Observation and modeling of ~(222)Rn daughters in liquid nitrogen

摘要

The results of alpha spectrometric measurements of the activity of ~(222)Rn daughters dissolved in liquefied nitrogen are presented. A direct detection method of ionized alpha-emitters from the ~(222)Rn decay chain (~(214)Po and ~(218)Po) in a cryogenic liquid in the presence of an external electric field is shown. Properties of the radioactive ions are derived from a proposed model of ion production and transport in the cryogenic liquid. Ionic life-time of the ions was found to be on the order of 10 s in liquid nitrogen (4.0 purity class). The presence of positive and negative ions was observed.