toolbox_scs.routines.knife_edge

Toolbox for SCS.

Various utilities function to quickly process data measured at the SCS instrument.

Copyright (2019-) SCS Team.

Module Contents

Functions

knife_edge(ds[, axisKey, signalKey, axisRange, p0, ...])

Calculates the beam radius at 1/e^2 from a knife-edge scan by
toolbox_scs.routines.knife_edge.knife_edge(ds, axisKey='scannerX', signalKey='FastADC4peaks', axisRange=None, p0=None, full=False, plot=False, display=False)[source]

Calculates the beam radius at 1/e^2 from a knife-edge scan by fitting with erfc function: f(x, x0, w0, a, b) = a*erfc(np.sqrt(2)*(x-x0)/w0) + b with w0 the beam radius at 1/e^2 and x0 the beam center.

Parameters

  • ds (xarray Dataset) – dataset containing the detector signal and the motor position.

  • axisKey (str) – key of the axis against which the knife-edge is performed.

  • signalKey (str) – key of the detector signal.

  • axisRange (list of floats) – edges of the scanning axis between which to apply the fit.

  • p0 (list of floats, numpy 1D array) – initial parameters used for the fit: x0, w0, a, b. If None, a beam radius of 100 micrometers is assumed.

  • full (bool) – If False, returns the beam radius and standard error. If True, returns the popt, pcov list of parameters and covariance matrix from scipy.optimize.curve_fit.

  • plot (bool) – If True, plots the data and the result of the fit. Default is False.

  • display (bool) – If True, displays info on the fit. True when plot is True, default is False.

Returns

error from the fit in mm. If full is True, returns parameters and covariance matrix from scipy.optimize.curve_fit function.

Return type

If full is False, tuple with beam radius at 1/e^2 in mm and standard