The mass–mobility distributions of ions produced by a Po-210 source in air

Examination of Organic Vapor Adsorption onto Alkali Metal and Halide Atomic Ions by using Ion Mobility Mass Spectrometry

“…Calculations were performed modeling ion‐gas molecule collisions as completely elastic and specular (elastic hard sphere scattering, EHSS), as well as with the diffuse‐inelastic scattering model (diffuse hard sphere scattering, DHSS) of Larriba and Hogan . While prior studies,, reveal that gas molecule‐ion collisions in diatomic gases are neither wholly specular nor wholly diffuse (and are presumably a function of ion size, chemical composition, and the temperature), measurements should be bounded by EHSS and DHSS predictions. With the exception of the potassium cation, we find this to be true; measurements are bounded by the DHSS prediction as an upper limit the EHSS calculation as a lower limit.…”

“…The DMA‐MS system is described in detail in prior studies . Briefly, it consists of a parallel‐plate DMA (P5, SEADM, Boecillo, Spain, with a resolving power in excess of 50) coupled with a QSTAR XL quadrupole‐time‐of‐flight mass spectrometer (MDS Sciex).…”

Charge distribution uncertainty in differential mobility analysis of aerosols

“…Filtered ambient lab air was transported through stainless steel tubing in this study, but another choice of sampled gas mixture or plumbing material used would have likely resulted in a different n i ± (Z i ) (Steiner and Reischl 2012;Steiner et al 2014;Maißer et al 2015). In order to probe the effect of ion mobility distribution on the charge distribution, and, consequently, on the biases in the particle size distribution measurements due to inaccurate assumptions of the charge distribution acquired in the charger, we conducted the simulations using two different ion mobility distributions: the one according to our measurements and another based on the measurements by Steiner and Reischl (2012), which are referred to as measured and SR distributions, respectively ( Figure S1).…”

“…Moreover, since the chemical composition of the air going into the charger affects the mobility distribution of the ions (Steiner et al 2014;Maißer et al 2015), the actual mobility distribution of the ions at 10 km altitude would likely differ from those in the laboratory. Assessing this difference requires data that are beyond the scope of this study.…”

“…While studies using the Brownian dynamics method to estimate the charge distribution have accounted for multiple ion species (Gopalakrishnan et al 2013;Maißer et al 2015;Gopalakrishnan et al 2015), in most previous studies (e.g., Hoppel and Frick 1986;López-Yglesias and Flagan 2013b) estimating the charge distribution from the ion-to-particle flux coefficients, the ions have been modeled using a single characteristic positive and negative ion. We conducted simulations to examine the effect of this simplification.…”