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Berthet F.,Laboratoire University Des Science Appliquees Of Cherbourg | Petitdidier S.,Laboratoire University Des Science Appliquees Of Cherbourg | Guhel Y.,Laboratoire University Des Science Appliquees Of Cherbourg | Trolet J.L.,Ecole des Applications Militaires de lEnergie Atomique | And 3 more authors.
IEEE Transactions on Nuclear Science | Year: 2016

This paper shows the impact of low fluence neutron irradiation on AlGaN/GaN HEMTs, AlInN/GaN HEMTs and AlInN/GaN MOS-HEMTs. We have shown that the technological structure of devices and the presence of electron traps in the devices seems to play a major role on the evolution of dc electrical characteristics of irradiated GaN based transistors. After having degrading the electrical performances of AlGaN/GaN HEMTs with an electrical stress, we have shown that it is possible to improve the electrical characteristics of the stressed devices by a neutron irradiation. Moreover, we have also reported that the degradation induced by neutron irradiation is more important for the AlInN/GaN HEMTs with a gate interfacial oxide than for the AlInN/GaN HEMTs without a gate interfacial oxide. © 2016 IEEE. Source

Trolet J.-L.,Ecole des Applications Militaires de lEnergie Atomique | Olivier A.,Laboratoire Danalyses Of Surveillance Et Dexpertise Of La Marine | Piccione M.,Ecole des Applications Militaires de lEnergie Atomique | Manduci L.,Ecole des Applications Militaires de lEnergie Atomique
Radioprotection | Year: 2011

An assessment method for tritium surface contamination by liquid scintillation on survey smears is proposed, which employs a special device, the TriathlerTM, till now used only by highly specialized laboratories. Based on the parameters involved in the measurements, an accurate and new procedure is developed which reduce to few minutes an activity measurement within the prescribed conditions of thresholds set by the radioactive materials transports. Though centered on transport contamination, this work may activate a more extended reflection about contamination itself in different fields of human activity. © 2011 EDP Sciences. Source

Tala-Ighil B.,University of Caen Lower Normandy | Oukaour A.,University of Caen Lower Normandy | Gualous H.,University of Caen Lower Normandy | Boudart B.,University of Caen Lower Normandy | And 3 more authors.
Microelectronics Reliability | Year: 2011

This paper deals with the effects of 60Co gamma irradiation on punch-through commercial insulated gate bipolar transistor turn-on switching behaviour. The response of the threshold voltage and the turn-on switching parameters under three different in situ gate biases are described. Charge trapping in the gate oxide causes the decrease of the threshold voltage. It is shown that the decrease of this parameter and the decrease of the Miller plateau level result in a decrease of the collector current rise-time, the collector-emitter voltage fall-time, the turn-on switching energy and in an increase of the peak of the turn-on switching instantaneous power and of the turn-on overshoot collector current. © 2011 Elsevier Ltd. All rights reserved. Source

Berthet F.,University of Caen Lower Normandy | Guhel Y.,University of Caen Lower Normandy | Boudart B.,University of Caen Lower Normandy | Gualous H.,University of Caen Lower Normandy | And 3 more authors.
IEEE Transactions on Nuclear Science | Year: 2012

The influence of thermal neutron irradiation and fast neutron irradiation on the electrical properties of AlGaN/GaN HEMTs is investigated. An increase in the drain current and a decrease in the access resistances are observed when devices are irradiated with a thermalized neutrons fluence of 4.3× 10 10 neutrons.cm -2 while no evolution is observed with the same fluence of fast neutrons. However, the same phenomenon is observed when the fast neutron fluence is higher (1.8\times; 10 12 neutrons.cm -2). AlGaN/GaN heterojunctions are analyzed by gamma spectroscopy after thermalized or fast neutron irradiations to understand the physical mechanisms induced by irradiations. In fact, we have shown that the improvement of electrical properties of devices after thermal neutrons irradiation is linked to a Ga-Ge transmutation effect. Moreover, the evolution of the drain current and access resistance when the AlGaN/GaN heterojunctions are irradiated by fast neutrons can be induced by N vacancies creation and/or a change of the strain state of the layers and/or Ga-Ge transmutation effect. © 2012 IEEE. Source

Chbihi A.,French Atomic Energy Commission | Frankland Jd.,French Atomic Energy Commission | Lopez O.,University of Caen Lower Normandy | Boisjoli M.,French Atomic Energy Commission | And 23 more authors.
EPJ Web of Conferences | Year: 2015

Recent results of the INDRA collaboration are presented in this contribution. They concern the evolution of reaction dynamics from the first stage of the collision to the production of fragments. Different probes are used to evidence the stopping/transparency, collective flow and the symmetry energy term of the nuclear equation of state. © 2015 Owned by the authors, published by EDP Sciences-SIF. Source

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