Oscillating Magnetic Fields: Magnetic Resonance

M. Allegrini, E. Arimondo

Noriaki Tsukada, T. Koyama, Toru Ogawa

Various magnetic resonances appearing in optical pumping experiments have been analysed theoretically and experimentally. However, there is little work on the saturation effects caused by strong RF fields. Recently, The saturation effects of the multiple quantum resonances and of the Haroche resonances have been investigated by Stenholm (1972) and by Tsukada and Ogawa (1973). The saturation effects are treated for the more general case of a static magnetic field in an arbitrary direction with respect to the oscillating RF field. The experimental results are compared with the exact solutions computed by the numerical integration of the Bloch equation. It is shown experimentally and theoretically that the resonances similar to the Haroche resonance appear at omega /sub ///=n omega , where omega /sub ///= gamma H/sub ///, n is an integer, H/sub /// is the parallel component of the static magnetic field with respect to the oscillating RF field, and gamma is the gyromagnetic ratio.

Antoine Weis

Zhichao Ding, Jie Yuan, Zhiguo Wang +2 more

A dip of the transverse component of the magnetic moment as a function of resonance frequency-detuning will emerge when the intensity of oscillating magnetic field exceeds a specific value, which is demonstrated theoretically and experimentally. The linewidth of magnetic-resonance signal can be much smaller than when the M x – M R magnetometer operates on condition that the intensity of oscillating magnetic field is smaller than this specific value, and the M x – M R magnetometer can possess a much higher signal-to-noise ratio. The experimental result shows that the sensitivity of M x – M R magnetometer can be improved by an order of magnitude under this condition.

William T. Dixon

David Thomas Pegg, George William Series

Abstract The problem in question is to find the motion of an atom having arbitrary spin J in a strong oscillating magnetic field and a static field whose component perpendicular to the oscillating field is small (case B). It is shown how to relate this problem to that of ordinary magnetic resonance–an atom in a small oscillating field perpendicular to a strong static field (case A)–by applying to each case a suitable transformation. In the transformed frames the dominant terms in the equations of motion are equivalent and subsidiary terms are similar, so that results well-known in case A may be taken over to case B. The dominant terms in case B describe a set of resonances whose line-shapes are given explicitly for a particular example. Subsidiary terms lead to shifts of the resonances analogous to the Bloch-Siegert shift. The leading term s in these shifts are given. Terms of higher order may be calculated by employing a technique due to Shirley which is described.