What is the range in water for N-13?

The range of a radionuclide in a medium, such as water, is an important factor in understanding its behavior and interactions in medical imaging, particularly in positron emission tomography (PET). For nitrogen-13 (N-13), the correct value for its range in water is approximately 5.4 mm.

This measurement indicates how far the positrons emitted from N-13 will travel in water before they lose energy and subsequently annihilate with electrons, producing detectable gamma rays. Understanding this range is crucial for optimizing imaging protocols, including ensuring sufficient tissue penetration and minimizing radiation dose to surrounding areas.

The significance of this specific value also ties in with the physical properties of N-13, including its half-life of about 9.97 minutes, which requires careful handling and precise timing in clinical settings. This contrasts with other isotopes which may have longer ranges or different interactions, underscoring the unique characteristics of N-13 in the context of PET imaging.