# Nuclear Magneton

1. Jun 6, 2004

### joecoss

Concerning the Magnetic Moments of the Nucleus (Nuclear Magneton mu sub N) and the Proton (mu sub p) respectively, is the first ever measured by experiment or only defined and if so is it measured with bound electrons around it, and is the second measured for free Protons without electrons in the vicinity ? Thanks.

2. Jun 6, 2004

### Orion1

Nuclear Magnetic Moments...

The nuclear magneton and proton magnetic moment has been measured by experiment, generally using magnetically guided particle beams or by submitting a sample in a tunable oscillator and measuring the Larmor precessional frequency resonance signal using an oscilloscope.

$$\mu_n = \frac{q \hbar}{2m_p}$$

The magnetic moment of a free proton in not $$\mu_n$$. but $$\mu_p = 2.7928 \mu_n$$. There is no general theory of nuclear magnetism that explains this value. Another surprising point is the fact that a neutron also has a magnetic moment of value $$-1.9135 \mu_n$$. The minus sign indicates that its magnetic moment is the opposite its spin angular momentum.

To my knowledge, orbital electrons have no quantum effect on the value of nuclear magnetic moments.