Search results for "TRITIUM"
showing 10 items of 165 documents
Quark-model based study of the triton binding energy
2001
The three-nucleon bound state problem is studied employing a nucleon-nucleon potential obtained from a basic quark-quark interaction in a five-channel Faddeev calculation. The obtained triton binding energy is comparable to those predicted by conventional models of the $NN$ force.
Recent progress in L-H transition studies at JET: tritium, helium, hydrogen and deuterium
2022
Abstract We present an overview of results from a series of L–H transition experiments undertaken at JET since the installation of the ITER-like-wall (JET-ILW), with beryllium wall tiles and a tungsten divertor. Tritium, helium and deuterium plasmas have been investigated. Initial results in tritium show ohmic L–H transitions at low density and the power threshold for the L–H transition (P LH) is lower in tritium plasmas than in deuterium ones at low densities, while we still lack contrasted data to provide a scaling at high densities. In helium plasmas there is a notable shift of the density at which the power threshold is minimum ( n ¯ e , min ) to higher values relative to deuterium and …
Overview of the HCPB Research Activities in EUROfusion
2018
In the framework of the EUROfusion’s Power Plant Physics and Technology, the working package breeding blanket (BB) aims at investigating four different BB concepts for an EU demonstration fusion reactor (DEMO). One of these concepts is the helium-cooled pebble bed (HCPB) BB, which is based on the use of pebble beds of lithiated ternary compounds and Be or beryllides as tritium breeder and multiplier materials, respectively, EUROFER97 as structural steel and He as coolant. This paper aims at giving an overview of the EU HCPB BB Research and Development (R&D) being developed at KIT, in collaboration with Wigner-RCP, BUTE-INT, and CIEMAT. The paper gives an outline of the HCPB BB design evolut…
Behaviour of neutron irradiated beryllium during temperature excursions up to and beyond its melting temperature
2015
Abstract Beryllium pebble behaviour has been studied regarding the accidental operation conditions of tritium breeding blanket of fusion reactors. Structure evolution, oxidation and thermal properties have been compared for nonirradiated and neutron irradiated beryllium pebbles during thermal treatment in a temperature range from ambient temperature to 1600 K. For neutron irradiated pebbles tritium release process was studied. Methods of temperature programmed tritium desorption (TPD) in combination with thermogravimetry (TG) and temperature differential analysis (TDA), scanning electron microscopy (SEM) in combination with Energy Dispersive X-ray analysis (EDX) have been used. It was found…
Water-cooled Pb–17Li test blanket module for ITER: Impact of the structural material grade on the neutronic responses
1998
Abstract The Water-Cooled Lithium Lead (WCLL) DEMO blanket is one of the two EU lines to be further developed with the aim of manufacturing by 2010 a Test Blanket Module for ITER (TBM). In this paper results of a 3D-Monte Carlo neutronic analysis of the TBM design are reported. A fully 3D heterogeneous model of the WCLL–TBM has been inserted into an existing ITER model accounting for a proper D–T neutron source. The structural material assumed for the calculations was martensitic 9% Cr steel code named Z 10 CDV Nb 9-1. Results have been compared with those obtained using MANET. The main nuclear responses of the TBM have been determined, such as detailed power deposition density, material da…
Structure, tritium depth profile and desorption from 'plasma-facing' beryllium materials of ITER-Like-Wall at JET
2017
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053 . The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Basic study of influence of radiation defects on tritium release processes from lithium silicates
1997
The radiolysis of Li2SiO3 and Li4SiO4 was studied using the chemical scavengers method (CSM), thermoluminescence, lyoluminescence, electron spin resonance and spectrometric methods. The influence of the absorbed dose and many another parameters such as: irradiation conditions, sample preparation conditions and concentration of impurities on the accumulation rate of each type RD and RP were studied. Several possibilities for reducing the radiolysis of silicates were discussed. It has been found that tritium localization on the surface and in grains proceed by two different mechanisms. Tritium thermoextraction from the surface proceeds as chemidesorption of tritiated water, but from the bulk …
Improved limit on the electron-antineutrino rest mass from tritium ß-decay
1993
Abstract The endpoint region of the β-spectrum of tritium was remeasured by an electrostatic spectrometer with magnetic guiding field. It enabled the search for a rest mass of the electron-antineutrino with improved precision. The result is m2v=−39±34stat±15syst(eV/c2)2, from which an upper limit of mv m( T )−m( 3 He )=18 591±3 eV /c 2 .
A new upper limit of the electron anti neutrino rest mass from tritium β-decay
1993
Abstract A new upper limit of the electron anti neutrino rest mass has been deduced from the tritium β-decay spectrum. A source of molecular tritium has been investigated with a new solenoid retarding spectrometer. The results are m ν ϵ 2 = −38.8 ± 34.1 stat ± 15.1 syst (eV) 2 /c 4 from which we conclude m ν ϵ ≤ 7.2 eV/c 2 with 95% c.l. Our β-endpoint corresponds to a 3H-3He atomic mass difference of Δm( 3 H- 3 He) = 18590.8 ± 3 eV/c 2 (1σ) .
The intermediate role of 18-hydroxycorticosteroids in aldosterone biosynthesis.
1968
Durch ihre Eigenschaft, bestimmte Stufen bei der Bildung radioaktiv markierten Aldosterons aus14C-Progesteron bzw.3H-11-Desoxycorticosteron zu hemmen, erwiesen sich 11-Desoxycorticosteron, Corticosteron und 18-Hydroxycorticosteron als wesentliche Zwischenstufen der Aldosteronbiosynthese. 18-Hydroxy-11-desoxycorticosteron hingegen scheint an der Bildung von Aldosteron nicht beteiligt zu sein.