MONTE CARLO MODEL FOR NEUTRON PRODUCTION BY THE INTERACTIONS OF LOW ENERGY DEUTERONS IN SOLID TARGETS Alberto Milocco
, 2012, doktorska disertacija
Opis: The construction of the nuclear fusion plant 'ITER' has started in 2009 at Cadarache, France. The ITER machine represents a milestone in the civil use of the nuclear fusion energy. The physics of ITER is based on the fusion reaction between deuteron and triton nuclei (d-t). The deuteron-deuteron reaction (d-d) is also interesting and is foreseen for the next generation of fusion reactors. The experimental activities carried out in the context of the ITER neutronics involve intense fields of neutrons produced with a linear accelerator for deuterons, a target containing tritium or deuterium and auxiliary structures, such as the detector system, cooling system, room walls, etc. Experimental data have been obtained from the FNG (Frascati Neutron Generator, Italy), FNS (Fast Neutron Source, Japan), OKTAVIAN (Osaka University, Japan) and IRMM (Institute for Reference Materials and Measurements, EU). An independent method was developed at FNG for the simulation of the d-t neutron spectra at different angles. The FNG source routine models the Monte Carlo deuteron transport in solid tritiated targets as done in the well known SRIM code. The neutrons are generated according to the tabulated probability of the d-t reactions as for the DROSG2000 code. The FNG source routine is implemented into the MCNP distributions. The user is asked to define into the MCNP input file the deuteron energy (up to 10 MeV), the beam width and the target dimensions and composition. This source routine has been chosen as starter for the present thesis. Improvements and extensions were introduced.
- The methodology, originally developed for the d-t neutron source, has been extended to d-d neutron sources.
- Assuming the the SRIM code constitutes the reference calculation for the deuteron transport in matter, its implementation in the source routine has been cross-checked by extracting from the latter the same quantities as provided by the original code.
- In the present version of the source routines, the cross sections are internally generated from built in table based on modern evaluated nuclear data files instead of tables obtained from the DROSG200 code.
- Since the model may be used up to 10 MeV deuteron energy, the relativistic kinematics has been implemented to avoid unnecessary approximations.
- Simulations of the bare neutron source spectra and angular yields measurements have been carried out to validate the model.
- New editions of the d-t and d-d source routine have been released for the latest versions of the MCNP codes and tested on LINUX and WINDOWS machines. The validation activities with the FNG and IRMM experimental data suggested a possible application of the source routine for the characterisation of neutron spectrometers in the MeV energy region.
The source routine has been adopted to simulate integral benchmark experiments at FNG, FNS and OKTAVIAN. Brand new MCNP benchmark models have been developed for inclusion of all the available experimental information. It is shown that the d-t source routine is an accurate tool for the generation of the source eutrons. It also demonstrates to be useful for the evaluation of the neutron source term and associated uncertainties. The accuracy of the analyses is pursued to the point that the quality of the nuclear data employed in the simulation can be assessed. To this extent, the case of a new evaluation of the neutron interaction nuclear data for Manganese-55 is tested. A set of integral benchmark experiments has been used in the validation phase of the nuclear data. The computational models rely on the source routine, the object of the thesis. In conclusion, the source routine claims the inclusion of the major features responsible for the experimental resolution associated with the source term. The doctoral thesis explores its usage in the context of the experimental activities for ITER. The future exploitation of the source routine for the simulation of worldwide experiments might become an occasion to compare it with the source models available in the other laboratories
Ključne besede: deuteron-triton reactions, low-energy deuterons, neutron source model, Monte Carlo method, solid tritium target, solid deuterium target, fusion neutronics, benchmark experiments, diamond detectors.
Objavljeno: 07.03.2012; Ogledov: 2947; Prenosov: 88
Celotno besedilo (8,50 MB)
Analysis of the Energy Market Operator activity in eight European countriesFrance Križanič
, Žan Oplotnik
, 2015, izvirni znanstveni članek
Opis: The article aims to analyze the connection between economic development, energy consumption, and prices of electricity and gas on one side and of the operation of the Energy Market Operator on the other. For this purpose we use a sample of eight EU countries with well-functioning energy markets but quite diverse characteristics. The results show that Market Operators in more developed countries in the sample have above average activity (according to revenue), and their primary goal is to achieve external economies. A higher level of Market Operator activity (greater revenue) is influenced by the decrease of transaction costs in energy markets and improves the prospect for greater use of energy. An active Market Operator is characteristically associated with international openness in the energy market as well as with the development of gas use in the given country. We find that a better equipped (greater assets used by the Market Operator) and more active (according to revenues) Market Operator is related with relatively higher levels of electricity and natural gas prices.
Ključne besede: energy, supply and demand, financial analysis, macroeconomics, international benchmark, comparison
Objavljeno: 06.07.2017; Ogledov: 289; Prenosov: 140
Celotno besedilo (323,78 KB)
Gradivo ima več datotek! Več...
Benchmarking firm-level resources, capabilities, and postures driving export performance of SMEsRobert Celec
, Dietfried Globocnik
, 2017, izvirni znanstveni članek
Opis: This paper aimed to identify success factors of export performance for small and medium-sized enterprises (SMEs). Drawing on the resource-based view, the dynamic capability view, and international entrepreneurship theory, we extracted relevant assets, capabilities, and postures at the firm level. An extended benchmarking method was applied to empirically test the proposed success factors with a cross-sectional sample of 99 Slovenian SMEs. The results highlight the crucial role of management competence, financial and human resources, market orientation, negotiation flexibility, and a proactive and risk-taking posture to achieve superior export performance.
Ključne besede: Export performance, resource-based view, dynamic capabilities, entrepreneurial orientation, SME, benchmark
Objavljeno: 03.11.2017; Ogledov: 481; Prenosov: 155
Celotno besedilo (490,88 KB)
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Analiza in možnosti dostopnega turizma na gradu PodsredaNina Perc
, 2019, diplomsko delo
Opis: Dostopni turizem zajema senzorno in gibalno ovirane, osebe s psihičnimi in intelektualnimi ovirami, tiste, ki potujejo z otroki v otroških vozičkih, starostnike ter osebe, ki jim je turizem težje dostopen iz drugih zdravstvenih razlogov (diabetes, alergije …).
Slovenija je po svoji dostopnosti prijazna gibalno oviranim osebam. Vse nove javne zgradbe in drugi večji poslovni in turistični objekti so bili v zadnjih letih zgrajeni s posluhom za ljudi z gibalnimi težavami. Prav tako je bil po mnenju Ministrstva za kulturo Republike Slovenije v slovenskem prostoru narejen opazen napredek muzejskih zbirk in s tem dosežen eden od pomembnih ciljev evropske kulturne politike.
Dostopnost turistične ponudbe nikakor ne pomeni le fizične dostopnosti v smislu prilagoditve okolja za invalidske vozičke. Zaradi izredne raznolikosti potreb je dostopno turistično ponudbo potrebno urediti na različnih nivojih. Pomagamo si s kriteriji dostopnosti, in sicer z dostopnostjo do informacij, fizično, psihosocialno in ekonomsko dostopnostjo. S pomočjo kriterijev dostopnosti, benchmark analize, proučitve domače in mednarodne literature ter opravljenih intervjujev smo v diplomskem delu izdali smernice za razvoj dostopne ponudbe na gradu Podsreda.
Ključne besede: dostopni turizem, osebe s posebnimi potrebami, zavod Premiki, benchmark analiza, grad Podsreda
Objavljeno: 14.11.2019; Ogledov: 47; Prenosov: 4
Celotno besedilo (1,42 MB)