A radiation detector includes a housing configured to contain a volume of water, the housing including an interior surface adjacent a first portion of the water having a first net charge. The radiation detector also includes a first electrode coupled to the housing within the first portion of the water, and a second electrode coupled to the housing within a second portion of the water adjacent the first portion of the water. The radiation detector further includes a current detector connected in series between the first electrode and the second electrode, the current detector configured to detect a current associated with an ionized radiation product that enters the housing.