Fabio Vitello

Muon tomography imaging algorithms for nuclear threat detection inside large volume containers with the Muon Portal detector

Abstract Muon tomographic visualization techniques try to reconstruct a 3D image as close as possible to the real localization of the objects being probed. Statistical algorithms under test for the reconstruction of muon tomographic images in the Muon Portal Project are discussed here. Autocorrelation analysis and clustering algorithms have been employed within the context of methods based on the Point Of Closest Approach (POCA) reconstruction tool. An iterative method based on the log-likelihood approach was also implemented. Relative merits of all such methods are discussed, with reference to full G eant 4 simulations of different scenarios, incorporating medium and high-Z objects inside a container.

Science gateway technologies for the astrophysics community

The availability of large‐scale digital surveys offers tremendous opportunities for advancing scientific knowledge in the astrophysics community. Nevertheless, the analysis of these data often requires very powerful computational resources. Science gateway technologies offer Web‐based environments to run applications with little concern for learning and managing the underlying infrastructures that execute them. This paper focuses on the issues related to the development of a science gateway customized for the needs of the astrophysics community. The VisIVO Science Gateway is wrapped around a WS‐PGRADE/grid User Support Environment portal integrating services for processing and visualizing large‐scale multidimensional astrophysical data sets on distributed computing infrastructures. We discuss the core tools and services supported including an application for mobile access to the gateway. We report our experiences in supporting specialized astrophysical communities requiring development of complex workflows for visualization and numerical simulations. Further, available platforms are discussed for sharing workflows in collaborative environments. Finally, we outline our vision for creating a federation of science gateways to benefit astrophysical communities by sharing a set of services for authentication, computing infrastructure access and data/workflow repositories. Copyright

Search for hidden high-Z materials inside containers with the Muon Portal Project

The Muon Portal is a recently born project that plans to build a large area muon detector for a noninvasive inspection of shipping containers in the ports, searching for the presence of potential fissile (U, Pu) threats. The technique employed by the project is the well-known muon tomography, based on cosmic muon scattering from high-Z materials. The design and operational parameters of the muon portal under construction will be described in this paper, together with preliminary simulation and test results.

An Innovative Science Gateway for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is currently building the next generation, ground-based, very high-energy gamma-ray instrumentation. CTA is expected to collect very large datasets (in the order of petabytes) which will have to be stored, managed and processed. This paper presents a graphical user interface built inside a science gateway aiming at providing CTA-users with a common working framework. The gateway is WS-PGRADE/gUSE workflow-oriented and is equipped with a flexible SSO (based on SAML) to control user access for authentication and authorization. An interactive desktop environment is provided, called Astronomical & Physics Cloud Interactive Desktop (ACID). Users are able to exploit the graphical interface as provided natively by the tools included in ACID. A cloud data service shares and synchronizes data files and output results between the user desktop and the science gateway. Our solution is a first attempt towards an ecosystem of new technologies with a high level of flexibility to suit present and future requirements of the CTA community.

VisIVOWeb: A WWW Environment for Large-Scale Astrophysical Visualization

ABSTRACT. This article presents a newly developed Web portal called VisIVOWeb that aims to provide the astrophysical community with powerful visualization tools for large-scale data sets in the context of Web 2.0. VisIVOWeb can effectively handle modern numerical simulations and real-world observations. Our open-source software is based on established visualization toolkits offering high-quality rendering algorithms. The underlying data management is discussed with the supported visualization interfaces and movie-making functionality. We introduce VisIVOWeb Network, a robust network of customized Web portals for visual discovery, and VisIVOWeb Connect, a lightweight and efficient solution for seamlessly connecting to existing astrophysical archives. A significant effort has been devoted for ensuring interoperability with existing tools by adhering to IVOA standards. We conclude with a summary of our work and a discussion on future developments.

VisIVO Workflow-Oriented Science Gateway for Astrophysical Visualization

Nowadays visualization-based knowledge discovery can play an important role in astrophysics. Collaborative visualization can enable multiple users to share visualization experiences, e.g. by interacting simultaneously with astrophysical datasets giving feedback on what other participants are doing/seeing. Further, workflow-driven applications allow reproduction of specific visualization results, a challenging task as selecting suitable visualization parameters may not be a straightforward process. This paper presents VisIVO Science Gateway, a web-based workflow-enabled framework integrating large-scale, multidimensional datasets and applications for visualization and data filtering on Distributed Computing Infrastructures (DCIs). Advanced users are able to create, change, invoke, and monitor workflows while standard users are provided with easy-to-use customised web interfaces hiding all technical aspects of the visualization algorithms and DCI configurations.

Design of a muonic tomographic detector to scan travelling containers

The Muon Portal Project aims at the construction of a large volume detector to inspect the content of travelling containers for the identification of high-Z hidden materials (U, Pu or other fissile samples), exploiting the secondary cosmic-ray muon radiation. An image of these materials is achieved reconstructing the deviations of the muons from their original trajectories inside the detector volume, by means of two particle trackers, placed one below and one above the container. The scan is performed without adding any external radiation, in a few minutes and with a high spatial and angular resolution. The detector consists of 4800 scintillating strips with two wavelength shifting (WLS) fibers inside each strip, coupled to Silicon photomultipliers (SiPMs). A smart strategy for the read out system allows a considerable reduction of the number of the read-out channels. Actually, an intense measurement campaign is in progress to carefully characterize any single component of the detector. A prototype of one of the 48 detection modules (1 × 3 m2) is actually under construction. This paper presents the detector architecture and the preliminary results.

Spatial distribution of star formation related to ionized regions throughout the inner Galactic plane

We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1360 bubble structures throughout the Galactic plane and their local environments. The compilation of ~70 000 star-forming sources, found in the proximity of the ionized (Hii) regions and detected in both Hi-GAL and GLIMPSE surveys, provided a broad overview of the different evolutionary stages of star-formation in bubbles, from prestellar objects to more evolved young stellar objects (YSOs). Surface density maps of star-forming objects clearly reveal an evolutionary trend where more evolved star-forming objects (Class II YSO candidates) are found spatially located near the center, while younger star-forming objects are found at the edge of the bubbles. We derived dynamic ages for a subsample of 182 H ii regions for which kinematic distances and radio continuum flux measurements were available. We detect approximately 80% more star-forming sources per unit area in the direction of bubbles than in the surrounding fields. We estimate the clump formation efficiency (CFE) of Hi-GAL clumps in the direction of the shell of the bubbles to be ~15%, around twice the value of the CFE in fields that are not affected by feedback effects. We find that the higher values of CFE are mostly due to the higher CFE of protostellar clumps, in particular in younger bubbles, whose density of the bubble shells is higher. We argue that the formation rate from prestellar to protostellar phase is probably higher during the early stages of the (H ii) bubble expansion. Furthermore, we also find a higher fraction of massive YSOs (MYSOs) in bubbles at the early stages of expansion ( < 2 Myr) than older bubbles. Evaluation of the fragmentation time inside the shell of bubbles advocates the preexistence of clumps in the medium before the bubble expansion in order to explain the formation of MYSOs in the youngest H ii regions ( < 1 Myr), as supported by numerical simulations. Approximately 23% of the Hi-GAL clumps are found located in the direction of a bubble, with 15% for prestellar clumps and 41% for protostellar clumps. We argue that the high fraction of protostellar clumps may be due to the acceleration of the star-formation process cause by the feedback of the (Hii) bubbles.

Clustering analysis for muon tomography data elaboration in the Muon Portal project

Clustering analysis is one of multivariate data analysis techniques which allows to gather statistical data units into groups, in order to minimize the logical distance within each group and to maximize the one between different groups. In these proceedings, the authors present a novel approach to the muontomography data analysis based on clustering algorithms. As a case study we present the Muon Portal project that aims to build and operate a dedicated particle detector for the inspection of harbor containers to hinder the smuggling of nuclear materials. Clustering techniques, working directly on scattering points, help to detect the presence of suspicious items inside the container, acting, as it will be shown, as a filter for a preliminary analysis of the data.

Mobile application development exploiting science gateway technologies

Nowadays, collaborative applications are valuable tools for scientists to share their studies and experiences, for example, by interacting simultaneously with their data and outcomes giving feedback to other colleagues on how the data are processed. This paper presents a mobile application connected to a workflow‐enabled framework to perform visualization and data analysis of large‐scale, multi‐dimensional datasets on distributed computing infrastructures. In particular, the usage of workflow‐driven applications, through science gateway technologies, allows the scientist to share heavy data exploration tasks as workflows and the relative results in a transparent and user‐friendly way. Copyright