ACMagneticField

The ACMagneticField potential models an alternating (AC) magnetic field applied to magnetic particles. It extends the ConstantMagneticField potential by adding time-dependent oscillation.

The magnetic field at time \(t\) is given by:

\[\mathbf{B}(t) = B_0 \sin(2\pi f t + \phi) \hat{n}\]

where \(B_0\) is the amplitude, \(f\) is the frequency, \(\phi\) is the phase, and \(\hat{n}\) is the normalized direction vector.

---

• type: External, ACMagneticField

• parameters:

  • b0: real: Amplitude of the magnetic field \([magnetic field]\)

  • direction: real3: Direction vector of the magnetic field (will be normalized)

  • frequency: real: Frequency of the AC field \([1/time]\)

  • phase: real: Initial phase of the AC field \([angle]\) (optional, default: 0)

Example:

"acMagneticField":{
  "type":["External","ACMagneticField"],
  "parameters":{
    "b0": 1.0,
    "direction": [0.0, 0.0, 1.0],
    "frequency": 1.0,
    "phase": 0.0
  }
}

Note

This potential requires magnetic moment information for each particle. Ensure that the magnetic moments are properly set for each particle before using this potential.

Warning

The ACMagneticField potential may require small time steps to accurately resolve the oscillations, especially at high frequencies.