Browsing by Author "Cortez, André F.V."

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Experimental ion mobility measurements for the LCTPC collaboration - Ar-CF4 mixtures
(IOP Publishing, 2018-03-28) Santos, M. A.G.; Kaja, Magdalena A.; Cortez, André F.V.; Neves, Pedro N.B.; Santos, Filomena P.; Borges, F. I.G.M.; Conde, Carlos A.N.; Veenhof, Robert J.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 6603742499
In this paper we present the results of the ion mobility measurements made in pure carbon tetrafluoride (CF4) and gaseous mixtures of argon with carbon tetrafluoride (Ar-CF4) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 Td to 25 Td range (2.4-6.1 kV center dot cm(-1)center dot bar(-1)), at room temperature. The time of arrival spectra revealed only one peak throughout the entire range studied which was attributed to CF3+. However, for Ar concentrations above 70%, a bump starts to appear at the left side of the main peak for reduced electric fields higher than 15 Td, which was attributed to impurities. The reduced mobilities obtained from the peak centroid of the time-of-arrival spectra are presented for Ar concentrations in the 5%-95% range.
Experimental ion mobility measurements in Ar-N2
(IOP Publishing Ltd, 2018-10-12) Santos, M. A.G.; Cortez, André F.V.; Perdigoto, J. M.C.; Escada, J.; Neves, P. N. B.; Santos, F. P.; Conde, C. A. N.; Borges, F. I. G. M.; Veenhof, Robert J.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 6603742499
Data on ion mobility is important to improve the performance of large volume gaseous detectors, since the detector signal can be influenced by the drift of the ions, namely in the cases where charge multiplication is used, for example in Multi-Wire Proportional Chambers (MWPCs) and in some Time Projection Chambers (TPCs). In the present work the results for the ion mobility measurements in Ar-N-2 mixtures are presented, using an experimental setup and method already tested in previous work. The results for this mixture show the presence of only one peak for all gas ratios of Ar-N-2, for reduced electric fields, E/N, in the range of 10-25 Td (2.4-6.1 kV.cm(-1).bar(-1)), and 8 Torr (10.6 mbar) pressure, at room temperature.
Experimental Ion Mobility measurements in Ne-CO2 and CO2-N-2 mixtures
(IOP Publishing, 2016-04-27) Encarnaçao, Pedro M.C.C.; Cortez, André F.V.; Neves, Pedro N.B.; Santos, Filomena P.; Trindade, Alexandre M.F.; Borges, F. I.G.M.; Conde, Carlos A.N.; Veenhof, Robert J.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 6603742499
In this paper we present the experimental results for the mobility, K-0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N-2) gaseous mixtures for total pressures ranging from 8-12 Torr, reduced electric fields in the 10-25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 +/- 0.05 and 1.07 +/- 0.01 cm(2)V(-1)s(-1) in the 10%-99% interval of CO2, and from 4.61 +/- 0.19 to 3.00 +/- 0.09 cm(2)V(-1)s(-1) for the second peak observed (10%-25% of CO2). For the CO2-N-2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+ (CO2), with a second peak appearing for CO2 concentrations below 10%. This second peak, with higher mobility, was attributed to CO2+ ions. The mobility values of the main peak range between 2.11 +/- 0.04 and 1.10 +/- 0.03 cm(2)V(-1)s(-1) in the 1%-99% interval of CO2, while the second peak's from 2.26 +/- 0.02 and 1.95 +/- 0.04 cm(2)V(-1)s(-1) (1%-10% of CO2). The inverse of the mobility displays an aproximately linear dependence on the CO2 concentration in the mixture.
Experimental ion mobility measurements in Xe-CF4 mixtures
(IOP Publishing, 2018-04) Cortez, André F.V.; Kaja, Magdalena A.; Escada, J. M.D.; Santos, M. A.G.; Neves, Pedro N.B.; Santos, Filomena P.; Borges, F. I.G.M.; Conde, Carlos A.N.; Veenhof, Robert J.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 6603742499
In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon with carbon tetrafluoride (Xe-CF4) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 to 25 Td range (2.4-6.1 kV.cm(-1).bar(-1)), at room temperature. The time-of-arrival spectra revealed one or two peaks depending on the gas relative abundances, which were attributed to CF3+ and to Xe-2(+) ions. However, for Xe concentrations above 60%, only one peak remains (Xe-2(+)). The reduced mobilities obtained from the peak centroid of the time-of-arrival spectra are presented for Xe concentrations in the 5%-95% range.
Experimental ion mobility measurements in Xe-CH4
(IOP Publishing, 2017-07-24) Perdigoto, J. M.C.; Cortez, André F.V.; Neves, Pedro N.B.; Santos, Filomena P.; Borges, F. I.G.M.; Conde, Carlos A.N.; Veenhof, Robert J.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 6603742499
Data on ion mobility is important to improve the performance of large volume gaseous detectors. In the present work, the method, experimental setup and results for the ion mobility measurements in Xe-CH4 mixtures are presented. The results for this mixture show the presence of two distinct groups of ions. The nature of the ions depend on the mixture ratio since they are originated by both Xe and CH4. The results here presented were obtained for low reduced electric fields, E/N, 10-25 Td (2.4-6.1 kV.cm(-1).bar 1), at low pressure (8 Torr) (10.6 mbar), and at room temperature.