Showing papers in "European Physical Journal A in 1959"

Precision determination of energies of gamma rays in Sm 152 , Gd 152, 154, 155, 156 , Yb 170 , and Os 188

Abstract: With the help of the bent-crystal gamma-ray diffraction spectrometer the energies of 13 gamma rays, most of them belonging to rotational levels, have been determined with high precision. Rotational parameters are presented for the nuclei of Sm152, Gd154, and Gd156. A complete level scheme is given for Gd155.

THE ISOMERISM OF $sub 72$Hf$sup 17$$sup 9$

Abstract: BS>The gamma and conversion electron spectra of the 19-sec Hf isomer were measured with scintillation spectrometers in a 4 The effects of geometry. The half life was measured as T/sub 1/2 = 18.6 sintering time 0.2 sec. From the spectra, the conversion coefficients for both transitions could be determined. For the 161-kev transition a total conversion coefficient alpha /sub ,161/ = 35 sintering time 2 and a K conversion coefficient alpha /sub K,161/ = 19.4 sintering time 1.2 were found, which agree well with the factors calculated for an M3 transition. The measurements gave E/sub 2/ = 217 sintering time 2 kev for the energy of the second transition and alpha /sub 217/ = 0.055 sintering time 0.010 for the total conversion coefficient. In contrast to earlier hypothesis, it is clear that it is a matter of E1 radiation in this transition. Spin and parity of the ground state and the excited states of Hf/sup 179/ are in agreement with the level sequence given by Nilsson for deformed nuclei. (tr- auth)

MEASUREMENT OF SOME (n,$gamma$) SPECTRA WITH A PAIR SPECTROMETER OF HIGH SENSITIVITY

Abstract: A pair spectrometer of the 180 deg -focusing type with high efficiency and good resolution is described. The efficiency was determined as a function of the energy both theoretically and experimentally, and it is possible, therefore, to use this spectrometer for absolute calibration of gamma rays above 2.5 Mev. The evaluation methods of the pair spectra allow the single line to be determined with an error as little as plus or minus 8 kev (from 2.5 to 9 Mev). The neutron capture gamma spectrum of I/sup 127/, Cs/sup 133/, Ir/sup 191,193/, and Bi/sup 2 were measured, and the energy and intensity of the resolved gamma rays were given. From these results it is possible to compute the binding energy of the last neutron and also some unknovm levels. The experiments, which were performed in connection with the pair spectrometer, have shown an interesting possibility for research work with reactors. With an appropriate experimental arrangement and some special neutron capture gamma spectra, monochromatic gamma rays in the energy range between 3 and 11 Mev are obtained, which are better and much more intense than corresponding gamma rays from (p, gamma ) reactions. (auth)

Über die Absorption von ZnO-Kristallen im Ultraroten

Abstract: Die Ultrarotabsorption von synthetischen ZnO-Einkristallen mit und ohne Dotierung wurde im Wellenlangenbereich von 1 bis 13 μ untersucht. Die Absorption zeigt im allgemeinen einen kontinuierlichen Anstieg zu groseren Wellenlangen hin. Nur stark Cu-dotierte Kristalle und solche ohne Dotierung, die hinreichend lange bei hoherer Temperatur in Sauerstoff behandelt wurden, sind bis etwa 8 μ vollkommen durchlassig. Bei 10,1 μ und 11,5 μ finden sich Absorptionsmaxima, die wahrscheinlich auf die Anregung von Gitterschwingungen zuruckzufuhren sind. Die Absorptionskonstante bei fester Wellenlange steigt in groben Zugen mit der Leitfahigkeit der Kristalle an. Jedoch treten starke Streuungen auf; wasserstoffbehandelte Kristalle, die gleiche Leitfahigkeit haben wie undotierte oder im Zinkdampf behandelte Kristalle, zeigen viel kleinere Absorption als letztere. Bei Abkuhlung auf 90° K wurde teils eine Erhohung teils eine Erniedrigung der Absorption beobachtet. Die experimentellen Ergebnisse werden als Uberlagerung einer Storstellenabsorption mit der Absorption freier Ladungstrager gedeutet.

Messung der Korrelation zwischen Beta- und zirkularpolarisierter Gammastrahlung im Zusammenhang mit der Nichterhaltung der Parität

Abstract: Parity violation in beta decay was investigated by measuring the (beta, gamma) circular polarization correlation. The asymmetry coefficients were redetermined with higher accuracy for Co 60 (A=− 0,33±0,01) and Na 22 (A=+0,36±0,08). The cosΘ-dependence of the polarizationP was verified for the allowed beta transition of Co 60.

Erhaltungssätze für die Wirkung in elektromagnetischen und gravischen Strahlungsfeldern

Abstract: Two generally covariant integral conservation laws concerning electromagnetic null fields and vacuum gravitational fields of type II with vanishing Riemanneigenvalue respectively are proved. The conserved quantities both have the dimensions of action. The electromagnetic law shows that with respect to the propagation of energy a null field may be represented by a stream of photons. The gravitational conservation theorem is in many respects similar to the electromagnetic one; it admits to calculate the change of intensity along a gravitational ray.

Die Elektronenpolarisation beim O − →O + -Beta-Zerfall des Ho 166

Abstract: The polarizationP of the beta-rays from Ho166 and P32 has been investigated using the method of combined multiple- and Mott-scattering. The result for $$P/\frac{v}{c}$$ averaged over the energy range accepted by our apparatus $$\left( {\frac{v}{c} \approx 0.8} \right)$$ is $$\left\langle {\left( { - P/\frac{v}{c}} \right)_{Ho^{1^{66} } } } \right\rangle _{Av} = (0.99 \pm 0.02)\left\langle {\left( { - P/\frac{v}{c}} \right)_{P^{3_2 } } } \right\rangle _{Av} .$$ . Furthermore, it is shown that only a small deviation of the polarization from the normal value $$ - P/\frac{v}{c} = 1$$ is to be expected for P32-electrons. Electron polarization and spectrum shape of the O−→O+-transition of Ho166 are discussed with respect to the contribution of pseudoscalar coupling. On the basis of the two component theory of the neutrino (C V =C ′ ,C A =C ′ ,C P =C ′ ) one obtains an upper limit on the contribution of P-coupling: (C 2 /C 2 )¦∫ βγ5¦2≲3·10−7. If on does not assume the validity of the two component theory of the neutrino, however, the experiments are compatible with an arbitrary amount of P-coupling. In this case the experimental result indicates, that the two component theory of the electron (C V =C ′ ,C A =C ′ ,C P =−C ′ ) is valid. As a by-product, this work contains a compilation of formulas which are needed for electron polarization calculations using tabulated functions.

Neutrinorückstoßexperiment am Li 8

Abstract: The beta-decay of Li8→Be8*→2α is especially suitable in neutrino recoil experiments on account of the large beta-decay energy available and on account of the subsequent break up of Be8* into two α-particles. For the angular correlation between the antineutrino and the α-particle one obtains for our counter geometry and a Gamow-Teller interaction the angular distributionw(v)dv=(1+b v/c 0.707 cosv)dv, whereb=−1 for axial vector interaction (A) orb=+1 for tensor interaction (T) and wherev is the angle between the direction of emission of the antineutrino and the α-particle. The measurement of the energy difference of the two α-particles in the Be8* decay, when the direction of the emission of the beta-particle is fixed, defines the angular correlation coefficientb. In this experiment the value ofb is found to be equal to −1.12±0.20, which shows axial vector interaction in the Gamow-Teller decay.

Production of a h atomic beam with the same directional nuclear spin. analysis of the beam, detection of the polarization conservation

Abstract: In connection with an earlier work (Z. Physik 144 atomic beam apparatus with two quadrupole fields: (1) The component moving at the center of the quadrupole field is suitable for the production of polarized protons. Non- adiabatic transitions in the fields are not within the scope of this measuring accuracy. (2) The alignment of the nuclear spin remains constant after the exit from the msanetic field. At least 80% of the hydrogen atoms of this component are spirning adiabatically in the earth's fie1d and also in an ex(sting magnetic field. (3) The polarization degree for the nuclear spin of the hydrogen atom in the separation from this component is 0.8 at an intensity of 10% of the unpolarized atomic bearn, higher at still lower intensities. (4) The perturbing influence of the residual gas ions was estimated by orientation measurements with a Penning ion source in the atomic beam. (tr-auth)

Motion of Electromagnetic Waves in the Braunbek Approximation. Part II

Abstract: The extension, given in a previous paper (Z. Physik 156, fraction of electromagnetic waves, is applied to the near field of the circular aperture and the circular disk. The field distributions along the central axis and in the plane of the screen are calculated and compared with the results of both the rigorous solution and Kirchhoff's approximation. The relation of Braunbek's method to other approximation methods for the optical region is discussed.

New emission spectrum of the TeO molecule

Abstract: The spectrum of Tellurium monoxide as excited in a heavy current arc run by a 2000 volt D.C. generator was studied in the visible and ultraviolet regions. Photographs of the spectrum revealed many new bands in the regionλ 6200 toλ 3300, which are clearly degraded to longer wavelengths. Some of the bands in the regionλ 3800 toλ 3300 were identified with those of the system in the regionλ 3800 toλ 3060 (here designated as system,B-X) observed and analysed byChoong Shin Piaw. The analysis of theB-X system was extended to include some of the new bands uptoλ 4500. In addition to those assigned toB-X system, a number of new bands in the regionλ 5000 toλ 3500 constitute another system designated asA-X system. The analysis of this system has led to the following quantum formula for the band heads.v=27835+408 (v′+1/2)−4·0(v′+1/2)2 −796 (v″+1/2)+3·5 (v″+1/2)2.

MEASUREMENT OF THE ZEEMAN gJ FACTOR OF BOTH YTTRIUM GROUND STATES $sup 2$D$sub 3$ over $sub 2$ AND $sup 2$D$sub 5$ over $sub 2$ WITH THE ATOMIC RADIATION RESONANCE METHOD

Abstract: The high-frequency transitions between the Zeeman components of a hyperfine structure term ( DELTA F = 0 transitions) in magnetic fields between 470 and 490 gauss were measured in both ground states /sup 2/d/dub 3/2 and /sup 2/ D/sub 5/2 with a magnetic atomic beam resonance apparatus. By simultaneous measurement of a corresponding transition of the /sup 2/S/sub 1/2 ground state of Ag/sup 107/ at equal field strengths, the ratios of the g/sub t/ factors of the ground states of Y and Ag were determined to be: g/sub j/(Y/sup 89/, /sup 2D/sub 3/2//g/sub j(Ag /sup 2 /D/sup 1/2/) = 7/,/sup 2/S/sub 1/2) =

Gamma spectrum of Se81

Abstract: The decay oi Se81 (18 min) produced by neutron bombardment of natural Se and 98% enriched Se81 has been studied with the aid of scintillation - spectrometers. Gamma-rays have been observed and could be identified as belonging to the decay of Se81, revealing three excited levels in Br81 at (282 plus or minus 3) kev, (565 plus or minus 6) kev and (820 plus or minus 10) kev. The branching ratios of the beta-components are 98.7% leadiing to the ground state and (0.06 plus or minus 0.03)%, (0.85 plus or minus 0.20)% and (0.40 plus or minus 0.10)% leading to the excited states, respectively. The 565 kev-level decays to the ground state directly or by a cascade-transition with nearly equal intensities, the 820 kev-level mainly by a direct transition.

VERIFICATION OF PARITY CONSERVATION IN STRONG INTERACTIONS BY $beta$- $alpha$ ANGULAR CORRELATION AND $alpha$-$alpha$ CORRELATION

Abstract: It is shown that heta-gamma directional correlations provide a means to test parity conservation in the nucleonnucleon-interaction. A parity nonconservation would lead to an asymmetra of the correlation relative to 90 deg and proportional to RF in magnitude. In this product F signifies the relative amplitude of the wave function of'wrong' parity in a nuclear state and R a matrix element factor. Some examples are discussed numerically; estimates of an upper limit for F/sup 2/ of about 10/sup -8/ seem possible in suitable experimental cases. The use of gamma-circular gammacorrelations as a means of testing parity conservation in nuclear states is briefly reviewed. (auth)

A measurement method for the investigation of fluorescence decay processes

Abstract: A method is described which permits the measurement of the temporal process of the fluorescence intensity in a decay tune from 10/sup -7/ to 10/sup -9/ sec in excitation wifh cathode beams. The temporal intensity pattern was scanned point by point in analogy to the strobescopic methods. The time resolution was 0.4 nsec. The rise and decay of anthracene, naphthalene, and three solid polyacene solutions, which contained a foreign component in various concentrations. were given. (tr-auth)

($gamma$,p) AND ($gamma$,np) REACTIONS IN ARGON-40

Abstract: Argon gas was irradiated with 34-Mev bremsstrahlung. The yieids of the reactions Ar/sup 40/(4gg/,p)Cl/sup 39/ and 6 wt.% Ru-U all counting. The resulting upper limits for the cross sections, integrated to 28 Mev, are 160 Mev- mb fur ( , p), and 35 Mev-mb for ( np). This does not confirm the anomalously high Ar/sup 40( ,p) cross section reponted in the literature. (auth)

Messung der Temperaturabhängigkeit des ferromagnetischen Hall-Effektes von Nickelaufdampfschichten zur Ermittlung der Curie-Temperatur

Abstract: Durch die Messung der Hall-Spannung bei konstanter Feldstarke (6000 Oe) in Abhangigkeit von der Temperatur (20 bis 400° C) last sich aus dieser Grose die Curie-Temperatur dunner Schichten ermitteln. Wahrend bei Schichten mit einer Tragertemperatur wahrend des Aufdampfprozesses von 200 oder 300° C die Temperaturabhangigkeit weitgehend reversibel verlauft (von einigen Erholungsvorgangen bei hoheren Temperaturen abgesehen), treten bei kalt aufgedampften Schichten (20° C) starke irreversible Anderungen des elektrischen Widerstandes und des ferromagnetischen Hall-Effektes auf. Diese Ergebnisse fuhren zu dem Schlus, das die kalt aufgedampften Schichten eine niedrigere Curie-Temperatur besitzen als die heis aufgedampften Schichten.

Über die Beeinflussung der Ionenleitfähigkeit von NaCl durch Röntgenstrahlung

Abstract: NaCl-Einkristalle wurden im Temperaturbereich zwischen 200 und 650° C Rontgenstrahlung ausgesetzt. Die wahrend der Bestrahlung bei konstanter Temperatur gemessene Ionenleitfahigkeit wird dadurch vermindert. Die maximal erreichbare Leitfahigkeitserniedrigung ist von der Temperatur abhangig. Oberhalb 400° C wurden keine Leitfahigkeitsanderungen festgestellt. Eine Deutung der beobachteten Leitfahigkeitserniedrigung ist auf Grund der bei ahnlichen Versuchen gemachten Annahmen vonSmoluchowski uber Leerstellenkomplexbildung moglich.

A simple derivation for the advance of the intensity maxima of x-ray Bremsstrahlung

Abstract: The advance of the intensity maxima of x-ray bremsstrahlung can be clearly described if one considers the emmission of quanta first in a reference system with the electrons in relative motion and then in a static reference system. From this accurate qualitative description a correct formula for the angular distribution of radiation intensity results. In addition it is pointed out that only in the relative motion reference system does the Doppler effect appear, and in the static system only the advice, without the doppler effect appears.

Eingeengte Xenon-Hochdruckentladungen hoher Stromdichte

Abstract: An einem mit zwei Sonden versehenen wassergekuhlten Quarzentladungsrohr von 1,5 mm Durchmesser wurden Entladungen durch Xenon bei Drucken von 25 bis 55 Atm untersucht Um zu hohen spezifischen Leistungsaufnahmen zu gelangen, wurde die Entladung von geringer Stromstarke in Zeiten von 1/10 sec auf eine maximale Stromstarke von 30 Amp hochgefahren und gleichzeitig am Schleifenoszillographen Strom, Lampenspannung und Lichtstarke gemessen Der Gradient der Saule wurde aus der Differenz der Sondenspannungen, die mit einem Kathodenstrahloszillographen aufgezeichnet wurden, erhalten Die Bogentemperaturen wurden sowohl aus der elektrischen Leitfahigkeit als auch aus der Strahldichte des Kontinuums bestimmt Der Verlauf von Strahldichte pro Volumeneinheit, Temperatur, Elektronendichte und elektrischer Leitfahigkeit als Funktion des Abstandes von der Achse der Bogensaule werden wiedergegeben

Directional correlation investigations on the gamma radiation of Cd110

Abstract: For the determination of the angular momentum quautum number of the excited state of the Cd110 nucleus, the directional correlation between the gamma radiation occurring in the decay of Ag110m was measured with two scintillation spectrometers connected in coincidence. For an evaluation of the measurements the coincidence rates measured at different calibrations of the spectrometer must be resolved into the constituents correlating the single cascades. A method was indicated. From the results of the measurements, the angular momentum quantum numbers of the levels of the Cd/sup 110/ nucleus at energies of 1539, 2484, and 2920 kev could be given.

Absorptions- und Emissionsspektren einfach und mehrfach aktivierter Kaliumbromidphosphore

Abstract: The absorption and emission spectra of Pb++-, Tl+-, Ag+- und Cu+-activated potassium bromide crystals have been studied at room temperature. The absorption spectra of KBr-crystals, which are activated with combinations of these ions are additively combined of the absorption bands of the singleactivated crystals. The emission spectrum of KBr(Tl) is changed by the addition of the other activators in KBr(Tl). This fact demonstrates that the absorption and emission of light in KBr(Tl)-phosphors is caused by transitions between states of the KBr-lattice and states of the Tl+-activator. A corresponding model for these transitions in KBr(Tl) is suggested.

Investigation on the large angle scattering of muons in copper

Abstract: The paper represents the observation of large-angle scattering ofμ-mesons above 1 Bev/c in copper studied by a cloud chamber 18″×18″×7″. The result favours the Moliere theoretical distribution based on point charge model of the nucleus and is not in agreement with the Olbert theory of uniform nuclear model.

Ein richtungsempfindliches Zählrohr und seine Anwendung beim Li 8 →Be 8* -Zerfall

Abstract: A new type of proportional counter having a directional dependent efficiency has been used to measure the angular distribution of the α-particles of Be8 in the reaction Li8→Be8*. From the experiment an upper limit of 10% for the amount of the Fermi contribution in the Li8 beta-decay is deduced.

The theory of particle size distribution in aerosols

Abstract: A simple theory of that part of the variation of the particle sizes in an aerosol, which originates from the spatiallynon-homogeneous distribution of the condensatfon nucleus, is given. In the hypothesis, purely statistically distributed nuclei result when the relative dispersion of the masses of the colloidal particles is equal to the fourth root of the fraction of the total volume which is occupied by the colloidal particles. (tr-auth)