  Transition-edge sensors (TESs) are capable of highly accurate single particle
energy measurement. TESs have been used for a wide range of photon detection
applications, particularly in astronomy, but very little consideration has been
given to their capabilities as electron calorimeters. Existing electron
spectrometers require electron filtering optics to achieve energy
discrimination, but this step discards the vast majority of electrons entering
the instrument. TESs require no such energy filtering, meaning they could
provide orders of magnitude improvement in measurement rate. To investigate the
capabilities of TESs in electron spectroscopy, a simulation pipeline has been
devised. The pipeline allows the results of a simulated experiment to be
compared with the actual spectrum of the incident beam, thereby allowing
measurement accuracy and efficiency to be studied. Using Fisher information,
the energy resolution of the simulated detectors was also calculated, allowing
the intrinsic limitations of the detector to be separated from the specific
data analysis method used. The simulation platform has been used to compare the
performance of TESs with existing X-ray photoelectron spectroscopy (XPS)
analysers. TESs cannot match the energy resolution of XPS analysers for
high-precision measurements but have comparable or better resolutions for high
count rate applications. The measurement rate of a typical XPS analyser can be
matched by an array of 10 TESs with 120 microsecond response times and there is
significant scope for improvement, without compromising energy resolution, by
increasing array size.
