Search results for "Valley"

DETERMINATION OF NUCLEAR GROUND STATE PROPERTIES FAR FROM STABILITY BY OPTICAL PUMPING

1973

The possibilities of determining nuclear spin, moments and variation in charge volume by optical pumping of on line masseparated isotopes are described for the example of the isotopic chain lY1Hg-205Hg. The variation in nuclear charge volume (6 ) along this chain and in particular its abrupt change for the lightest Hg-isotopes, indicating a phase transition in nuclear structure, are discussed. 1. Introduction. - This talk is based on expe- riments (I), (2), (3) performed recently by a visiting team (*) at the ISOLDE facility at CERN with the members : J. Bonn, G. Huber, H.-J. Kluge, U. Kopf, L. Kugler, J. Rodriguez, and E. W. Otten. The investigation of the hyperfine structure (hfs) and iso…

Experimental Neutron Capture Rate Constraint Far from Stability

2016

Nuclear reactions where an exotic nucleus captures a neutron are critical for a wide variety of applications, from energy production and national security, to astrophysical processes, and nucleosynthesis. Neutron capture rates are well constrained near stable isotopes where experimental data are available; however, moving far from the valley of stability, uncertainties grow by orders of magnitude. This is due to the complete lack of experimental constraints, as the direct measurement of a neutron-capture reaction on a short-lived nucleus is extremely challenging. Here, we report on the first experimental extraction of a neutron capture reaction rate on ^{69}Ni, a nucleus that is five neutro…

Nuclear structure studies for the astrophysical r-process

2001

Abstract The production of the heaviest elements in nature occurs via the r-process, i.e. a combination of rapid neutron captures, the inverse photodisintegrations, and slower β − -decays, β -delayed processes as well as fission and possibly interactions with intense neutrino fluxes. A correct understanding and modeling requires the knowledge of nuclear properties far from stability and a detailed prescription of the astrophysical environment. Experiments at radioactive ion beam facilities have played a pioneering role in exploring the characteristics of nuclear structure in terms of masses and β -decay properties. Initial examinations paid attention to highly unstable nuclei with magic neu…

Le Néolithique du Morvan : état des connaissances

2012

The region of Morvan, in particular the granitic massif, forms a very large geographic area of which the prehistoric remains largely unknown. The situation regarding the zone lying between Morvan massif and the adjacent Serein, Arroux, A leine and Yonne valleys is very different. The lithic industry of several sites in Upper Morvan has demonstrated a first inhabitation during the Mesolithic and several hill sites occupied from the Middle Neolithic and during the Final Neolithic, including a probable enclosure on Mont Beuvray. Complementary studies in the A rroux Valley confirm a large expansion of the habitat and the erection of menhirs during the Middle Neolithic. Discoveries relating to t…

Interim Report on the Research Phase

1993

This is the report of one year of interdisciplinary team research in preparation of the Dassenetch Integrated Development Program (DIDP), SNV (Netherlands Development Organization) – ETHIOPIA

Written Past: Explorers’ Histories

2018

Architettura e archeologia. L’esperienza de La grande Akragas

2021

Riflettere sul rapporto tra architettura e archeologia, a proposito degli esiti di un laboratorio di laurea intitolato "La Grande Akragas" e di un workshop organizzato alla Valle dei Templi di Agrigento, è stata l’occasione per recuperare alcune precedenti esperienze comprese fra didattica e ricerca. Individuare la sequenza di alcuni approfondimenti ha svelato l’osmosi generatasi fra attività di studio disposte, cronologicamente, in momenti differenti. In questa petite recherche, il momento di avvio è rappresentato dalle considerazioni scaturite da un concorso di idee per la «sistemazione e messa in sicurezza della strada perimetrale di Pantelleria», progetto nel quale era parte integrante …

The Malawi Rift and vertebrate paleobiogeography of the African Rift Valley

2017

Oscillator realization of the q-deformed anti-de Sitter algebra

1992

Abstract We construct a realization of the q-deformed anti-de Sitter algebra in terms of two q-oscillators. We use the standard Drinfel'd-Jimbo prescription for the q-deformation of the Chevalley basis which we express in terms of q-oscillators. We also discuss the anti-de Sitter radius R → ∞ limit and the structure of the first so (3, 2)q Casimir operator.

Extension of the ratio method to proton-rich nuclei

2019

The ratio method has been developed to improve the study of one-neutron halo nuclei through reactions. By taking the ratio of angular distributions for two processes, viz. breakup and elastic scattering, this new observable is nearly independent of the reaction mechanism and hence much more sensitive to the projectile structure than the cross sections for each single process. We study the extension of the ratio method to proton-rich nuclei and also explore the optimum experimental conditions for measuring this new observable. We compare accurate dynamical calculations of reactions for proton-rich projectiles to the prediction of the ratio method. We use the dynamical eikonal approximation t…