Leonsmedegaard8079

This paper presents a new method for combined measurements of persistent luminescence (PersL), thermoluminescence (TL), and mechanoluminescence (ML) of luminescent materials in the micrometer scale. Both the hardware and software designs have been illustrated in detail, and the experimental procedures to execute the emission map, PersL, TL, and ML measurements have been demonstrated. The PersL, TL, and ML properties of the SrAl2O4Eu2+, Dy3+ micropowder, as well as the corresponding temperature variable emission spectra, have been measured. The results show good agreement with published investigations, indicating the accomplishment of designed functions. The instrument would be a powerful tool for exploring phosphorescent materials in the micrometer and smaller scales.We present an effective approach using a matched pair of polymer-based condenser-objective lenses to build a compact full-field x-ray microscope with a high spatial resolution. A unique condenser comprising arrays of high-aspect-ratio prisms with equilateral cross section is used for uniformly illuminating samples over a large field of view (FOV) from all angles, which match the acceptance of an objective made of interdigitated orthogonal rows of one-dimensional lenses. State-of-the-art Talbot grating interferometry used to characterize these lenses for the first time revealed excellent focusing properties and minimal wavefront distortions. Using a specific lens pair designed for 20 keV x rays, short-exposure times, and image registration with a cross-correlation technique, we circumvent vibrational instabilities to obtain distortion-free images with a uniform resolution of 240 nm (smallest resolvable line pair) over a large FOV, 80 × 80 µm2 in extent. The results were contrasted with those collected using commercial two-dimensional parabolic lenses with a smaller FOV. This approach implemented on a diffractometer would enable diffraction-contrast or dark-field microscopy for fast observations of "mesoscopic" phenomena in real space complementing reciprocal-space studies using diffraction on the same instrument.The application of giga-Pascal scale pressures has been widely used as a tool to systematically tune the properties of materials in order to access such general questions as the driving mechanisms underlying phase transitions. While there is a large and growing set of experimental tools successfully applied to high-pressure environments, the compatibility between diamond anvil cells and optical probes offers further potential for examining lattice, magnetic, and electronic states, along with their excitations. Here, we describe the construction of a highly efficient optical Raman spectrometer that enables measurements of magnetic excitations in single crystals down to energies of 9 cm-1 (1.1 meV or 13 K) at cryogenic temperatures and under pressures of tens of GPa.The application of electric thrusters on spacecrafts has become more and more extensive. Accurate, direct measurement of thrust is not only one of the most critical elements of electric thruster characterization but also one of the most difficult measurements to make in the ground test and verification of electric propulsion. It is hard to measure the thrust in a finite simulation environment due to small thrust and interference factors in the measurement. A cantilever beam thrust stand has been designed and tested in our propulsion laboratory. The device is used to measure the thrust of a plasma thruster multiple times a day. CompK The thrust stand allows adjusting the instrument sensibility by changing the size of the cantilever beam. The range of thrust depends on the thrusters; e.g., for a 15 kg ion thruster, the thrust can vary from 10 mN up to 220 mN. Calibration of the system is carried out using calibrated mass. The balance results are compared to the thrust calculated using electrical parameters, showing an agreement within 3.16%.Versatile high-power pulsed electron-beam accelerators that meet the requirements of pulsed high-power specifications are needed for appropriate applications in medical industry, defense, and other industries. The pulsed electron beam accelerator comprising a Marx generator and Blumlein pulse forming line (PFL) is designed to accelerate the electron beams at the level of 1 MeV when electrostatically discharging. The performance specifications of Marx generators consisting of a 100 kV DC power supply, R-L-C circuit, and high voltage switch are at a maximum 800 kV. At this time, by using the capacitance mismatching principle between the Marx generator and the Blumlein PFL under the law of preserving the amount of charge, it is possible to generate a high voltage in the form of a square pulse up to about 1.1 MV, as much as 1.37 times the charged voltage of the Marx generator. As a result, energy transmission from the Marx generator with a high efficiency of about 85% to the Blumlein PFL is possible. The aim of this study is that the pulsed high-power electron-beam accelerator can be used to change the diode impedance, and the energy of the accelerated electron beam reaches a level of 1 MeV with the square pulse width of about 100 ns at the flat-top in the range of relativistic electron beam generation. Performance tests were securely carried out by installing a dummy load based on CuSO4 solution varying the diode impedance to deter damage to the circuit by preventing reflected waves from being generated in the load.Thermal Helium Beam (THB) diagnostic is widely used for measuring the electron density and temperature in the boundary region of fusion plasmas, edges, and scrape-off layers. In its standard configuration, it measures three HeI lines (667.8 nm, 706.5 nm, and 728.1 nm) and, by using a collisional-radiative model, evaluates ne and Te from the ratios of their intensities. At large neutral He density (n0 ≳ 1017 m-3), radiation re-absorption is not negligible and it has to be taken into account; it can be estimated by measuring the intensity of the fourth HeI line, λ = 501.6 nm. The original THB diagnostic of the RFX-mod experiment has been upgraded, setting up the fourth line intensity acquisition. A Czerny-Turner spectrograph separates the lines, and the old multichannel photomultiplier (PMT) detectors are replaced with the new Multi-Pixel Photon Counter (MPPC). Two 16-channel MPPC array modules allow the observation of 32 signals (4 lines × 8 spatial points). Since the MPPCs are not sensitive to the magnetic field, the whole system can be installed near the experimental device, allowing a large reduction in the optical fibers' length with a gain in the collected signal intensity.