Fragmentation of gold projectiles: From evaporation to total disassembly

We have studied the fragmentation of Au projectiles interacting with targets of C, Al and Cu at an incident energy ofE/A=600 MeV. The employed inverse kinematics allowed a nearly complete detection of projectile fragments with chargeZ≧2. The recorded fragmentation events were sorted according to three observables, the multiplicityM _lp of light charged particles, the largest atomic numberZ _max within an event, and a new observable,Z _bound, representing the sum of the atomic numbersZ of all fragments withZ≧2. Using these observables, the impact parameter dependence of the fragmentation process was investigated. For all three targets, a maximum mean multiplicity of 3 to 4 intermediate mass fragments (IMFs) is observed. The corresponding impact parameters range from central collisions for theC target to increasingly peripheral collisions for the heavier targets. It is found that the correlation between the IMF multiplicity andZ _bound, extending from evaporation type processes (largeZ _bound) to the total disassembly of the projectile (smallZ _bound), is independent of the target nucleus. This universal behaviour may suggest an — at least partial — equilibration of the projectile fragment prior to its decay.     

Ebene Äquiforme Zwangläufe im Grossen II

Im ersten Teil dieser Arbeit¹ wurden die orientierten Flächeninhalte der Punktbahnen ebener äquiformer Zwangläufe studiert und einige Anwendungen der erzielten Resultate angeführt. Der vorliegende zweite Teil beschäftigt sich - unter Beibehaltung der Bezeichnungen, der Numerierung der Abschnitte, Sätze usw. - einerseits mit Geradenhüllbahnen, andererseits mit globalen Eigenschaften spezieller äquiformer Zwangläufe, und zwar mit der äquiformen Bewegung der Krümmungsstrecken einer ebenen Kurve, mit äquiformen Konchoiden-bewegungen und mit der äquiformen Bewegung der Durchmesser eines beschränkten konvexen Bereichs. Beim Studium der durch formale Integration gewonnenen, vorzeichenbehafteten “Längen” der Geradenhüllbahnen wurden zur Interpretation des Vorzeichens orientierte Geraden des Gangsystems betrachtet. Dieser anscheinend notwendige Übergang zu Speeren wurde bislang bei der Formulierung von Holditch-Sätzen über Längen von Geradenhüllbahnen (vgl.[11],[39]) nicht beachtet. Wie schon im ersten Teil gestatten die Ergebnisse eine Anwendung in der globalen euklidischen n-Lagentheorie sowie auf nichtgeschlossene euklidische Zwangläufe.     

Über einen Fundamentalsatz der synthetischen algebraischen Geometrie von W. Burau und H. Timmermann

Ohne ZusammenfassungWerner Burau zum 80. Geburtstag gewidmet     

Antisymmetry and analytic structure in the spectrum of a uniform Fréchet algebra

Let M be a C-smooth submanifold of a domain GCⁿ. Denote by 0(M) the algebra of germs of holomorphic functions on M, that is, each f0(M) is holomorphic in some neighbourhood of M, the neighbourhood dependent of f. Now define A(M) as the closure of 0(M) with respect to the topology of compact convergence on M.If M coincides with A(M), the spectrum of A(M), we give a necessary and sufficient condition for A(M) such that M is a complex manifold.     

On static and radiative space-times

The conformal constraint equations on space-like hypersurfaces are discussed near points which represent either time-like or spatial infinity for an asymptotically flat solution of Einstein's vacuum field equations. In the case of time-like infinity a certain radiativity condition, is derived which must be satisfied by the data at that point. The case of space-like infinity is analysed in detail for static space-times with non-vanishing mass. It is shown that the conformal structure implied here on a slice of constant Killing time, which extends analytically through infinity, satisfies at spatial infinity the radiativity condition. Thus to any static solution exists a certain radiative solution which has a smooth structure at past null infinity and is regular at past time-like infinity. A characterization of these solutions by their free data is given and non-symmetry properties are discussed.     

A 94/47 GHz frequency halver using a GaAs Gunn device

This paper describes the basic principles and the set up of a new kind of frequency halvers suited for millimeter wave applications. A Ga As Gunn-device is used to act like a nonostable multivibrator having a hold time adequate to the domain transit time T_t of the Gunn-device.In a certain frequency range depending on the transit frequency f_T=1/T_T, bias voltage and circuit parameters a harmonic wave synchronized fundamental/2nd harnonic mode oscillator is able to perform as a frequency halver. An input power of only 1mW is sufficient to achieve a bandwidth of 5 GHz respectively 2.5 GHz centered around 94 GHz respectively 47GHz. Since the output power is 50 mW at fundamental frequency f_F, this halver offers 17dB conversion gain.     

High pressure Raman spectra of Gd,Lu and Y

Abstract

The pressure dependence of Raman phonons was studied for Gd, Lu and Y. The TO phonon mode of the hcp phase goes down in frequency for all three metals on approaching the hcp → Sm-type phase transition. Phonon softening also occurs in the high pressure Sm-type phase.