Neutralization kinetics for polonium-218

In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The diffusion coefficient of polonium-218 under various concentrations of trace gas NO sub(2) in nitrogen was measured. The mobilities of Po super(+) and PoO sub(2) super(+) are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small-ion recombination rate has been found to be proportional to the square root of radon concentration. The electron-scavenging mechanism is responsible for the neutralization of Po super(+) in NO sub(2) or H sub(2)O in nitrogen.