Xenon-133

Xenon-133 is a radioactive isotope of xenon, a noble gas. It is primarily used in nuclear medicine for diagnostic procedures, specifically for lung ventilation studies.

Production

Xenon-133 is produced in nuclear reactors through the neutron irradiation of uranium-235. The uranium-235 absorbs a neutron and undergoes fission, producing a variety of fission products, one of which is xenon-133.

Properties

Xenon-133 is a gamma emitter, with a primary gamma energy of 81 keV. It has a half-life of approximately 5.2 days. As a noble gas, it is chemically inert and does not react with other substances. This makes it ideal for use in medical imaging, as it can be inhaled or injected into the body without causing any chemical reactions.

Medical Use

In nuclear medicine, xenon-133 is used in lung ventilation studies. Patients inhale the gas, and its distribution in the lungs is imaged using a gamma camera. This allows doctors to assess lung function and detect any abnormalities, such as blockages or reduced airflow.

Safety

While xenon-133 is radioactive, it is considered safe for medical use. The radiation dose received by patients is relatively low and is comparable to that received during a standard X-ray examination. However, as with all medical procedures, the potential benefits must be weighed against the potential risks.

Disposal

After use, xenon-133 decays to stable cesium-133, which is not radioactive. However, the gas must be properly contained and disposed of to prevent any potential radiation exposure. This is typically done by storing the gas in a sealed container until it has fully decayed.

See Also

• Nuclear medicine
• Radioactive decay
• Nuclear reactor
• Uranium-235