kärnmagneton

The kärnmagneton, often represented by the symbol $\mu_N$, is a fundamental physical constant representing the magnetic dipole moment of a nucleon. Specifically, it is the magnetic moment associated with the intrinsic angular momentum (spin) of a proton or neutron. It is defined as $e\hbar / (2m_p)$, where $e$ is the elementary charge, $\hbar$ is the reduced Planck constant, and $m_p$ is the proton mass.

This unit is analogous to the Bohr magneton, which is used for the magnetic dipole moment of an electron. However, because protons and neutrons are significantly more massive than electrons, the kärnmagneton is considerably smaller than the Bohr magneton. Its value is approximately $5.05078 \times 10^{-27} \text{ joule per tesla} (\text{J/T})$.

The kärnmagneton is a crucial quantity in nuclear physics and quantum mechanics. It is used to describe the magnetic properties of atomic nuclei, particularly in the context of nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). The magnetic moments of protons and neutrons, when measured in units of the kärnmagneton, provide insights into their internal structure and the forces that bind them within the nucleus. Experimental measurements of nuclear magnetic moments are often compared to theoretical predictions, which rely on the concept of the kärnmagneton.