[en] A derivation is presented for the compact integral representation that describes the first-order perturbed wavefunction of an electron in a fixed Coulomb field and in a harmonic uniform electric field, for the case of an initial stationary Stark state with the symmetry axis along the electric field

[en] This work is devoted to the development and experimentation of a radiometric method for the measurement of the thickness of materials having a band-shape, in order to improve nuclear installations designed to control the rolling processes. The present installations used for this purpose have the transmission and backscattering of gamma radiations as operating principles, with optimum performances within certain thickness limits, depending on the material features and radiation energy. The method combines the two measuring principles of transmission and backscattering, leading to performances superior to the case when only one principle is used. The transducer achieved on the basis of this method is a mono-block, including the radiation source and the detector and it uses a passive screen for backscattering, situated on the other side of the sample to be measured. It presents optimized characteristics concerning the materials type, thickness and distance from the band. The most important metrological performances, checked on the experimental model, using a source of Am-241 and an ionization chamber detector, satisfy the main requirements of rolling processes for investigated materials (bands of Al, Cu, Fe and glass), i.e. thickness ranges: 0.5-10 mm (Al and glass), 0.05-1 mm (Cu and Fe); basic error: 1%; response time: 1 sec. (authors)

[en] A new thickness gauging method was worked out to eliminate certain drawbacks of the radiometric methods (e.g., measuring error dependency on the thickness and composition of materials, use of high activity sources). The method will prove itself, in many circumstances, more effective than gamma-ray methods and occurs as a good substitute for them. In this work the project of the experimental model for a transducer and computing system using electromagnetic radiation reflection for high-accuracy measurements of thickness was performed. As transducers, two laser displacement sensors, type Z4M-W40, equipped with a selecting controller are used. Acquisition and computing of the transducer signals are made by an electronic unit that uses a high performance controller 80C552 and was provided with low-power transceivers for RS-485 communication with a PC. The main thickness measurement parameters are: - Measurement error, 1%; - Linearity, 1% (for full scale); - Response time, 0.15 ms, 2 ms, 60 ms. (authors)

[en] The goal of this research was to modernize the radiometric equipment used for the control and automation of technological processes. A microcontroller-equipped electronic block was designed and realized, capable of performing all the tasks of a radiometric system, regardless of the application range (i.e. measurement of density, thickness, level, composition, etc.) or the detector type employed. In this work, the experimental model for the multipurpose radiometric equipment was devised. The electronic unit was designed using a high performance controller 80C552 and was provided with low-power transceivers for RS-232 and RS-485 communication with a PC. The results of the measured parameters are displayed using a graphic liquid crystal display, LCD G 242 C, that allows both graphics and character display. (authors)