A5026635129- Electron and X-Ray Spectroscopy Techniques
- Semiconductor materials and devices
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Game Theory and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Gyrotron and Vacuum Electronics Research
- Economic theories and models
- Particle Accelerators and Free-Electron Lasers
- Advancements in Photolithography Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
- High voltage insulation and dielectric phenomena
- Magnetic confinement fusion research
- Semiconductor Quantum Structures and Devices
- Photocathodes and Microchannel Plates
- Experimental Behavioral Economics Studies
- Radiation Effects in Electronics
- Metal and Thin Film Mechanics
- Ga2O3 and related materials
- Non-Destructive Testing Techniques
- Muon and positron interactions and applications
- Banking stability, regulation, efficiency
- Advancements in Semiconductor Devices and Circuit Design
- Radio Frequency Integrated Circuit Design
Office National d'Études et de Recherches Aérospatiales
2014-2024
Université de Toulouse
2017-2024
McPhy Energy (France)
2024
Aix-Marseille Université
2016-2023
University of Sfax
2022
Institut Superieur de l'Aeronautique et de l'Espace (ISAE-SUPAERO)
2011-2021
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2021
Centrale Marseille
2009-2018
Centre National de la Recherche Scientifique
2000-2018
École des hautes études en sciences sociales
2012-2018
Secondary electron emission (SEE) is one of the main parameters controlling spacecraft potential. It also plays an important role in triggering multipactor phenomenon occurring waveguides (electron avalanche microwave electric fields). In this paper, we propose original method adapted to low-energy SEE measurements on dielectrics and conductors (incident energy below 20 eV). based Kelvin probe (KP) surface potential after irradiation. particularly well suited insulating materials but can be...
As a source of heat load on cryogenic sections, the electron cloud is currently major limitation to intensity some modern particle accelerators such as LHC and its high luminosity upgrade at CERN. During operation, conditioning copper beam pipe surface occurs, leading decrease intensity. To understand role different chemical components air exposed in process, samples well specific model surfaces produced laboratory, namely sputter-cleaned carbon-free cuprous oxide...
Microchannel plates are electron multipliers widely used in applications such as particle detection, imaging, or mass spectrometry and often paired with a photocathode to enable photon detection. Conventional microchannel plates, made of glass fibers, face limitations manufacturing flexibility integration electronic readouts. Hydrogenated amorphous silicon-based offer compelling alternative provide unique advantages these areas. Here, we report on the characterization time resolution plates....
We address the problem of a planner looking for efficient network when agents play game with local complementarities and links are costly. show that general cost functions, networks belong to class nested split graphs. Next, we refine our results find that, depending on specification function, complete networks, core–periphery dominant group architectures, quasi-star quasi-complete can be efficient.
We consider a model in which firm faces two types of liquidity risks: Brownian risk and Poisson risk. The chooses dividend policy to maximize shareholder value. characterize the optimal value we show that is barrier strategy: keeps cash inside when reserves level less than critical threshold pays excess this threshold. also analyze problem insurance against find it for buy full its are above not insure otherwise.
The radiation-induced conductivity of some polymers was described mainly in literature by a competition between ionization, trapping/detrapping, and recombination processes or radiation assisted ageing mechanisms. Our aim is to revise the effect aforementioned mechanisms on complex evolution Teflon® FEP under space representative ionizing radiation. Through definition new experimental protocol, revealing dose relaxation time, we have been able demonstrate that trapping/recombination model...
This study investigates the use of atomic layer deposition (ALD) to mitigate multipacting phenomena inside superconducting radio frequency cavities used in particle accelerators while preserving high quality factors 1010 range. The unique ALD capability control film thickness down level on arbitrary complex shape objects enables fine-tuning TiN resistivity and total electron emission yield (TEEY) from coupons devices. allows us adequately choose a that provides both prevent Ohmic losses low...
Radio-frequency (RF) systems used in vacuum can be damaged by electronic avalanches triggered the multipactor effect. This undesirable phenomenon appear for RF components space communication payloads as well experimental fusion devices, among others. To determine breakdown threshold, expensive tests made or simulations performed. second method uses Total Electron Emission Yield (TEEY) curve input and threshold predicted simulation highly depends on this curve. Consequently we decided to make...
A method is described which uses a scanning electron microscope for the investigation of charge trapping in insulators under bombardment. The technique commonly used to deduce amount trapped and its spatial extent based on mirror effect, while present approach electron-beam deflections are measured during primary irradiation. We have performed measurements time an Al2O3–sapphire sample Furthermore, effects energy current charging also examined errors concerning discussed detail.
Surface and internal charging of dielectric materials is a potential cause surface discharges satellite anomalies, due to the fluctuating irradiation levels induced by space environment. Understanding conduction mechanisms reducing are therefore important industrial issues for designers manufacturers. measurements under after (potential decay) most significant laboratory tests qualify understand discharging behavior insulating materials. We present here experimental results obtained using...
In this study, we demonstrate the effect of change sputtering power and deposition pressure on ignition combustion properties Al/CuO reactive thin films. A reduced Al along with carried out at a higher-pressure result in high-quality film showing 200% improvement burn rate 50% drop energy. This highlights direct implication process parameters responsivity reactivity while maintaining CuO thin-film integrity both crystallographically chemically. Atomically resolved structural chemical...
A technique for the accurate determination of surface potential US and its evolution during irradiation, is proposed. The based on detecting both backscattered (BSE) secondary electrons (SE) in a scanning electron microscope (SEM). (BSE+SE) spectra are measured using compact, highly sensitive electrostatic toroidal spectrometer (ETS), specially adapted SEM applications. use an ETS analyzer set deducing from (SE+BSE) irradiated insulators introduced here. determined, either maximum energy...
Experiments are performed on polycrystalline MgO in order to investigate the internal effects of positive charging total electron emission yield (TEEY) under low incident fluence (a few hundreds fC mm−2) at 200 eV irradiation energy. It is experimentally shown that Coulomb-attractive recombination electrons undergoing with holes generated by previously emitted significantly affects TEEY. Furthermore, quantitative analyses experimental data done deduce electron–hole cross-section which found...
The electron emission under impact between 10 eV and 2 keV is investigated with a Monte Carlo (MC) code in aluminum, silver, silicon. based on the complex dielectric function theory to describe inelastic scattering uses Mott's model of partial waves elastic scattering. It takes into account both volume surface plasmon excitations. simulation results are compared experimental measurements yields (EEY) energy spectra low electrons performed ultrahigh vacuum Ar-etched bulk samples. Our MC...
A new multipactor saturation mechanism is presented for high power microwave devices in the presence of dielectrics. Recent measures have shown that positive charge deposited on a dielectric as consequence secondary electron emission causes reduction its yield. This work shows dynamics within partially filled parallel-plate waveguide where both decrease yield with and subsequent electrostatic field produced are taken into account. The results obtained show these two mechanisms predict well...
In a scanning electron microscope, electron-beam irradiation of insulators may induce strong electric field due to the trapping charges within specimen interaction volume. On one hand, this modifies trajectories beam electrons subsequently entering specimen, resulting in reduced penetration depth into bulk specimen. other it leads acceleration vacuum emitted secondary (SE) and also distortion their angular distribution. Among others, consequences concern an anomalous contrast SE image. This...
A method is described that allows the trapping charge kinetics in insulating materials during their electron irradiation a scanning microscope (SEM) to be studied and total trapped evaluated. The consists analyzing leakage displacement currents measured simultaneously, after irradiation, using an arrangement adapted SEM. dynamic properties of glass-ceramic are investigated time constants for charging discharging processes By correlating currents, yield σ also determined.
This paper deals with charge trapping and transport of polyethylene terephthalate (PET) polymer subjected to electron irradiation in a scanning microscope (SEM). Measurement displacement current leakage using an arrangement adapted the SEM allows amount trapped during after be determined mechanisms regulation studied. These involve several parameters related electronic injection, characteristics insulator effects itself. The dynamic properties PET samples are investigated time constants...
The charge properties, under electron irradiation, of three types glasses are studied by employing scanning microscope (SEM) associated with the technique called electrostatic influence method. experimental conditions closed to those typical field emission display (FED) operation. To determine amount trapped charges during and after a special arrangement adapted SEM was used. This allows displacement leakage currents be simultaneously measured. secondary yield irradiation is also deduced....
The effects of temperature and incident electron current density on the total emission yield (TEEY) polycrystalline diamond deposited by chemical vapour deposition technique (CVD) were investigated at low beam fluence. It was found that TEEY reversibly increases with decreases density. This behaviour is explained basis a dynamic competition between accumulation holes (positive space charge), which internally reduces secondary emission, thermally activated conductivity tends to reduce charge...