This simulation allows you to explore the properties of nuclear radiation, and to explore the effect of background radiation when measuring the activity of a radioactive source.
Radioactivity mode – Click Radioactivity at the top of the settings panel
Click Pause/Resume to pause or resume the action, and Slow mode to toggle into slow mode which reduces speeds by a factor of five.
Select a source from the Source drop-down menu; selecting Custom will being up some sliders so you can adjust the intensity of each radiation type produced by the source.
Toggle Counter type to Detailed to view a detailed radiation counter that gives the number of particles per second of each type of radiation leaving the source and detected at the GM tube.
Toggle the Add paper / aluminium / lead / paper toggles to add materials which can absorb the radiation. Drag them to move them, and drag in the blue circles on their top tabs to change their thicknesses.
Toggle radiation mode to switch between Linear and Radiating modes; in linear mode, you can drag the GM tube closer and further from the source, in the radiating mode you can also move it in an arc around the source. In radiating mode, toggle the Show ruler toggle to see the distance between the source and the GM tube.
Background radiation mode – Click Background radiation at the top of the settings panel
Select an environment type from the Select environment drop-down, or choose Custom to set your own using the sliders.
Select an object to study from the Select object drop-down, or choose Custom to set your own using the sliders.
Toggle Experiment mode to Yes to run an experiment to measure the activity of a sample by taking the background activity into account.
Set the number of repeat measurements to take with the Measurement count drop-down and the measurement time with the Measurement interval drop-down.
Click Start and follow the on-screen instructions to run the experiment.