Measurement of the rate coefficient of the reactions Hplus;plus; 2H2rarr; H3plus;plus; H2and Dplus;plus; 2D2rarr; D3plus;plus; D2in a drift tube mass spectrometer

摘要

The rate coefficient of the reaction Hplus;plus; 2H2rarr; H3plus;plus; H2has been measured at a gas temperature of 300 deg;K and over a pressure range 0.25ndash;0.50 torr. The transport properties and average energy of a given species of ion drifting in a gas in a uniform electric field are determined byEsol;N, whereEis the electric field intensity andNis the gas number density.Esol;Nis expressed in units of the townsend (Td), where 1 Td equals; 10minus;17V middot; cm2. Our measurements were made over a range 25ndash;50 Td, where the lower value corresponds to an average energy for the reacting Hplus;ions which is very close to the thermal energy of the H2molecules at 300 deg;K. No systematic variation of the rate coefficient was observed over the range ofEsol;Nwhich was covered. The measurements were made with a drift tube mass spectrometer and involved the detailed analysis of the arrival time spectra of the productH3plus;ion. The rate coefficient was evaluated to be (3.05 plusmn; 0.15) times; 10minus;29cm6sol;sec. The same result was also obtained for the reaction Dplus;plus; 2D2rarr; D3plus;plus; D2.