495 research outputs found
Amplification of the runaway electrons flow in the Uragan-3М torsatron
In this work the results of amplification of the runaway electrons flow and interaction runaway electrons with
RF-heating wave on the Uragan-3M torsatron are presented. Results described in the article confirm using runaway
electrons for gas breakdown. The results allow making some recommendations for using of self-created flows of
accelerated particles for stimulation of gas breakdown.Наведено результати експериментальних досліджень щодо посилення потоку утікаючих електронів, а
також взаємодії потоку утікаючих електронів з електромагнітним полем хвилі, що збуджується
високочастотним імпульсом у торсатроні Ураган-3М. Отримані результати підтверджують можливість
пробою газу утікаючими електронами. Це дозволяє представити ряд рекомендацій по використанню потоків
прискорених частинок для стимуляції високочастотного пробою.Приведены результаты экспериментальных исследований по усилению потока убегающих электронов, а
также взаимодействию потока убегающих электронов с электромагнитным полем волны, возбуждаемой
высокочастотным импульсом в торсатроне Ураган-3М. Полученные результаты подтверждают возможность
пробоя газа убегающими электронами. Это позволяет представить ряд рекомендаций по использованию
самопроизвольно формирующихся потоков ускоренных частиц для стимуляции высокочастотного пробоя
Influence of working gas pulse injection and fluctuations of the magnetic field on the runaway electrons dynamics in Uragan-3M
Generation of runaway electrons in fusion experiments can drive to serious damage of plasma devices components. Injection of gas with a large mass number decreases the generation processes. Also, magnetic perturbations decrease generation of runaway electrons by increasing the loss rate. We investigated the influence of working gas pulse injection and natural fluctuations of the magnetic confining field on runaway electrons dynamics. The interaction of runaway electrons with an Alfven wave in plasma is noted.Генерація утікаючих електронів в експериментах синтезу може привести до серйозного пошкодження компонентів плазмових пристроїв. Інжекція важкого газу зменшує процеси генерації. Магнітні збурення також пригнічують генерацію утікаючих електронів за рахунок збільшення швидкості втрат. Досліджено вплив імпульсного напуску газу і природних флуктуацій утримуючого магнітного поля на динаміку утікаючих електронів. Відзначено взаємодія утікаючих електронів з альфвеновською хвилею в плазмі.Генерация убегающих электронов в экспериментах синтеза может привести к серьезному повреждению компонентов плазменных устройств. Инжекция тяжелого газа уменьшает процессы генерации. Магнитные возмущения также подавляют генерацию убегающих электронов за счет увеличения скорости потерь. Исследовалось влияние импульсного напускающего газа и естественных флуктуаций удерживающего магнитного поля на динамику убегающих электронов. Отмечено взаимодействие убегающих электронов с альфвеновской волной в плазме
The dynamics of inductively accelerated electrons in the U-3M torsatron
Additional experimental data for the runaway electrons flow in the Uragan-3M torsatron were obtained. In particular the synchrotron and ultrahigh frequency radiation were measured. Also the flow current dynamics was studied by Rogovski coil and toroidal loop. Finally the experiments with the runaway flow stimulation were carried out.Получены дополнительные экспериментальные данные о динамике потока убегающих электронов в торсатроне Ураган-3М. Произведены измерения синхротронного и СВЧ-излучения потока, получены результаты измерений тока потока и напряжения на обходе стелларатора. Кроме того, проведены эксперименты по стимуляции потока убегающих электронов.Отримано додаткові експериментальні дані щодо динаміки потоку утікаючих електронів у торсатроні Ураган-3М. Проведено вимірювання синхротронного та НВЧ-випромінювання потоку, отримано дані вимірювань струму потоку та напруги на обході стеларатора. Проведено експерименти зі стимуляції потоку утікаючих електронів
Albumin Is a Component of the Esterase Status of Human Blood Plasma
open access articleThe esterase status of blood plasma can claim to be one of the universal markers of various
diseases; therefore, it deserves attention when searching for markers of the severity of COVID-19
and other infectious and non-infectious pathologies. When analyzing the esterase status of blood
plasma, the esterase activity of serum albumin, which is the major protein in the blood of mammals,
should not be ignored. The purpose of this study is to expand understanding of the esterase status
of blood plasma and to evaluate the relationship of the esterase status, which includes information
on the amount and enzymatic activity of human serum albumin (HSA), with other biochemical
parameters of human blood, using the example of surviving and deceased patients with confirmed
COVID-19. In experiments in vitro and in silico, the activity of human plasma and pure HSA towards
various substrates was studied, and the effect of various inhibitors on this activity was tested. Then,
a comparative analysis of the esterase status and a number of basic biochemical parameters of the
blood plasma of healthy subjects and patients with confirmed COVID-19 was performed. Statistically
significant differences have been found in esterase status and biochemical indices (including albumin
levels) between healthy subjects and patients with COVID-19, as well as between surviving and
deceased patients. Additional evidence has been obtained for the importance of albumin as a
diagnostic marker. Of particular interest is a new index, [Urea] x [MDA] x 1000/(BChEb x [ALB]),
which in the group of deceased patients was 10 times higher than in the group of survivors and
26 times higher than the value in the group of apparently healthy elderly subjects
de Sitter Vacua in String Theory
We outline the construction of metastable de Sitter vacua of type IIB string
theory. Our starting point is highly warped IIB compactifications with
nontrivial NS and RR three-form fluxes. By incorporating known corrections to
the superpotential from Euclidean D-brane instantons or gaugino condensation,
one can make models with all moduli fixed, yielding a supersymmetric AdS
vacuum. Inclusion of a small number of anti-D3 branes in the resulting warped
geometry allows one to uplift the AdS minimum and make it a metastable de
Sitter ground state. The lifetime of our metastable de Sitter vacua is much
greater than the cosmological timescale of 10^10 years. We also prove, under
certain conditions, that the lifetime of dS space in string theory will always
be shorter than the recurrence time.Comment: 12 pages, 2 figs, added comments on the thin wall approximation to
tunnelin
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
Isolated photon production is measured in proton-proton and lead-lead
collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the
pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80
GeV with the CMS detector at the LHC. The measured ET spectra are found to be
in good agreement with next-to-leading-order perturbative QCD predictions. The
ratio of PbPb to pp isolated photon ET-differential yields, scaled by the
number of incoherent nucleon-nucleon collisions, is consistent with unity for
all PbPb reaction centralities.Comment: Submitted to Physics Letters
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