Energy loss measurement for charged particles in very thin silicon layers

The energy loss distribution f(D) of highly relativistic charged particles has been measured for thin silicon layers with thickness ranging from 5.6 to 120 mm. In this work, using an innovative method, the dependence of the energy loss distribution from the thickness of the silicon absorber has been investigated in great detail with reference to CMOS Active Pixel Sensors. The measured energy loss distributions are well-reproduced by calculations also when the target electrons binding energy is taken into account. Finally the results obtained with this method are compared with existing experimental results and theoretical data

A formação de redes interorganizacionais para o desenvolvimento regional

The research deals with the construction of interorganizational networks and the role of an institution of technical and higher education in regional development. The objective is to analyze the formation of interorganizational networks and the importance of the action of the Federal Institute of Education, Science and Technology of Rio Grande do Sul (IFRS) campus Erechim (RS), for regional development. The research is justified because it is proposed to observe the interaction of the educational institution with the regional social actors and how the research areas contribute to the region of Alto Uruguai (RS), considered peripheral in the socioeconomic context of Rio Grande do Sul. The paper works with a descriptive approach with a qualitative research focus and the research strategy is framed as a single case study, based on the IFRS and its respective interorganizational networks, regardless of their density. The techniques of data collection used are the documentary research and the search database of the IFRS and the content analysis was used to treatment and exposition of the data. The Institution contributes to the regional development, besides the incorporation of added value of knowledge in the qualification of human resources. The formation of interorganizational networks should intensify the effectiveness of its activities in the region of Alto Uruguay (RS). Despite the strong interaction of the Institution with other regional actors and the presence of a formal network constituted with the institutional support of the IFRS, the Institution's atuaction time may be a limiting factor for the creation of interorganizational networks that promote the development regional. Keywords: Interorganizational Networks. Regional Development. Technical and Higher Education.A pesquisa versa sobre a construção de redes interorganizacionais e o papel de uma Instituição de ensino técnico e superior no desenvolvimento regional. O objetivo é analisar a formação de redes interorganizacionais e a importância da atuação do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul (IFRS) campus Erechim (RS), para o desenvolvimento regional. A pesquisa justifica-se, pois se propõe observar a interação da Instituição de ensino com os atores sociais regionais e de que forma as áreas de pesquisa contribuem com a região do Alto Uruguai (RS), considerada periférica no contexto socioeconômico do Rio Grande do Sul. Insere-se em uma abordagem descritiva com enfoque de pesquisa qualitativa e a estratégia de pesquisa, se enquadra como estudo de caso único, com base no IFRS e suas respectivas redes interorganizacionais, independentemente de sua densidade. As técnicas de coleta de dados foram a pesquisa documental e a base de dados de pesquisa do IFRS e foi utilizada a análise de conteúdo. A Instituição contribui para o desenvolvimento regional, além da incorporação de valor agregado de conhecimento na qualificação de recursos humanos. A formação de redes interorganizacionais poderia intensificar a eficácia de sua atuação na região do Alto Uruguai (RS). Mesmo verificando a forte interação da Instituição com demais atores regionais e a presença de uma rede formal constituída, com o auxílio do IFRS, o tempo de atuação da Instituição pode ser um limitador para a criação de redes interorganizacionais que promovam o desenvolvimento regional. Palavras chave: Desenvolvimento Regional. Ensino Técnico e Superior. Redes Interorganizacionais

A 5 Gb/s Radiation Tolerant Laser Driver

A laser driver for data transmission at 5 Gb/s has been developed as a part of the Giga Bit Transceiver (GBT) project. The Giga Bit Laser Driver (GBLD) targets High Energy Physics (HEP) applications for which radiation tolerance is mandatory. The GBLD ASIC can drive both VCSELs and some types of edge emitting lasers. It is essentially composed of two drivers capable of sinking up to 12 mA each from the load at a maximum data rate of 5 Gb/s, and of a current sink for the laser bias current. The laser driver include also pre-emphasis and duty cycle control capabilities

Impacto da sustentabilidade econômico - financeira do desenvolvimento dos municípios da região a AMOSC

This study sought to identify the development level of problems facing from economic and financial sustainability from four selected municipalities at the AMOSC region. Furthermore, we sought to identify the economic and financial dependency from municipalities across government transfers according the municipal degree of resource dependence development level. The study consists of a exploratory and descriptive survey and quantitative approach with regard to procedures, consists of a multiple study case with secondary analysis data. It was found that there is a bias between the level of dependence and the development of these counties, where the municipalities with higher volumes of shipments, mostly are those with higher levels of development. It was demonstrated, in particular, that although there is a direct relationship between the variables, this condition does not hold up over time according to each municipality own peculiarities. The study indicates that the development does not clump by articulated alone actions, but from the sum of locally channeled systematically actions which imply the modification of regional socio-economic structureEste estudo buscou identificar o nível de desenvolvimento frente à problemática da sustentabilidade econômico-financeira dos quatro municípios selecionados na região da AMOSC. Além disso, buscou-se identificar a dependência econômico-financeira destes municípios frente às transferências governamentais relacionando o nível de desenvolvimento municipal de acordo com o grau de dependência de recursos. O estudo consiste em uma pesquisa cuja abordagem é exploratória e descritiva, com enfoque quantitativo, com relação aos procedimentos, consiste em um estudo de múltiplos casos, com análise de dados secundários. Foi possível constatar que há um viés entre o nível de dependência e o desenvolvimento de cada um destes municípios, onde os municípios com maiores volumes de transferências, majoritariamente são aqueles com maior nível de desenvolvimento. Ficou constatado, sobretudo, que apesar de haver relação direta entre as variáveis, essa condição não se sustenta ao longo do tempo em função de que cada município tem suas particularidades. O estudo indica que o desenvolvimento não se cristaliza por ações articuladas isoladamente, mas a partir da soma de ações canalizadas localmente, de forma sistemática as quais implicam na modificação da estrutura socioeconômica regional.

Dose ratio proton radiography using the proximal side of the Bragg peak

Purpose: In recent years there has been a movement towards single-detector proton radiography, due to its potential ease of implementation within the clinical environment. One such single-detector technique is the dose ratio method, in which the dose maps from two pristine Bragg peaks are recorded beyond the patient. To date, this has only been investigated on the distal side of the lower energy Bragg peak, due to the sharp fall-off. We investigate the limits and applicability of the dose ratio method on the proximal side of the lower energy Bragg peak, which has the potential to allow a much wider range of water-equivalent thicknesses (WET) to be imaged. Comparisons are made with the use of the distal side of the Bragg peak. Methods: Using the analytical approximation for the Bragg peak we generated theoretical dose ratio curves for a range of energy pairs, and then determined how an uncertainty in the dose ratio would translate to a spread in the WET estimate. By defining this spread as the accuracy one could achieve in the WET estimate, we were able to generate look-up graphs of the range on the proximal side of the Bragg peak that one could reliably use. These were dependent on the energy pair, noise level in the dose ratio image and the required accuracy in the WET. Using these look-up graphs we investigated the applicability of the technique for a range of patient treatment sites. We validated the theoretical approach with experimental measurements using a complementary metal oxide semiconductor active pixel sensor (CMOS APS), by imaging a small sapphire sphere in a high energy proton beam. Results: Provided the noise level in the dose ratio image was 1% or less, a larger spread of WETs could be imaged using the proximal side of the Bragg peak (max 5.31 cm) compared to the distal side (max 2.42 cm). In simulation it was found that, for a pediatric brain, it is possible to use the technique to image a region with a square field equivalent size of 7.6 cm2, for a required accuracy in the WET of 3 mm and a 1% noise level in the dose ratio image. The technique showed limited applicability for other patient sites. The CMOS APS demonstrated a good accuracy, with a root-mean-square-error of 1.6 mm WET. The noise in the measured images was found to be σ =1.2% (standard deviation) and theoretical predictions with a 1.96σ noise level showed good agreement with the measured errors. Conclusions: After validating the theoretical approach with measurements, we have shown that the use of the proximal side of the Bragg peak when performing dose ratio imaging is feasible, and allows for a wider dynamic range than when using the distal side. The dynamic range available increases as the demand on the accuracy of the WET decreases. The technique can only be applied to clinical sites with small maximum WETs such as for pediatric brains

Geant4-based simulations of charge collection in CMOS Active Pixel Sensors

Geant4 is an object-oriented toolkit for the simulation of the interaction of particles and radiation with matter. It provides a snapshot of the state of a simulated particle in time, as it travels through a specified geometry. One important area of application is the modelling of radiation detector systems. Here, we extend the abilities of such modelling to include charge transport and sharing in pixelated CMOS Active Pixel Sensors (APSs); though similar effects occur in other pixel detectors. The CMOS APSs discussed were developed in the framework of the PRaVDA consortium to assist the design of custom sensors to be used in an energy-range detector for proton Computed Tomography (pCT). The development of ad-hoc classes, providing a charge transport model for a CMOS APS and its integration into the standard Geant4 toolkit, is described. The proposed charge transport model includes, charge generation, diffusion, collection, and sharing across adjacent pixels, as well as the full electronic chain for a CMOS APS. The proposed model is validated against experimental data acquired with protons in an energy range relevant for pCT

Evolution of optical fibre cabling components at CERN: Performance and technology trends analysis

CERN optical fibre infrastructure has been growing constantly over the past decade due to ever increasing connectivity demands. The provisioning plan and fibre installation of this vast laboratory is performed by Fibre Optics and Cabling Section at Engineering Department. In this paper we analyze the procurement data for essential fibre cabling components during a five-year interval to extract the existing trends and anticipate future directions. The analysis predicts high contribution of LC connector and an increasing usage of multi-fibre connectors. It is foreseen that single-mode fibres become the main fibre type for mid and long-range installations while air blowing would be the major installation technique. Performance assessment of various connectors shows that the expanded beam ferrule is favored for emerging on-board optical interconnections thanks to its scalable density and stable return-loss