# Scan on BornAgain

file:///usr/share/doc/bornagain/html/ref/instr/scan/index.html Recent content in Scan on BornAgain Hugo en-us

# TOF reflectometry

file:///usr/share/doc/bornagain/html/ref/instr/scan/tof.html Mon, 01 Jan 0001 00:00:00 +0000 file:///usr/share/doc/bornagain/html/ref/instr/scan/tof.html <h2 id="time-of-flight-reflectometry">Time-of-flight reflectometry</h2> <p>This example shows how to set up a $q_z$ scan using a NumPy array. This can be used to simulate a time-of-flight (TOF) reflectometry experiment.</p> <div class="galleryscg "> <div class="row justify-content-center align-items-center"> <figure > <a href="file:///usr/share/doc/bornagain/html/img/auto/specular/TimeOfFlightReflectometry.png"> <img src="file:///usr/share/doc/bornagain/html/img/auto/specular/TimeOfFlightReflectometry.png" width="500px"> </a> <figcaption> <p></p> </figcaption> </figure> </div> </div> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"></code></pre></td></tr></table> </div> </div> <a class="linktofile" href="https://jugit.fz-juelich.de/mlz/bornagain/-/tree/r23/auto/Examples/specular/TimeOfFlightReflectometry.py"/>auto/Examples/specular/TimeOfFlightReflectometry.py</a>

# TOF resolution

file:///usr/share/doc/bornagain/html/ref/instr/scan/tof-resolution.html Mon, 01 Jan 0001 00:00:00 +0000 file:///usr/share/doc/bornagain/html/ref/instr/scan/tof-resolution.html <h2 id="resolution-effects-in-tof-reflectometry">Resolution effects in TOF Reflectometry</h2> <p>In the following reflectometry example, each scan point has a distribution of $q_z$ values.</p> <p>The constructor</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"><span class="line"><span class="cl"><span class="n">ba</span><span class="o">.</span><span class="n">DistributionGaussian</span><span class="p">(</span><span class="mf">0.</span><span class="p">,</span> <span class="mf">1.</span><span class="p">,</span> <span class="mi">25</span><span class="p">,</span> <span class="mf">2.</span><span class="p">)</span> </span></span></code></pre></div><p>specifies a Gaussian distribution with mean 0, standard deviation 1, 25 sampling points, and a cut-off at 2 sigma. For other distributions (besides Gaussian), see <a href="file:///usr/share/doc/bornagain/html/ref/other/distributions">distributions</a>.</p> <p>The statements</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"><span class="line"><span class="cl"><span class="n">scan</span> <span class="o">=</span> <span class="n">ba</span><span class="o">.</span><span class="n">QzScan</span><span class="p">(</span><span class="n">qzs</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="n">scan</span><span class="o">.</span><span class="n">setVectorResolution</span><span class="p">(</span><span class="n">distr</span><span class="p">,</span> <span class="n">dq</span><span class="p">)</span> </span></span></code></pre></div><p>take arrays <code>qzs</code> and <code>dq</code> as arguments. These arrays must have the same length <code>n</code>. For each scan point (i=0,..,n-1), the $q_z$ values have a Gaussian distribution with mean <code>qzs[i]</code> and <code>dq[i]</code>.</p>

# Beam Angular Spread

file:///usr/share/doc/bornagain/html/ref/instr/scan/angular-divergence.html Mon, 01 Jan 0001 00:00:00 +0000 file:///usr/share/doc/bornagain/html/ref/instr/scan/angular-divergence.html <h3 id="beam-angular-spread-in-specular-simulations">Beam Angular Spread in Specular Simulations</h3> <p>This example demonstrates beam angular spread effects in reflectivity computations. It also offers a comparison with data generated using another well known code: GenX. Further information about reflectometry simulations can be found in the <a href="file:///usr/share/doc/bornagain/html/ref/sim/class/specular">Reflectometry Simulation Tutorial</a>.</p> <p>The observed reflectometry signal can be affected either by a spread in the beam wavelength or in the incident angle.</p> <div class="galleryscg "> <div class="row justify-content-center align-items-center"> <figure > <a href="file:///usr/share/doc/bornagain/html/img/auto/specular/VsGenx.png"> <img src="file:///usr/share/doc/bornagain/html/img/auto/specular/VsGenx.png" width="500px"> </a> <figcaption> <p>Scattering intensity</p> </figcaption> </figure> </div> </div> <p>In this example, a Gaussian distribution is used to spread the incident angle, with a standard deviation of $\sigma_{\alpha} = 0.01^{\circ}$.</p>

# Beam Wavelength Spread

file:///usr/share/doc/bornagain/html/ref/instr/scan/full-divergence.html Mon, 01 Jan 0001 00:00:00 +0000 file:///usr/share/doc/bornagain/html/ref/instr/scan/full-divergence.html <h3 id="beam-wavelength-spread-in-specular-simulations">Beam Wavelength Spread in Specular Simulations</h3> <p>This example demonstrates beam wavelength spread effects in reflectivity computations. All simulation parameters (except for those related to beam spread itself) coincide with those defined in <a href="file:///usr/share/doc/bornagain/html/ref/sim/class/specular">reflectometry simulation tutorial</a>.</p> <p>In real specular experiments the observed reflectivity is always affected by the beam spread in both wavelength and incident angle.</p> <div class="galleryscg "> <div class="row justify-content-center align-items-center"> <figure > <a href="file:///usr/share/doc/bornagain/html/img/auto/specular/BeamFullDivergence.png"> <img src="file:///usr/share/doc/bornagain/html/img/auto/specular/BeamFullDivergence.png" width="500px"> </a> <figcaption> <p>Scattering intensity</p> </figcaption> </figure> </div> </div> <p>In this example the following parameters related to the spread of the beam were set to the simulation:</p>