Search results for "RELIABILITY"
showing 10 items of 1563 documents
Impact of Terrestrial Neutrons on the Reliability of SiC VD-MOSFET Technologies
2021
Accelerated terrestrial neutron irradiations were performed on different commercial SiC power MOSFETs with planar, trench and double-trench architectures. The results were used to calculate the failure cross-sections and the failure in time (FIT) rates at sea level. Enhanced gate and drain leakage were observed in some devices which did not exhibit a destructive failure during the exposure. In particular, a different mechanism was observed for planar and trench gate MOSFETs, the first showing a partial gate rupture with a leakage path mostly between drain and gate, similar to what was previously observed with heavy-ions, while the second exhibiting a complete gate rupture. The observed fail…
Reliability of Monte Carlo event generators for gamma-ray dark matter searches
2013
We study the differences in the gamma-ray spectra simulated by four Monte Carlo event generator packages developed in particle physics. Two different versions of PYTHIA and two of HERWIG are analyzed, namely PYTHIA 6.418 and HERWIG 6.5.10 in Fortran and PYTHIA 8.165 and HERWIG 2.6.1 in C++. For all the studied channels, the intrinsic differences between them are shown to be significative and may play an important role in misunderstanding dark matter signals.
Applicability of the dielectric barrier discharge for helium ash measurements in the divertor region
2016
Abstract Controlled fusion based on the magnetic confinement of the plasma is one of the main aims of the Euro-fusion programme. In the fusion device, the hydrogen isotopes, in nuclear reactions, will produce helium nuclei. The products, as the ash, will be removed from the plasma in the region of the so-called divertor. Controlling the helium to hydrogen ratio in this ‘exhaust gas’ will provide information about the efficiency of the fusion process as well as of the efficiency of the helium removal system. One of the methods to perform this task is to study the properties of the discharge conducted in such exhaust gas. In this paper, the applicability of the dielectric barrier discharge (D…
Cooling of the plasma chamber for the AECR-U type electron cyclotron resonance ion source ARTEMIS
2001
Abstract The temperature distribution inside the ECRIS plasma chamber has been studied using finite element analysis. The main goal of these studies was to find out the safest cooling design for the temperature sensitive permanent magnets. In ECR ion sources they are used to provide the hexapole field. Two different designs for the cooling of the magnets were investigated. The temperature distribution on the surface of the plasma electrode was also studied. With the aid of the cooling simulations the most efficient cooling for the new ECR ion source was found. As a result of which, safety and higher reliability of operation can be reached.
Fuzzy modelling of HEART methodology: application in safety analyses of accidental exposure in irradiation plants
2009
The present paper refers to the obtained results by using Fuzzy Fault Tree analyses of accidental scenarios which entail the potential exposure of operators working in irradiation industrial plants. For these analyses the HEART methodology, a first generation of the Human Reliability Analysis method, has been employed to evaluate the probability of human erroneous actions. This technique has been modified by us on the basis of fuzzy set concept to more directly take into account the uncertainties of the so called error-promoting factors, on which the method is grounded. The results allow also to provide some recommendations on procedures and safety equipments to reduce the radiological expo…
The dynamics of the surface layer of lipid membranes doped by vanadium complex: computer modeling and EPR studies
2015
Abstract Penetration of the liposome membranes doped with vanadium complex formed in the liquid-crystalline phase from egg yolk lecithin (EYL) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) spin probes has been investigated. The penetration process was followed by 360 hours at 24°C, using the electron spin resonance (EPR) method. The spectroscopic parameter of the partition (F) of this probe indicated that a maximum rigidity of the membrane was at 3% concentration of the vanadium complex. Computer simulations showed that the increase in the rigidity of the membrane corresponds to the closure of gaps in the surface layer of the membrane, and indicates the essential role of the membrane …
Second order reflection from crystals used in soft X-ray spectroscopy
2015
Abstract In this note the ratio of the second to the first order reflection is determined for the KAP and PbSt crystals, for wavelengths corresponding to the Al K-line emission. The source of the radiation was a low-voltage stabilized X-ray tube. The X-rays were detected with a Bragg spectrometer equipped with a proportional counter detector. The signal measured by the proportional counter was subsequently pulse height analyzed.
Statistical Analysis of Heavy-Ion Induced Gate Rupture in Power MOSFETs—Methodology for Radiation Hardness Assurance
2012
A methodology for power MOSFET radiation hardness assurance is proposed. It is based on the statistical analysis of destructive events, such as gate oxide rupture. Examples of failure rate calculations are performed.
Stopping power measurement of 48Ca in a broad energy range in solid absorbers
2006
Abstract Stopping power of 48 Ca ions in C, Ni and Au was measured using TOF-E method. The results cover energy range from 0.1 to 5.3 MeV/u (5–250 MeV). The reliability of our experimental method was verified and confirmed by TOF–TOF measurements. The results are compared with theoretical (PASS) and semi empirical (SRIM2003) predictions.
Studies for low mass, large area monolithic silicon pixel detector modules using the MALTA CMOS pixel chip
2021
Abstract The MALTA monolithic silicon pixel sensors have been used to study dicing and thinning of monolithic silicon pixel detectors for large area and low mass modules. Dicing as close as possible to the active circuitry will allow to build modules with very narrow inactive regions between the sensors. Inactive edge regions of less than 5 μ m to the electronic circuitry could be achieved for 100 μ m thick sensors. The MALTA chip (Cardella et al., 2019) also offers the possibility to transfer data and power directly from chip to chip. Tests have been carried out connecting two MALTA chips directly using ultrasonic wedge wire bonding. Results from lab tests show that the data accumulated in…