Marian Ghena

Mr. Marian Ghena

National Institute for Laser Plasma & Radiation Physics, Atomistilor 409 str, Bucharest- Magurele, Romania
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 April 2022 in Materials
Verified
Journal Article
Open access
PDF file
MHMikko Hongisto
Mikko Hongisto
SDSylvain Danto
Sylvain Danto
MGMarian Ghena
Marian Ghena
DIDecebal Iancu
Decebal Iancu
DIDaniel Ighigeanu
Daniel Ighigeanu
Laeticia PetitLaeticia Petit
Laeticia Petit
The radiation effects of electrons and protons on the spectroscopic and optical properties of oxide glasses doped with Yb3+ in various glass systems were investigated to understand the impact of the glass composition on the glass photo-response. Changes in the optical and emission properties were seen after the radiation treatment, and the magnitude of the changes depended on the irradiation source and dose. For all the investigated materials, the absorption coefficients in the 200–550 nm range increase post-irradiation, revealing the formation of defects in the glasses during the irradiation. While the spectroscopic properties of the tellurite glass remain unchanged, a small reduction in the Yb3+ emission intensity was seen after irradiating the phosphate, borosilicate, and germanate glasses, indicating that a reduction of Yb3+ to Yb2+ might occur in these glasses during the radiation treatment. The changes in the optical and spectroscopic properties after proton irradiation are small as they are localized at the surface of the glasses due to the shallow penetration depth of the proton in the glass. Even though the doses are small, the electron irradiation produces larger changes in the optical and spectroscopic properties since the electrons penetrate the entire volume of the glasses. All the changes in the optical and spectroscopic properties of the glasses were successfully reversed after a short heat treatment revealing the reversible nature of the photo-response of the investigated glasses.

24 July 2020 in Sensors
Verified
Journal Article
Open access
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Andrei StancalieAndrei Stancalie
Andrei Stancalie
Flavio EspositoFlavio Esposito
Flavio Esposito
CNConstantin Daniel Negut
Constantin Daniel Negut
MGMarian Ghena
Marian Ghena
Mihalcea Razvan MarianMihalcea Razvan Marian
Mihalcea Razvan Marian
Agostino IadiciccoAgostino Iadicicco
Agostino Iadicicco
In this work, we present a new setup for real-time investigations of optical fibers and optical fiber sensors while being subjected to gamma-rays. The investigation of the radiation effects on novel or well-assessed sensing devices has attracted a lot of interest, however, the facilities required to do this (when available) are barely accessible to the device to be characterized. In order to reduce the limitations of these types of experiments and ensure a highly controlled environment, we implemented a configuration that permits the on-line testing of optical components inside a Co-60 gamma chamber research irradiator. To show the advantages of this new approach, we present a case study that compares an arc-induced optical fiber long period grating (LPG) irradiated in a gamma chamber with the same type of grating irradiated with gamma-rays from a Co-60 industrial irradiator. In order to better understand the effects of radiation on such components and their behavior in radiation environments, we focus on the homogeneity of the radiation field and parameter customizability as well as the high reproducibility of the experiments.