Detecting single-electron events in TEM using low-cost electronics and a silicon strip sensor

Equivalent circuit of a silicon-lithium p-i-n nuclear radiation detector

Nuclear radiation detectors are indispensable for research in the field of nuclear radiation, X-ray spectroscopy and other areas. Interest in silicon p-i-n detectors of nuclear radiation is increasing today due to the possibility of their operation under normal conditions. In this paper, an equivalent circuit of a silicon-lithium p-i-n nuclear radiation detector is proposed. The proposed circuit is obtained using the classical Shockley equation for silicon semiconductors and the telegraph equations. The parameters of the equivalent circuit were determined using the multiple regression method. As a result of simulation of the model in the MATLAB Simulink graphical development environment, the amplitude-frequency and phase-frequency characteristics of the proposed model were obtained. Using the Monte Carlo method, the alpha-decay of the uranium isotope [Formula: see text], thorium isotope [Formula: see text] and americium isotope [Formula: see text] the alpha-decay spectrum was obtained. Obtained alpha-decay spectra coincides with the experimental data, presented in previous works of other authors.

High spatial resolution detection of low-energy electrons using an event-counting method, application to point projection microscopy

An event-counting method using a two-microchannel plate stack in a low-energy electron point projection microscope is implemented. 15 μm detector spatial resolution, i.e., the distance between first-neighbor microchannels, is demonstrated. This leads to a 7 times better microscope resolution. Compared to previous work with neutrons [Tremsin et al., Nucl. Instrum. Methods Phys. Res., Sect. A 592, 374 (2008)], the large number of detection events achieved with electrons shows that the local response of the detector is mainly governed by the angle between the hexagonal structures of the two microchannel plates. Using this method in point projection microscopy offers the prospect of working with a greater source-object distance (350 nm instead of 50 nm), advancing toward atomic resolution.

Massively parallel WRNN reconstructors for spectrum recovery in astronomical photometrical surveys

The investigation of solar-like oscillations for probing star interiors has enjoyed a tremendous growth in the last decade. Once observations are over, the most notable difficulties in properly identifying the true oscillation frequencies of stars are due to the gaps in the observation time-series and the intrinsic stellar granulation noise. This paper presents an innovative neuro-wavelet reconstructor for the missing data of photometric signals. Firstly, gathered data are transformed using wavelet operators and filters, and this operation removes granulation noise, then we predict missing data by a composite of two neural networks, which together allow a "forward and backward" reconstruction. This resulting error is greatly lower than the absolute a priori measurement error. The devised reconstruction approach gives a signal that is better suited to be Fourier transformed when compared with other existing methods.