Comparative Analysis of the Mechanisms of Fast Light Particle Formation in Nucleus-Nucleus Collisions at Low and Intermediate Energies

The dynamics and the mechanisms of preequilibrium-light-particle formation in nucleus-nucleus collisions at low and intermediate energies are studied on the basis of a classical four-body model. The angular and energy distributions of light particles from such processes are calculated. It is found that, at energies below 50 MeV per nucleon, the hardest section of the energy spectrum is formed owing to the acceleration of light particles from the target by the mean field of the projectile nucleus. Good agreement with available experimental data is obtained.Comment: 23 pages, 10 figures, LaTeX, published in Physics of Atomic Nuclei v.65, No. 8, 2002, pp. 1459 - 1473 translated from Yadernaya Fizika v. 65, No. 8, 2002, pp. 1494 - 150

Coaxial Mono-Energetic Gamma Generator for Active Interrogation

Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,gamma)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 mu s long pulses, and a 1percent duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing

ANTI-STOKES RAMAN LASERS : A CONCEPT FOR THE GENERATION OF SHORT-WAVELENGTH COHERENT RADIATION

The anti-Stokes Raman process allows frequency up-conversion of coherent pulsed or cw radiation. For the process, a population inversion on a two-photon transition is needed. The principale of this technique, the present experimental situation and some developments will be described and discussed

Grundlegende Untersuchungen zum Rohrlaser und grundlegende Messverfahren zur Qualifizierung sehr grosser Laserkristalle Abschlussbericht

1. More than 1.5 kW laser output power can be produced out of one single pumping chamber using an annular Nd:YAG rod as an active medium. Temperature and stress behaviour, output power, efficiency and beam quality were investigated at an outside pumped tube laser. The incoupling of the tube laser beam into the core of a 1 mm fiber could be shown. In comparison to multi rod laser systems the beam quality of the tube laser is inferior. All other beam parameters are of equal rank. 2. For the realisation of high power solid state lasers laser crystals are of major concern. To inspect the quality of those crystals a measurement technique was developed and tested to determine the transversal doping concentration. The doping distribution of up to 250 mm long Nd:YAG laser rods were measured. In addition the laser-active parameters of the laser crystals were investigated. The tested laser rods showed a very good quality. (orig.)SIGLEAvailable from TIB Hannover: F95B2376+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); European Union (Euro), Brussels (Belgium)DEGerman

Diodengepumpte Festkoerperlaser hoher Brillanz. Teilvorhaben: Untersuchung von Scheibenlasern im Hochleistungsbereich Abschlussbericht

SIGLEAvailable from TIB Hannover: F02B693 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Novel methodology for the quantitative assay of fissil materials using temporal and spectral beta-delayed gamma-ray signatures

Active interrogatio

Analyse neuartiger Kristallstrukturen unter dem Einfluss hoher spektraler Leistungsdichten. Teilvorhaben: Grundlegende Untersuchungen zum Pumpen mit fasergekoppelten Diodenlasern und Erforschung eines Hochleistungslasers Abschlussbericht

SIGLEAvailable from TIB Hannover: F98B883+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman