Browsing by Author "Kowalski, T. Z."

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    Measurements and calculations of electron avalanche growth in ternary mixture of Ne-CO2-N-2
    (IOP Publishing, 2016) Kowalski, T. Z.; Şahin, Özkan; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0003-3940-7222; AAH-6445-2021; I-9715-2017; 36053592700
    A Time Projection Chamber (TPC) is an ideal device for three-dimensional tracking. It is used in many experiments including ALICE at LHC. The choice of the gas mixture is crucial for this type detector performance. For the operation of the TPC at ALICE, Ne-CO2-N-2 was chosen. Because of the relatively low primary ionisation of Ne, the readout chambers have to be operated at high gas gains near 10(4). Therefore gas gain factor has been measured and calculated for this mixture. The Diethorn, Williams and Sara and of Aoyama models of the first Townsend coefficient have been used to determine the basic gas properties. Photon feedback parameters and Penning transfer rates have been also determined.
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    Measurements and calculations of gas gains in Ne-N-2 mixtures - Pressure and concentration scaling
    (IOP Publishing, 2020-12-09) Kowalski, T. Z.; Şahin, Özkan; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0003-3940-7222; AAH-6445-2021; 6053592700
    Systematic high-precision measurements of gas gains in Ne-N-2 mixtures have been made. The concentration of N-2 was changed from 2,5% to 20% and the mixtures pressures were varying from 0.05 to 1.8 atm. In Ne-N-2 mixtures, excitation energy of Ne atom can be used to ionize N-2 molecule by the Penning transfer. Comparing the measured and calculated with MAGBOLTZ simulation program gas gains the Penning energy transfer probability and the second Townsend ionization coefficient, beta, describing secondary processes playing a role in avalanche formations have been determined.