A DOUBLE CHAMBER SYSTEM FOR PRODUCING CONSTANT RADON CONCENTRATION

An experimental arrangement of a radon chamber with an intrinsic const ancy of the relative radon concentration is described. The system cons ists of a reference chamber and an auxiliary storage chamber. The only active device is a timer-controlled pump or valve which feeds radon g as from the storage into the reference chamber. The switching pattern of the timer is extracted from model calculations and theoretically pe rforms an exact compensation of the radon loss by radioactive decay. I f the calculations are done in real time and online, every known exter nal event influencing the radon concentration can be compensated. This paper presents a simple timer circuit and a computer code which gener ates the timer program. The influence of the air flow stability and th e leakage of the chambers are discussed. It is planned to apply this t heoretical approach to provide a constant radon gas concentration for an actual chamber.