Introduction to architectural design: first term experience of architectural design education

Ponencia presentada a Session 3: Educación y arquitectura en las universidades / Architectural education in the universitie

Simulation and Efficiency Studies of Optical Photon Transportation and Detection with Plastic Antineutrino Detector Modules

In this work, the simulation of optical photons is carried out in an antineutrino detector module consisting of a plastic scintillator connected to light guides and photomultipliers on both ends, which is considered to be used for remote reactor monitoring in the field of nuclear safety. Using Monte Carlo (MC) based GEANT4 simulation, numerous parameters influencing the light collection and thereby the energy resolution of the antineutrino detector module are studied: e.g., degrees of scintillator surface roughness, reflector type, and its ap- plying method onto scintillator and light guide surface, the reflectivity of the reflector, light guide geometries and diameter of the photocathode. The impact of each parameter is inves- tigated by looking at the detected spectrum, i.e. the number photoelectrons per depositing energy. In addition, the average light collection efficiency of the detector module and its spatial variation are calculated for each simulation setup. According to the simulation re- sults, it is found that photocathode size, light guide shape, reflectivity of reflecting material and wrapping method show a significant impact on the light collection efficiency while scin- tillator surface polishing level and the choose of reflector type show relatively less impact. This study demonstrates that these parameters are very important in the design of plastic scintillator included antineutrino detectors to improve the energy resolution efficiency

Comparison of Plastic Antineutrino Detector Designs in the Context of Near Field Reactor Monitoring

We compare existing segmented plastic antineutrino detectors with our new geometrically improved design for antineutrino detection and light collection efficiency. The purpose of this study is to determine the most suitable design style for remote reactor monitoring in the context of nuclear safeguards. Using Monte Carlo based GEANT4 simulation package, we perform detector simulation based on two prominent experiments: Plastic antineutrino detector array (Panda) and Core monitoring by reactor antineutrino detector (Cormorad). In addition to these two well-known designs, another concept, the Panda2, can be obtained by making a small variation of Panda detector, is also considered in the simulation. The results show that the light collection efficiency of the Cormorad is substantially less with respect to the other two detectors while the highest antineutrino detection efficiency is achieved with the Cormorad and Panda2. Furthermore, as an alternative to these design choices, which are composed of an array of identical rectangular-shaped modules, we propose to combine regular hexagonal-shaped modules which minimizes the surface area of the whole detector and consequently reduces the number of optical readout channels considerably. With this approach, it is possible to obtain a detector configuration with a slightly higher detection efficiency with respect to the Panda design and a better energy resolution detector compared to the Cormorad design

Variational Approach for the Effects of Periodic Modulations on the Spectrum of Massless Dirac Fermion

In the variational framework, we study the electronic energy spectrum of massless Dirac fermions of graphene subjected to one-dimensional oscillating magnetic and electrostatic fields centered around a constant uniform static magnetic field. We analyze the influence of the lateral periodic modulations in one direction, created by these oscillating electric and magnetic fields, on Dirac like Landau levels depending on amplitudes and periods of the field modulations. We compare our theoretical results with those found within the framework of non-degenerate perturbation theory. We found that the technique presented here yields energies lower than that obtained by the perturbation calculation, and thus gives more stable solutions for the electronic spectrum of massless Dirac fermion subjected to a magnetic field perpendicular to graphene layer under the influence of additional periodic potentials.Comment: 8 pages, 7 figure

Boundaries of Subcritical Coulomb Impurity Region in Gapped Graphene

The electronic energy spectrum of graphene electron subjected to a homogeneous magnetic field in the presence of a charged Coulomb impurity is studied analytically within two-dimensional Dirac-Weyl picture by using variational approach. The variational scheme we used is just based on utilizing the exact eigenstates of two-dimensional Dirac fermion in the presence of a uniform magnetic field as a basis for determining analytical energy eigenvalues in the presence of an attractive/repulsive charged Coulomb impurity. This approach allows us to determine under which conditions bound state solutions can or can not exist in gapped graphene in the presence of magnetic field. In addition, the effects of uniform magnetic field on the boundaries of subcritical Coulomb impurity region in the massless limit are also analyzed. Our analytical results show that the critical impurity strength decreases with increasing gap/mass parameter, and also that it increases with increasing magnetic field strength. In the massless limit, we investigate that the critical Coulomb coupling strength is independent of magnetic field, and its upper value for the ground-state energy is 0.752.Comment: 9 pages,10 figure

Real effects of inflation uncertainty in the US

We empirically investigate the effects of inflation uncertainty on output growth for the US using both monthly and quarterly data over 1985-2009. Employing a Markov regime switching approach to model output dynamics, we show that inflation uncertainty obtained from a Markov regime switching GARCH model exerts a negative and regime dependant impact on output growth. In particular, we show that the negative impact of inflation uncertainty on output growth is almost 4.5 times higher during the low growth regime than that during the high growth regime. We verify the robustness of our findings using quarterly data