Zwischengitterplätzen, teils auf thermischen Leerstellen sitzen.

The electrical conductivity of molten and solid (Li, K) 2 SO 4 has been measured from 550 to 1086°C. The electrical conductivity of the high temperature modification of lithium sulphate increases when potassium and rubidium ions are added to the salt, but decreases when sodium ions are added. An explanation of these changes is proposed.

Two methods are utilized to study the relaxation behaviour and molecular motion in solutions of free radicals in toluene: the investigation of longitudinal and transversal solvent proton relaxation at a properly chosen frequency (48 MHz), and the determination of enhancement factors of the dynamic proton polarization over a large frequency range. The temperature dependence of the quantities concerned is measured between +70°C and —120°C. The results can be interpreted in terms of a pure dipole-dipole interaction between proton and electron spins whose time dependence is provided by translational random motions of the molecules and rotational tumbling of associated complexes. The activation energies for both processes are 3.1 kcal/mole and 7.8 kcal/mole, respectively. The solvation is only very weak. The relative contribution of rotational tumbling is R=0.26, from which the average co-ordination number is estimated to be less than one.

Proton magnetic resonance investigations on solid dimethylether (DM) , diethylether (DE) , dipropylether (DP), diisopropylether (DIP), dibutylether (DB), dimethoxymethane (DMM), diethoxymethane (DEM), dimethoxyethane (DME), diethoxyethane (DEE), acetaldehyde (ACA) and diethylketone (DEK) yielded information on molecular motion, solid state phase transitions and deglassing processes. The temperature-dependence of the spin-lattice relaxation time and the second moment was studied between the melting point and 77 °K using radiofrequency pulse techniques. Both spin-lattice relaxation and line shapes are governed by dipolar interactions which are modulated in time by hindered rotations of CH 3 -groups. The parameters for this relaxation mechanism are given in detail. Concerning the general results it was possible to distinguish between three cases : a) substances that form only one crystalline phase in the solid state (DM, DIP, DEM, DME, ACA, and DEK); b) ethers that form only a vitreous state (DP and DEE) and c) ethers that form both crystalline and vitreous states depending on the way in which the liquid was cooled. In the last case a pronounced decrease of the second moment of the absorption line was observed near the phase transition from the vitreous to the polycrystalline state. This means that within a small range of temperatures far below the melting point some kind of melting of the glass occurs before the crystal is formed.

Im Frequenzbereich 11—29 GHz wurden bei Temperaturen zwischen 430 und 500°C Rotationsübergänge von 18 Isotopenkombinationen des GeSe gemessen. Es werden Rotationskonstanten, Kernabstände und Massenverhältnisse von Germanium- und Selenisotopen mitgeteilt. Für den Kernabstand des GeSe ergibt sich der Wert r e = (2,134632 ± 0,000063) A. Aus der Quadrupol-Hyperfeinstruktur eines Rotationsüberganges des Ge 78 Se 80 folgt für die Kernquadrupol-Kopplungskonstante des Ge 73 e q Q = ( + 175 ± 3) MHz.

An einer undotierten, polykristallinen n-InP-Probe wurden galvano- und thermomagnetische Messungen im schwachen transversalen Magnetfeld durchgeführt. Eine Analyse der Meßdaten bei 500°K zeigt, daß die Elektronen hauptsächlich an optischen Phononen gestreut werden. Für die effektive Elektronenmasse ermält man m n =0,068 m 0 .

The epitaxy of Cu 2 O grown on copper crystal spheres by thermal oxidation is well known. Allways one pair of 〈110〉 directions in the metal and the oxide are parallel. The complicate epitaxial situation of the antiparallel orientation on the 〈110〉 great circles is now established by two principles: The atomic relievo of a {hhl} plane consists of {111}, {001} or {110} facets. Adjacent facets of metal and oxide must contain the same number of 〈110〉 rows of metal atoms and the distance between 〈110〉 rows in adjacent facets must not deviate more than 20%. An older rule was concerned with the distance of 〈110〉 rows in the {hhl} planes. This rule is a consequence of the two principles but solely it is not sufficient.

Negative ion formation by electron impact has been studied in hydrogen sulphide, methylmercaptan, phenylmercaptan, benzylmercaptan, allylmercaptan, dimethylthioether, dimethyldisulphide and diallyldisulpbide. Appearance potentials, ionization efficiency curves and the kinetic energies of negative ions were measured by using a Fox ion source. The energies of various dissociative electron capture processses are discussed and electron affinities of some radicals of the types RS and RS 2 are derived. Two chemical reactions of the CH 2 S - ion with dimethyldisulphide have been detected.

Starting from a parallel jet concept the linearized magnetogasdynamic equations are solved for a supersonic free plasma jet with an axial current. The solution is given in terms of the magnetic pressure number. A critical magnetic pressure number depending on the MACH number is derived. Below this value standing periodic pressure waves occur, as in the gasdynamic case. For higher values the pressure distribution is non-periodic. Experiments are performed with a supersonic argon jet. The MACH number is determined by the shock angle at a cone. The pressure distribution in the axis of the jet is measured by a pressure probe. The experimental results are consistent with the theoretical predictions.

It is shown that ALFVÉN waves in a collisionless plasma, permeated by an inhomogeneous magnetic field, are affected by a strong anomalous damping. This anomalous collisionless damping seems to correspond to collision-free LANDAU damping in homogeneous magnetic fields in a similar way as the anomalous viscous and OHMic damping of ALFVÉN waves propagating in inhomogeneous magnetic fields 1 corresponds to the ordinary collisional viscous and OHMic damping of ALFVÉN waves propagating in homogeneous magnetic fields. It is found that the predicted collision-free anomalous damping will obey a law of the form exp{ — (t/τ) 2 } where the damping time τ depends on the wave-length, the temperature of the plasma, and the magnetic field gradient. Starting from a simplified BOLTZMANN-VLASOV equation, valid for low frequency plasma waves 2 , a LAPLACE transform is carried out with regard to the time dependence and an integral equation is derived for the mean plasma velocity. By the faltung theorem this integral equation can be FOURIER transformed into a differential equation for which a W.K.B. solution can be obtained. The inverse transforms can be carried out by making a simple analytic approximation for the W.K.B. solution which is valid over a large range of values. The predicted anomalous damping of ALFVÉN waves is so strong that it may be useful for the purpose of heating a plasma up to high temperatures within a short time.

In a foregoing paper 1 the effects of a turbulent motion on magnetic fields were investigated. Especially turbulence was treated under the influence of CORIOLiS-forces and gradients of density and/or turbulence intensity. It was shown that on these conditions the average cross-product of velocity and magnetic field has a non-vanishing component parallel to the average magnetic field. Here we give the consequences of this effect for rotating, electrically conducting spheres. At first a sphere rotating with constant angular velocity is investigated. The quadratic effect provides for dynamo maintainance of the magnetic fields. A field of dipol-type has the weakest condition for maintainance. Applications to the magnetic field of the earth show a good agreement with the conceptions of the physical state of the earth’s core. For a second model differential rotation is included. We have also dynamo maintainance. Since we have to assume that generally the angular velocity is a function decreasing with the distance from the centre of the sphere, the calculations show that we have a preferred self-excited build-up of a quadrupol-type field. This model may be applicable to magnetic stars. Finally we look for dynamo maintainance of alternating fields. We consider the skin-depth to be small compared with the radius of the sphere, then we have plane geometry. The existence of periodical solutions is proved. Applications to the general magnetic field of the sun, which has a period of 22 years, are discussed.

The penetration profiles of 70 keV krypton-85 ions in gold single crystals were determined for different incident angles between the ion beam and the 〈110〉 or 〈111〉 crystal axis. Channelling is most pronounced in the 110 direction but it falls off at first steeply, then at angular deviations larger than 10° rather slowly by tilting to 〈111〉 or 〈100〉. A sharp aperture cannot be defined for the 110 channel; its half width is of the order of 2 ... 3°. In 〈111〉 no directional channel seems to be operative, although the long tail range distribution indicates a steering of the penetrating ions.

The relation between the intensities of CH frequencies and TAFT'S inductive substituent constant σ I found recently for mono-substituted benzenes X —C 6 H 5 can be accounted for by the interaction of a CX dipole moment μ CX with the CH dipoles in ortho, meta, or para positions. The intensities are then given by equations of the type I=A μ 2 CX—Β μ CX +C. Comparison with the experimental result I=ασ I 2 — b σ I +c shows that σ I can be interpreted as being a measure of the inducing dipole moment.