Performance of novel silicon n-in-p planar Pixel Sensors

The performance of novel n-in-p planar pixel detectors, designed for future upgrades of the ATLAS Pixel system is presented. The n-in-p silicon sensors technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. The n-in-p modules presented here are composed of pixel sensors produced by CiS connected by bump-bonding to the ATLAS readout chip FE-I3. The characterization of these devices has been performed before and after irradiation up to a fluence of 5 x 10**15 1 MeV neq cm-2 . Charge collection measurements carried out with radioactive sources have proven the functioning of this technology up to these particle fluences. First results from beam test data with a 120 GeV/c pion beam at the CERN-SPS are also discussed, demonstrating a high tracking efficiency of (98.6 \pm 0.3)% and a high collected charge of about 10 ke for a device irradiated at the maximum fluence and biased at 1 kV.Comment: Preprint submitted to Nuclear Instruments and Methods A. 7 pages, 13 figure

The progenitor of a type Ia supernova with a short delay time?

HD49798/RXJ0648.0-4418 is the only known X-ray binary composed of a hot subdwarf and a massive white dwarf (M=1.28+/-0.05 Msun). This system, with an orbital period of 1.55 days, is the outcome of a common envelope evolution, most likely of a pair of stars with initial masses of about 8-10 Msun. When the hot subdwarf, currently in a He-burning phase, will expand again and fill its Roche-lobe, the enhanced mass transfer can rapidly bring the already massive white dwarf above the Chandrasekhar limit. The possible final fate, either a Type Ia supernova explosion or an accretion induced collapse, is particularly interesting in view of the high rotational velocity of this star, which has the shortest spin period (13 s) observed in a white dwarf.Comment: 4 pages, to appear in Proceedings of IAU Symp. 281, Binary Paths to Type Ia Supernovae Explosions, ed. R. Di Stefano and M. Ori

Novel Silicon n-in-p Pixel Sensors for the future ATLAS Upgrades

In view of the LHC upgrade phases towards HL-LHC the ATLAS experiment plans to upgrade the Inner Detector with an all silicon system. The n-in-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. We present the characterization and performance of novel n-in-p planar pixel sensors produced by CiS (Germany) connected by bump bonding to the ATLAS readout chip FE-I3. These results are obtained before and after irradiation up to a fluence of 10^16 1-MeV n_eq/cm^2, and prove the operability of this kind of sensors in the harsh radiation environment foreseen for the pixel system at HL-LHC. We also present an overview of the new pixel production, which is on-going at CiS for sensors compatible with the new ATLAS readout chip FE-I4.Comment: Preprint submitted to NIM-A Proceedings (Elba 2012

Orientaciones básicas para potenciar las altas capacidades intelectuales en niños de preescolar

Tesis (Educación Parvularia, Licenciado en Educación)La presente investigación tiene por objetivo principal formular orientaciones básicas para la identificación de niños que puedan presentar altas capacidades intelectuales en la etapa de Educación Parvularia; focalizándose en un colegio particular del sector oriente; esperando que éstas sean una herramienta eficaz que guíe la identificación de sus educadoras de párvulos

State Estimation For An Agonistic‐Antagonistic Muscle System

Research on assistive technology, rehabilitation, and prosthetics requires the understanding of human machine interaction, in which human muscular properties play a pivotal role. This paper studies a nonlinear agonistic‐antagonistic muscle system based on the Hill muscle model. To investigate the characteristics of the muscle model, the problem of estimating the state variables and activation signals of the dual muscle system is considered. In this work, parameter uncertainty and unknown inputs are taken into account for the estimation problem. Three observers are presented: a high gain observer, a sliding mode observer, and an adaptive sliding mode observer. Theoretical analysis shows the convergence of the three observers. Numerical simulations reveal that the three observers are comparable and provide reliable estimates

Detection of molecular hydrogen at z=1.15 toward HE 0515-4414

A new molecular hydrogen cloud is found in the sub-damped Ly-alpha absorber [log N(HI)=19.88+/-0.05] at the redshift z=1.15 toward the bright quasar HE0515-4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2 are identified in the UV spectrum of this quasar obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope. The H2-bearing cloud shows a total H2 column density N(H2)=(8.7^{+8.7}_-{4.0}) 10^16 cm^-2, and a fractional molecular abundance f(H2)=(2.3^{+2.3}_{-1.1}) 10^-3 derived from the H2 lines arising from the J=0-5 rotational levels of the ground electronic vibrational state. The estimated rate of photodissociation at the cloud edge I_0<=1.8 10^{-8} s^-1 is much higher than the mean Galactic disk value, I_MW~=5.5 10^{-11} s^-1. This may indicate an enhanced star-formation activity in the z=1.15 system as compared with molecular clouds at z~=3 where I~=I_MW. We also find a tentative evidence that the formation rate coefficient of H2 upon grain surfaces at z=1.15 is a factor of 10 larger than a canonical Milky Way value, R_MW~=3 10^-17 cm^3 s^-1. The relative dust-to-gas ratio estimated from the [Cr/Zn] ratio is equal to k=0.89+/-0.19 (in units of the mean Galactic disk value), which is in good agreement with a high molecular fraction in this system. The estimated line-of-sight size of L~=0.25 pc may imply that the H2 is confined within small and dense filaments embedded in a more rarefied gas giving rise to the z=1.15 sub-damped Ly-alpha absorber.Comment: 10 pages, 7 figures, accepted for publication in A&

Performance of n-in-p pixel detectors irradiated at fluences up to 5x10**15 neq/cm**2 for the future ATLAS upgrades

We present the results of the characterization of novel n-in-p planar pixel detectors, designed for the future upgrades of the ATLAS pixel system. N-in-p silicon devices are a promising candidate to replace the n-in-n sensors thanks to their radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. The n-in-p modules presented here are composed of pixel sensors produced by CiS connected by bump-bonding to the ATLAS readout chip FE-I3. The characterization of these devices has been performed with the ATLAS pixel read-out systems, TurboDAQ and USBPIX, before and after irradiation with 25 MeV protons and neutrons up to a fluence of 5x10**15 neq /cm2. The charge collection measurements carried out with radioactive sources have proven the feasibility of employing this kind of detectors up to these particle fluences. The collected charge has been measured to be for any fluence in excess of twice the value of the FE-I3 threshold, tuned to 3200 e. The first results from beam test data with 120 GeV pions at the CERN-SPS are also presented, demonstrating a high tracking efficiency before irradiation and a high collected charge for a device irradiated at 10**15 neq /cm2. This work has been performed within the framework of the RD50 Collaboration.Comment: Proceedings of the Conference "Technology and Instrumentation in Particle Physics 2011

Development of a transnational accident prediction model.

AbstractThe PRACT Project (Predicting Road ACcidents – a Transferable methodology across Europe) is an ongoing project aimed at developing a European accident prediction model structure that could, with proper calibration, be applied to different European road networks.The core principles behind the PRACT project structure are that:•it is unrealistic to think that one unique Accident Prediction Model (APM) model with a unique set of Crash Modification Factors (CMFs) can actually be developed, valid for all Europe and for all the different type of networks;•the development of a specific APM model and a set of CMFs based on local data is extremely time consuming and expensive and requires data and experience that most road administrations do not have;•the development of “local” CMFs only based on historical local data prevents the possibility of evaluating the effectiveness of new technologies.The PRACT project addresses these issues by developing a practical guideline and a user friendly tool that will allow for an easier implementation of APMs and CMFs in different countries and on different road networks