Search results for "Light nucleus"

Commissioning of the vacuum system of the KATRIN Main Spectrometer

2016

The KATRIN experiment will probe the neutrino mass by measuring the β-electron energy spectrum near the endpoint of tritium β-decay. An integral energy analysis will be performed by an electro-static spectrometer (``Main Spectrometer''), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m[superscript 3], and a complex inner electrode system with about 120 000 individual parts. The strong magnetic field that guides the β-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips ha…

Influence of humic acid on neptunium(V) sorption and diffusion in Opalinus Clay

2013

SummaryThe influence of14C-labeled M42 humic acid (HA) on the interaction between neptunium(V) and natural clay rock (Opalinus Clay (OPA), Switzerland) has been investigated in batch sorption and diffusion experiments under ambient air conditions. The effect of 10 mg/L HA on the diffusion of 8 μM Np(V) in OPA has been investigated in synthetic OPA pore water (pH 7.6, I = 0.4M) for the first time. Batch sorption experiments as a function of solid-to-liquid ratio (4-20 g/L) were performed under same experimental conditions to compare distribution coefficients obtained from both diffusion and sorption experiments. These experiments showed only a slight influence of HA on Np(V) uptake by OPA in…

Molecular structures inT=1states of10B

2011

Multi-center (molecular) structures can play an important role in light nuclei. The highly deformed rotational band in 10Be with band head at 6.179 MeV has been observed recently and suggested to have an exotic alpha:2n:alpha configuration. A search for states with alpha:pn:alpha two-center molecular configurations in 10B that are analogous to the states with alpha:2n:alpha structure in 10Be has been performed. The T=1 isobaric analog states in 10B were studied in the excitation energy range of E=8.7-12.1 MeV using the reaction 1H(9Be,alpha)6Li*(T=1, 0+, 3.56 MeV). An R-matrix analysis was used to extract parameters for the states observed in the (p,alpha) excitation function. Five T=1 stat…

Place de l’imagerie dans l’évaluation de l’efficacité des traitements dans le cancer du sein

2010

Resume Cette revue decrit le role de differentes methodes d’imagerie pour evaluer la reponse au traitement dans le cancer du sein. Deux situations sont envisageables : celle de la chimiotherapie neoadjuvante du cancer du sein et celle des metastases. Beaucoup de donnees cliniques sont disponibles pour trois criteres : le volume de la tumeur, la captation du fluorodeoxyglucose mesuree en TEP et la perfusion de la tumeur evaluee soit par IRM dynamique, soit en TEP. La TEP au 2-18F fluoro-2-desoxy-D-glucose (FDG) permet la prediction de la reponse apres une ou deux cures de chimiotherapie. De nouvelles approches pourraient prochainement affiner le role de l’imagerie. Ainsi, la TEP a la thymidi…

Design and manufacturing feasibility of ITER TBM Frame and Dummy TBMs

2016

Abstract The operation and test of mock-ups of tritium breeding blankets relevant for a future commercial reactor is one of the goals of the ITER machine. To accomplish this goal, mock-ups of breeding blankets, called Test Blanket Modules (TBMs), are installed in three ITER equatorial ports. Each TBM and the associated shield form a TBM-set that is mechanically attached to a steel frame called TBM Frame. A Frame and two TBM-Sets form a TBM Port Plug (TBM PP). The ITER Organization is responsible for the design and manufacture of the TBM Frames and of the Dummy TBMs that could replace the TBM-sets in case they were not available. This paper describes the recent results of the design supporti…

Proterozoic dykes of Salvador and Ilhéus-Olivença areas: a geological geoghemical comparison

1991

Dependence of two-proton radioactivity on nuclear pairing models

2017

Sensitivity of two-proton emitting decay to nuclear pairing correlation is discussed within a time-dependent three-body model. We focus on the $^6$Be nucleus assuming $\alpha + p + p$ configuration, and its decay process is described as a time-evolution of the three-body resonance state. For a proton-proton subsystem, a schematic density-dependent contact (SDDC) pairing model is employed. From the time-dependent calculation, we observed the exponential decay rule of a two-proton emission. It is shown that the density dependence does not play a major role in determining the decay width, which can be controlled only by the asymptotic strength of the pairing interaction. This asymptotic pairin…

EU dissemination of the provisional ultra-low-temperature scale, PLTS-2000

2003

Following the introduction of the provisional low-temperature scale from 0.9 mK to 1K, PLTS-2000, there is a need for primary and secondary thermometers and fixed points, which can disseminate the scale to users. This paper reports on the progress, within the EU collaborative project ‘ULT Dissemination’, in the development and evaluation of several devices with associated instrumentation. Principal among them are a current-sensing noise thermometer, a CMN thermometer adapted for industrial use, a Coulomb blockade thermometer, a second-sound thermometer, a 3He melting pressure thermometer for a direct realisation of the PLTS-2000. A superconductive reference device has also been developed, a…

Modelling of JET hybrid plasmas with emphasis on performance of combined ICRF and NBI heating

2018

International audience; During the 2015--2016 JET campaigns, many efforts have been devoted to the exploration of high-performance plasma scenarios envisaged for DT operation in JET. In this paper, we review various key recent hybrid discharges and model the combined ICRF NBI heating. These deuterium discharges with deuterium beams had the ICRF antenna frequency tuned to match the cyclotron frequency of minority H at the centre of the tokamak coinciding with the second harmonic cyclotron resonance of D. The modelling takes into account the synergy between ICRF and NBI heating through the second harmonic cyclotron resonance of D beam ions, allowing us to assess its impact on the neutron rate…

Electron Scattering Experiments on Light Nuclei

2020

In this contribution we discuss double-polarised quasi-elastic electron scattering from \({}^{3}\mathrm {He}\) and \({}^{12}\mathrm {C}\). For these nuclei precise data from recent experiments at Jefferson Lab and Mainz have become available, accompanied by a very strong theoretical effort dedicated to understanding these nuclei. The double polarisation experiments presented here offer insight into some of the details of the nuclear structure that could not be accessed by traditional cross-section measurements. The new experimental results show only rough agreement with the calculations and indicate that we do not yet fully understand the structure of these nuclei and nucleon dynamics insid…