Beam dumps are installed at the experimental areas of the ELBE facility. Their purpose is to absorb the primary electron beam and the secondary radiation. The beam dump consists of a purified graphite core inside a water cooled stainless steel vessel. The radiation shield surrounding the beam dump will be designed individually for each experimental area. In this context, dose rate calculations were carried out to estimate the dose rate source term around the stainless steel vessel of the beam dump. Detailed Monte Carlo simulations were carried out using the code FLUKA. The energy dependent photon and neutron fluences and the equivalent dose rates were obtained near the surface of the cylindrical steel vessel for a beam current of 1 mA and energies of 20 MeV and 50 MeV.

Les prédictions concernant le fonctionnement des divertors de tokamak reposent généralement sur des codes de transport de bord, consistant en un code de plasma fluide associé à un code de Monte Carlo pour les espèces neutres. Les machines linéaires Magnum-PSI et Pilot-PSI chez DIFFER, produisant des plasmas comparables à ceux d'ITER ($T_e \sim 1$ eV, $n_e\sim10^{20}$ m$^{- 3}$). Dans cette thèse, les décharges de plasma ont été étudiées expérimentalement et par modélisation utilisant le code Soledge2D-Eirene afin de: a) rechercher quels phénomènes doivent être inclus dans la modélisation pour reproduire les tendances expérimentales et b) pour mieux interpréter les expériences . Expérimentalement, l’effet de la pression neutre $P_n$ a été étudié par diffusion Thomson, par une sonde de Langmuir, par spectroscopie visible et par calorimétrie. Nous avons montré qu'un faisceau de plasma peut être efficacement terminé par une couche de gaz neutre. Ensuite, à partir de comparaisons d’expériences et de simulations, nous avons montré qu’il était essentiel d’inclure les collisions élastiques entre le plasma et les molécules pour pouvoir reproduire les expériences. De plus, la $T_e$ proche de la cible est systématiquement surestimé, ce qui sous-estime le taux de recombinaison. Enfin, nous avons montré expérimentalement l’importance de l’inclusion de la recombinaison de surface dans le flux d’énergie de surface dans les plasmas à basse température. Les travaux présentés dans cette thèse contribuent à la compréhension des interactions plasma-neutre, en particulier dans les concepts de divertors plus fermés de nouvelle génération (MAST-upgrade, DIII-D). / Predictions for the operation of tokamak divertors typically rely on edge transport codes, consisting of a fluid plasma code in combination with a Monte Carlo code for neutral species. The linear devices Magnum-PSI and Pilot-PSI at DIFFER, operating with a cascaded arc plasma source that produces plasmas comparable to those expected in the ITER divertor ($T_e \sim 1 $ eV, $n_e \sim 10^{20}$m$^{-3}$). In this thesis, plasma discharges have been studied both experimentally and by modelling using the Soledge2D-Eirene code in order to a) investigate which phenomena need to be included in the modeling to reproduce experimental trends and b) provide new insights to the interpretation of experiments. Experimentally, the effect of neutral pressure $P_n$ was investigated using Thomson scattering, a Langmuir probe, visible spectroscopy and calorimetry. We have shown that a plasma beam can be effectively terminated by a blanket of neutral gas. Next, from comparisons of experiments and simulations, we have found that it is critical to include elastic collisions between the plasma and molecules if experiments are to be reproduced. Furthermore, the near-target $T_e$ is systematically overestimated by the code, underestimating the recombination rate thereby. Lastly, we have experimentally shown the importance of the inclusion of surface recombination to the surface energy flux in low temperature plasmas, an effect that is generally known but difficult to measure in fusion devices. The work presented in this thesis contributes to the understanding of plasma-neutral interactions especially in new generation, closed divertor concepts (i.e. MAST-upgrade, DIII-D).

The conventional approach for estimation of in-situ porosity is the combined use of neutron and density logs. These nuclear borehole measurements are influenced by fundamental petrophysical, fluid, and geometrical properties of the probed formation including saturating fluids, matrix composition, mud-filtrate invasion and shoulder beds. Advanced interpretation methods that include numerical modeling and inversion are necessary to reduce environmental effects and non-uniqueness in the estimation of porosity. The objective of this dissertation is two-fold: (1) to develop a numerical procedure to rapidly and accurately simulate nuclear borehole measurements, and (2) to simulate nuclear borehole measurements in conjunction with inversion techniques. Of special interest is the case of composite rock formations of sand-shale laminations penetrated by high-angle and horizontal (HA/HZ) wells. In order to quantify shoulder-bed effects on neutron and density borehole measurements, we perform Monte Carlo simulations across formations of various thicknesses and borehole deviation angles with the multiple-particle transport code MCNP. In so doing, we assume dual-detector tool configurations that are analogous to those of commercial neutron and density wireline measuring devices. Simulations indicate significant variations of vertical (axial) resolution of neutron and density measurements acquired in HA/HZ wells. In addition, combined azimuthal- and dip-angle effects can originate biases on porosity estimation and bed boundary detection, which are critical for the assessment of hydrocarbon reserves. To enable inversion and more quantitative integration with other borehole measurements, we develop and successfully test a linear iterative refinement approximation to rapidly simulate neutron, density, and passive gamma-ray borehole measurements. Linear iterative refinement accounts for spatial variations of Monte Carlo-derived flux sensitivity functions (FSFs) used to simulate nuclear measurements acquired in non-homogeneous formations. We use first-order Born approximations to simulate variations of a detector response due to spatial variations of formation energy-dependent cross-section. The method incorporates two- (2D) and three-dimensional (3D) capabilities of FSFs to simulate neutron and density measurements acquired in vertical and HA/HZ wells, respectively. We calculate FSFs for a wide range of formation cross-section variations and for borehole environmental effects to quantify the spatial sensitivity and resolution of neutron and density measurements. Results confirm that the spatial resolution limits of neutron measurements can be significantly influenced by the proximity of layers with large contrasts in porosity. Finally, we implement 2D sector-based inversion of azimuthal logging-while-drilling (LWD) density field measurements with the fast simulation technique. Results indicate that inversion improves the petrophysical interpretation of density measurements acquired in HA/HZ wells. Density images constructed with inversion yield improved porosity-feet estimations compared to standard and enhanced compensation techniques used commercially to post-process mono-sensor densities. / text

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第18664号 / エネ博第309号 / 新制||エネ||63(附属図書館) / 31578 / 京都大学大学院エネルギー科学研究科エネルギー応用科学専攻 / (主査)教授 大垣 英明, 教授 白井 康之, 教授 松田 一成 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Ionizing radiation has a harmful potential to humans, so the protection of workers and public individuals is fundamental for the safe use of radiation in different practical purpose. Therefore, is necessary to set exposure limits to radiation using dosimetric quantities such as equivalent dose and effective dose. However equivalent and effective dose are not directly measured, so it is necessary calculate conversion coefficients (CC¡¦s) which relates this quantities with measured quantities such as particles fluence. In the literature exposure scenarios are, in general, built with simulator in the standing posture, but exposure of individuals to radiation can occur in other posture, so the aim of this work is calculate and compare the absorbed dose-to-fluence conversion coefficients (DT/ ¶) and effective dose-to-fluence conversion coefficients (E/ ¶) for the female hybrid simulator (UFHADF) in the standing and sitting posture and for the male hybrid simulator (UFHADM) in the standing posture using the Monte Carlo code MCNPX for monoenergetic protons from 2 MeV to 10 GeV and in the antero posterior (AP), postero anterior (PA), right lateral (RLAT), left lateral (LLAT), rotational (ROT) and isotropic (ISO) exposure scenarios. Comparing the CC¡¦s between standing and sitting posture of UFHADF simulator, it was observed that in the AP and PA irradiation geometry the relative differences in the head, chest and the superior abdomen organs were not relevant. However in the others irradiation geometries, for some organs in the abdomen and chest region differences in CC¡¦s were observed. The organs that presented more differences in CC¡¦s were uterus (538 % in RLAT geometry), bladder (80 % in ROT geometry) and ovaries (2861 % in LLAT geometry) since this organs are located in the lower abdominal region, in which the position of legs and arms are different between standing and sitting posture. Calculate the DT/ ¶ e E/ ¶ nconversion coefficients using simulator in the sitting posture is important to estimate more precisely the dose in individuals exposed to radiation in actual scenarios. / As radiacoes ionizantes tem um potencial danoso aos seres humanos e, por isso, a protecao de trabalhadores e de individuos do publico e essencial para o uso seguro das mesmas nos diversos fins praticos. Desta forma, e necessario estabelecer limites de exposicao com relacao a estes tipos de radiacao e, para tanto, sao utilizadas grandezas dosimetricas como a dose equivalente e a dose efetiva. Como a dose equivalente e a dose efetiva nao sao medidas diretamente faz-se necessario o calculo de coeficientes de conversao (CC¡¦s) em ambito computacional, pois eles relacionam estas grandezas com grandezas mensuraveis, como a fluencia de particulas. Como na literatura os cenarios de exposicao sao, em geral, construidos com simuladores implementados na postura vertical e nem sempre a exposicao de individuos a radiacao ocorre nessa postura, esse trabalho tem como finalidade, utilizar o codigo de transporte de radiacao Monte Carlo MCNPX e o simulador antropomorfico adulto feminino UFHADF nas posturas vertical e sentada e o simulador masculino UFHADM na postura vertical para obter e comparar os coeficientes de conversao para dose absorvida (DT) e dose efetiva (E) em termos da fluencia (£X) (DT/£X e E/£X) para protons monoenergeticos de 2 MeV ate 10 GeV, para os cenarios de irradiacao antero-posterior (AP), postero-anterior (PA), lateral direito (RLAT), lateral esquerdo (LLAT), rotacional (ROT) e isotropico (ISO). Na comparacao dos CC¡¦s entre o simulador UFHADF nas posturas vertical e sentada, foi observado que a diferenca relativa entre os CC¡¦s nos orgaos da regiao da cabeca, do torax e do abdomen superior nao foram relevantes nas geometrias de irradiacao AP e PA. Ja nas demais geometrias de irradiacao, para alguns orgaos da regiao do abdomen e torax diferencas nos CC¡¦s foram observadas. Os orgaos que mais apresentaram diferencas nos CC¡¦s foram o utero (538 % na geometria RLAT), a bexiga (80 % na geometria ROT) e os ovarios (2861 % na geometria LLAT) que se localizam na regiao abdominal inferior, regiao onde ha a diferenca na posicao das pernas e bracos do simulador. Assim, o calculo dos coeficientes de conversao DT/ ¶ e E/ ¶ utilizando simuladores antropomorficos na postura sentada e importante para uma estimativa mais precisa da dose em individuos submetidos a cenarios reais de exposicao a radiacao.

Ionizing radiation has a harmful potential to humans, so the protection of workers and public individuals is fundamental for the safe use of radiation in different practical purpose. Therefore, is necessary to set exposure limits to radiation using dosimetric quantities such as equivalent dose and effective dose. However equivalent and effective dose are not directly measured, so it is necessary calculate conversion coefficients (CCs) which relates this quantities with measured quantities such as particles fluence. In the literature exposure scenarios are, in general, built with simulator in the standing posture, but exposure of individuals to radiation can occur in other posture, so the aim of this work is calculate and compare the absorbed dose-to-fluence conversion coefficients (DT/ ) and effective dose-to-fluence conversion coefficients (E/ ) for the female hybrid simulator (UFHADF) in the standing and sitting posture and for the male hybrid simulator (UFHADM) in the standing posture using the Monte Carlo code MCNPX for monoenergetic protons from 2 MeV to 10 GeV and in the antero posterior (AP), postero anterior (PA), right lateral (RLAT), left lateral (LLAT), rotational (ROT) and isotropic (ISO) exposure scenarios. Comparing the CCs between standing and sitting posture of UFHADF simulator, it was observed that in the AP and PA irradiation geometry the relative differences in the head, chest and the superior abdomen organs were not relevant. However in the others irradiation geometries, for some organs in the abdomen and chest region differences in CCs were observed. The organs that presented more differences in CCs were uterus (538 % in RLAT geometry), bladder (80 % in ROT geometry) and ovaries (2861 % in LLAT geometry) since this organs are located in the lower abdominal region, in which the position of legs and arms are different between standing and sitting posture. Calculate the DT/ e E/ nconversion coefficients using simulator in the sitting posture is important to estimate more precisely the dose in individuals exposed to radiation in actual scenarios. / As radiacoes ionizantes tem um potencial danoso aos seres humanos e, por isso, a protecao de trabalhadores e de individuos do publico e essencial para o uso seguro das mesmas nos diversos fins praticos. Desta forma, e necessario estabelecer limites de exposicao com relacao a estes tipos de radiacao e, para tanto, sao utilizadas grandezas dosimetricas como a dose equivalente e a dose efetiva. Como a dose equivalente e a dose efetiva nao sao medidas diretamente faz-se necessario o calculo de coeficientes de conversao (CCs) em ambito computacional, pois eles relacionam estas grandezas com grandezas mensuraveis, como a fluencia de particulas. Como na literatura os cenarios de exposicao sao, em geral, construidos com simuladores implementados na postura vertical e nem sempre a exposicao de individuos a radiacao ocorre nessa postura, esse trabalho tem como finalidade, utilizar o codigo de transporte de radiacao Monte Carlo MCNPX e o simulador antropomorfico adulto feminino UFHADF nas posturas vertical e sentada e o simulador masculino UFHADM na postura vertical para obter e comparar os coeficientes de conversao para dose absorvida (DT) e dose efetiva (E) em termos da fluencia (X) (DT/X e E/X) para protons monoenergeticos de 2 MeV ate 10 GeV, para os cenarios de irradiacao antero-posterior (AP), postero-anterior (PA), lateral direito (RLAT), lateral esquerdo (LLAT), rotacional (ROT) e isotropico (ISO). Na comparacao dos CCs entre o simulador UFHADF nas posturas vertical e sentada, foi observado que a diferenca relativa entre os CCs nos orgaos da regiao da cabeca, do torax e do abdomen superior nao foram relevantes nas geometrias de irradiacao AP e PA. Ja nas demais geometrias de irradiacao, para alguns orgaos da regiao do abdomen e torax diferencas nos CCs foram observadas. Os orgaos que mais apresentaram diferencas nos CCs foram o utero (538 % na geometria RLAT), a bexiga (80 % na geometria ROT) e os ovarios (2861 % na geometria LLAT) que se localizam na regiao abdominal inferior, regiao onde ha a diferenca na posicao das pernas e bracos do simulador. Assim, o calculo dos coeficientes de conversao DT/ e E/ utilizando simuladores antropomorficos na postura sentada e importante para uma estimativa mais precisa da dose em individuos submetidos a cenarios reais de exposicao a radiacao.

Le code des transports accueille désormais les règles de droit social maritime. Le gouvernement a été habilité à procéder, en 2010, à une recodification à droit constant de ses dispositions éparses, notamment contenues dans le code du travail et le code du travail maritime. Alors que cette opération devait intervenir sans modification de l’état du droit, une certaine inconstance s’est révélée. La structure de la matière a été bouleversée. Elle démontre une ambivalence : le code des transports est exhibé comme instrument du progrès social, mais il peut également devenir un outil de dérèglementation. D'autant que sa partie réglementaire reste très incomplète. L'articulation du nouveau code avec le code du travail interroge également, notamment sous l'angle des rapports entre le droit commun et le droit spécial. Cette réécriture a, de surcroît, subit l'influence du droit international. L’intégration de la convention du travail maritime de l’Organisation internationale du travail a permis de réaffirmer les principes directeurs au fondement de la matière ainsi que la spécificité du droit applicable aux gens de mer. Pour autant, ces dynamiques normatives ont des effets paradoxaux car le droit international participe tour à tour à la destruction et à la reconstruction des droits nationaux. Aussi, la réécriture de la matière au sein du code des transports pourrait être annonciatrice d’un alignement du fond du droit social maritime sur les standards internationaux qui, à l'échelle du droit national français, ne sont pas nécessairement plus protecteurs. Ce mouvement du droit s'explique par une rude concurrence internationale propice à l'expression du dumping social / The transport code now hosts social maritime law rules. The government was empowered to proceed, in 2010, to a recodification on the basis of established law of its disparate provisions, including those contained in both the labour code and the maritime labour code. Although this operation was to take place without changing the rule of law, a certain instability became obvious. The subject matter's structure was dramatically altered. It reveals an ambivalence : the transport code is exhibited as an instrument of social progress, yet it may also become a deregulation tool. To compound matters, its regulatory aspect remains very incomplete. The articulation of the new code with the labour code is equally perplexing, most notably with regard to the relationship between common law and special law. This rewriting has, in addition, undergone the influence of international law. The integration of the International labour organization's maritime labour convention made it possible to reaffirm the foundational guidelines of this topic as well as the specificity of laws applicable to seafarers. Moreover, these normative dynamics have paradoxical effects. In fact, international law contributes alternately to the destruction and reconstruction of national rights. Thus, the rewriting of the topic within the transport code could be the harbinger of an alignment of maritime social legal foundations with international standards, which, when compared with french law, are not necessarily more protective. This legal evolution reflects is due to a ruthless international competition that enables social dumping conditions