{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "\n# Point source\n\nBasic example of computation of the field emitted by an isotropic point source.\n"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Import required libraries\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "import matplotlib.pyplot as plt\nimport numpy as np\n\nimport pysrw as srw"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Ccreate the point emitter radiating 1 ph/(s mm^2)\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "ptSrc = srw.emitters.PointSource(flux=1)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Create a 10 mm x 10 mm observation mesh, with a resolution of 10 um, \nplaced 10 cm downstream of the source\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "observer = srw.wavefronts.Observer(centerCoord=[0, 0, .1],\n                                   obsXextension=10e-3, \n                                   obsYextension=10e-3,\n                                   obsXres=10e-6,\n                                   obsYres=10e-6)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Compute the wavefront at the observation wavelength of 600 nm.\nThe multiprocessing version is reported for comparison\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "wfr = srw.computePtSrcWfr(ptSrc, observer, wavelength=600)\nwfr_mp = srw.computePtSrcWfrMultiProcess(4, ptSrc, observer, wavelength=600)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Compute the corresponding optical intensity\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "intensity = wfr.getWfrI()\nintensity_mp = wfr_mp.getWfrI()"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Plot the 2D intensity distribution\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "srw.plotI(intensity)\nsrw.plotI(intensity_mp)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Extract cross-cut using :py:func:`~pysrw.tools.extractCrossCuts`\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "crosscuts = srw.extractCrossCuts(intensity)\nxax = crosscuts[\"xax\"]\nxcut = crosscuts[\"xdata\"]"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Compare with the intensity decay due to spherical attenuation\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "theta = np.arctan(xax / observer.zPos)\nxcut_theo = 1/(4 * np.pi * observer.zPos**2) * np.cos(theta)**3 * 1e-6 # ph / (s mm^2)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Plot the resulting cuts\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "fig, ax = plt.subplots()\nax.plot(xax * 1e3, xcut, label=\"sim\")\nax.plot(xax * 1e3, xcut_theo, linestyle=\"--\", label=\"theo\")\nax.set_xlabel(\"x position [mm]\")\nax.set_ylabel(\"Intensity [ph/(s mm^2 0.1%BW)]\")\nax.legend()\nplt.show()"
      ]
    }
  ],
  "metadata": {
    "kernelspec": {
      "display_name": "Python 3",
      "language": "python",
      "name": "python3"
    },
    "language_info": {
      "codemirror_mode": {
        "name": "ipython",
        "version": 3
      },
      "file_extension": ".py",
      "mimetype": "text/x-python",
      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.9.9"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}