Effect of the superconducting wiggler on the DELSY beam dynamics

The project DELSY is being under development at JINR, Dubna, Russia. This synchrotron radiation source is dedicated to the investigation on condensed matter physics, atomic physics, biology, medicine, chemistry, micromechanics, lithography and others. The storage ring DELSY is an electron storage ring with the beam energy 1.2 GeV and 4 straight sections to accommodate accelerator equipment and insertion devices. One of the straight sections is intended for a 10 T superconducting wiggler (wavelength shifter) and one for the undulator with 150 periods and a magnetic field of 0.75 T. The wiggler will influence many aspects of beam dynamics: linear motion, dynamic aperture, emittance, damping times etc. The problem is rather serious for the DELSY machine because the energy of the electron beam is small while the wiggler's magnetic field is strong. In this paper we consider two models of the wiggler's magnetic field with and without the focusing caused by the sextupolar field of the wiggler as we need to develop the requirements to the wiggler design. We study the influence of the 10 T wiggler on the beam dynamics in the DELSY storage ring and propose a possible scheme to cure it. The combined work of the insertion device is presented too.Comment: 17 pages, submitted to journal NIM

The Symmetries of Nature

The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of symmetries during the last century has produced many breakthroughs in our understanding of the substructure of matter. In this talk, a number of these advances are discussed, and the important role that George Sudarshan played in their development is emphasize

Constraining the Nature of X-ray Cavities in Clusters and Galaxies

We present results from an extensive survey of 64 cavities in the X-ray halos of clusters, groups and normal elliptical galaxies. We show that the evolution of the size of the cavities as they rise in the X-ray atmosphere is inconsistent with the standard model of adiabatic expansion of purely hydrodynamic models. We also note that the majority of the observed bubbles should have already been shredded apart by Rayleigh-Taylor and Richtmyer-Meshkov instabilities if they were of purely hydrodynamic nature. Instead we find that the data agrees much better with a model where the cavities are magnetically dominated and inflated by a current-dominated magneto-hydrodynamic jet model, recently developed by Li et al. (2006) and Nakamura et al. (2006). We conduct complex Monte-Carlo simulations of the cavity detection process including incompleteness effects to reproduce the cavity sample's characteristics. We find that the current-dominated model agrees within 1sigma, whereas the other models can be excluded at >5sigma confidence. To bring hydrodynamic models into better agreement, cavities would have to be continuously inflated. However, these assessments are dependent on our correct understanding of the detectability of cavities in X-ray atmospheres, and will await confirmation when automated cavity detection tools become available in the future. Our results have considerable impact on the energy budget associated with active galactic nucleus feedback.Comment: 21 pages, 12 figures, emulateapj, accepted for publication in ApJ, responded to referee's comments and added a new model, conclusions unchange

Scaling supernova hydrodynamics to the laboratory

Supernova (SN) 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. To test the modeling of these instabilities, we are developing laboratory experiments of hydrodynamic mixing under conditions relevant to supernovae. Initial results were reported in J. Kane et al. [Astrophys. J. 478, L75 (1997) and B. A. Remington et al., Phys. Plasmas 4, 1994 (1997)]. The Nova laser is used to generate a 10–15 Mbar shock at the interface of a two-layer planar target, which triggers perturbation growth due to the Richtmyer–Meshkov instability, and to the Rayleigh–Taylor instability as the interface decelerates. This resembles the hydrodynamics of the He-H interface of a Type II supernova at intermediate times, up to a few ×103 s.×103s. The scaling of hydrodynamics on microscopic laser scales to the SN-size scales is presented. The experiment is modeled using the hydrodynamics codes HYADES [J. T. Larson and S. M. Lane, J. Quant. Spect. Rad. Trans. 51, 179 (1994)] and CALE [R. T. Barton, Numerical Astrophysics (Jones and Bartlett, Boston, 1985), pp. 482–497], and the supernova code PROMETHEUS [P. R. Woodward and P. Collela, J. Comp. Phys. 54, 115 (1984)]. Results of the experiments and simulations are presented. Analysis of the spike-and-bubble velocities using potential flow theory and Ott thin-shell theory is presented, as well as a study of 2D versus 3D differences in perturbation growth at the He-H interface of SN 1987A.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69672/2/PHPAEN-6-5-2065-1.pd

Nonlocal symmetries of integrable two-field divergent evolutionary systems

Nonlocal symmetries for exactly integrable two-field evolutionary systems of the third order have been computed. Differentiation of the nonlocal symmetries with respect to spatial variable gives a few nonevolutionary systems for each evolutionary system. Zero curvature representations for some new nonevolution systems are presented

Persistent holes in a fluid

We observe stable holes in a vertically oscillated 0.5 cm deep aqueous suspension of cornstarch for accelerations a above 10g. Holes appear only if a finite perturbation is applied to the layer. Holes are circular and approximately 0.5 cm wide, and can persist for more than 10^5 cycles. Above a = 17g the rim of the hole becomes unstable producing finger-like protrusions or hole division. At higher acceleration, the hole delocalizes, growing to cover the entire surface with erratic undulations. We find similar behavior in an aqueous suspension of glass microspheres.Comment: 4 pages, 6 figure

Scaling the Incompressible Richtmyer-Meshkov Instability

We derive a scaling relation for Richtmyer-Meshkov instability of incompressible fluids. The relation is tested using both numerical simulations and experimental data. We obtain collapse of growth rates for a wide range of initial conditions by using vorticity and velocity scales associated with the interfacial perturbations and the acceleration impulse. A curve fit to the collapsed growth rates yields a fairly universal model for the mixing layer thickness versus time

МЕТОДОЛОГІЧНІ ПІДХОДИ ДО ЕКСПЕРТНОГО ДОСЛІДЖЕННЯ З РОЗРАХУНКУ ШКОДИ, ЗУМОВЛЕНОЇ ЗАСМІЧЕННЯМ ЗЕМЕЛЬНИХ РЕСУРСІВ

Definition of damage caused through land clogging constitutes a significant share in the total amount of environmental offenses that are considered by courts in Ukraine and their investigations are the most difficult in this category. Majority of losses from land clogging are determined as significant amounts considered according to the Criminal Code of Ukraine as grave or especially grave consequences of environmental legislation violations. From the point of view of legal mechanism, the definition of damage caused through clogging of land resources is based on the branch Methodology for determining the amount of damage caused through pollution and clogging land resources by means of violation of environmental legislation, approved by order of the Ministry of Ecology and Natural Resources No 171 from 27.10.1997 (as amended). Failure to comply with legislation on the protection and rational use of land resources resulting in land clogging is determined according to this Methodology. This Methodology is applied in case of violations revealed during the state supervision (control) of economic activities to comply with environmental (land) legislation by economic entities (according to the Law of Ukraine "On the Main Principles of State Supervision (Control) in the Area of Commercial Activity"). Employees of the State Ecological Inspectorate of Ukraine use the Methodology in particular to calculate the amount of compensation for damage caused to the state as a result of land clogging. Analysis of an expert practice of using the Methodology demonstrates its low arbitrage effect, since a significant part of the claims brought forward to debtors for compensation of damages or charges are not satisfied by the judicial authorities. Comprehensive methodology developed at KhRIFE makes possible to obtain correct from a legal point of view, complete, objective, scientifically, technically and economically justified answers to questions related to the calculation of the damage caused through land clogging. Разработанная в Харьковском НИИСЭ Комплексная методика дает возможность получить корректные с правовой точки зрения, полные, объективные, научно, технически и экономически обоснованные ответы на вопросы, которые касаются расчетов размера вреда, обусловленного засорением земельных ресурсов.Определение ущерба, обусловленного засорением земельных ресурсов, составляет значительную долю в общем объеме экологических правонарушений, которые рассматриваются судами в Украине, а их расследования являются наиболее сложными в этой категории. Большинство убытков от засорения земельных ресурсов определяются значительными суммами, которые по Уголовному кодексу Украины рассматриваются как тяжкие или особо тяжкие последствия нарушений природоохранного законодательства. С точки зрения правового механизма определения ущерба, обусловленного засорением земельных ресурсов, базируется на отраслевой Методике определения размеров ущерба, обусловленного загрязнением и засорением земельных ресурсов через нарушение природоохранного законодательства, утвержденная приказом Министерства охраны окружающей природной среды № 171 от 27.10.1997 (с изменениями). Невыполнение законодательства об охране и рациональном использовании земельных ресурсов, повлекшие засорения земель, определяется в соответствии с этой Методикой. Методика применяется в случае нарушений, выявленных при государственном надзоре (контроле) хозяйственной деятельности по соблюдению субъектами хозяйствования природоохранного (земельного) законодательства (по закону Украины «Об основных принципах государственного надзора (контроля) в сфере хозяйственной деятельности»). Работники Государственной экологической инспекции Украины используют Методику, в частности, для расчетов размеров возмещения вреда, причиненного государству в результате засорения земель. Анализ экспертной практики использования Методики свидетельствует о ее низком арбитражном эффекте, поскольку значительная часть выдвинутых должникам исков о возмещении убытков или обвинений не удовлетворяются судебными органами. Разработанная в Харьковском НИИСЭ Комплексная методика дает возможность получить корректные с правовой точки зрения, полные, объективные, научно, технически и экономически обоснованные ответы на вопросы, касающиеся расчетов ущерба, обусловленного засорением земельных ресурсов.Розглянуто методологічні підходи до експертного дослідження розрахунку шкоди, зумовленої засміченням земельних ресурсів

Production of para-- and orthopositronium at relativistic heavy ion colliders

We consider the ortho-- and parapositronium production in the process $AA \to AA+$ Ps where A is a nucleus with the charge number Z. The inclusive cross section and the energy distribution of the relativistic Ps are calculated which are of primary interest from the experimental point of view. The accuracy of the corresponding cross sections is given by omitting terms $\sim (Z\alpha )^2/L^2$ for the para--Ps and $\sim (Z\alpha)^2/L$ for the ortho--Ps production where $L=\ln{\gamma^2} \approx 9$ and 16 for the RHIC and the LHC. Within this accuracy the multiphoton (Coulomb) corrections are taken into account. We show that the RHIC and the LHC will be Ps factories with a productions rate of about $10^5 \div 10^8$ relativistic Ps per day. The fraction of the ortho--Ps is expected to be of the same order as that of the para--Ps for Au--Au and Pb--Pb collisions.Comment: 22 pages, 5 figures, RevTeX, misprint correcte