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Energetic electrons of several hundred-kilo electron volts (keV) as used in transmission electron microscopy applications do not deposit their energy completely at their point of entry (PoE). Instead, in a detector with a thickness of 450 $\mu \text{m}$ , they produce randomly 3-D tracks often extending over many pixels. The length and the shape of these tracks strongly depend on the primary energy of the electrons. Statistically, an electron deposits most of its energy at the end of its track. The output of a tracking detector system is the pixelated 2-D projection of the energy deposition. The proposed convolutional neural network (CNN) is capable of performing a frame-based event analysis and PoE reconstruction. The resulting modulation transfer function (MTF) is 0.77 at a Nyquist frequency of 0.5 obtained from a slanted edge. It is based on a U-net with a specially designed loss function using the confusion matrix. The input data to the CNN only need to be offset corrected. The output of the CNN is a PoE map containing the probability of a PoE of an electron for each pixel and frame. The architecture of the designed CNN also allows reconstructing different frame sizes without retraining the network. [ABSTRACT FROM AUTHOR]

The Mercury imaging X-ray spectrometer (MIXS) on board of ESA's fifth cornerstone mission BepiColombo will be the first space instrument using DEpleted P-channel FET (DEPFET) based detectors. The MIXS spectrometer comprises two channels with identical focal plane detectors and is dedicated to energy resolved imaging of X-ray fluorescence from the mercurial surface. [ABSTRACT FROM PUBLISHER]

DEPFET detectors are silicon (Si) active pixel sensors designed and manufactured in the Max-Planck-Institut semiconductor lab. Their high spatial resolution and high energy resolution in X-rays make them attractive for particle tracking in colliders and for X-ray astronomy. This technology is foreseen for the Wide Field Imager of the International X-ray Observatory currently in study with ESA, NASA, and JAXA. New DEPFET matrixes with 256\,\times\,256 pixels of 75-\mum pitch have been produced, mounted on ceramic boards with dedicated front-end electronics and integrated in a new setup able to acquire large-format images and spectra. Excellent homogeneity has been observed. Energy resolution as low as 127 eV FWHM at 5.9 keV has been obtained including all single events of the matrix back illuminated at -45\,^\circC and read out at a 300-frames/s rate. This paper presents experimental methods and results. [ABSTRACT FROM AUTHOR]