Diffusion and mobility measurements for propane gas with a nanodosimetric detector

For the operation of nanodosimetric detectors with propane gas, it is essential to know the gas properties at room temperature, such as drift velocity, ion mobility, longitudinal and transversal diffusion coefficients. For propane gas there is only limited experimental data available for the ion mobility and transverse diffusion coefficients. In this work, the drift velocities and ion mobilities for propane were obtained over the reduced electric field range $E/N$ from 24 to 212 Td (1 Td = $10^{-17}$ Vcm${}^2$) based on arrival time measurements. The reduced ion mobility $K_0$ for propane was determined to be $(0.71\pm 0.09)$ cm${}^2/$Vs. The longitudinal diffusion coefficients were determined from the widths of the experimental arrival time spectra and found to be $N{D}_L$ = (3.7 $\pm$ 0.5)$\cdot 10^{19}$ 1/ms in the low field limit below 30 Td.

The results presented in this work extend the range of available experimental data for propane, as well as introduce first experimental measurements of the longitudinal diffusion coefficient of propane.