Simulation of beam induced lattice defects of diamond detectors using FLUKA

Diamond is more and more used as detector material for particle detection. One argument for diamond is its higher radiation hardness compared to silicon. Since various particles have different potential for radiation damage at different energies a scaling rule is necessary for the prediction of radiation damage. For silicon detectors the non-ionising energy loss (NIEL) is used for scaling the effects of different particles. A different way of predicting the radiation damage is based on the Norget-Robinson-Torrens theorem to predict the number of displacements per atom (DPA). This provides a better scaling rule since recombination effects are taken into account. This model is implemented in the FLUKA Monte Carlo simulations package for protons, neutrons and pions. We compare simulation results of NIEL and DPA for diamond and silicon material exposed to protons, neutrons and pions for a wide range of energies

Description of radiation damage in diamond sensors using an effective defect model

The BCML system is a beam monitoring device in the CMS experiment at the LHC. As detectors poly-crystalline diamond sensors are used. Here high particle rates occur from the colliding beams scattering particles outside the beam pipe. These particles cause defects, which act as traps for the ionization, thus reducing the CCE. However, the loss in CCE was much more severe than expected. The reason why in real experiments the CCE is so much worse than in laboratory experiments is related to the rate of incident particles. At high particle rates the trapping rate of the ionization is so high compared with the detrapping rate, that space charge builds up. This space charge reduces locally the internal electric field, which in turn increases the trapping rate and hence reduces the CCE even further. In order to connect these macroscopic measurements with the microscopic defects acting as traps for the ionization charge the TCAD simulation program SILVACO was used. Two effective acceptor and donor levels were needed to fit the data. Using this effective defect model the highly non- linear rate dependent diamond polarization as function of the particle rate environment and the resulting signal loss could be simulated

A Deep Architecture for Semantic Parsing

Many successful approaches to semantic parsing build on top of the syntactic analysis of text, and make use of distributional representations or statistical models to match parses to ontology-specific queries. This paper presents a novel deep learning architecture which provides a semantic parsing system through the union of two neural models of language semantics. It allows for the generation of ontology-specific queries from natural language statements and questions without the need for parsing, which makes it especially suitable to grammatically malformed or syntactically atypical text, such as tweets, as well as permitting the development of semantic parsers for resource-poor languages.Comment: In Proceedings of the Semantic Parsing Workshop at ACL 2014 (forthcoming

A Pós-Graduação brasileira: evolução e principais desafios no ambiente de cenários prospectivos.

O presente artigo tem por objetivo analisar a evolução da Pós-Graduação brasileira, desde a sua criação até os dias atuais, com base nos trabalhos desenvolvidos pelos órgãos de fomento CAPES (MEC) e CNPq (MCTI)1, identificando as variáveis mais importantes e suas perspectivas no ambiente de Cenários Prospectivos. Destaca-se, também que, hoje, o país passa pelo período de maior amplitude e importância da pós-graduação, segmento que caminha para possuir alta qualificação nacional e internacional. O estudo apóia-se na revisão bibliográfica e no exame documental, para o resgate da história da pós-graduação brasileira e seus principais desafios, substanciado em uma análise envolvendo variáveis portadoras de futuro desse ambiente, buscando através da metodologia de cenários prospectivos, estabelecer estratégias favoráveis à continuidade dessas boas práticas no futuro

Large-scale multilayer architecture of single-atom arrays with individual addressability

We report on the realization of large-scale 3D multilayer configurations of planar arrays of individual neutral atoms with immediate applications in quantum science and technology: a microlens-generated Talbot optical lattice In this novel platform, the single-beam illumination of a microlens array constitutes a structurally robust and wavelength-universal method for the realization of 3D atom arrays with favourable scaling properties due to the inherent self-imaging of the focal structure. Thus, 3D scaling comes without the requirement of extra resources. We demonstrate the trapping and imaging of individual rubidium atoms and the in-plane assembly of defect-free single-atom arrays in several Talbot planes. We present interleaved lattices with dynamic position control and parallelized sub-lattice addressing of spin states