Barrier and internal wave contributions to the quantum probability density and flux in light heavy-ion elastic scattering

We investigate the properties of the optical model wave function for light heavy-ion systems where absorption is incomplete, such as $\alpha + ^{40}$Ca and $\alpha + ^{16}$O around 30 MeV incident energy. Strong focusing effects are predicted to occur well inside the nucleus, where the probability density can reach values much higher than that of the incident wave. This focusing is shown to be correlated with the presence at back angles of a strong enhancement in the elastic cross section, the so-called ALAS (anomalous large angle scattering) phenomenon; this is substantiated by calculations of the quantum probability flux and of classical trajectories. To clarify this mechanism, we decompose the scattering wave function and the associated probability flux into their barrier and internal wave contributions within a fully quantal calculation. Finally, a calculation of the divergence of the quantum flux shows that when absorption is incomplete, the focal region gives a sizeable contribution to nonelastic processes.Comment: 16 pages, 15 figures. RevTeX file. To appear in Phys. Rev. C. The figures are only available via anonynous FTP on ftp://umhsp02.umh.ac.be/pub/ftp_pnt/figscat

Instrumentierte Eindringprüfung bei Hochtemperatur für die Charakterisierung bestrahlter Materialien

Zur Qualifizierung von Materialien für Strukturkomponenten künftiger Fusionsreaktoren eignet sich insbesondere die Instrumentierte Eindringprüfung. Um die Betriebsbedingungen im Fusionsreaktor nachzubilden, ist ein Erhitzen strahlungsgeschädigter Proben während des Versuchs notwendig. So hatte diese Arbeit zum Ziel, eine bis dato nicht existente Anlage zur Hochtemperatur-Indentation an bestrahlten Materialien zu realisieren und Versuche bei maximal 650°C zu ermöglichen

Study of the effects of Pauli blocking and Pauli non-locality on the optical potential

Elastic scattering angular distributions for systems with reduced mass between 3 and 34 and energies varying between 25 and 120 MeV/nucleon were analyzed. The stable $^4$He, its exotic partner $^6$He, and the weakly bound $^{6,7}$Li nuclei were included as projectiles in the systematics. Optical model data analyzes were performed with an adjustable factor of normalization included in the imaginary part of the potential. These analyzes indicated a reduction of absorption for systems with small reduced masses that was detected due to the refractive nature of the scattering by light systems.Comment: 16 pages, 7 figure

Instrumentierte Eindringprüfung bei Hochtemperatur für die Charakterisierung bestrahlter Materialien

Zur Qualifizierung von Materialien für Strukturkomponenten künftiger Fusionsreaktoren eignet sich insbesondere die Instrumentierte Eindringprüfung. Um die Betriebsbedingungen im Fusionsreaktor nachzubilden, ist ein Erhitzen strahlungsgeschädigter Proben während des Versuchs notwendig. So hatte diese Arbeit zum Ziel, eine bis dato nicht existente Anlage zur Hochtemperatur-Indentation an bestrahlten Materialien zu realisieren und Versuche bei maximal 650°C zu ermöglichen

Perspectives on the Political and Security Influence of Outside Powers

Paper presented at public lectures and a graduate student seminar in the Pacific Islands Studies Program, UH-Manoa, fall 1984. Lectures and seminar co-sponsored by the Pacific Islands Development Program and the East-West Cente