189 research outputs found
The laser calibration system of the TOP detector
No full textThe TOP detector at the Belle II Experiment is a particle identification detector, devoted mainly to the separation of charged pions and kaons. The charged particles emit Cherenkov photons when traversing a quartz radiator and these photons are converted inside micro-channel plates photomultipliers. The time of arrival and position of the photoelectrons, detected with excellent spatial and time resolution, are used to reconstruct the angle of the Cherenkov light emitted by the charged particle. The monitoring of the time stability and the measurement of the quantum efficiency of the photomultipliers are performed with a laser calibration system, with a target time resolution better than 50 ps. The system is a combination of a picosecond laser source, long single mode fibers, fiber bundles, and microlenses, which are needed to illuminate all the channels of the photomultipliers. A detailed description of the laser calibration system and its properties is given
FETAL TRICUSPID VALVE DYSPLASIA AND PULMONARY ATRESIA AT 14 WEEKS.J ULTRASOUND MED 1995;14:623-25.
No full textThe network of photodetectors and diode lasers of the CMS Link alignment system
No full textArce, P., Barcala, J.M., Calvo, E., Ferrando, A., Josa, M.I., Molinero, A., Navarrete, J., Oller, J.C., Brochero, J., Calderón, A., Fernández, M.G., Gómez, G., González-Sánchez, F.J., Martínez-Rivero, C., Matorras, F., Rodrigo, T., Ruiz-Árbol, P., Scodellaro, L., Sobrón, M., Vila, I., Virto, A.L., Fernández, J., Raics, P., Szabó, Z., Trócsnyi, Z., Ujvári, B., Zilizi, G., Béni, N., Christian, G., Imrek, J., Molnar, J., Novak, D., Pálinkás, J., Székely, G., Szillási, Z., Bencze, G.L., Vestergombi, G., Benettoni, M., Gasparini, F., Montecassiano, F., Rampazzo, M., Zago, M., Benvenuti, A., Reithler, H., Jiang, C
Conotruncal anomalies in prenatal life
No full textThis retrospective multicenter study represents an analysis of the intrauterine determinants of the prognosis for conotruncal anomalies. Data regarding reason for referral, presence of chromosomal or extracardiac anomalies, pregnancy and surgical outcome were recorded in 67 cases of conotruncal anomalies from three Italian referral units. Chromosomal aberrations affected 11 of the 60 (18.3%) fetuses in which a karyotype was available. Extra-cardiac malformations were present in 25/67 cases (37.3%). No chromosomal anomalies were present in fetuses with complete or corrected transposition of the great arteries. However, tetralogy of Fallot and double-outlet right ventricle were associated with chromosomal anomalies in 22% and 38% of cases, respectively, and with extracardiac anomalies in 45% and 46% of cases, respectively. Only 20 of the 67 (31%) cardiac malformations were associated with an abnormal four-chamber view. There were 28 (41.7%) terminations of pregnancy, six (8.9%) intrauterine deaths and 16 (23.8%) neonatal deaths. Seventeen neonates (25.3%) are currently alive, and 15 of these have undergone reparative surgery. The prognosis of conotruncal anomalies is poorer when the condition is diagnosed in utero. This is mainly due to the frequent association with chromosomal and/or extra-cardiac anomalies, often leading to intrauterine or early neonatal death
Muon Tomography: Results on Material Identification and Imaging with a Large Volume Prototipe
No full textDevelopment of a sapphire microstrip detector for gamma beam monitoring
No full textArtificial sapphire gained interest as radiation detector in the recent years, as an alternative to diamond. The research and development campaign to design, build and characterize a radiation-hard detector for gamma beam monitoring takes place in the scientific context of the Laser Und XFEL Experiment (LUXE) at DESY. The experiment requirements of beam profile reconstruction with micro-metric precision and radiation hardness led to a proposed sapphire microstrip detector design. This work introduces the scientific context for a sapphire microstrip gamma beam profiler (GBP) and describes the experimental campaign for sapphire characterization from early prototypes to the final development of a 192-strip detector.<br/
A c.3037G>a mutation in FBN1 gene causing marfan syndrome with an atypically severe phenotype
No full textMarfan syndrome is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, mostly caused by mutations in the FBN1 gene, which is located on chromosome 15q21.1 and encoding fibrillin 1. We report a case of Marfan syndrome presenting with severe ocular and systemic manifestations, such as cardiac congenital anomalies. The patient underwent a multidisciplinary approach and his clinical diagnosis was associated with a c.3037G>A mutation in the FBN1 gene. Identification of this genetic alteration should instigate a prompt multidisciplinary assessment and monitoring, in order to prevent devastating consequences such as cardiac and ocular phenotype. Molecular modeling of the mutation highlighted the importance of the preservation of the calcium-dependent structure of an epidermal-growth-factor-like domain of fibrillin-1 and consequently the microfibrillar formation process. This report aims to highlight the importance of an early clinical and molecular diagnosis and once more, the importance of the multidisciplinary approach of this genetic entity
First results on material identification and imaging with a large-volume muon tomography prototype
No full textThe muon tomography technique, based on the multiple Coulomb scattering of cosmic ray muons, has been proposed recently as a tool to perform non-destructive assays of large volume objects without any radiation hazard. In this paper we discuss experimental results obtained with a scanning system prototype, assembled using two large area CMS Muon Barrel drift chambers. The capability of the apparatus to produce 3D images of objects and to classify them according to their density are presented. We show that the absorption of low momentum muons in the scanned objects produces an underestimate of their scattering density, making more difficult the discrimination of materials heavier than lead
Securing the metal recycling chain for the steel industry by detecting orphan radioactive sources in scrap metal
No full textExperimental tests are reported for the detection of the heavy metal shielding of orphan sources hidden inside scrap metal by using a recently developed muon tomography system. Shielded sources do not trigger alarm in radiation portal commonly employed at the entrance of steel industry using scrap metal. Future systems integrating radiation portals with muon tomography inspection gates will substantially reduce the possibility of accidental melting of radioactive sources securing the use of recycled metal. © 2010 American Institute of Physics
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