Is the statement "An alpha-track (AT) detector consists of a small piece of plastic or film enclosed in a container with a filter-covered opening" true or false?

The statement is true. An alpha-track (AT) detector is specifically designed to measure alpha radiation by utilizing a small piece of detecting material, which can be a plastic or film, placed within a container that has a filter-covered opening. This design allows the detector to capture alpha particles emitted from radon and its decay products as they enter through the filter. When these particles interact with the detector, they create tracks that can later be analyzed to quantify the level of alpha radiation present. This method is widely used in radon measurement because it offers an effective way to monitor and assess exposure to alpha radiation in various environments.