150 research outputs found
О ТЕХНОЛОГИЯХ РЕНТГЕНОВСКИХ СИСТЕМ ДЛЯ КОНТРОЛЯ ЭЛЕКТРОННЫХ КОМПОНЕНТОВ
Introduction. X-ray methods are currently widely used in manufacturing of various products and components of the electronics industry, including micro- and nano-electronics. One of the most informative and illustrative methods is projection X-ray microscopy. Specialized X-ray systems for process control are developed and used in industry. The key element in the design of an X-ray inspection system is an X-ray tube. In the overwhelming majority of cases, X-ray inspection systems are based on collapsible microfocus x-ray tubes with constant pumping. This greatly complicates the design of the installation, increases its dimensions, weight and cost. Objective. Analysis of possible technical and technological solutions that improve the availability of the X-ray system for monitoring of electronic components while maintaining the information content of the control. Materials and methods. The article presents the results of analytical studies of assessment of the degree of influence of the main parameters of the X-ray tube – the size of the focal spot and the focal length – on the resolution of the resulting X-ray images. The advantages and disadvantages of two variants of the construction of the X-ray inspection systems are described: based on collapsible and based on sealed X-ray tubes. The dependence of the size of the focal spot on the voltage on the X-ray tube and on the power supplied by the electron beam to the target of the X-ray tube is analyzed. It is shown that sealed (from a vacuum pumping system) micro focus X-ray tubes can be successfully used as a radiation source in installations for X-ray inspection. It is concluded that in most cases, sealed tubes are more practical. Results. In solving of most problems of non-destructive testing of electronic components in the composition of the Xray system, X-ray sources based on sealed X-ray tubes can be successfully used. Due to this, dimensions, weight, and the cost of an X-ray system for monitoring of electronic components are substantially reduced. Conclusion. Sealed X-ray tubes are an effective alternative in the development of an X-ray system for monitoring of electronic components, which enables to fundamentally increase the availability of such a system.Введение. Рентгенографические методы широко распространены в настоящее время при производстве различных изделий и компонентов электронной промышленности, в том числе микро- и наноэлектроники. Одним из наиболее информативных и наглядных методов является проекционная рентгеновская микроскопия. Разработаны и используются в промышленности специализированные рентгеновские системы для технологического контроля. Ключевым элементом конструкции системы рентгеновского контроля (СРК) является рентгеновская трубка. В подавляющем большинстве случаев СРК построены на основе разборных микрофокусных рентгеновских трубок с постоянной откачкой. Это существенно усложняет конструкцию установки, увеличивает ее габариты, массу и стоимость. Цель работы. Анализ возможных технических и технологических решений, позволяющих повысить доступность рентгеновской системы для контроля электронных компонентов при сохранении информативности контроля. Материалы и методы. Представлены результаты аналитических исследований оценки степени влияния основных параметров рентгеновской трубки – размера фокусного пятна и фокусного расстояния – на разрешающую способность получаемых рентгеновских изображений. Описаны достоинства и недостатки двух вариантов конструкции СРК: на основе разборных и отпаянных от вакуумной откачной системы рентгеновских трубок. Проанализированы зависимости размеров фокусного пятна от напряжения на рентгеновской трубке и от мощности, подводимой электронным пучком к мишени рентгеновской трубки. Показано, что отпаянные микрофокусные рентгеновские трубки могут быть с успехом использованы в качестве источника излучения в установках для рентгенографического контроля. Сделан вывод о том, что в большинстве случаев отпаянные трубки более практичны. Результаты. При решении большинства задач по неразрушающему контролю электронных компонентов в составе рентгеновской системы с успехом могут быть использованы источники рентгеновского излучения на основе отпаянных рентгеновских трубок. Благодаря этому существенно уменьшаются габариты, масса, а также стоимость рентгеновской системы контроля электронных компонентов. Заключение. Отпаянные рентгеновские трубки могут служить эффективной альтернативой при разработке рентгеновской системы контроля электронных компонентов, позволяющей принципиально повысить доступность такой системы
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states
A first study of CP violation in the decay modes and , where labels a or meson and labels a or meson, is performed. The analysis uses the LHCb data set collected in collisions, corresponding to an integrated luminosity of 3 fb. The analysis is sensitive to the CP-violating CKM phase through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of using other decay modes
Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state
A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation
Observation of the B0 → ρ0ρ0 decay from an amplitude analysis of B0 → (π+π−)(π+π−) decays
Proton–proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb−1 , are analysed to search for the charmless B0→ρ0ρ0 decay. More than 600 B0→(π+π−)(π+π−) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0→ρ0ρ0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0→ρ0ρ0 decays yielding a longitudinally polarised final state is measured to be fL=0.745−0.058+0.048(stat)±0.034(syst) . The B0→ρ0ρ0 branching fraction, using the B0→ϕK⁎(892)0 decay as reference, is also reported as B(B0→ρ0ρ0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))×10−6
Measurement of the (eta c)(1S) production cross-section in proton-proton collisions via the decay (eta c)(1S) -> p(p)over-bar
The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c.The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range . The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy using data corresponding to an integrated luminosity of 0.7 fb , and at using 2.0 fb . The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be .The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c
Search for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-)
A search for the lepton flavour violating decay is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, .A search for the lepton flavour violating decay τ → μ μ μ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, .A search for the lepton flavour violating decay is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of of proton-proton collisions at a centre-of-mass energy of and at . No evidence is found for a signal, and a limit is set at confidence level on the branching fraction,
Angular analysis of the B-0 -> K*(0) e(+) e(-) decay in the low-q(2) region
An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions.An angular analysis of the B → K^{*}^{0} e e decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q) interval between 0.002 and 1.120 GeV /c. The angular observables F and A which are related to the K^{*}^{0} polarisation and to the lepton forward-backward asymmetry, are measured to be F = 0.16 ± 0.06 ± 0.03 and A = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables A and A which are sensitive to the photon polarisation in this q range, are found to be A = − 0.23 ± 0.23 ± 0.05 and A = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions
Measurement of the CP-violating phase in decays and limits on penguin effects
Time-dependent CP violation is measured in the channel for each resonant final state using data collected with an integrated luminosity of 3.0 fb in collisions using the LHCb detector. The final state with the largest rate, , is used to measure the CP-violating angle to be . This result can be used to limit the size of penguin amplitude contributions to CP violation measurements in, for example, decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase is limited to be within the interval [, +] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed.Time-dependent CP violation is measured in the B(−−−)0→J/ψπ+π− channel for each π+π− resonant final state using data collected with an integrated luminosity of 3.0 fb −1 in pp collisions using the LHCb detector. The final state with the largest rate, J/ψρ0(770) , is used to measure the CP -violating angle 2βeff to be (41.7±9.6−6.3+2.8)° . This result can be used to limit the size of penguin amplitude contributions to CP violation measurements in, for example, B(−−−)s0→J/ψϕ decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP -violating phase ϕs is limited to be within the interval [ −1.05°,+1.18° ] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed.Time-dependent CP violation is measured in the channel for each resonant final state using data collected with an integrated luminosity of 3.0 fb in collisions using the LHCb detector. The final state with the largest rate, , is used to measure the CP-violating angle to be . This result can be used to limit the size of penguin amplitude contributions to CP violation measurements in, for example, decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase is limited to be within the interval [, +] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed.Time-dependent CP violation is measured in the B0→J/ψπ+π− channel for each π+π− resonant final state using data collected with an integrated luminosity of 3.0 fb −1 in pp collisions using the LHCb detector. The final state with the largest rate, J/ψρ0(770) , is used to measure the CP -violating angle 2βeff to be (41.7±9.6−6.3+2.8)° . This result can be used to limit the size of penguin amplitude contributions to CP violation measurements in, for example, Bs0→J/ψϕ decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP -violating phase ϕs is limited to be within the interval [ −1.05°,+1.18° ] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed
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