Search results for "Beryllium"

Comparison of the structure of the plasma-facing surface and tritium accumulation in beryllium tiles from JET ILW campaigns 2011-2012 and 2013-2014

2019

In this study, beryllium tiles from Joint European Torus (JET) vacuum vessel wall were analysed and compared regarding their position in the vacuum vessel and differences in the exploitation conditions during two campaigns of ITER-Like-Wall (ILW) in 2011-2012 (ILW1) and 2013-2014 (ILW2) Tritium content in beryllium samples were assessed. Two methods were used to measure tritium content in the samples - dissolution under controlled conditions and tritium thermal desorption. Prior to desorption and dissolution experiments, scanning electron microscopy and energy dispersive x-ray spectroscopy were used to study structure and chemical composition of plasma-facing-surfaces of the beryllium sampl…

S3-Leitlinie Gesundheitsüberwachung bei Beryllium-Exposition und diagnostisches Vorgehen bei berylliumassoziierter Erkrankung

2013

Experimental study of the 15O(2p, γ)17Ne cross section by Coulomb Dissociation for the rp process

2016

6th Nuclear Physics in Astrophysics Conference (NPA), Lisbon, Portugal, 19 May 2013 - 24 May 2013; Journal of physics / Conference Series 665, 012046 (2016). doi:10.1088/1742-6596/665/1/012046

Experimental investigations of the hypernucleus $_Λ^4$H

2015

International audience; Negatively charged pions from two-body decays of stopped _Lambda^4H hypernuclei were studied in 2012 at the Mainz Microtron MAMI, Germany. The momenta of the decay-pions were measured with unprecedented precision by using high-resolution magnetic spectrometers. A challenge of the experiment was the tagging of kaons from associated K^+∧ production off a Be target at very forward angles. In the year 2014, this experiment was continued with a better control of the systematic uncertainties, with better suppression of coincident and random background, improved particle identification, and with higher luminosities. Another key point of the progress was the improvemen…

Progress in the benchmark exercise for analyzing the lithiate breeder pebble bed thermo-mechanical behaviour

2006

The Helium Cooled Pebble Bed (HCPB) Blanket is one of the reference concepts for the European Breeding Blanket Programme for DEMO. In the reference blanket module, alternate layers of lithiated ceramics and beryllium pebbles act, respectively, as tritium breeder and neutron multiplier. The thermo-mechanical behaviour of both the pebble beds and their performances in reactor relevant conditions are also dependent on the pebble size and cell geometries (bed thickness, pebble packing factor, bed thermal conductivity). Therefore, in the EU Fusion Technology Programme, several out-of-pile experimental test campaigns have been performed to determine these behaviours. Theoretical calculations have…

Systematic review: progression of beryllium sensitization to chronic beryllium disease

2012

BACKGROUND The relevance of beryllium sensitization testing for occupational health practice and prevention is unclear. AIMS To analyse the natural course of beryllium sensitization and clarify the prognosis following cessation of exposure among sensitized workers. METHODS An electronic literature search was conducted in PubMed, Embase, Toxline and Cochrane databases supplemented by a manual search. Data abstraction and study quality assessment with adapted guideline checklists were performed independently by three reviewers. Seven studies met the eligibility criteria and were included in the systematic review; however, six of the seven studies were of low methodological quality. RESULTS A …

Tritium sorption and desorption from JET beryllium tiles under temperature, electron radiation and magnetic field

2008

Abstract Tritium release at annealing of samples cut from beryllium tiles exposed to D + D, D + T plasma in the Joint European Torus (JET) was investigated under 5 MeV fast-electron radiation at the dose rate 14 MGy h −1 and in a magnetic field of 1.7 T separately and simultaneously in order to evaluate possible effects of these factors. Abundances of chemical forms of tritium—molecular T 2 (44%), atomic T 0 (42%), and ionic T + (14%) and their distribution were determined in the plasma-exposed beryllium samples with lyomethods. Fast-electron radiation considerably increased the fractional tritium release at annealing by a factor of approximately 5. The magnetic field increased the fraction…

Tritium release from breeding blanket materials in high magnetic field

2007

Abstract Under the operating conditions of a fusion reactor, the blanket materials: ceramic and Be pebbles will be at a high temperature (up to 1123 K), under action of intense radiation (up to 10 19  n m −2  s −1 ) and magnetic field (MF) up to 7–10 T. In order to introduce action of radiation and MF in post-irradiation investigations of the tritium release from the blanket materials, a special rig for thermo-annealing of pre-irradiated samples at a high temperature up to 1120 K under irradiation with fast electrons of 5 MeV and dose rate 14 MGy/h in MF up to 1.7 T was used for this study. A delay of the tritium release in MF of 2.4 T at thermo-annealing of the lithium orthosilicate Li 4 S…

Effects of external energetic factors on tritium release from the EXOTIC 8-3/13 neutron-irradiated beryllium pebbles

2009

Abstract Tritium release from samples of 9–13 mg of the EXOTIC 8-3/13 neutron-irradiated beryllium pebbles under the separate and simultaneous action of temperature 490–770 K, 5 MeV fast-electron radiation 14 MGy h−1 for 3 h and magnetic field (MF) of 1.7 T was investigated. The pebbles were found to be very dissimilar with respect to their total tritium content—2.5–9 MBq g−1. The batch contained also some coarse agglomerates of the pebbles containing 10–19 MBq g−1 of tritium having also a high tritium release. For the pebbles having the total tritium 2.5–5.3 MBq g−1, the electron radiation for 3 h caused the fractional tritium release 17–26% (B = 0) and 21–29% (B = 1.7 T), the temperature …

Modelling of the thermal mechanical behaviour of a single size beryllium pebble bed

2001

The Helium Cooled Pebble Bed (HCPB) Blanket for fusion power reactors and the ITER breeding blanket are based on the use of pebble beds of lithium ceramics as breeder and beryllium as neutron multiplier. Experimental activities were performed at Forschungszentrum Karlsruhe concerning the measurement of pebble bed heat transfer parameters. At the Department of Nuclear Engineering of the University of Palermo, the experimental results have been reproduced by means of the ABAQUS finite element code. Moreover, a thermal-mechanical theoretical model has been developed for single size beryllium pebble beds. In the paper the results from the numerical and theoretical analyses and the comparison wi…