Search results for "nuclear fusion"

Eurofusion-DEMO Divertor - Cassette Design and Integration

2020

International audience; The Eurofusion-DEMO design will complete the Pre Conceptual Design phase (PCD) with a PCD Gate, named G1, scheduled to take place in Q4 2020 that will focus on assessing the feasibility of the plant and its main components prior to entering into the Conceptual Design phase. In the paper first an overview is given of the Eurofusion-DEMO Divertor Assembly including design and interface description, systems and functional requirements, load specification, system classification, manufacturing procedures and cost estimate. Then critical issues are discussed and potential design solutions are proposed, e.g.:- Neutron material damage limits of the different (structural) mat…

Deeply bound pionic states with the (? ?,?) reaction

1992

We study the reactionΣ− +A→Λ + (Aπ−) with the π− bound in the nucleus, as a means of producing deeply bound pionic states in nuclei, so far unobserved. The reaction is similar to the (n, p) reaction but, because of theΣ−, Λ mass difference, it allows the reaction to occur with smaller momentum transfer, thus increasing the transition probability and reducing the effects of distortion. The ratios of signal to background are one to two orders of magnitude better than in the (n, p) reaction.

Integral approach to the safety design of the EU-DEMO Helium-Cooled Pebble Beds with reference to the associated relevant systems

2020

Study of Cluster Structures in Nuclei through the Ratio Method. A Tribute to Mahir Hussein

2020

For one-neutron halo nuclei, the cross sections for elastic scattering and breakup at intermediate energy exhibit similar angular dependences. The Recoil Excitation and Breakup (REB) model of reactions elegantly explains this feature. It also leads to the idea of a new reaction observable to study the structure of loosely-bound nuclear systems: the Ratio. This observable consists of the ratio of angular distributions for different reaction channels, viz. elastic scattering and breakup, which cancels most of the dependence on the reaction mechanism; in particular it is insensitive to the choice of optical potentials that simulate the projectile-target interaction. This new observable is very…

�ber die Abh�ngigkeit des Polarisationsgrades vom Streuwinkel bei Mott-Streuung langsamer Elektronen

1965

The angular dependence of polarizationP(Θ) of electrons elastically scattered by a beam of mercury atoms is measured in a double scattering experiment for electron energies of 0,9; 1,2; and 1,5 keV. The results are compared with theory and found to be in good agreement. Maximum degree of polarization measured isP=0,53±0,10 (electron current 10−12A).

The European DEMO fusion reactor: Design status and challenges from balance of plant point of view

2017

DEMO initial conceptual design studies are being conducted in Europe as part of the European Union Roadmap to Fusion Electricity, which aims to demonstrate the feasibility of electricity produced by nuclear fusion reactors around the middle of this century. The aim of this paper is to provide an overview of the DEMO project, highlighting its main characteristics and challenges in terms of design, integration, and operation. Particular emphasis is given on some important systems of the Balance of Plant (BoP), such as the primary heat transfer systems, the related power conversion systems, and the electrical power plant. The relevance of such systems is due to the need of a continuous reanaly…

Engineering design and steady state thermomechanical analysis of the IFMIF European lithium target system

2013

In the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). In this work, the results of the steady state thermomechanical analysis of the IFMIF EU target assembly are briefly reported highlighting the relevant indications obtained with respect to the fulfillment of the design requirements. © 2013 IEEE.

Resonances in the electron impact excitation of metastable states of mercury

1984

Metastable excitation of mercury by electron impact is studied at energies up to the first ionisation potential using an energy selected electron beam with an energy spread of 50 meV FWHM. A great number of resonances is observed in the excitation function. Agreement is good on the whole with a recent relativisticR-matrix calculation and with a former analysis of resonances in the elastic cross section.

Observation of the3nEvaporation Channel in the Complete Hot-Fusion ReactionMg26+Cm248Leading to the New Superheavy NuclideHs271

2008

The analysis of a large body of heavy ion fusion reaction data with medium-heavy projectiles ($6\ensuremath{\le}Z\ensuremath{\le}18$) and actinide targets suggests a disappearance of the $3n$ exit channel with increasing atomic number of the projectile. Here, we report a measurement of the excitation function of the reaction $^{248}\mathrm{Cm}(^{26}\mathrm{Mg},xn)^{274\mathrm{\text{\ensuremath{-}}}x}\mathrm{Hs}$ and the observation of the new nuclide $^{271}\mathrm{Hs}$ produced in the $3n$ evaporation channel at a beam energy well below the Bass fusion barrier with a cross section comparable to the maxima of the $4n$ and $5n$ channels. This indicates the possible discovery of new neutron-r…

Decay properties of neutron-deficient isotopes 256, 257Db, 255Rf, 252, 253Lr

2001

Isotopes of dubnium (element 105) with mass numbers A = 256, 257, and 258 were produced by the reaction 209Bi(50Ti,xn) 259-xDb (x = 1, 2, 3) at projectile energies of (4.59-5.08) AMeV. Excitation functions were measured for the 1n, 2n and 3n evaporation channels. The same position of the excitation function was observed for the 1n channel as for the previously measured 1n channel of the reaction 208Pb(50Ti,1n)257Rf. The measured α-decay data of 257Db and its daughter products resulted in the identification of α-decaying isomeric states in 257Db and 253Lr. Two new isotopes, 256Db and 252Lr, were produced at the highest bombarding energies of 4.97 AMeV and 5.08 AMeV. They were identified by d…