K. S. Gadedjisso-Tossou
A5014427805- Muon and positron interactions and applications
- Atomic and Molecular Physics
- Spectroscopy and Laser Applications
- Particle Detector Development and Performance
- Semiconductor Quantum Structures and Devices
- Semiconductor Lasers and Optical Devices
- Solid State Laser Technologies
- X-ray Spectroscopy and Fluorescence Analysis
- Laser Design and Applications
- Atomic and Subatomic Physics Research
- Photonic and Optical Devices
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Nonlinear Photonic Systems
- Growth and nutrition in plants
- ZnO doping and properties
- Optical Coatings and Gratings
- Semiconductor materials and interfaces
- Strong Light-Matter Interactions
- Nanowire Synthesis and Applications
- CCD and CMOS Imaging Sensors
- Organic Electronics and Photovoltaics
University of Lomé
2012-2025
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2024
The Abdus Salam International Centre for Theoretical Physics (ICTP)
2016-2024
National Institute for Astrophysics
2024
RIKEN Nishina Center
2024
Consorzio Roma Ricerche
2024
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2016-2023
University of Trieste
2020
Weatherford College
2019
Institute Belniis
2019
Abstract The FAMU experiment aims to measure for the first time hyperfine splitting of muonic hydrogen ground state. From this measurement proton Zemach radius can be derived and will shed light on determination charge radius. In paper, we describe scientific goal, method detailed preparatory work. This includes outcome preliminary measurements, subsequent refined simulations evaluation expected results. experimental setup being built performed at RAL laboratory muon facility is also described.
The high precision measurement of the hyperfine splitting muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in construction a gas target detectors. In June 2014, pressurized FAMU experiment was exposed to low energy at RIKEN RAL facility. objectives test were characterization target, hodoscope X-ray apparatus consisted X-rays detectors made purity Germanium Lanthanum Bromide crystals. this paper experimental setup is described...
A pulsed, tunable, narrow linewidth mid-infrared (mid-IR) laser radiation source was developed to meet the needs of FAMU project (Fisica Atomi MUonici). The main goal this experiment is measure hyperfine splitting ground state muonic hydrogen using pulsed spectroscopy. requires a high energy, mid-IR around resonance energy ΔE1Shfs∼ 0.1828 eV (6.79μm) atom excite it from para (F = 0) ortho 1) spin state. system designed fulfill these requirements based on Difference Frequency Generation (DFG)...
The collection and transport of charges at the electrodes are main factors limiting efficiency organic solar cells. Zinc oxide (ZnO) in nanostructured form helps to overcome this problem by introducing a ZnO buffer layer between photoanode donor material. To achieve this, thin film must exhibit good crystallinity, along with electrical conductivity high optical transparency visible range. aim work is investigate effect precursor sources concentrations on structural, morphological, properties...
A trace gas sensor based on pulsed cavity ring-down spectroscopy (CRDS) was developed for measurement of the ν4 fundamental vibrational band ammonia (NH3) centered at 1468.898 cm−1. distributed feedback quantum cascade laser (DFB-QCL) operating 6.8 µm (1470.58 cm−1) quite well covered absorption and strong bands different molecular gases in this unexplored region. The partially evacuated down to 0.4 Atm by a turbo-molecular pump reduce partial interference between NH3 spectra water near peak...
Abstract The FAMU experiment at RIKEN-RAL is a muonic atom with the aim to determine Zemach radius of proton by measuring 1s hyperfine splitting in hydrogen. activity Collaboration years 2015–2023 enabled final optimisation detector-target setup as well gas working condition terms temperature, pressure and mixture composition. has started its data taking July 2023. status detector for 2023 experimental runs, beam characterisation X-ray detection 100–200 keV energy range, presented discussed.
Spontaneous emission has been used to evaluate the proportion of different recombination channels in 2.4–3.2 µm type I- GaInAsSb quantum-well lasers operating at room temperature. The method consists using square root integrated spontaneous rate as a value proportional carrier density. A second-degree polynomial relationship can then be determine currents (monomolecular, radiative and Auger) laser diode operated below threshold. notable increase Auger observed with increasing wavelength....
We report on a laser system based difference frequency generation (DFG) to produce tunable, narrow-linewidth (<30pm), and comparatively high-energy mid-IR radiation in the 6.8 µm region. The exploits lithium thioindate (LiInS2) nonlinear crystal nanosecond pulses generated by single-frequency Nd:YAG Cr:forsterite lasers at 1064 1262 nm, respectively. Two experimental configurations are used: first one, single-pass, energy achieved is 205 µJ. Additional increments, up 540 µJ, obtained...
The aim of the FAMU (Fisica degli Atomi Muonici) experiment is to realize first measurement hyperfine splitting (hfs) in 1S state muonic hydrogen Δ Ehfs1S, by using RIKEN-RAL intense pulsed muon beam and a high-energy mid-infrared tunable laser. This requires detailed study transfer mechanism at different temperatures hence epithermal states system. experimental setup involves cryogenic pressurized gas target detection system based on silicon photomultipliers-fiber hodoscopes high purity...
Tetrachlorodiethyl Benzimidazo Carbocyanine (TDBC) layers are very interesting for photonics applications due to their huge oscillator strength, narrow absorption and low-cost fabrication. They mainly used in strong coupling studies but also wavelength selective grating fabrication, light concentration, enhancement so on. However, these intrinsic properties, particularly the refractive index, require further investigation. In this work, we first reviewed values of index TDBC reported...
We present the design of a Cr:forsterite based single-frequency master-oscillator power-amplifier laser system delivering much higher output energy compared to previous literature reports. The has four amplifying stages with two-pass configuration each, thus enabling generation 24 mJ in spectral region around 1262 nm. It is demonstrated that presented amplifier preserves high and pulse quality, allowing straightforward scaling. This promising tool for tunable nonlinear down-conversion...
The article gives the motivations for measurement of hyperfine splitting (hfs) in ground state muonic hydrogen to explore properties proton at low momentum transfer. It summarizes these proposed methods and finally describes FAMU experiment more detail.
An efficient multi-pass Cr:forsterite master oscillator-power amplifier laser system operating in the single-longitudinal mode was demonstrated and characterized. A significant increase energy obtained a six-pass configuration giving maximum value of up to 10.8 mJ, with good beam quality without significantly broadening linewidth or increasing M2. The performance evaluated as function pump number passes. Fourier transformation pulses performed confirm measured using Fabry–Perot etalon.
The FAMU experiment aims to accurately measure the hyperfine splitting of ground state muonic hydrogen atom. A measurement transfer rate muons from heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, pressurized gas-target was exposed pulsed low-energy muon beam at RIKEN RAL facility (Rutherford Appleton Laboratory, U.K.). main goal test characterization both noise induced by and X-ray detectors. apparatus, some extent rudimental, has served admirably...
We report the first measurement of temperature dependence muon transfer rate from $μ$p atoms to oxygen between 100 and 300 K. Data were obtained X-ray spectra delayed events in gaseous target H$_2$/O$_2$ exposed a beam. Based on data, we determined energy up 0.1 eV, showing an 8-fold increase contrast with predictions constant low limit. This work set constraints theoretical models transfer, is fundamental importance for hyperfine splitting by FAMU collaboration.
We have studied the local photobleaching in TDBC layers for grating and strong coupling applications. With this method, refractive index can be both locally spectrally modulated. In work, fabricated micro-devices been investigated highlighting high potential of interesting materials photonics
Tetrachlorodiethyl Benzimidazo Carbocyanine (TDBC) layers are very interesting for photonics applications due to their huge oscillator strength, narrow absorption, local photo-bleaching, and low-cost fabrication. They mainly used in strong coupling studies, but also light concentration, absorption enhancement, so on. However, these intrinsic properties still not well understood need be investigated fully exploit the high potential of this material, especially regarding bleaching properties.
The main goal of the FAMU experiment is measurement hyperfine splitting (hfs) in 1S state muonic hydrogen $\Delta E_{hfs}(\mu^-p)1S$. physical process behind this following: $\mu p$ are formed a mixture and higher-Z gas. When absorbing photon at resonance-energy E_{hfs}\approx0.182$~eV, subsequent collisions with surrounding $H_2$ molecules, quickly de-excited accelerated by $\sim2/3$ excitation energy. observable time distribution K-lines X-rays emitted from Z$ muon transfer $(\mu p) +Z...
We investigated the structural and optoelectronic properties of p-n germanium nanocrystals based junctions embedded between GaAs substrate layers ZnO:Al or a-Si:H.Scanning electron microscopy scanning tunneling were used on these in this work.Calculations current showed effect localized defects trapping Fermi level at surface tending to make a semi-insulating substrate.The average value diameter Ge nanoparticle is around 12.5 nm.These results lay foundation for development solar cells which...