Radiation Damage and Activation from Proton Irradiation of Advanced Scintillators

We present results from a proton accelerator beam test to measure radiation damage and activation in advanced scintillator materials. Samples of LaBr3:Ce and LaCl3:Ce were exposed to protons from 40-250 MeV at the Proton Irradiation Facility of the Paul Scherrer Institute in Switzerland. Twelve energy bands were used to simulate the spectrum of the South Atlantic Anomaly (SAA), with different samples exposed to the equivalent of 4 months, 1 year, and 5 years of SAA passage. No significant decrease in light output was found due to radiation damage, indicating that these new scintillator materials are radiation tolerant. High-resolution spectra of the samples were obtained before and after irradiation with a Germanium spectrometer to study activation. We present a detailed analysis of these spectra and a discussion of the suitability of these scintillator materials for detectors in future space missions

Development of the fast neutron imaging telescope

We report on the development of a next generation neutron telescope, with imaging and energy measurement capabilities, sensitive to neutrons in the 2-20 MeV energy range. The Fast Neutron Imaging Telescope (FNIT) was initially conceived to study solar neutrons as a candidate instrument for the Inner Heliosphere Sentinels (IHS) program under formulation at NASA. This detector is now being adapted to locate Special Nuclear Material (SNM) for homeland security purposes by detecting fission neutrons and reconstructing the image of their source. In either case, the detection principle is based on multiple elastic neutron-proton scatterings in organic scintillator. By reconstructing the scattering coordinates and measuring the recoil proton energy, the direction and energy of each neutron can be determined and discrete neutron sources identified. We describe the performance of the FNIT prototype, report on the current status of R&D efforts and present the results of recent laboratory measurements

Design optimization and performance capabilities of the fast neutron imaging telescope (FNIT)

We describe the design optimization process and performance characterization of a next generation neutron telescope, with imaging and energy measurement capabilities, sensitive to neutrons in the 1-20 MeV energy range. The response of the Fast Neutron Imaging Telescope (FNIT), its efficiency in neutron detection, energy resolution and imaging capabilities were characterized through a combination of lab tests and Monte Carlo simulations. Monte Carlo simulations, together with experimental data, are also being used in the development and testing of the image reconstruction algorithm. FNIT was initially conceived to study solar neutrons as a candidate instrument for the Inner Heliosphere Sentinel (IHS) spacecraft. However, the design of this detector was eventually adapted to locate Special Nuclear Material (SNM) sources for homeland security purposes, by detecting fission neutrons. In either case, the detection principle is based on multiple elastic neutron-proton scatterings in organic scintillator. By reconstructing event locations and measuring the recoil proton energies, the direction and energy spectrum of the primary neutron flux can be determined and neutron sources identified. This paper presents the most recent results arising from our efforts and outlines the performance of the FNIT detector

Informatics in the French Secondary Curricula: Recent Moves and Perspectives

International audienceIn France, since 2010, the situation regarding informatics education in secondary school has changed: Algorithmic was introduced in mathematics curricula at grade 11 and an elective Computer Science course (called ISN) has been introduced at grade 12 (Fall 2012). These changes have encouraged some initiatives for the promotion of informatics education, among them the French 2012-Bebras contest. However, the 'informatics as a tool approach' continues to guide decision makers in education. This context renews the issue of informatics education (including Computer Science) for all students at the different levels of secondary school. We submit some ideas to re-open the debat

Design and Testing of a Position-Sensitive Plastic Scintillator Detector for Fast Neutron Imaging

We describe the design and performance of a position sensitive scintillator detector developed forneutron measurements. Several of these detectors are to be used in the assembly of the Fast NeutronImaging Telescope (FNIT), an instrument with imaging and energy measurement capabilities, sensitive to neutrons in the 2-20 MeV energy range. FNIT was initially conceived to study solar neutrons as a candidate instrument for the Inner Heliospheric Sentinels (IHS) program under formulation at NASA. It is now being adapted to locate Special Nuclear Material (SNM) for homeland security purposes by detecting fission neutrons and reconstructing the image of their source. The detection principle is based on multiple elastic neutron-proton scatterings in organic scintillator. The detector presented here utilizes wavelength-shifting (WLS) fibers, grooved into the plastic scintillator and read out by multianode photomultiplier tubes (MAPMTs) to determine scattering locations. By also measuring the recoil proton and scattered neutron\u27s energies, the direction and energy spectrum of incidents neutrons can be determined and discrete sources identified