Search results for "Fluence"
showing 10 items of 482 documents
Young People and the Dark Side of Social Media: Possible Threats to National Security
2020
Social media is increasingly becoming a forum for criminality, misuse, and hate speech, as there are no filters or other controlling mechanisms to filter user-generated content.Furthermore, disinformation and propaganda are becoming more sophisticated and harder to track. Hence, this dark side of social media can pose a viable threat to national security. Future generations will be born into an environment of polluted and polarised online information networks. Consequently, young people, many of whom use social media on a daily basis, will have to find ways to survive in these circumstances,often without the help, knowledge, or experience of earlier generations. Thus, young people are at ri…
Appetizer or main dish? Explaining the use of Facebook news posts as a substitute for other news sources
2019
An increasing number of, especially younger, users use Facebook as their primary source for news about political and societal issues. At the same time, research suggests that Facebook use contributes to societal knowledge gaps. Against this background, we investigate the antecedents of using Facebook as a substitute for other news sources. We argue that exposure to news posts on Facebook increases the feeling of being well-informed, regardless of actual knowledge acquisition. This might lead users, especially those with a low need for cognition (NfC), to use Facebook as a substitute for other news sources. We test these assumptions with an online survey (n=390) of German Internet users. Res…
Radiation Tolerance Tests of Small-Sized CsI(Tl) Scintillators Coupled to Photodiodes
2009
Radiation tolerance of small-sized CsI (Tl) crystals coupled to silicon photodiodes was studied by using protons. Irradiations up to the fluence of 1012 protons/cm2 were used. Degradation of light output by less than 5% was achieved.
LiF crystals irradiated with 150MeV Kr ions: Peculiarities of color center creation and thermal annealing
2013
Abstract Color centers in LiF crystals are studied under irradiation at room temperature with 150 MeV Kr ions in the fluence (Φ) range of 1010–1014 ions/cm2 with a beam current density of 10, 50, and 100 nA/cm2, corresponding to flux of 4.46 × 109, 2.23 × 1010 and 4.46 × 1010 ions/(cm2 × s), respectively. At Φ ⩾ 3 × 1012 ions/cm2 besides F and Fn centers also charged F 3 + centers are created. Thermal annealing of irradiated LiF crystals with Φ ⩾ 1013 ions/cm2 at 400 K leads to a decrease of F centers (due to annihilation with H centers) and an enhancement of complex Fn color centers (neutral and charged) due to interaction with thermally activated anion vacancies. Annealing LiF crystals at…
Thermal annealing and transformation of dimer F centers in neutron-irradiated Al2O3 single crystals
2020
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. In addition, the research leading to these results has received funding from the Estonian Research Council grant (PUT PRG619).
Neutron–gamma mixed field measurements by means of MCP–TLD600 dosimeter pair
2007
Abstract In this paper, we compared the TL response of three types of thermoluminescence dosimeters, TLD600 (6LiF:Mg,Ti), TLD700 (7LiF:Mg,Ti) and MCP (LiF:Mg,Cu,P) after exposure to a n–γ mixed field in the fluence range of radiotherapeutic applications. Since a dosimeter pair is required to discriminate the two components of the mixed field, we analyzed the ability of each dosimeter pair to provide the fluence value in the mixed field. At this aim we performed a 60Co–γ calibration and a neutron calibration for all three dosimeter types. Finally, a blind test was performed in order to analyze the accuracy of each dosimeter pair and we found that in this mixed field the fluence value obtaine…
Ion-induced hardening in LiF: Energy loss and fluence effects
2006
The behavior of hardening of LiF crystals irradiated with swift Au, Pb, Bi, Kr, Ni, Ti and S ions with a specific energy of 10 MeV/u is analyzed. The dispersion strengthening as the main mechanism of hardening is verified.
Ion track template technique for fabrication of ZnSe2O5 nanocrystals
2020
The work was performed under the grant of the Ministry of Education and Science of the Republic of Kazakhstan AP05134367 and Latvian grant lzp
Heavy Ion Induced Degradation in SiC Schottky Diodes : Bias and Energy Deposition Dependence
2017
Experimental results on ion-induced leakage current increase in 4H-SiC Schottky power diodes are presented. Monte Carlo and TCAD simulations show that degradation is due to the synergy between applied bias and ion energy deposition. This degradation is possibly related to thermal spot annealing at the metal semiconductor interface. This thermal annealing leads to an inhomogeneity of the Schottky barrier that could be responsible for the increase leakage current as a function of fluence. peerReviewed
Tracking with heavily irradiated silicon detectors operated at cryogenic temperatures
1998
In this work we show that a heavily irradiated double-sided silicon microstrip detector recovers its performance when operated at cryogenic temperatures. A DELPHI microstrip detector, irradiated to a fluence of /spl sim/4/spl times/10/sup 14/ p/cm/sup 2/, no longer operational at room temperature, cannot be distinguished from a non-irradiated one when operated at T<120 K. Besides confirming the previously observed 'Lazarus effect' in single diodes, these results establish, for the first time, the possibility of using standard silicon detectors for tracking applications in extremely demanding radiation environments.