Current advances on Talbot–Lau x-ray imaging diagnostics for high energy density experiments (invited)

Producción CientíficaTalbot–Lau x-ray interferometry is a refraction-based diagnostic that can map electron density gradients through phase-contrast methods. The Talbot–Lau x-ray deflectometry (TXD) diagnostics have been deployed in several high energy density experiments. To improve diagnostic performance, a monochromatic TXD was implemented on the Multi-Tera Watt (MTW) laser using 8 keV multilayer mirrors (Δθ/θ = 4.5%-5.6%). Copper foil and wire targets were irradiated at 1014–1015 W/cm2. Laser pulse length (∼10 to 80 ps) and backlighter target configurations were explored in the context of Moiré fringe contrast and spatial resolution. Foil and wire targets delivered increased contrast <30%. The best spatial resolution (<6 μm) was measured for foils irradiated 80° from the surface. Further TXD diagnostic capability enhancement was achieved through the development of advanced data postprocessing tools. The Talbot Interferometry Analysis (TIA) code enabled x-ray refraction measurements from the MTW monochromatic TXD. Additionally, phase, attenuation, and dark-field maps of an ablating x-pinch load were retrieved through TXD. The images show a dense wire core of ∼60 μm diameter surrounded by low-density material of ∼40 μm thickness with an outer diameter ratio of ∼2.3. Attenuation at 8 keV was measured at ∼20% for the dense core and ∼10% for the low-density material. Instrumental and experimental limitations for monochromatic TXD diagnostics are presented. Enhanced postprocessing capabilities enabled by TIA are demonstrated in the context of high-intensity laser and pulsed power experimental data analysis. Significant advances in TXD diagnostic capabilities are presented. These results inform future diagnostic technique upgrades that will improve the accuracy of plasma characterization through TXD

Resource Queuing System with Preemptive Priority for Performance Analysis of 5G NR Systems

One of the ways to enable smooth coexistence of ultra reliable low latency communication (URRLC) and enhances mobile broadband (eMBB) services at the air interface of perspective 5G New Radio (NR) technology is to utilize preemptive priority service. In this paper, we provide approximate analysis of the queuing system with random resource requirements, two types of customers and preemptive priority service procedure. The distinctive feature of the systems – the random resource requirements – allows to capture the essentials of 5G NR radio interface but inherently increases the complexity of analysis. We present the main performance metrics of interest including session drop probability and system resource utilization as well as assess their accuracy by comparing with computer simulations. The developed model is not inherently limited to URLLC and eMBB coexistence and can be utilized in performance evaluation of 5G NR systems with priority-based service discipline at the air interface, e.g., in context of network slicing. Among other conclusions we explicitly show that both session drop and interruption probabilities of low priority traffic heavily depend not only on the intensity of high priority traffic but on stochastic characteristics of the resource request distribution.acceptedVersionPeer reviewe

Experience of civil government of Russian federation subjects with institutions of civil society in the sphere of corruption counteraction

© BEIESP. The anti-corruption principles established by the legislation of Russia are represented by state cooperation with civil society institutions, international organizations and individuals. This work gives the author's interpretation of “civil society institution” concept. In order to disclose and implement the provisions of the law, they formulate the criteria to classify various associations of citizens as civil society institutions. The study describes the possible trends of joint activities of regional government bodies of the Russian Federation and civil society institutions on anti-corruption issues. According to the Decree of the President of Russia, specialized anti-corruption bodies have been created in each constituent entity of the Russian Federation-the commissions for coordination of efforts to combat corruption, which are endowed with serious powers described in the work. The composition of these commissions may include the representatives of public chambers, scientific and educational organizations, as well as public organizations whose statutory tasks is to participate in the fight against corruption. Such a solution makes it possible to increase the transparency of government body activities and improve public control over it. Based on the results of the work, they formulate main conclusions, proposals and recommendations for state bodies and civil society institutions. The thesis is proved that the principle of cooperation between the state and civil society institutions in the activities of the commissions for anti-corruption work coordination in a number of Russian regions is not implemented or is implemented formally. The statement is substantiated that the inclusion of civil society institution representatives in the commissions is often takes place on the basis of loyalty (“convenient sampling”)

Optical Parametric Chirped-Pulse-Amplification Contrast Enhancement By Regenerative Pump Spectral Filtering

A method for fundamentally improving the temporal contrast of optical parametric chirped-pulse-amplification (OPCPA) systems by using a volume Bragg grating to regeneratively filter the OPCPA pump spectrum is demonstrated for the first time. © 2008 Optical Society of America

Optical Parametric Chirped-Pulse-Amplification Contrast Enhancement By Regenerative Pump Spectral Filtering

A method for fundamentally improving the temporal contrast of optical parametric chirped-pulse-amplification (OPCPA) systems by using a volume Bragg grating to regeneratively filter the OPCPA pump spectrum is demonstrated for the first time. © 2008 Optical Society of America

Optical Parametric Chirped-Pulse-Amplification Contrast Enhancement By Regenerative Pump Spectral Filtering

A method for fundamentally improving the temporal contrast of optical parametric chirped-pulse-amplification (OPCPA) systems by using a volume Bragg grating to regeneratively filter the OPCPA pump spectrum is demonstrated for the first time. © 2008 Optical Society of America

Optical Parametric Chirped-Pulse-Amplification Contrast Enhancement By Regenerative Pump Spectral Filtering

We demonstrate an approach to fundamentally improve the contrast of optical parametric chirped-pulse amplifiers (OPCPA). The instantaneous parametric gain couples the temporal variations of the pump-pulse intensity to spectral variations of the intensity of the stretched signal pulse being amplified, which significantly degrade the temporal contrast of the amplified pulse after recompression. Simple and efficient pumpintensity noise reduction in an OPCPA system using a volume Bragg grating in a regenerative amplifier demonstrates contrast improvements up to 30 dB. ©2007 Optical Society of America

Optical Parametric Chirped-Pulse-Amplification Contrast Enhancement By Regenerative Pump Spectral Filtering

A method for fundamentally improving the temporal contrast of optical parametric chirped-pulse-amplification (OPCPA) systems by using a volume Bragg grating to regeneratively filter the OPCPA pump spectrum is demonstrated for the first time. © 2008 Optical Society of America

Modeling radio resource allocation scheme with fixed transmission zones for multiservice M2M communications in wireless IoT infrastructure

This paper focuses on the paradigm of Internet of Things (IoT), which gives rise to communications between a large number of different technological devices, e.g. sensors and controllers. The increasing demand for various services without human intervention motivates service providers to apply machine-tomachine (M2M) communications. In this paper, a LTE cellular system where M2M devices and human-to-human (H2H) users transmit their data into the wireless network is considered. In particular, a radio resource allocation scheme for M2M communications in IoT infrastructure is proposed and analyzed. The scheme is based on fixed transmission zones at which M2M traffic is served according to the Processor Sharing (PS) discipline. Also, the Markovian model to evaluate main performance measures, i.e. data transmission delays and blocking probabilities, is proposed. To carry out the numerical analysis the recursive algorithm for computing the stationary probability distribution is developed. © Springer International Publishing Switzerland 2015