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Larmor precession is important in nuclear magnetic resonance, magnetic resonance imaging, electron paramagnetic resonance, muon spin resonance, and neutron spin echo. It is also important for the alignment of cosmic dust grains, which is a cause of the polarization of starlight .
The Larmor formula can only be used for non-relativistic particles, which limits its usefulness. The Liénard-Wiechert potential is a more comprehensive formula that must be employed for particles travelling at relativistic speeds. In certain situations, more intricate calculations including numerical techniques or perturbation theory could be ...
The spin–orbit potential consists of two parts. The Larmor part is connected to the interaction of the spin magnetic moment of the electron with the magnetic field of the nucleus in the co-moving frame of the electron. The second contribution is related to Thomas precession.
Atoms after passing the first inhomogeneous field will split into 2 beams corresponding the spin up and spin down state. Select one beam (spin up state, for example) and let it pass the rotating field. If the rotating field has frequency (ω) equal to the Larmor frequency, it will produce a high intensity of the other beam (spin down state).
In physics and chemistry, specifically in nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), and electron spin resonance (ESR), the Bloch equations are a set of macroscopic equations that are used to calculate the nuclear magnetization M = (M x, M y, M z) as a function of time when relaxation times T 1 and T 2 are present.
Taking for example the H 2 O molecules in liquid phase without the contamination of oxygen-17, the value of K is 1.02×10 10 s −2 and the correlation time is on the order of picoseconds = s, while hydrogen nuclei 1 H at 1.5 tesla precess at a Larmor frequency of approximately 64 MHz (Simplified. BPP theory uses angular frequency indeed).
For example, phenomena in the microscopic domain that can to some extent be described by classical analogy are not really quantum phenomena. Since the basic elements of magnetic resonance have no classical origin, although analogy can be made with classical Larmor precession , MR should be treated as a quantum phenomenon.
The precession frequency is known as the Larmor frequency ω L. [5] = where γ is the gyromagnetic ratio and B 0 the magnetic field. The electron spins are characterized by two quantum mechanical states, one parallel and one antiparallel to B 0.