Class: Diag_SaddleCoils

The Diag_SaddleCoils class simulates magnetic flux measurements using saddle coils, which are placed at two different spatial locations. These diagnostics are commonly used in tokamaks to measure the difference in poloidal flux between two points.

Properties

  • R1, Z1: Horizontal and vertical coordinates (in meters) of the first end of the saddle coil.
  • R2, Z2: Horizontal and vertical coordinates (in meters) of the second end of the saddle coil.
  • Dpsi: Simulated flux difference measurement, including noise.
  • ideal: Structure containing the noise-free flux difference.
  • unit: Unit of measurement, typically "Wb/rad" (Weber per radian).
  • config: Structure containing configuration settings, such as parameters for random noise.

Methods

measure(equi)

Simulates the flux measurement between two points on the equilibrium flux surface.

  • Interpolates the poloidal flux (psi) at both ends of the coil using the equilibrium object.
  • Computes the flux difference between the two points.
  • Adds configurable random noise:
    • Absolute noise sampled from a normal distribution with fixed standard deviation.
    • Proportional noise scaled with respect to the magnitude of the ideal signal.
  • Stores both the ideal and noisy measurements.

Upload(configuration)

Loads predefined coil configurations.

  • If no configuration index is given, defaults to configuration 1.
  • Loads coil endpoint positions from an external .mat file (e.g., SaddleCoilsData_config_1.mat).
  • Initializes noise parameters.

Plotting Methods

plot_geo()

Plots the spatial layout of the saddle coils as line segments connecting their endpoints.

plot_meas()

Plots the noisy flux difference measurements for each saddle coil.

plot_StandAlone()

Plots both the ideal and noisy flux difference measurements for comparison.

Usage Example

saddle = Diag_SaddleCoils();
saddle = saddle.Upload();            % Load default configuration
saddle = saddle.measure(equilibrium); % Simulate measurement
saddle.plot_StandAlone();            % Visualize results

⚠️ This documentation is still a work in progress. There may be errors or inaccuracies. Please feel free to contact us if you notice any issues.