Search results for "TIME"
showing 10 items of 12336 documents
Analysis of thin high-k and silicide films by means of heavy ion time-of-flight forward-scattering spectrometry
2006
The use of forward scattered heavy incident ions in combination with a time-of-flight-energy telescope provides a powerful tool for the analysis of very thin (5–30 nm) films. This is because of greater stopping powers and better detector energy resolution for heavier ions than in conventional He-RBS. Because of the forward scattering angle, the sensitivity is greatly enhanced, thus reducing the ion beam induced desorption during the analysis of very thin films. The drawback of forward scattering angle is the limited mass separation for target elements. We demonstrate the performance of the technique with the analysis of 25 nm thick NiSi films and atomic layer deposited 6 nm thick HfxSiyOz f…
Mechanisms of Electron-Induced Single-Event Upsets in Medical and Experimental Linacs
2018
In this paper, we perform an in-depth analysis of the single-event effects observed during testing at medical electron linacs and an experimental high-energy electron linac. For electron irradiations, the medical linacs are most commonly used due to their availability and flexibility. Whereas previous efforts were made to characterize the cross sections at higher energies, where the nuclear interaction cross section is higher, the focus of this paper is on the complete overview of relevant electron energies. Irradiations at an electron linac were made with two different devices, with a large difference in feature size. The irradiations at an experimental linac were performed with varying en…
Dynamics of quantum discord of two coupled spin-1/2’s subjected to time-dependent magnetic fields
2019
Abstract We describe the dynamics of quantum discord of two interacting spin-1/2’s subjected to controllable time-dependent magnetic fields. The exact time evolution of discord is given for various input mixed states consisting of classical mixtures of two Bell states. The quantum discord manifests a complex oscillatory behaviour in time and is compared with that of quantum entanglement, measured by concurrence. The interplay of the action of the time-dependent magnetic fields and the spin-coupling mechanism in the occurrence and evolution of quantum correlations is examined in detail.
The Role of Right Interpretation of Space Charge Distribution for Optimized Design of HVDC Cables
2019
In the field of high-voltage transmission systems, different degradation phenomena affect the reliability of the employed components. In particular, under dc stress, the space charge accumulation phenomenon is believed to be the most responsible of the dielectrics lifetime reduction. To measure the accumulated space charges in flat specimens, the pulsed electro-acoustic (PEA) method is one of the most used techniques. The working principle of the PEA cell is based on the acoustic waves propagation and detection. As is well known, the acoustic waves propagating in different means are partially transmitted and partially reflected. Therefore, the piezoelectric sensor of the PEA cell is subject…
Multimode time-dependent gyrotron equations for different time scales
2017
The work of H.K. was supported by the European Regional Development Funding of the Project No. 1.1.1.1/ 16/A/004.
Measurements of the energy distribution of electrons lost from the minimum B-field -- the effect of instabilities and two-frequency heating
2020
Further progress in the development of ECR ion sources (ECRIS) requires deeper understanding of the underlying physics. One of the topics that remains obscure, though being crucial for the performance of the ECRIS, is the electron energy distribution (EED). A well-developed technique of measuring the EED of electrons escaping axially from the magnetically confined plasma of an ECRIS was used for the study of EED in unstable mode of plasma confinement, i.e. in the presence of kinetic instabilities. The experimental data were recorded for pulsed and CW discharges with a room-temperature 14 GHz ECRIS at the JYFL accelerator laboratory. The measurements were focused on observing differences bet…
Simulations on time-of-flight ERDA spectrometer performance
2016
The performance of a time-of-flight spectrometer consisting of two timing detectors and an ionization chamber energy detector has been studied using Monte Carlo simulations for the recoil creation and ion transport in the sample and detectors. The ionization chamber pulses have been calculated using Shockley-Ramo theorem and the pulse processing of a digitizing data acquisition setup has been modeled. Complete time-of-flight–energy histograms were simulated under realistic experimental conditions. The simulations were used to study instrumentation related effects in coincidence timing and position sensitivity, such as background in time-of-flight–energy histograms. Corresponding measurement…
THE GYROTRON STARTUP SCENARIO IN THE SINGLE MODE TIME DEPENDENT APPROACH
2019
The paper explains how to solve the Gyrotron equation system in the Single Mode Time Dependent Approach. In particular, we point out problems encountered when solving these well-known equations. The starting current estimation approach a using time model is suggested. The solution has been implemented in the Matlab code, which is attached to the article.
Sub-nanosecond excitonic luminescence in ZnO:In nanocrystals
2019
The financial support of research European Union ERA.NET RUS_ST20170-51 . This work was partly supported by Russian Foundation for Basic Research, Russia , project No. 18-52-76002 . The sample preparation was carried out as part of SFERA II project -Transnational Access activities ( European Union 7th Framework Programme Grant Agreement N3126430 ).
Lead evaporation instabilities and failure mechanisms of the micro oven at the GTS-LHC ECR ion source at CERN
2020
The GTS-LHC ECR ion source (named after the Grenoble Test Source and the Large Hadron Collider) at CERN provides heavy ion beams for the chain of accelerators from Linac3 up to the LHC for high energy collision experiments and to the Super Proton Synchrotron for fixed target experiments. During the standard operation, the oven technique is used to evaporate lead into the source plasma to produce multiple charged lead ion beams. Intensity and stability are key parameters for the beam, and the operational experience is that some of the source instabilities can be linked to the oven performance. Over long operation periods of several weeks, the evaporation is not stable which makes the tuning …