Search results for "IRRADIATION"
showing 10 items of 1012 documents
Radiation tolerance of NROM embedded products
2010
Radiation tolerance of NROM memories is demonstrated at the level of industrial 4 Mbit memory embedded modules, specifically not designed for operation in radiation harsh environments. The memory fabricated in 0.18 um technology remains fully functional after total ionization doses exceeding 100 krad. The tests were performed by irradiating with γ-rays (60Co source) and 10 MeV 11B ions in active (during programming/erase and read-out) and passive (no bias) modes. Comprehensive statistics were obtained by using large memory arrays and comparison of the data with the parameters of irradiated single cells allowed deep understanding of the physical phenomena in the irradiated NROM devices for b…
Influence of <formula formulatype="inline"><tex Notation="TeX">${\hbox{O}}_2$</tex></formula>-Loading Pretreatment on the Rad…
2014
We investigated the impact of an oxygen preloading on pure-silica-core or fluorine-doped-core fiber responses to high irradiation doses (up to 1 MGy (SiO 2 )). Oxygen enrichment was achieved through a diffusion-based technique, and the long-term presence of O 2 molecules was confirmed by micro-Raman experiments. Online radiation induced attenuation (RIA) experiments were carried out in both the pristine and the O 2 -loaded optical fibers to investigate the differences induced by this pretreatment in the UV and visible ranges. Contrary to results recently published on the positive impact of O 2 on infrared RIA, our results reveal a RIA increase with O 2 presence. Data are analyzed in order t…
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.
Hardening and long-range stress formation in lithium fluoride induced by energetic ions
2003
Abstract LiF crystals were irradiated with Au, Pb, Bi and S ions in the energy range 400–2300 MeV and studied by means of Vickers microindentation. Remarkable hardening effects are observed which depend on the applied fluence and ion species, and correlate with the ion energy loss along the ion path. Structural investigations reveal irradiation-induced stress extending deep into the adjacent non-irradiated crystal and leading to the formation of dislocations. X-ray diffraction measurements of the irradiated crystals show a decrease of the lattice constant indicating the presence of internal stress.
Ionizing radiation induced curing of epoxy resin for advanced composites matrices
2005
Abstract The radiation curing of an epoxy monomer in the presence of an iodonium salt, as photo initiator, is studied. Systems with different concentrations of photo initiators have been polymerized via both gamma rays and e-beam, at various dose rates. The aim of this work is to investigate how the photo initiator concentration and the irradiation dose rate affect the temperature of the systems during curing and how the different thermal histories influence the dynamic mechanical thermal properties of the obtained materials.
Impact of Electrical Stress and Neutron Irradiation on Reliability of Silicon Carbide Power MOSFET
2020
International audience; The combined effects of electrical stress and neutron irradiation of the last generation of commercial discrete silicon carbide power MOSFETs are studied. The single-event burnout (SEB) sensitivity during neutron irradiation is analyzed for unstressed and electrically stressed devices. For surviving devices, a comprehensive study of the breakdown voltage degradation is performed by coupling the electrical stress and irradiation effects. In addition, mutual influences between electrical stress and radiative constraints are investigated through TCAD modeling.
Formation and accumulation of radiation-induced defects and radiolysis products in modified lithium orthosilicate pebbles with additions of titanium …
2016
Abstract Lithium orthosilicate (Li4SiO4) pebbles with 2.5 wt.% excess of silicon dioxide (SiO2) are the European Union's designated reference tritium breeding ceramics for the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM). However, the latest irradiation experiments showed that the reference Li4SiO4 pebbles may crack and form fragments under operation conditions as expected in the HCPB TBM. Therefore, it has been suggested to change the chemical composition of the reference Li4SiO4 pebbles and to add titanium dioxide (TiO2), to obtain lithium metatitanate (Li2TiO3) as a second phase. The aim of this research was to investigate the formation and accumulation of radiation-induced …
ESR response of watch glasses to neutron irradiation
2012
Abstract In this paper we report the results of the electron spin resonance (ESR) study of the radiation-induced signal of watch glasses exposed to neutrons. This work extends the series of analyses of the response of watch glasses to various radiation beams which our research group is carrying out for possible applications in retrospective dosimetry. We have considered fluences up to about 3 × 1011 cm−2. We evaluated the signal fading and we found that in the first hours after exposure the signal rapidly decreases. After about 1000 h, it decreases much more slowly. The signal was reduced by about 25% in about 5 months. The radiation induced signal is found to be linearly dependent on neutr…
Current Transport Mechanism for Heavy-Ion Degraded SiC MOSFETs
2019
IEEE Transactions on Nuclear Science, 66 (7)
Wettability and compositional analysis of hydroxyapatite films modified by low and high energy ion irradiation
2008
Abstract Hydroxyapatite-like thin films on silicon substrate were deposited using atomic layer deposition and were subjected to irradiation with Ar ions accelerated through 0.6–1.2 kV as well as 2 MeV 16 O + ions. After low energy Ar irradiation a significant reduction in contact angle was observed. However, the Ca/P atomic ratio remained unchanged. No reduction in contact angle was seen for high energy 16 O + irradiation. Atomic force microscopy showed the enhancement of floral-like pattern after low energy Ar bombardment while high energy oxygen irradiation lead to raised islands on as-deposited films.