Nuclear detonations caught the world's attention this summer when India and Pakistan tested their potential strength. To monitor the Comprehensive Nuclear-Test-Ban-Treaty, scientists at the Department of Energy's Pacific Northwest National Laboratory (Richland, WA) developed two devices for detect nuclear detonations. The Automated Radioxenon Sampler/Analyzer (ARSA) and the Radionuclide Aerosol Sampler/Analyzer (RASA) inspect the atmosphere for traces of radioactive material. Once activated, the systems will be located around the globe as an international monitoring system. ARSA analyzes air samples for radioactive xenon or radioxenon that seeps from underground nuclear explosions. The system collects air samples and processes them to trap the radioactive xenon on cold charcoal. RASA detects fission products from atmospheric explosions. It daily filters a huge volume of air to check for evidence of fission products from a nuclear explosion that attach to dust particles. Information collected by the ARSA, RASA, and other monitoring systems at the global stations will be passed on to an international data center. Call (202) 586-5806.