Square to stripe transition and superlattice patterns in vertically oscillated granular layers

We investigated the physical mechanism for the pattern transition from square lattice to stripes, which appears in vertically oscillating granular layers. We present a continuum model to show that the transition depends on the competition between inertial force and local saturation of transport. By introducing multiple free-flight times, this model further enables us to analyze the formation of superlattices as well as hexagonal lattice

Collective flow in central Au-Au collisions at 150, 250 and 400 A MeV

Radial collective flow and thermalization are studied in gold on gold collisions at 150, 250 and 400 A MeV bombarding energies with a relativistically covariant formulation of a QMD code. We find that radial flow and "thermal" energies calculated for all the charged fragments agree reasonably with the experimental values. The experimental hardware filter at small angles used in the FOPI experiments at higher energies selects mainly the thermalized particles.Comment: 4 pages with 4 EPS figures included. Version accepted for publication in Phys. Rev.

The project of a high-power FEL driven by an SC ERL at KAERI

The project of a high-power FEL at Korea Atomic Energy Research Institute and its recent status are described. The FEL is driven by a superconducting energy recovery linac. The first-stage machine will operate in the far IR region and its CW power is expected to be a few kW. Possible upgrade of the machine is also considered. The upgraded machine will operate in the near IR region and its expected power is a few tens kW.Описан проект мощного ЛСЭ в Корейском институте атомной энергии, а также текущее состояние дел. В ЛСЭ будет использован сверхпроводящий линак-рекуператор. Машина первой очереди будет работать в дальнем ИК-диапазоне, ее ожидаемая средняя мощность несколько киловатт. Рассматривается возможная модернизация машины. Модернизированная машина будет генерировать десятки киловатт средней мощности в ближнем ИК-диапазоне.Описано проект потужного ЛВЕ в Корейському інституті атомної енергії, а також поточний стан справ. У ЛВЕ буде використаний надпровідний лінак-рекуператор. Машина першої черги буде працювати в далекому ІЧ-діапазоні, її очікувана середня потужність − кілька кіловат. Розглядається можлива модернізація машини. Модернізована машина буде генерувати десятки кіловатів середньої потужності в ближньому ІЧ-діапазоні

The project of a high-power FEL driven by an SC ERL at KAERI

The project of a high-power FEL at Korea Atomic Energy Research Institute and its recent status are described. The FEL is driven by a superconducting energy recovery linac. The first-stage machine will operate in the far IR region and its CW power is expected to be a few kW. Possible upgrade of the machine is also considered. The upgraded machine will operate in the near IR region and its expected power is a few tens kW.Описан проект мощного ЛСЭ в Корейском институте атомной энергии, а также текущее состояние дел. В ЛСЭ будет использован сверхпроводящий линак-рекуператор. Машина первой очереди будет работать в дальнем ИК-диапазоне, ее ожидаемая средняя мощность несколько киловатт. Рассматривается возможная модернизация машины. Модернизированная машина будет генерировать десятки киловатт средней мощности в ближнем ИК-диапазоне.Описано проект потужного ЛВЕ в Корейському інституті атомної енергії, а також поточний стан справ. У ЛВЕ буде використаний надпровідний лінак-рекуператор. Машина першої черги буде працювати в далекому ІЧ-діапазоні, її очікувана середня потужність − кілька кіловат. Розглядається можлива модернізація машини. Модернізована машина буде генерувати десятки кіловатів середньої потужності в ближньому ІЧ-діапазоні

D-concurrence bounds for pair coherent states

The pair coherent state is a state of a two-mode radiation field which is known as a state with non-Gaussian wave function. In this paper, the upper and lower bounds for D-concurrence (a new entanglement measure) have been studied over this state and calculated.Comment: 11 page

Isospin Effects in Nuclear Multifragmentation

We develop an improved Statistical Multifragmentation Model that provides the capability to calculate calorimetric and isotopic observables with precision. With this new model we examine the influence of nuclear isospin on the fragment elemental and isotopic distributions. We show that the proposed improvements on the model are essential for studying isospin effects in nuclear multifragmentation. In particular, these calculations show that accurate comparisons to experimental data require that the nuclear masses, free energies and secondary decay must be handled with higher precision than many current models accord.Comment: 46 pages, 16 figure

Effect of Purity and Substrate on Field Emission Properties of Multi-walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWNT) have been synthesized by chemical vapour decomposition (CVD) of acetylene over Rare Earth (RE) based AB2(DyNi2) alloy hydride catalyst. The as-grown carbon nanotubes were purified by acid and heat treatments and characterized using powder X-ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Thermo Gravimetric Analysis and Raman Spectroscopy. Fully carbon based field emitters have been fabricated by spin coating a solutions of both as-grown and purified MWNT and dichloro ethane (DCE) over carbon paper with and without graphitized layer. The use of graphitized carbon paper as substrate opens several new possibilities for carbon nanotube (CNT) field emitters, as the presence of the graphitic layer provides strong adhesion between the nanotubes and carbon paper and reduces contact resistance. The field emission characteristics have been studied using an indigenously fabricated set up and the results are discussed. CNT field emitter prepared by spin coating of the purified MWNT–DCE solution over graphitized carbon paper shows excellent emission properties with a fairly stable emission current over a period of 4 h. Analysis of the field emission characteristics based on the Fowler–Nordheim (FN) theory reveals current saturation effects at high applied fields for all the samples

Heavy Quarks and Heavy Quarkonia as Tests of Thermalization

We present here a brief summary of new results on heavy quarks and heavy quarkonia from the PHENIX experiment as presented at the "Quark Gluon Plasma Thermalization" Workshop in Vienna, Austria in August 2005, directly following the International Quark Matter Conference in Hungary.Comment: 8 pages, 5 figures, Quark Gluon Plasma Thermalization Workshop (Vienna August 2005) Proceeding

Single Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV

The invariant differential cross section for inclusive electron production in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range $0.4 <= p_T <= 5.0 GeV/c at midrapidity (eta <= 0.35). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e. charm quarks or, at high p_T, bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined as sigma_(c c^bar) = 0.92 +/- 0.15 (stat.) +- 0.54 (sys.) mb.Comment: 329 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm