ВЫЧИСЛЕНИЕ ЛИНЕЙНЫХ ПО МОЩНОСТИ ПОПРАВОК К СПЕКТРАЛЬНЫМ ФУНКЦИЯМ СВЕРХПРОВОДНИКА И ИХ ВКЛАДА В ОТКЛИК СВЕРХПРОВОДНИКОВЫХ ДЕТЕКТОРОВ ИЗЛУЧЕНИЯ
We investigate contribution to the detectivity of superconducting radiation sensors, originated from a change in spectral functions of the absorber under influence of the absorbed power. For the absorber manufactured of dirty superconducting film we demonstrate that at low temperature the only cause of the change in spectral functions is the change of the order parameter. A method for calculation corrections to the spectral functions for the case of dirty film is suggested.
This paper presents an ultrafast niobium nitride (NbN) superconducting single-photon detector (SSPD) with an active area of 3 × 3 μm^2 that offers better timing performance metrics than the previous SSPD with an active area of 7 × 7 μm^2. The improved SSPD demonstrates a record timing jitter (<25 ps), an ultrashort recovery time (<2 ns), an extremely low dark count rate, and a high detection efficiency in a wide spectral range from visible part to near infrared. The record parameters were obtained due to the development of a new technique providing effective optical coupling between a detector with a reduced active area and a standard singlemode telecommunication fiber. The advantages of the new approach are experimentally confirmed by taking electro-optical measurements.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.