TY - JOUR

T1 - High-temperature mass spectrometric study of vaporization and thermodynamics of the Cs2O-B2O3 system

T2 - Review and experimental investigation

AU - Stolyarova, Valentina L.

AU - Vorozhtcov, Viktor A.

AU - Lopatin, Sergey I.

AU - Shugurov, Sergey M.

AU - Simonenko, Elizaveta P.

AU - Simonenko, Nikolay P.

AU - Kurata, Masaki

AU - Costa, Davide

N1 - Publisher Copyright: © 2021 John Wiley & Sons Ltd Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/6/15

Y1 - 2021/6/15

N2 - Rationale: The compounds in the Cs2O-B2O3 system are of particular interest for nuclear applications since cesium borates may be formed during accidents in nuclear reactors, affecting the rate of release of radiotoxic isotopes into the environment. Thus, information on the vaporization and thermodynamic properties of cesium borates is necessary for simulation and modeling of the isotope release processes taking place during the nuclear reactor accidents. Methods: Compounds in the Cs2O-B2O3 system were synthesized by the co-crystallization method with subsequent sintering. The sample characterization was carried out using XRD, TGA/DSC/DTA, IR spectroscopy, and ICP atomic emission spectroscopy. The vaporization and thermodynamics of the samples under consideration were investigated using an MS-1301 mass spectrometer and a single molybdenum effusion cell. The electron ionization method was employed for ionization of the vapor species with an electron energy of 30 eV. The scale of the ionizing voltage was calibrated according to the traditional technique by measuring the appearance energy of gold in the mass spectrum of the vapor over pure gold. Results: The main vapor species over the samples in the Cs2O-B2O3 system were CsBO2 and Cs2B2O4 in the temperature range 789–1215 K and in the concentration range 0.1–0.5 mole fraction of Cs2O. The temperature dependences of the CsBO2 and Cs2B2O4 partial pressures over cesium borate were obtained in the temperature range 767–990 K. The CsBO2 and B2O3 activities, the Gibbs energies of mixing, the excess Gibbs energies, the partial mole enthalpies of mixing, and total enthalpies of mixing were determined as functions of temperature and composition of the condensed phase. Conclusions: As the Cs2O and B2O3 activity values evidenced, negative deviations from the ideal behavior were observed in the Cs2O-B2O3 system in the temperature range 800–1000 K. The total enthalpies of mixing and the Gibbs energies of mixing in the Cs2O-B2O3 system were compared with the literature data, illustrating their mutual agreement.

AB - Rationale: The compounds in the Cs2O-B2O3 system are of particular interest for nuclear applications since cesium borates may be formed during accidents in nuclear reactors, affecting the rate of release of radiotoxic isotopes into the environment. Thus, information on the vaporization and thermodynamic properties of cesium borates is necessary for simulation and modeling of the isotope release processes taking place during the nuclear reactor accidents. Methods: Compounds in the Cs2O-B2O3 system were synthesized by the co-crystallization method with subsequent sintering. The sample characterization was carried out using XRD, TGA/DSC/DTA, IR spectroscopy, and ICP atomic emission spectroscopy. The vaporization and thermodynamics of the samples under consideration were investigated using an MS-1301 mass spectrometer and a single molybdenum effusion cell. The electron ionization method was employed for ionization of the vapor species with an electron energy of 30 eV. The scale of the ionizing voltage was calibrated according to the traditional technique by measuring the appearance energy of gold in the mass spectrum of the vapor over pure gold. Results: The main vapor species over the samples in the Cs2O-B2O3 system were CsBO2 and Cs2B2O4 in the temperature range 789–1215 K and in the concentration range 0.1–0.5 mole fraction of Cs2O. The temperature dependences of the CsBO2 and Cs2B2O4 partial pressures over cesium borate were obtained in the temperature range 767–990 K. The CsBO2 and B2O3 activities, the Gibbs energies of mixing, the excess Gibbs energies, the partial mole enthalpies of mixing, and total enthalpies of mixing were determined as functions of temperature and composition of the condensed phase. Conclusions: As the Cs2O and B2O3 activity values evidenced, negative deviations from the ideal behavior were observed in the Cs2O-B2O3 system in the temperature range 800–1000 K. The total enthalpies of mixing and the Gibbs energies of mixing in the Cs2O-B2O3 system were compared with the literature data, illustrating their mutual agreement.

KW - IONIZATION CROSS-SECTIONS

KW - CRYSTAL-STRUCTURE

KW - VAPOR-PRESSURES

KW - PRIMARY CIRCUIT

KW - BORIC OXIDE

KW - CESIUM

KW - POLYANION

KW - MOLECULES

KW - BEHAVIOR

KW - CSBO2

UR - http://www.scopus.com/inward/record.url?scp=85105262470&partnerID=8YFLogxK

U2 - 10.1002/rcm.9079

DO - 10.1002/rcm.9079

M3 - Review article

AN - SCOPUS:85105262470

VL - 35

JO - Rapid Communications in Mass Spectrometry

JF - Rapid Communications in Mass Spectrometry

SN - 0951-4198

IS - 11

M1 - e9079

ER -