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1. Laboratory tests for MIR light detection and transport with specialty optical fibres

Author

Roberto Benocci, M. Rossella, M. Baruzzo, Humberto Cabrera, K. S. Gadedjisso-Tossou, M. Consonni, M. Bonesini, L. Stoychev, J.J. Suarez-Vargas, Benocci, R, Bonesini, M, Gadedjisso-Tossou, K, Cabrera, H, Stoychev, L, Rossella, M, Baruzzo, M, Consonni, M, and Suarez-Vargas, J

Subjects
sources, Optical fiber, Materials science, Proton, Physics::Instrumentation and Detectors, Physics::Optics, FOS: Physical sciences, Electron, Applied Physics (physics.app-ph), Radiation, 01 natural sciences, Electromagnetic radiation, 030218 nuclear medicine & medical imaging, law.invention, 03 medical and health sciences, 0302 clinical medicine, Optics, law, 0103 physical sciences, Detector alignment and calibration methods (lasers, Lasers, particle-beams), Photon detectors for UV, visible and IR photons (solid-state), Detector alignment and calibration methods, Lasers, Optics, particle-beams, Photon detectors for UV, sources, visible and IR photons (solid-state), Instrumentation, Mathematical Physics, Muon, 010308 nuclear & particles physics, business.industry, Physics - Applied Physics, Laser, Optical cavity, business, Physics - Optics, Optics (physics.optics)
Abstract

The FAMU (Fisica degli Atomi Muonici) experiment at the RIKEN RAL pulsed muon facility will measure the proton Zemach radius with high precision, thus contributing to the solution of the so-called "proton radius puzzle". The situation is now confused and new measurements will help reduce the discrepancy as measured with electrons or muons. To this aim, FAMU will make use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target and a tunable Mid-infrared (MIR) laser emitting at about 6.78 μm, to measure the hyperfine (HFS) splitting of the 1S state of muonic hydrogen. The injection of light into the cryogenic target and its monitoring via dedicated MIR sensors is an asset for the experiment. A possible solution is via specialty MIR fibres based on hollow core waveguides or polycrystalline fibres. Two dedicated setups based on pulsed QCL lasers, from Alpes Laser, emitting around 6.78 μm have been used to study the fibre attenuation while the high energy laser specifically developed for the FAMU project has been used to study the damage threshold at high energies. The alignment of MIR laser radiation into an optical cavity presents criticalities due to geometrical constraints. Its control requires the use of small and sensitive detectors. The results obtained with a quantum IR sensor with an integrated circuit for signal processing are reported.

Published
2020

2. The FAMU experiment: muonic hydrogen high precision spectroscopy studies

Author

Joseph Niemela, E. Vallazza, Alessandro Menegolli, Giuseppe Baldazzi, Eugenio Fasci, V. Bonvicini, F. Fuschino, E. Furlanetto, Massimiliano Clemenza, R. Mazza, Barbara Patrizi, R. Sarkar, M. Citossi, P. J. C. King, D. Cirrincione, L. Stoychev, Humberto Cabrera, D. Guffanti, R. Bertoni, C. De Vecchi, A. Pullia, A. de Bari, K. Ishida, M. Baruzzo, Roberta Ramponi, C. Xiao, K. S. Gadedjisso-Tossou, Angela Pirri, P. Danev, Miltcho B. Danailov, H. E. Roman, A. Vacchi, Dimitar Bakalov, M. Stoilov, Gianluca Morgante, L. Colace, M. Rossella, C. Pizzolotto, Livio Gianfrani, L. Tortora, Valter Maggi, Guido Toci, A. Sbrizzi, Luigi Moretti, M. Bonesini, E. Mocchiutti, Andrzej Adamczak, M. Vannini, J. J. Suárez-Vargas, Adrian D. Hillier, Roberto Benocci, G. Zampa, M. De Vincenzi, L. P. Rignanese, Claudio Labanti, F. Chignoli, Pizzolotto, C., Adamczak, A., Bakalov, D., Baldazzi, G., Baruzzo, M., Benocci, R., Bertoni, R., Bonesini, M., Bonvicini, V., Cabrera, H., Cirrincione, D., Citossi, M., Chignoli, F., Clemenza, M., Colace, L., Danailov, M., Danev, P., de Bari, A., De Vecchi, C., de Vincenzi, M., Fasci, E., Furlanetto, E., Fuschino, F., Gadedjisso-Tossou, K. S., Gianfrani, L., Guffanti, D., Hillier, A. D., Ishida, K., King, P. J. C., Labanti, C., Maggi, V., Mazza, R., Menegolli, A., Mocchiutti, E., Moretti, L., Morgante, G., Niemela, J., Patrizi, B., Pirri, A., Pullia, A., Ramponi, R., Rignanese, L. P., Roman, H. E., Rossella, M., Sarkar, R., Sbrizzi, A., Stoilov, M., Stoychev, L., Suarez-Vargas, J. J., Toci, G., Tortora, L., Vallazza, E., Vannini, M., Xiao, C., Zampa, G., Vacchi, A., Suárez-Vargas, J. J., Pizzolotto, C, Adamczak, A, Bakalov, D, Baldazzi, G, Baruzzo, M, Benocci, R, Bertoni, R, Bonesini, M, Bonvicini, V, Cabrera, H, Cirrincione, D, Citossi, M, Chignoli, F, Clemenza, M, Colace, L, Danailov, M, Danev, P, de Bari, A, De Vecchi, C, de Vincenzi, M, Fasci, E, Furlanetto, E, Fuschino, F, Gadedjisso-Tossou, K, Gianfrani, L, Guffanti, D, Hillier, A, Ishida, K, King, P, Labanti, C, Maggi, V, Mazza, R, Menegolli, A, Mocchiutti, E, Moretti, L, Morgante, G, Niemela, J, Patrizi, B, Pirri, A, Pullia, A, Ramponi, R, Rignanese, L, Roman, H, Rossella, M, Sarkar, R, Sbrizzi, A, Stoilov, M, Stoychev, L, Suarez-Vargas, J, Toci, G, Tortora, L, Vallazza, E, Vannini, M, Xiao, C, Zampa, G, and Vacchi, A

Subjects
X-ray detector, Physics, Nuclear and High Energy Physics, Muon, Proton, 010308 nuclear & particles physics, hyperfine splitting, Hadron, proton Zemach radiu, Radius, 01 natural sciences, Oxygen, Nuclear physics, Charge radius, Transfer rate, 0103 physical sciences, LaBr3:Ce scintillator, Physics::Atomic Physics, 010306 general physics, Ground state, Hyperfine structure, muonic hydrogen, Exotic atom
Abstract

The FAMU experiment aims to measure for the first time the hyperfine splitting of the muonic hydrogen ground state. From this measurement the proton Zemach radius can be derived and this will shed light on the determination of the proton charge radius. In this paper, we describe the scientific goal, the method and the detailed preparatory work. This includes the outcome of preliminary measurements, subsequent refined simulations and the evaluation of the expected results. The experimental setup being built for the measurement of the hyperfine splitting to be performed at the RAL laboratory muon facility is also described.

Published
2020
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3. Measurement of the muon transfer rate from muonic hydrogen to oxygen in the range 70-336 K

Author

Massimiliano Clemenza, Miltcho B. Danailov, Dimitar Bakalov, M. Stoilov, D. Cirrincione, L. Stoychev, Luigi Moretti, A. de Bari, M. Rossella, L. Colace, Roberto Benocci, Livio Gianfrani, M. De Vincenzi, L. Tortora, K. S. Gadedjisso-Tossou, S. Monzani, Eugenio Fasci, L. P. Rignanese, E. Mocchiutti, A. Pullia, F. Fuschino, R. Mazza, M. Bonesini, Andrzej Adamczak, A. Sbrizzi, Valter Maggi, C. Pizzolotto, P. Danev, José J. Suárez-Vargas, A. Vacchi, E. Vallazza, C. De Vecchi, Giuseppe Baldazzi, Humberto Cabrera, Alessandro Menegolli, Joseph Niemela, M. Baruzzo, Roberta Ramponi, Claudio Labanti, K. Ishida, R. Bertoni, Gianluca Morgante, Pizzolotto C., Sbrizzi A., Adamczak A., Bakalov D., Baldazzi G., Baruzzo M., Benocci R., Bertoni R., Bonesini M., Cabrera H., Cirrincione D., Clemenza M., Colace L., Danailov M., Danev P., de Bari A., De Vecchi C., De Vincenzi M., Fasci E., Fuschino F., Gadedjisso-Tossou K.S., Gianfrani L., Ishida K., Labanti C., Maggi V., Mazza R., Menegolli A., Mocchiutti E., Monzani S., Moretti L., Morgante G., Niemela J., Pullia A., Ramponi R., Rignanese L.P., Rossella M., Stoilov M., Stoychev L., Suarez-Vargas J.J., Tortora L., Vallazza E., Vacchi A., Pizzolotto, C, Sbrizzi, A, Adamczak, A, Bakalov, D, Baldazzi, G, Baruzzo, M, Benocci, R, Bertoni, R, Bonesini, M, Cabrera, H, Cirrincione, D, Clemenza, M, Colace, L, Danailov, M, Danev, P, de Bari, A, De Vecchi, C, De Vincenzi, M, Fasci, E, Fuschino, F, Gadedjisso-Tossou, K, Gianfrani, L, Ishida, K, Labanti, C, Maggi, V, Mazza, R, Menegolli, A, Mocchiutti, E, Monzani, S, Moretti, L, Morgante, G, Niemela, J, Pullia, A, Ramponi, R, Rignanese, L, Rossella, M, Stoilov, M, Stoychev, L, Suarez-Vargas, J, Tortora, L, Vallazza, E, Vacchi, A, Pizzolotto, C., Sbrizzi, A., Adamczak, A., Bakalov, D., Baldazzi, G., Baruzzo, M., Benocci, R., Bertoni, R., Bonesini, M., Cabrera, H., Cirrincione, D., Clemenza, M., Colace, L., Danailov, M., Danev, P., de Bari, A., De Vecchi, C., De Vincenzi, M., Fasci, E., Fuschino, F., Gadedjisso-Tossou, K. S., Gianfrani, L., Ishida, K., Labanti, C., Maggi, V., Mazza, R., Menegolli, A., Mocchiutti, E., Monzani, S., Moretti, L., Morgante, G., Niemela, J., Pullia, A., Ramponi, R., Rignanese, L. P., Rossella, M., Stoilov, M., Stoychev, L., Suarez-Vargas, J. J., Tortora, L., Vallazza, E., and Vacchi, A.

Subjects
Atomic Physics (physics.atom-ph), LaBr, 3, (Ce), Muonic hydrogen, Muonic X-rays, Oxygen, Transfer rate, X-rays, FOS: Physical sciences, General Physics and Astronomy, chemistry.chemical_element, 01 natural sciences, Physics - Atomic Physics, 010305 fluids & plasmas, X-ray, Transfer (computing), 0103 physical sciences, 010306 general physics, Exotic atom, Physics, Range (particle radiation), Muon, Muonic X-ray, chemistry, LaBr3(Ce), Atomic physics
Abstract

The first measurement of the temperature dependence of the muon transfer rate from muonic hydrogen to oxygen was performed by the FAMU collaboration in 2016. The results provide evidence that the transfer rate rises with the temperature in the range 104-300 K. This paper presents the results of the experiment done in 2018 to extend the measurements towards lower (70 K) and higher (336 K) temperatures. The 2018 results confirm the temperature dependence of Λ p O observed in 2016 and sets firm ground for comparison with the theoretical predictions.

Published
2021
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4. Photodegradation mechanisms of reactive blue 19 dye under UV and simulated solar light irradiation

Author

Urška Lavrenčič Štangar, Dorota Korte, Mladen Franko, Zeinab Ebrahimpour, Mahmoud Abdel-Hamid, Olena Pliekhova, Humberto Cabrera, Joseph Niemela, and K. S. Gadedjisso-Tossou

Subjects
Absorption spectroscopy, Chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Analytical Chemistry, Blueshift, Ultraviolet visible spectroscopy, Photocatalysis, Irradiation, 0210 nano-technology, Spectroscopy, Photodegradation, Absorption (electromagnetic radiation), Instrumentation
Abstract

In this work we performed dye photodegradation experiments in presence of TiO2 and Cu/Zr modified TiO2. The changes in the shape of the spectra of RB19 caused by photocatalysts under the simulated solar or UV light were monitored. Since the predominant photocatalytic mechanism can only be observed in very dilute solution of RB19, UV–Vis absorption spectrometry for higher concentrations and thermal lens spectrometry for lower concentrations have been applied to elucidate the mechanistic details of degradation processes. Bleaching of the dye was a characteristic feature, that occurred under both simulated solar and UV lights. It was also evident, that the absorption peak with maximum centered at 592 nm undergoes a slight blue shift during irradiation. The experiments carried out using UV and simulated solar light demonstrated, that two different processes responsible for the RB19 dye degradation occurred. In the initial stage of irradiation one of the processes appears under the UV light and can be recognized by a characteristic blue shift in the absorption spectrum of the solution. The second process is characteristic for irradiation by the simulated solar light which involve a blue shift at longer periods (100 min). These phenomena were attributed to the photocatalytic and photosensitization mechanisms, respectively. However, photocatalytic mechanism was also observed under simulated solar radiation, when the initial dye concentration was decreased to 5 mgL-1, and was recognized by the increase of the thermal lens signal during the initial stages of degradation process. This was possible because the thermal lens spectroscopy technique provides a limit of quantification for RB19 at the concentration level of 0.12 mg L−1, while UV–Vis spectrometry enables quantification of RB19 only down to 4 mg L−1 levels.

Published
2021
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5. DFG-based mid-IR tunable source with 0.5 mJ energy and a 30 pm linewidth

Author

L. Stoychev, Humberto Cabrera, Andrea Vacchi, K. S. Gadedjisso-Tossou, Alexander Demidovich, Guido Toci, E. Mocchiutti, Joseph Niemela, Ivaylo Nikolov, Miltcho B. Danailov, M. Baruzzo, Paolo Sigalotti, C. Pizzolotto, José J. Suárez-Vargas, Lyubomir Stoychev, Humberto Cabrera, Andrea G Vacchi, Komlan Segbeya GADEDJISSO-TOSSOU, and Cecilia Pizzolotto

Subjects
Materials science, difference frequency generation (DFG), business.industry, narrow linewidth mid-IR tunable source, chemistry.chemical_element, Forsterite, Radiation, engineering.material, Nanosecond, Laser, Atomic and Molecular Physics, and Optics, law.invention, Crystal, Laser linewidth, Optics, chemistry, law, engineering, Lithium, muonoc hydeogen, state, business, Spectroscopy
Abstract

We report on a laser system based on difference frequency generation (DFG) to produce tunable, narrow-linewidth ( < 30 p m ), and comparatively high-energy mid-IR radiation in the 6.8 µm region. The system exploits a lithium thioindate ( L i I n S 2 ) nonlinear crystal and nanosecond pulses generated by single-frequency Nd:YAG and Cr:forsterite lasers at 1064 and 1262 nm, respectively. Two experimental configurations are used: in the first one, single-pass, the mid-IR energy achieved is 205 µJ. Additional increments, up to 540 µJ, are obtained by performing double-pass through the nonlinear crystal. This laser has been developed for high-resolution photon-hungry spectroscopy in the mid-IR.

Published
2020
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6. 24 mJ Cr+4:forsterite four-stage master-oscillator power-amplifier laser system for high resolution mid-infrared spectroscopy

Author

L. Stoychev, José J. Suárez-Vargas, Miltcho B. Danailov, M. Baruzzo, Nikolai Vasiliev, Joseph Niemela, Paolo Sigalotti, Yuri Zaporozhchenko, Andrea Vacchi, Humberto Cabrera, E. Mocchiutti, K. S. Gadedjisso-Tossou, Alexander Demidovich, Ivaylo Nikolov, and C. Pizzolotto

Subjects
010302 applied physics, Range (particle radiation), Materials science, business.industry, Amplifier, Forsterite, engineering.material, Laser, 01 natural sciences, 010305 fluids & plasmas, law.invention, Nonlinear system, Quality (physics), law, 0103 physical sciences, engineering, Optoelectronics, Spectroscopy, business, Instrumentation, Energy (signal processing)
Abstract

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 system has four amplifying stages with two-pass configuration each, thus enabling the generation of 24 mJ output energy in the spectral region around 1262 nm. It is demonstrated that the presented Cr:forsterite amplifier preserves high spectral and pulse quality, allowing a straightforward energy scaling. This laser system is a promising tool for tunable nonlinear down-conversion to the mid-infrared spectral range and will be a key building block in a system for high-resolution muonic hydrogen spectroscopy in the 6.8 μm range.

Published
2019

7. First FAMU observation of muon transfer from μp atoms to higher-Z elements

Author

L. Tortora, A. Vacchi, L. Colace, Maurizio Bonesini, A. Tomaselli, M. Rossella, Anselmo Margotti, E. Vallazza, Claudio Labanti, D. Guffanti, G. Zampa, R. Mazza, A. Curioni, T. Cervi, P. Danev, R. Carbone, Germano Baldazzi, Ezio Previtali, Paolo Rossi, Roberto Benocci, R. Bertoni, M. Furini, K. S. Gadedjisso-Tossou, L. Stoychev, Miltcho B. Danailov, Dimitar Bakalov, Giovanni Baccolo, M. Stoilov, K. Ishida, F. Fuschino, E. Furlanetto, L. P. Rignanese, M. Moretti, Gianluca Morgante, R. Nardò, Massimiliano Nastasi, G. Campana, C. De Vecchi, F. Chignoli, M. De Vincenzi, I. D'Antone, Andrzej Adamczak, C. Pizzolotto, E. Mocchiutti, A. Iaciofano, S. Meneghini, F. Somma, Valter Maggi, M. Zuffa, Alessandro Menegolli, A. Rachevski, A. de Bari, M. Clemenza, V. Bonvicini, Joseph Niemela, Roberta Ramponi, Mocchiutti, E., Bonvicini, V., Carbone, R., Danailov, M., Furlanetto, E., Gadedjisso-Tossou, K.S., Guffanti, D., Pizzolotto, C., Rachevski, A., Stoychev, L., Vallazza, E., Zampa, G., Niemela, J., Ishida, K., Adamczak, A., Baccolo, G., Benocci, R., Bertoni, R., Bonesini, M., Chignoli, F., Clemenza, M., Curioni, A., Maggi, V., Mazza, R., Moretti, M., Nastasi, M., Previtali, E., Bakalov, D., Danev, P., Stoilov, M., Baldazzi, G., Campana, G., D'Antone, I., Furini, M., Fuschino, F., Labanti, C., Margotti, A., Meneghini, S., Morgante, G., Rignanese, L.P., Rossi, P.L., Zuffa, M., Cervi, T., Bari, A.D., Menegolli, A., Vecchi, C.D., Nardò, R., Rossella, M., Tomaselli, A., Colace, L., Vincenzi, M.D., Iaciofano, A., Somma, F., Tortora, L., Ramponi, R., Vacchi, A., Gadedjisso-Tossou, K. S., Baldazzi, Germano, Rignanese, L. P., Rossi, P. L., Bari, A. De, Vecchi, C. De, Vincenzi, M. De, Iaciofano, Alfredo, Mocchiutti, E, Bonvicini, V, Carbone, R, Danailov, M, Furlanetto, E, Gadedjisso-Tossou, K, Guffanti, D, Pizzolotto, C, Rachevski, A, Stoychev, L, Vallazza, E, Zampa, G, Niemela, J, Ishidaf, K, Adamczak, A, Baccolo, G, Benocci, R, Bertoni, R, Bonesini, M, Chignoli, F, Clemenza, M, Curioni, A, Maggi, V, Mazza, R, Moretti, M, Nastasi, M, Previtali, E, Bakalov, D, Danev, P, Stoilov, M, Baldazzi, G, Campana, G, D'Antone, I, Furini, M, Fuschino, F, Labanti, C, Margotti, A, Meneghini, S, Morgante, G, Rignanese, L, Rossi, P, Zuffa, M, Cervi, T, De Bari, A, Menegolli, A, De Vecchi, C, Nardò, R, Rossella, M, Tomaselli, A, Colace, L, De Vincenzi, M, Iaciofano, A, Somma, F, Tortora, L, and Vacchi, R

Subjects
X-ray detector, Pressurized ga, Ground state, chemistry.chemical_element, Charged particle, Measurements of, Atom, 01 natural sciences, Timing detectors, Nuclear physics, 0103 physical sciences, 010306 general physics, Instrumentation, Hyperfine structure, Mathematical Physics, Exotic atom, X rays, Hyperfine splitting, Physics, Kinetic, Argon, Muon, Rutherford appleton laboratorie, 010308 nuclear & particles physics, Muonic hydrogen, X-ray detectors, Transfer rates, X ray detector, Carbon, chemistry, Carbon dioxide, Timing detector, Excited state, Analysis and statistical methods, Physics::Accelerator Physics, X ray apparatu, Analysis and statistical method, Kinetic energy, Beam (structure), Muon transfer rate
Abstract

The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited μp atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the μp currently under way. © 2018 The Author(s).

Published
2018

8. Pulse amplification in a Cr4+:forsterite single longitudinal mode (SLM) multi-pass amplifier

Author

N Vasiliev, Andrea Vacchi, J J Suárez-Vargas, Paolo Sigalotti, Y Zaporozhchenko, Joseph Niemela, Humberto Cabrera, K. S. Gadedjisso-Tossou, Alexander Demidovich, E. Mocchiutti, L.I. Stoychev, Ivaylo Nikolov, M. Baruzzo, and M. B. Danailov

Subjects
Materials science, business.industry, Amplifier, Lasers amplifier on forsterite crystals (Mg2SiO4:Cr4+) source of narrow-band tunable radiation, Forsterite, engineering.material, Condensed Matter Physics, Laser, Industrial and Manufacturing Engineering, Atomic and Molecular Physics, and Optics, Charged particle, Ion, law.invention, Pulse (physics), Longitudinal mode, symbols.namesake, Fourier transform, law, symbols, engineering, Optoelectronics, business, Instrumentation
Published
2019
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9. FAMU: study of the energy dependent transfer rate Λ μp → μO

Author

Roberto Benocci, F. Somma, M. Zuffa, C. D. Vecchi, Massimiliano Clemenza, Miltcho B. Danailov, Dimitar Bakalov, F. Fuschino, M. Stoilov, K. Ishida, Ezio Previtali, L. Stoychev, L. P. Rignanese, Roberta Ramponi, Alessandro Menegolli, C. Pizzolotto, Andrzej Adamczak, K. S. Gadedjisso-Tossou, R. Nardò, D. Guffaanti, A. Rachevski, A. Tomaselli, F. Chignoli, M. I. Moretti, Paolo Rossi, A. Iaciofano, M. Rossella, S. Meneghini, M. Furini, R. Mazza, T. Cervi, G. Zampa, Valter Maggi, I. D'Antone, A. D. Bari, Giovanni Baccolo, E. Mocchiutti, Maurizio Bonesini, Claudio Labanti, M. D. Vincenzi, Giuseppe Baldazzi, V. Bonvicini, E. Furlanetto, A. Curioni, E. Vallazza, Riccardo Campana, Joseph Niemela, Gianluca Morgante, L. Tortora, A. Vacchi, L. Colace, P. Danev, Anselmo Margotti, Massimiliano Nastasi, R. Bertoni, Mocchiutti, E., Bonvicini, V., Danailov, M., Furlanetto, E., Gadedjisso-Tossou, K. S., Guffaanti, D., Pizzolotto, C., Rachevski, A., Stoychev, L., Vallazza, E., Zampa, G., Niemela, J., Ishida, K., Adamczak, A., Baccolo, G., Benocci, R., Bertoni, R., Bonesini, M., Chignoli, F., Clemenza, M., Curioni, A., Maggi, V., Mazza, R., Moretti, M., Nastasi, M., Previtali, E., Bakalov, D., Danev, P., Stoilov, M., Baldazzi, G., Campana, R., D'Antone, I., Furini, M., Fuschino, F., Labanti, C., Margotti, A., Meneghini, S., Morgante, G., Rignanese, L. P., Rossi, P. L., Zuffa, M., Cervi, T., Bari, A. D., Menegolli, A., Vecchi, C. D., DI NARDO, Roberto, Rossella, M., Tomaselli, A., Colace, L., Vincenzi, M. D., Iaciofano, A., Somma, F., Tortora, L., Ramponi, R., Vacchi, A., Mocchiutti, E, Bonvicini, V, Danailov, M, Furlanetto, E, Gadedjisso-Tossou, K, Guffaanti, D, Pizzolotto, C, Rachevski, A, Stoychev, L, Vallazza, E, Zampa, G, Niemela, J, Ishida, K, Adamczak, A, Baccolo, G, Benocci, R, Bertoni, R, Bonesini, M, Chignoli, F, Clemenza, M, Curioni, A, Maggi, V, Mazza, R, Moretti, M, Nastasi, M, Previtali, E, Bakalov, D, Danev, P, Stoilov, M, Baldazzi, G, Campana, R, D’Antone, I, Furini, M, Fuschino, F, Labanti, C, Margotti, A, Meneghini, S, Morgante, G, Rignanese, L, Rossi, P, Zuffa, M, Cervi, T, Bari, A, Menegolli, A, Vecchi, C, Nardò, R, Rossella, M, Tomaselli, A, Colace, L, Vincenzi, M, Iaciofano, A, Somma, F, Tortora, L, Ramponi, R, Vacchi, A, Gadedjisso-Tossou, K.S., Rignanese, L.P., Rossi, P.L., Bari, A De, Vecchi, C De, Nardò, R., and Vincenzi, M De

Subjects
Energy dependent, Physics, History, muonic atom, Kinetics, Energy dependence, Time distribution, X rays, Muon transfer, Muonic Hydrogen, Muon transfer, Computer Science Applications, Education, Hyperfine splitting, Laser wavelength, Spectroscopic measurement, Transfer (computing), Atomic physic, Atomic physics, Physical proce, Kinetic energy, muonic hydrogen, Exotic atom
Abstract

The main goal of the FAMU experiment is the measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen ΔE hfs (μ - p)1S. The physical process behind this experiment is the following: μp are formed in a mixture of hydrogen and a higher-Z gas. When absorbing a photon at resonance-energy ΔE hfs ≈ 0.182 eV, in subsequent collisions with the surrounding H 2 molecules, the μp is quickly de-excited and accelerated by ∼ 2/3 of the excitation energy. The observable is the time distribution of the K-lines X-rays emitted from the μZ formed by muon transfer (μp) + Z → (μZ)∗ + p, a reaction whose rate depends on the μp kinetic energy. The maximal response, to the tuned laser wavelength, of the time distribution of X-ray from K-lines of the (μZ)∗ cascade indicate the resonance. During the preparatory phase of the FAMU experiment, several measurements have been performed both to validate the methodology and to prepare the best configuration of target and detectors for the spectroscopic measurement. We present here the crucial study of the energy dependence of the transfer rate from muonic hydrogen to oxygen (Λ μp → μ0 ), precisely measured for the first time.

Published
2018
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10. Optical and Structural Characterization of Pin Photodetector Based on Germanium Nanocrystals for Third Generation Solar Cells

Author

Bruno Grandidier, K. S. Gadedjisso-Tossou, K. K. Sossoe, Agbeko Messanh Mohou, and M. M. Dzagli

Subjects
Solar cells, Renewable energy, Radiation, Materials science, business.industry, Photodetector, chemistry.chemical_element, Germanium, Quantum dot solar cell, Condensed Matter Physics, Third generation, Characterization (materials science), Nanocrystal, chemistry, Scanning tunneling spectroscopy, Germanium nanocrystals, Optoelectronics, General Materials Science, business
Abstract

We investigated the structural and optoelectronic properties of p-n germanium nanocrystals based junctions embedded between GaAs substrate and layers of ZnO:Al or a-Si:H. Scanning electron microscopy and scanning tunneling microscopy were used on these junctions in this work. Calculations of tunneling current on the substrate showed effect of localized defects trapping Fermi level at the surface tending to make a semi-insulating substrate. The average value of the diameter of the Ge nanoparticle is around 12.5 nm. These results lay the foundation for the development of solar cells which active part is made of GeNCs.

Published
2016

11. Measuring the size of the proton

Author

Joe Niemela, L. Stoychev, N. Zampa, Andrea Vacchi, M. M. Dzagli, Miltcho B. Danailov, K. S. Gadedjisso-Tossou, Dimitar Bakalov, Alexander Demidovich, Paul Urbach, Andrzej Adamczak, Maurizio Bonesini, Kumar Sumeet, Michail Stoilov, Giuseppe Battistoni, Nandini Bhattacharya, Mirko Boezio, Roberta Ramponi, W. Bonvicini, and Benjamin Andreson

Subjects
Nuclear magnetic resonance, Materials science, Proton
Published
2012
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12. Etude du champ lointain de la double hétérostructure laser GaInAsSb/GaAlAsSb

Author

M. A. Mohou, K. S. Gadedjisso-Tossou, and M. M. Dzagli

Subjects
Double hétérostructure, Equations de Maxwell, Diode laser, champ lointain, Earth-Surface Processes
Abstract

La theorie electromagnetique de la double heterostructure (DH) laser Ga1-xAlxAsySb1-y/Ga1-x’Inx’Asy’Sb1-y’/Ga1-xAlxAsySb1-y a ete realisee a partir des equations de Maxwell, Huyghens et Fraunhofer. Elle a permis d’etablir l’expression du champ lointain dans le plan orthogonal a l’heterojonction. L’optimisation de la structure laser a permis d’etablir les conditions pour un meilleur couplage de la DH laser avec la fibre optique. En particulier, nous montrons que le champ perpendiculaire depend de la difference d’indices Δn= (n2 – n1). Mots-cles : Double heterostructure, Equations de Maxwell, Diode laser, champ lointain.

Published
2010

13. Recombination channels in 2.4–3.2 µm GaInAsSb quantum-well lasers

Author

Yves Rouillard, Eric Tournié, K S Gadedjisso-Tossou, M A Mohou, Sofiane Belahsene, Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Composants à Nanostructure pour le moyen infrarouge (NANOMIR), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Laser diode, Auger effect, Chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, [SPI.TRON]Engineering Sciences [physics]/Electronics, Electronic, Optical and Magnetic Materials, law.invention, Auger, Wavelength, symbols.namesake, 020210 optoelectronics & photonics, law, 0202 electrical engineering, electronic engineering, information engineering, Materials Chemistry, symbols, Spontaneous emission, Electrical and Electronic Engineering, Atomic physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Recombination, Quantum well
Abstract

Spontaneous emission has been used to evaluate the proportion of the different recombination channels in 2.4–3.2 µm type I- GaInAsSb quantum-well lasers operating at room temperature. The method consists in using the square root of the integrated spontaneous emission rate as a value proportional to the carrier density. A second-degree polynomial relationship can then be used to determine the proportion of the different recombination currents (monomolecular, radiative and Auger) in a laser diode operated below threshold. A notable increase of the Auger recombination has been observed with increasing wavelength. Auger recombination currents account for only 26% of the total current at threshold at 2.4 µm, while the proportion reaches 55% at 2.8 µm and 64% at 3.2 µm.

Published
2012
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14. Pulse amplification in a Cr4+:forsterite single longitudinal mode (SLM) multi-pass amplifier.

Author

L I Stoychev, H Cabrera, K S Gadedjisso-Tossou, I P Nikolov, P Sigalotti, A A Demidovich, J J Suárez-Vargas, E Mocchiutti, J Niemela, M Baruzzo, N Vasiliev, Y Zaporozhchenko, M B Danailov, and Andrea Vacchi

Abstract

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 in energy was obtained in a six-pass amplifier configuration giving a maximum value of up to 10.8 mJ, with a good beam quality and without significantly broadening the linewidth or increasing the M2. The amplifier performance was evaluated as a function of the pump energy and the number of passes. A Fourier transformation of the laser pulses was performed to confirm the linewidth value measured using a Fabry–Perot etalon. [ABSTRACT FROM AUTHOR]

Published
2019
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