Tutorial: ELS energy

To interpret the electron data, it is important to know the energy of measured electrons. The information is provided as tables. Which table to choose depends on the observation mode, and therefore not very straightforward.

Nevertheless, one may get the energy of VEX/ELS as following, using irfpy.vels.energy.get_default_table_128().

>>> import irfpy.vels.energy as vels_energy
>>> el_enetbl = vels_energy.get_default_table_128()
>>> print(el_enetbl.shape)
(128, )
>>> print(el_enetbl)
array([  3.04956255e+04,   2.80753378e+04,   2.58561201e+04,
         2.38081843e+04,   2.19240834e+04,   2.01889233e+04,
         1.85878098e+04,   1.71207431e+04,   1.57653820e+04,
...
         1.57843978e+00,   1.46151832e+00,   1.34459685e+00,
         1.22767538e+00,   1.11075392e+00,   1.05229319e+00,
         9.35371722e-01,              nan])

The central energy is provided here. The last step is nan because this step is for the “flyback” of the energy sweep, providing meaningless data.

For MEX/ELS, use the function irfpy.mels.energy.get_default_table().

>>> import irfpy.mels.energy as mels_energy
>>> el_enetbl = mels_energy.get_default_table()

Exercise

1. Plot energy spectra (x-axis as energy and y-axis as counts) of the electron data obtained at 2007-10-23T23:00:00 both for MEX and VEX.