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Name: jamie
Status: student
Age: 16
Location: N/A
Country: N/A
Date: 1999 

How do radioactive detectors work?


"Radioactive detectors" work in different ways depending on what is being detected. As a material decays (breaks up) it can emit alpha particles, beta particles, gamma rays, neutrons, etc. The most common means of detecting radioactivity is to measure these emissions using an ionization chamber. When held in the vicinity of the material, the particles emitted from radioactive material pass through a membrane and into the gas-filled box (chamber). Because the particles are energetic, they ionize the gas, i.e., separate the gas molecules into positively and negatively charged parts. The charge can be made to flow in nearby wires. This flow creates an electrical current. The strength of this current determines how much activity there is. From that, and a knowledge of the the radioactive materials, one can estimate the amount of radioactivity.

Dr. Ali Khounsary
Advanced Photon Source
Argonne National Laboratory
Argonne, IL 60439

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