Plot the counts for an exciting-photon energy scan

First import the EnergyScan class and the class for processing the “raw” detector data.

from agepy.spec.photons import EnergyScan, available_anodes

The available anodes can be viewed with

print(available_anodes)

{'poco': <class 'agepy.spec._anodes.PocoAnode'>, 'wsa': <class 'agepy.spec._anodes.WsaAnode'>, 'dld_xy': <class 'agepy.spec._anodes.DldAnodeXY'>, 'dld_uvw': <class 'agepy.spec._anodes.DldAnodeUVW'>, 'dld_uv': <class 'agepy.spec._anodes.DldAnodeUV'>, 'dld_uw': <class 'agepy.spec._anodes.DldAnodeUW'>, 'dld_vw': <class 'agepy.spec._anodes.DldAnodeVW'>, 'old_wsa': <class 'agepy.spec._anodes.Old_WsaAnode'>, 'old_dld': <class 'agepy.spec._anodes.Old_DldAnode'>}

You can access the anode using the dictionary or import it directly

from agepy.spec.photons import DldAnodeUVW

Create an instance of the chosen anode class with the detector rotation:

anode = DldAnodeUVW(-8.3)

Now load the energy scan data from a .h5 file using the EnergyScan class:

scan = EnergyScan("scan.h5", anode, energies="epics#energy",
                  raw="dld_rd#raw", time_per_step=60,
                  target_density="Baratron#avg",
                  intensity_upstream="Mirror#avg")

The class needs the path to the file, the anode and the directories inside the .h5 file, where the data is saved. In this case the scan energies are in epics#energy/0, the “raw” data in dld_rd#raw/0. Additionally, values for normalization can be loaded, if available. Here, a target density and the upstream intensity of the incoming photons was recorded and is loaded from their directories.

The directory structure in an .h5 file can be viewed with h5glance scan.h5, after installing it with pip install h5glance.

The photon excitation spectrum can now be calculated and plotted with

n, err, energies = scan.counts(
    roi={"x": {"min": 0.25, "max": 0.80}, "y": {"min": 0.35, "max": 0.56}})

%matplotlib inline
# Import matplotlib for plotting
import matplotlib.pyplot as plt
# Set the agepy plotting style
from agepy import ageplot
ageplot.use("age")

fig, ax = plt.subplots()
# Scale the counts to a reasonable size
ax.plot(energies, n * 1e-10, '-', color=ageplot.colors[1])
ax.errorbar(energies, n * 1e-10, yerr=err * 1e-10, fmt='s', markersize=3,
            color=ageplot.colors[0])
ax.set_xlabel("Energy (eV)")
ax.set_ylabel("Counts (arb. u.)")
ax.set_title("Energy scan")
plt.show()