First escaping fast ion mesurements in ITER-like geometry using an activation probe

More research is needed to develop suitable diagnostics for measuring alpha particle confinement in ITER and techniques relevant for fusion reactor conditions need further development. Based on nuclear reactions, the activation probe is a novel concept first tested in JET. It may offer a more robust solution for performing alpha particle measurements in ITER. This paper describes the first escaping fast ion measurements performed at ASDEX Upgrade (AUG) tokamak using an activation probe. A detailed analysis, outside the scope of this contribution, will be published in a journal paper.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

The Glauber model and the heavy ion reaction cross section

We reexamine the Glauber model and calculate the total reaction cross section as a function of energy in the low and intermediate energy range, where many of the corrections in the model, are effective. The most significant effect in this energy range is by the modification of the trajectory due to the Coulomb field. The modification in the trajectory due to nuclear field is also taken into account in a self consistent way. The energy ranges in which particular corrections are effective, are quantified and it is found that when the center of mass energy of the system becomes 30 times the Coulomb barrier, none of the trajectory modification to the Glauber model is really required. The reaction cross sections for light and heavy systems, right from near coulomb barrier to intermediate energies have been calculated. The exact nuclear densities and free nucleon-nucleon (NN) cross sections have been used in the calculations. The center of mass correction which is important for light systems, has also been taken into account. There is an excellent agreement between the calculations with the modified Glauber model and the experimental data. This suggests that the heavy ion reactions in this energy range can be explained by the Glauber model in terms of free NN cross sections without incorporating any medium modification.Comment: RevTeX, 21 pages including 9 Postscript figures, submitted to Phys. Rev.

Probing the 6He halo structure with elastic and inelastic proton scattering

Proton elastic scattering and inelastic scattering to the first excited state of 6He have been measured over a wide angular range using a 40.9A MeV 6He beam. The data have been analyzed with a fully microscopic model of proton-nucleus scattering using 6He wave functions generated from large space shell model calculations. The inelastic scattering data show a remarkable sensitivity to the halo structure of 6He.Comment: 9 pages, 3 figures. RevTeX. Replaced figure 3 with updated figur

The calculation of total reaction cross sections induced by intermediate energy α\alpha-particles with BUU Model

The Boltzmann-Uehling-Uhlenbeck (BUU) Model, which includes the Fermi motion, the mean field, individual nucleon-nucleon (N-N) interactions and the Pauli blocking effect etc., is used to calculate the total reaction cross section $\sigma_R$ induced by $\alpha$-particles on different targets in the incident energy range from 17.4 to 48.1 MeV/u. The calculation result can reproduce the experimental data well. The nucleus-nucleus interaction radius parameter $r_0$ was extracted from experimental $\sigma_R$. It is found that $r_0$ becomes constant with increasing the mass number of target.Comment: 4 pages, 4 fig

Single-neutron transfer from 11Be gs via the (p,d) reaction with a radioactive beam

The 11Be(p,d)10Be reaction has been performed in inverse kinematics with a radioactive 11Be beam of E/A = 35.3 MeV. Angular distributions for the 0+ ground state, the 2+, 3.37 MeV state and the multiplet of states around 6 MeV in 10Be were measured at angles up to 16 deg CM by detecting the 10Be in a dispersion-matched spectrometer and the coincident deuterons in a silicon array. Distorted wave and coupled-channels calculations have been performed to investigate the amount of 2+ core excitation in 11Be gs. The use of "realistic" 11Be wave functions is emphasised and bound state form factors have been obtained by solving the particle-vibration coupling equations. This calculation gives a dominant 2s component in the 11Be gs wave function with a 16% [2+ x 1d] core excitation admixture. Cross sections calculated with these form factors are in good agreement with the present data. The Separation Energy prescription for the bound state wave function also gives satisfactory fits to the data, but leads to a significantly larger [2 x 1d] component in 11Be gs.Comment: 39 pages, 12 figures. Accepted for publication in Nuclear Physics A. Added minor corrections made in proof to pages 26 and 3

Détermination de l'interaction entre protons et noyaux exotiques riches en neutrons par mesure de sections efficaces de réaction.

The study of exotic nuclei is of great interest and has been particularly developed for severalyears thanks to the improvement of the intensities and optical qualities of the secondary exoticbeams. In this context, an experiment of reaction cross sections measurement of exotic nucleion protons was undertaken at GANIL.During this experiment, the proton-nucleus reaction cross sections have been measured, forthe first time around 50 MeV per nucleon, for several light neutron-rich nuclei (He->Mg) on aliquid hydrogen target built especially for this experiment.The reaction cross sections are fundamental data and also allow to check the validity oftheoretical models. Our experimental reaction cross section have thus allowed to concludethat Kox's parameterisation can not be applied to the nuclei far from stability and that thephenomenological potential CH89 is not appropriate to describe the nuclei with mass AMg) sur une cible d'hydrogène liquide construite pour les besoins del'expérience.Les sections efficaces de réaction sont des données fondamentales et permettent également devérifier la validité de modèles théoriques. Nos données expérimentales de section efficace deréaction ont ainsi permis de conclure que la paramétrisation de Kox ne peut s'appliquer auxnoyaux loin de la stabilité et confirment que le potentiel phénoménologique CH89 n'est pasadapté pour décrire les noyaux de masse A<40.Le cas de l'6He, pour lequel nous disposons désormais d'un ensemble complet de données dediffusion élastique, d'échange de charge et, par cette expérience, de section efficace deréaction, montre que les différents types de données apportent des contraintescomplémentaires sur le potentiel d'interaction proton-noyau. En particulier, la mesure desection efficace de réaction et la distribution angulaire d'échange de charge mettent descontraintes très fortes sur la partie imaginaire du potentiel, ainsi que sur le rapport entre lapartie isovectorielle et isoscalaire de l'interaction

Anti-Compton gamma spectrometry for environmental samples

The results of the low-level performance of an anti-Compton device are presented. The anti-coincidence action of the NaI detectors lowers the total background of the HPGe detector integrated on the energy range 30 keV to 2730 keV by a factor 8.1 and suppresses the continuum above 300 keV by a factor larger than 10. Qualitative and quantitative results on environmental samples are described to illustrate the improvement of uncertainties determination and the significant reduction of detection limits. This provides ever more accurate and precise data on natural and anthropogenic radionuclides often used as tracers for environmental studies

Fission product activity ratios measured at trace level over France during the Fukushima accident

International audienceThe nuclear accident of Fukushima Dai-ichi (Japan) which occurred after the tsunami that impacted the northeast coasts of Japan on March 11th, 2011 led to significant releases of radionuclides into the atmosphere and resulted in the detection of those radionuclides at a global scale. In order to track airborne radionuclides from the damaged reactors and to survey their potential impact on the French territory, the French Institute of Radiation Protection and Nuclear Safety (Institut de Radioprotection et de Sureté Nucléaire IRSN) set up an enhanced surveillance system to give quick results as needed and later give quality trace level measurements. Radionuclides usually measured at trace levels such as 137Cs and in a very sporadic way 131I were reported. Radionuclides that we had never measured in air since the Chernobyl accident 134Cs, 136Cs, the mother/daughter pairs 129mTe-129Te and 132Te-132I, and 140La (from the mother-daughter pair 140Ba- 140La) were also reported. Except the 131I/137Cs ratio, activity concentration ratios were constant. These ratios could be used to help source term assessment, or as data for transfer studies realized after the passage of contaminated air masses, typically using the 134Cs/137Cs ratio. © 2013 Elsevier Ltd

Self-attenuation correction factors for bioindicators measured by γ spectrometry for energies < 100 keV

The mass attenuation coefficients for a number of marine and terrestrial bioindicators were measured using γ spectrometry for energies between 22 and 80 keV. These values were then used to find the correction factor k for the apparent radioactivity. The experimental results were compared with a Monte Carlo simulation performed using PENELOPE in order to evaluate the reliability of the simplified calculation and to determine the correction factors. © 2009 Elsevier B.V. All rights reserved