Bulletin of the American Physical Society
2007 APS April Meeting
Volume 52, Number 3
Saturday–Tuesday, April 14–17, 2007; Jacksonville, Florida
Session S1: Poster Session III 
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Sponsoring Units: APS Room: Hyatt Regency Jacksonville Riverfront Terrace Pavilion, 2:00pm  5:00pm 

S1.00001: ACCELERATORS AND STORAGE RINGS 

S1.00002: ABSTRACT WITHDRAWN 

S1.00003: BEAM PHYSICS 

S1.00004: The optical assembly of a microelectron column and its application. WonKweon Jang, JongSeon Park, SungSoon Park, HoSeob Kim, KwangHo Choi Microelectron column has been intensively studied due to its high potential for application to multielectron beam system. Its full length is less than 15mm, very short comparing that (1$\sim $2m) of conventional electron column. Research is focused on how it can be assembled in shrunk size and work at the same or better level. The resolution and performance of a microelectron column is determined by factors of spherical, chromatic aberration, astigmatism, coma, etc., and these factors critically depend on size, roundness of the lens aperture and precise alignment To date, many precise equipments have been used, such as aligner, piezoelectric transducer (PZT), and scanning tunneling microscope (STM). However, those methods were difficult to use and complicated. In this paper, we used the laser diffraction pattern method for optical alignment of microelectron lenses, and laser bonding was employed for exact fabrication of microlenses within 4{\%} error. After assembled it was fully functioned in nanoscale reading with current image. Application to LCD tester and comb wire imaging in micro, nanoscale were successfully demonstrated. [Preview Abstract] 

S1.00005: ASTROPHYSICS 

S1.00006: Ab initio Calculation of Galactic Rotation Curves in vacuo Michael Makoid, Russell Anania Galactic rotation curves appear to become asymptotically flat far from the core, a feature that can be explained with an optical model of gravitational forces. With the core as a central lens, gravity from one side of the galaxy can be focused by the core onto the oposite side, thereby increasing radial forces, above those expected from a central Newtonian model. Using basic optics, the asymptotic rotational features of galaxies are easily calculated. The need for dark matter in galaxies is obviated. [Preview Abstract] 

S1.00007: Modeling the spectral evolution of prompt GRBs and Xray flares S. Pothapragada, S. Reynolds, S. Graham, M.V. Medvedev We use the detailed theory of jitter radiation from relativistic shocks containing smallscale magnetic fields and relativistic shock kinematics to build a numerical model of spectral variability of GRB emission. It is, then, applied to the conditions of the internal shocks in order to model the prompt phase and Xray flares. We derive the lighcurves, spectral evolution in time within each subpulse of a prompt GRB and during an Xray flare. Correlations of spectral parameters are also deduced. We demonstrate that the model lightcurves and spectra agree well with observation data. We discuss how one can deduce certain parameters of the plasma of the shock and the ejected material. [Preview Abstract] 

S1.00008: Phasespace distribution of accelerated electrons in relativistic GRB shocks S. Graham, S. Pothapragada, S. Reynolds, M.V. Medvedev The shock model of gammaray bursts (GRBs) contains two equipartition parameters: the magnetic energy density and the kinetic energy density of the electrons relative to the total energy density of the shock, $\epsilon_B$ and $\epsilon_e$, respectively. These are free parameters within the model. Whereas the Weibel shock theory and numerical simulations fix $\epsilon_B$ at the level of $\sim$few$\times(10^{3}...10^{4})$, no understanding of $\epsilon_e$ existed until recently. Medvedev (2006) has demonstrated that it inevitably follows from the Weibel shock theory that $\epsilon_e\simeq\sqrt{\epsilon_B}$, thus explaining why the electrons are close to equipartition in GRBs. The GRB afterglow data fully agree with this theoretical prediction. It has been suggested that the $\epsilon_e \epsilon_B$ relation can be used to reduce the number of free parameters in afterglow models. Here we further develop the model of nonFermi acceleration of electrons in prompt GRBs. We developed a numerical code, which computes full phase space distribution of electrons in Weibel electromagnetic fields. This distribution is further used to compute the electron energy distribution, the distribution over pitchangle, the angular pattern of jitter emissivity, and so on. Relevance of the results to modeling of GRBs is discussed. [Preview Abstract] 

S1.00009: Spiral Galaxy Model with Axial Plasma/Gas Vortex: A Possible Suggestion C.F. Gallo From the measured rotational velocity profiles of spiral galaxies, there appears a central ``core'' with zero central velocity that increases quickly with distance ($\sim $15{\%} of galactic radius) to large constant velocity. This data implies a large centrifugal hydrodynamic force suggesting the ``core'' is a central axial plasma/gas vortex with the following features. (1) MINIMUM central Pressure/Density of Plasma/Gas. (2) Axial Vortex which is manifested as the observed axial Galactic Jets? (3) MAXIMUM central light intensity due to high temperature of energetic central axial vortex? Extensions of the model follow. (1) Matter is sucked into the Galactic Center by the Central Axial Vortex, and that matter is expelled via the central axial galactic jets in dynamic equilibrium over long time scale? (2) No galactic black holes? This vortex model does not address many other important issues such as Dark Matter, galactic evolution, plasma effects, galactic stability, relativistic effects, spiral details, galactic clusters, etc. [Preview Abstract] 

S1.00010: Variability in Circumbinary Disks Following Massive Black Hole Mergers Nathaniel Bode, Sterl Phinney When two supermassive black holes merge, a significant fraction of their total initial massenergy is lost in gravitational waves. From the point of view of a circumbinary gaseous disk, much of this mass loss is effectively instantaneous, occurring on less than an orbital period. In a collisionless disk, we show that this leads to the immediate excitation of substantial epicyclic motion, and subsequent orbitcrossing. In a real gas disk, it leads to the excitation of acoustic waves and shock fronts, and consequent characteristic electromagnetic variability of the circumbinary disk around the newly merged black hole. We describe the dynamics and the variability, and show that the variations in disks around supermassive black hole binaries whose mergers will be observed by the Laser Interferometer Space Antenna (LISA) can be detected and used to provide unique insights into accretion disks e.g. maps of temperature, disk thickness, and thermal timescale versus radius. [Preview Abstract] 

S1.00011: Dimensional Stability of Materials for SpaceBased Missions Alix Preston, Benjamin Balaban, Gabrial Boothe, Guido Mueller Spacebased missions such as LISA, SIM, or Darwin rely on Michelsontype interferometry for detection. Optical systems for these missions must be made out of materials that can withstand significant acceleration and vibrational stresses endured during launch in addition to maintaining their dimensional stability. Of equal importance are the bonding methods used to adhere optical components. A recent bonding technique known as hydroxide bonding has proven to have superior strength to most other bonding techniques like optical contacting. Thermal expansion and material or bond internal effects like stress relaxation, creep, aging of the material or bonds often affect the interferometric stability of optical systems. In this poster we present results for the dimensional stability of silicon carbide, Zerodur, and Super Invar; all of which are commonly used materials in spacebased missions. In addition, we expand on existing results for glass to glass bonding and introduce new results for glass to silicon carbide bond strengths using the hydroxide bonding technique. This work is supported by NASA/OSS grant APRA0400950007. [Preview Abstract] 

S1.00012: Cosmicray strangelets in the Earth's atmosphere Benjamin Monreal If strange quark matter is stable in small lumps, we expect to find such lumps, called ``strangelets'', on Earth due to a steady flux in cosmic rays. Following recent astrophysical models, we predict the strangelet flux at the top of the atmosphere, and trace the strangelets' behavior in atmospheric chemistry and circulation. We show that several strangelet species may have large abundances in the atmosphere; that they should respond favorably to laboratoryscale preconcentration techniques; and that they present promising targets for mass spectroscopy experiments. [Preview Abstract] 

S1.00013: Zenith Angle Dependence of Prompt Neutrino and Muon Fluxes in Cosmic Ray Interactions Mohammed Zakaria, Gintaras Duda Upon entering earth's atmosphere, high energy cosmic rays generate a shower of particles in which high energy muons and neutrinos are created. These high energy ($>$ 10$^{18}$ eV) particles can mimic signals coming from astrophysical sources currently hunted for by neutrino telescopes. In particular the prompt component of such shower is important as prompt muons and neutrinos dominate over conventional particles at higher energies. We simulate the flux of prompt muons and neutrinos using pQCD calculations with NLO corrections to charm production cross sections. Prompt muon and neutrino fluxes for UHECR with nonzero zenith angles will be presented. We will discuss the effect of the Earth's curvature, newly added tau neutrino fluxes, and several techniques for numerically optimizing the simulation. [Preview Abstract] 

S1.00014: Scalar Potential Model progress John Hodge Because observations of galaxies and clusters have been found inconsistent with General Relativity (GR), the focus of effort in developing a Scalar Potential Model (SPM) has been on the examination of galaxies and clusters. The SPM has been found to be consistent with cluster cellular structure, the flow of IGM from spiral galaxies to elliptical galaxies, intergalactic redshift without an expanding universe, discrete redshift, rotation curve (RC) data without dark matter, asymmetric RCs, galaxy central mass, galaxy central velocity dispersion, and the Pioneer Anomaly. In addition, the SPM suggests a model of past expansion, past contraction, and current expansion of the universe. GR corresponds to the SPM in the limit in which a flat and static scalar potential field replaces the Sources and Sinks such as between clusters and on the solar system scale which is small relative to the distance to a Source. The papers may be viewed at http://web.infoave.net/$\sim$scjh/ . [Preview Abstract] 

S1.00015: Using Fourier Analysis and Wavelet Analysis to Analyze Atmospheric Data. Joseph Trout Fourier Analysis and wavelet analysis are used to analyze temperature data at various locations in the United States. Fourier analysis is used to analyze the frequency components of the temperature time series. Wavelet analysis is used to analyze the more localized features of the temperature time series. [Preview Abstract] 

S1.00016: An overview of the NASA Balloon Program in Support of Space and Earth Sciences Research David Pierce For the past several decades, the NASA Balloon Program contributed significantly to space sciences. Scientific ballooning has been a key research tool and advances in the capability of ballooning can keep it at the forefront of research. Balloon payloads can incorporate cutting edge technologies that are not yet ready for a space mission. Balloon platforms provide a cost effective means to test and demonstrate these new technologies in a space environment. Ballooning has often been the pathfinder major space missions and made early results available years in advance. Balloon payloads have also been one of the most important training grounds for the next generation of instrumentalists. The purpose of this paper is to update the space and Earth science communities on new developments, current capabilities, recent accomplishments, record flights and future directions of the NASA balloon program. [Preview Abstract] 

S1.00017: PLASMA PHYSICS 

S1.00018: ABSTRACT WITHDRAWN 

S1.00019: Collisionless current collection by a spherical particle in a flowing, weakly magnetized plasma Leonardo Patacchini, Ian H. Hutchinson Collisionlessplasma current collection by a spherical object such as a dust particle or probe under weakly magnetized conditions (Larmor radius larger than particle radius) is an important, longstudied, but analytically intractable problem. We solve it computationally by means of the hybrid Boltzmann/ParticleinCell code SCEPTIC[1] for a wide range of parameters, with finite Debye length. In addition to reducing the ion current, the magnetic field is shown to cancel the ion focusing effects present in an unmagnetized plasma when the drift velocity is comparable to the sound speed. Thus, the magnetic field prevents such phenomena as the reversal of angular flux density asymmetry (greater collection on the downstream side) or the local maximum of the drag force. The floating potential dependence on the ratio of the probe radius to Larmor radius is computed using a newly developed empirical formula for the electron current, which is also documented. \par\noindent [1] I.H. Hutchinson, {\it Plasma Phys. Control. Fusion} {\bf 45} (2003) [Preview Abstract] 

S1.00020: Resolution of the Mesoscopic Reconnection Theoretical Dilemma$^*$ B. Coppi, C. Crabtree, V. Roytershteyn The drifttearing mode\footnote{B. Coppi, \textit{Phys. Fluids} \textbf{8}, 2273 (1965)} involves magnetic reconnection and the gradients of electron temperature and density as well as that of the current density. Experiments with lower degrees of collisionality than those for which the mode was identified have shown that magnetic reconnection leading to relatively large islands persists, while according to subsequent theories\footnote{B. Coppi, et al., \textit{Phys. Rev. Lett.} \textbf{42}, 1058 (1978)} the effects of electron temperature gradients and Landau damping or longitudinal thermal conductivity$^2$ prevent, in practice, the excitation of this mode. To resolve this paradox, we consider\footnote{B. Coppi, et al., 21 IAEA FEC(Chengdu, China), TH/R219, 2006} that mesoscopic reconnecting modes develop from a coherent background of microreconnecting modes with short scale distances ($< c/\omega_{pe}$) generating a series of strings of small magnetic islands that are driven by the electron temperature gradient. Thus a reduction of the electron thermal conductivity along the field lines and an increase of the transverse thermal conductivity can take place. The combination of both effects is shown to restore the excitation of mesoscopic modes involving the effects of finite resistivity, electron thermal conductivities, and temperature and current grandients. $^*$Sponsored by the U.S. D.O.E. [Preview Abstract] 

S1.00021: Theoretical aspects of jitter radiation from Weibel turbulence laboratory experiments. S. Reynolds, S. Pothapragada, S. Graham, M.V. Medvedev Weibel instability development and structure is planned to be studied in Hercules and some other laboratory HighEnergy Density experiments. In such experiments, a primary beam will induce current filamentation whereas the secondary beam can be used to probe the generated magnetic field structure. In particuar, jitter radiation emitted by the electrons of the secondary beam in smallscale magnetic fields, can be used for accurate diagnostics. For this purpose, we further develop the theory of jitter radiation from magnetic fields generated by the Weibel instability and demonstrate that the spectra vary considerably with the viewing angle. Furthermore, we quantify how the lowenergy photon index, alpha, ranges changes with the apparent viewing angle for various models of magnetic field spatial distribution. We discuss astrophysical applications of this study. [Preview Abstract] 

S1.00022: Multicenter Scattering Influences on the Equation of State of Hot Dense Plasmas. James Albritton, Brian Wilson, Duane Johnson A prototypical high temperature denseplasma equationofstate model consists of a single average ion embedded in a spherically symmetric effective field. This effective field models the influence of all the other ions and freeelectrons of the plasma; and it is computed in a selfconsistent manner. The internal energy of the plasma is then obtained primarily from the electronic states of the average ion, which consists of a discrete set of eigenvalues and a continuum density of states deformed from that of an ideal electron gas. In such a model bound states may pressure ionize with increasing density, and initially reappear as sharp resonances in the continuum. It is clear that in a more physically realistic model of a dense plasma, the spherically symmetric field must be replaced by a multiple centered potential from the plasma ions. The main effects are that bound states may form bands prior to pressure ionization and that multicenter scattering influences the structure in the continuum density of states. We are investigating these effects via solidstate KohnKorringaRostoker electronic structure methods with extensions to finite temperatures and many angular momentum channels. Initially we will use periodically replicated cells of ions in random configurations and average over ensembles of configurations to obtain the equation of state.. [Preview Abstract] 

S1.00023: Anomalous Absorption of HighHarmonic Relativistic Electron Bernstein Modes in Spherical Tokamak Plasmas V. Stefan It is shown that an efficient control of anomalous absorption in Spherical Tokamaks (ST) is possible, leading to a favorable convective EB harmonics excitation. In this model an external electron cyclotron waves, O or Xmode, excite relativistic Electron Bernstein Mode$^{1}$\footnote{$^{1}$ V. Stefan, Anomalous Absorption of X2Driver Pump Power in DIIID Tokamak Plasma Via Relativistic Electron Bernstein Modes and Lower Hybrid Waves (Abstract: K1.00028; The American Physical Society, April2006 Meeting, April 2225, 2006; Dallas, TX.)\par \par } harmonics (EB harmonics) in the edge region of ST plasma. Nonlinear relativistic EB harmonics, in turn, propagate toward the central region of ST, whereby they are effectively absorbed in the electron cyclotron resonance region. The scaling laws for the thermonuclear yield, ratio of the thermonuclear power to the external power, for the case of excitation of EB harmonics, n(EB)$_{ }$+ (n1) (EB), n= 5,6 harmonic number, and for the excitation of n(EB)$_{ }$ + (UH)$_{ }$, (UH)$_{ }$the upper hybrid mode, are obtained. The plasmaignition criterion is analyzed in terms of O and XMode power. [Preview Abstract] 

S1.00024: Simulation of propagation and absorption of IBW via reduced 5D high frequency gyrokinetic (HFGK) particle simulation Roman Kolesnikov, W.W. Lee, Hong Qin, Ed Startsev We developed a reduced 5D high frequency gyrokinetic (HFGK) algorithm for particleincell simulation of arbitrary frequency phenomena in magnetized plasmas. This new algorithm is based on the gyrocentergauge kinetic theory [H. Qin, W.~M. Tang, W.~W. Lee and G. Rewoldt, Phys.\ Plasmas \textbf{6}, 1575 (1999)], which utilizes the separation of the ion gyromotion from its gyrocenter motion. While the 5D HFGK description [R. A. Kolesnikov, W. W. Lee, H. Qin, E. Startsev, APS (2006)] is an alternative to the original 6D Lorentzforce description for $\rho/L_B \ll 1$, the former approach takes much less computer time since the gyrophase dependence is removed from the kinetic system (but which still describes an arbitrary frequency dynamics). We performed a nonlinear $\delta f$ particle simulation of electrostatic system in slab geometry using the new 5D HFGK algorithm. We study propagation of the ion Bernstein wave (IBW) launched by an antenna in inhomogeneous system as well as its absorption near resonant layer via linear and nonlinear mechanisms. Illustrations of numerical efficiency of the new 5D algorithm compared to the direct 6D Lorentzforce simulation are given. [Preview Abstract] 

S1.00025: Confinement Regime Transition, Spontaneous Rotation and Phase Velocity Inversion of Edge Modes* C. Di Sanzo, B. Coppi, M. Landreman The transition from the Lconfinement regime to the Hregime is associated with the inversion of the phase velocity of collisional ballooning\footnote{Coppi, B., et. al., 33rd E.P.S. Plasma Conf., Paper O4.017 (2006)} modes excited at the edge of the plasma column and driven by the pressure gradient. Electronion, ionion and ionion neutral collisions are involved in an essential way. The phase velocity inversion from the electron diamagnetic velocity direction (Lregime) to the ion's occurs when ii collisions and in collisions begin to prevail\footnote{B. Coppi, MIT(LNS) Report HEP 06/12 and in Paper TH/P621, 2006 Intern. Fusion Energy Conf. (IAEA, Vienna)} and is very similar to the one found originally,\footnote{Coppi, B., H. Hendel, et al., Report MATT 523 (P.P.P.L., 1967); Intern. Conf. on Phys. of Quiescent Plasmas (Frascati, 1967)} in order to identify collisional electron drift modes in Qmachine experiments. The quality of confinement is associated with the effective rate of expulsion of angular momentum in the same direction as the mode phase velocity, toward the surrounding material wall, and rotation of the main plasma column resulting from recoil.\footnote{Coppi, B., Nucl. Fusion \textbf {42}, 1 (2002)}*Sponsored in part by the U.S. D.O.E. [Preview Abstract] 

S1.00026: Solutions and Objectives of the Ignitor Program$^*$ F. Bombarda, B. Coppi The main purpose of the Ignitor experiment$^1$ is to establish the ``plasma reactor physics" in regimes close to ignition, as required for realistic and economical reactors, where the ``thermonuclear instability" can set in with all its associated nonlinear effects. Reactor relevant plasma regimes require$^2$ $Q > 50 $. The only appropriate technological solution at this time to reach this objective is the adoption of normalconducting magnets. Furthermore, experiments without a divertor chamber can sustain, for equal overall sizes and magnetic field values, higher currents and therefore achieve better confinement parameters$^2$. In fact, Ignitor can operate with both an ``extended first wall" configuration and double Xpoints on the first wall and lower currents to access Hmode regimes. Since the process of attaining ignition has been investigated extensively$^1$, a special effort has been devoted to identify the conditions where the thermonuclear instability is barely prevented over the entire length of the current pulse. While tritium is the necessary step forward of any advanced fusion facility, Ignitor can provide novel and important results even when limited to operate with H, D, and He plasmas in the early phase of its experimental life. $^*$Sponsored in part by ENEA of Italy and by the U.S. D.O.E.\\ B. Coppi, et al., \textit{Nucl. Fusion} \textbf{41(9)}, 1253 (2001) \\ P.H. Rebut, \textit{Proc. 33rd EPS Conf. Plasma Phys.}, Rome (Italy), 2006 [Preview Abstract] 

S1.00027: Dielectronic Recombination in hightemperature fusion plasma Khondkar Karim Dielectronic recombination is the dominant recombination channel in a lowdensity hightemperature plasma. In a laboratory fusion plasma with heavy impurity atoms, dielectronic recombination is an important energyloss mechanism and is to be taken into account in any realistic plasma modeling. We have calculated dielectronic recombination rate coefficients for ions of various ionization stages as a function of plasma temperature. We have also calculated the autoionization rates, radiative transition rates, fluorescence yields, and satellite intensity factors for the relevant atoms and ions. Dielectronic recombination may proceed through an enormous number of intermediate resonance states. We have studied and introduced a scaling law for including the effects of the highlying resonance states without doing detailed calculations. In particular, we shall report the variation of radiative rates, autoionization rates, satellite intensity factors, and dielectronic recombination rates as a function of atomic number Z and the principal quantum numbers of the resonance states. [Preview Abstract] 

S1.00028: Electron Impact Innershell Ionization including relativistic corrections. BIdhan C. Saha, M. Alfaz Uddin, Arun K. Basak We report a simple method to evaluate the electron impact innershell ionization cross sections at ultra high energy regime; there still remains a sparse cross sections due to lack of reliable method. To extend the validity domains of the siBED model [1] in terms of targets and incident energies in this work we modified the RQIBED model [2], and denoted it as MUIBED. It is examined for the description of the experimental EIICS data of various target atoms up to E=250MeV. Details will be presented at the meeting. [1] W. M. Huo, Phys. Rev A 64, 042719 (2001). [2] M. A. Uddin, A. K. F. Haque, M. S. Mahbub, K. R. Karim, A. K. Basak and B. C. Saha, Phys. Rev. A 71, 032715 (2005). [Preview Abstract] 

S1.00029: COMPUTATIONAL PHYSICS 

S1.00030: Stochastical modeling for Viral Disease: Statistical Mechanics and Network Theory Hao Zhou, Michael Deem Theoretical methods of statistical mechanics are developed and applied to study the immunological response against viral disease, such as dengue. We use this theory to show how the immune response to four different dengue serotypes may be sculpted. It is the ability of avian influenza, to change and to mix, that has given rise to the fear of a new human flu pandemic. Here we propose to utilize a scale free network based stochastic model to investigate the mitigation strategies and analyze the risk. [Preview Abstract] 

S1.00031: Calculation of Berry Phases by Elementary Methods. Thomas Walnut The Berry (geometrical) phases of two systems, an electron on a rotating circular track and an electron spin in a precessing magnetic field, are recalculated using an elementary method. The results are compared with previous advanced calculations. It is found that: (1) in principle, and frequently in practice, the elementary procedure gives the correct results; (2) the results are sensitive to the previous specification of the problem; (3) the elementary and advanced treatments show only partial agreement. [Preview Abstract] 

S1.00032: Elastic Waves in Binary Solid Liquid Mixtures, Similarities at Macro and Nano Scales Hasson M. Tavossi Stress wave propagation in solid liquid mixtures at ultrasonic frequencies, in some cases, resembles wave propagation behaviors of materials at nanometer or atomic scales. For instance, it can be shown that wave; dispersion, attenuation, and cutofffrequency effects depend on the same structural parameters as those observed at nano or atomic levels and can have similar interpretations at both scales. It follows that, to investigate theoretical models of wave and matter interactions at nano scale it is more convenient to use, as experimental tools, the readily analyzable models of propagation at macroscales. Experimental findings on elastic wave propagation in the mixtures of liquid and solid particles will be presented and discussed. Results of wave dispersion, attenuation, bandpass, and cutoff frequency measured for ultrasonic waves in inhomogeneous mixtures of solid and liquid will be presented showing these similarities at the radically different scales. [Preview Abstract] 

S1.00033: Quantum Emitter Ballistic Electron Transistor for Nanotechnology Applications Shekhar Pradhan The invention is a new type of high speed three terminal, functional devices fabricated using silicon technology which performs a function such as logic normally performed by a circuit consisting of several conventional transistors. Such a device reduces circuit complexity and results in increased circuit speed. The device consists of a metal film deposited on a layer of silicon microcrystallites embedded in a SiO2 matrix constituting a quantized electron emitter, and a substrate containing n n+ p junctions. Electrons are injected into the substrate by resonant tunneling through the emitter. The injected electrons ballistically traverse the n n+ region in the substrate, and surmount a barrier to enter the p region. The height of this barrier is varied with the applied bias allowing passage to ballistic electrons at resonant tunneling, but suppressing them as bias is increased further. This effect produces a negative resistance which is repeated for every emitter energy level. Thus, the forward transfer characteristic consists of a sequence of zero, one zero etc. forming the basis for functional device operation. The author wishes to acknowledge the guidance and support of late Professor Edward Nicholian for his mentoring during the research. [Preview Abstract] 

S1.00034: Effect of High Field Stressing on Charge Generation and Trapping in Ammonia Annealed Nitrided Oxides Shekhar Pradhan The effects of thermal nitridation of silicon dioxide in ammonia on dielectric conduction; charge generation and trapping; and breakdown characteristics were examined. Using high field, constant current stressing nitridation is observed to introduce significant numbers ($\sim $ 10$^{18}$/cm$^{3})$ of electron traps of large crosssection ($\sim $ 10$^{15}$ / cm$^{2})$ that enhance negative charge generation at higher fields and low fluence. At much higher fluence levels electron trapping similar to that observed in the oxide is seen, but total chargetobreakdown is observed to be larger by 20{\%} to 46{\%} for the nitrided oxides. Enhanced lowfield conduction is observed, but only a modest 7{\%} reduction in the effective barrier height is observed for conduction in the high field regime. The author wish to acknowledge the guidance and support of Professor K.P. Roenker for his mentoring during the research [Preview Abstract] 

S1.00035: POSTDEADLINE 

S1.00036: EnergyEnergy Correlations and Other DiJet/JetPhoton Correlations Justin Frantz An integral part of the RHIC program has been to use jet probes to study the Heavy Ion Medium. Such measurements have progressed from comparisons of plain particle yields at high pt, to twoparticle opening angle correlations, and currently further jet observables are being explored. For example, as a new twist and point of view on the interesting ptdependence of the dijet azimuthal correlations, we have explored the Energy Energy Correlation (EEC) in both 200 GeV Au+Au (run4 dataset) and p+p collisions. The EEC represents the autocorrelation of the energy flow of the jet fragmentation. Such measurements are attractive since they require no jetfinding in Au+Au but are a step towards event shape observables used to study perturbative and nonperturbative QCD. We've explored a technique for measuring the EEC using photontriggered events, and we will also present other observables related to the PHENIX photonjet and jetjet measurements. [Preview Abstract] 

S1.00037: Supersymmetric twodimensional QCD at finite temperature John Hiller We study the spectrum and finitetemperature properties of supersymmetric twodimensional QCD at large $N_c$, with a ChernSimons term included to give mass to the adjoint partons. The theory is solved nonperturbatively by the technique of supersymmetric discrete lightcone quantization, which uses a discrete momentum grid in lightcone coordinates to convert integral equations for Fockspace wave functions to a supersymmetric matrix representation. The spectral distribution of the representation is computed by Lanczos iteration of the masssquared eigenvalue problem. [Preview Abstract] 

S1.00038: TwoPhoton Absorption by H2 Molecules: Origin of the 2175A Astronomical Band? Peter P. Sorokin, James H. Glownia The near UV spectra of OB stars are often dominated by a broad extinction band peaking at 2175A. Forty years after its discovery, the origin of this band remains unknown, although it is usually attributed to linear scattering or linear absorption by interstellar dust particles. Here we report that twophoton absorption by H2 molecules in gaseous clouds enveloping OB stars should lead to a strong band peaking near 2175A. We first show that if the product of the H2 density in the gaseous cloud times the emitted stellar VUV flux is sufficiently great, the threshold for stimulated Rayleigh scattering will be exceeded, resulting in the generation of intense, monochromatic VUV light at the rest frame frequencies of H2 B and Cstate resonance lines originating from levels J$''$=0 and J$''$=1 of X0. This coherently generated light must necessarily propagate radially inwards towards the photosphere of the illuminating OB star, and therefore cannot be detected externally. However, this same light effectively constitutes intense ``first step'' monochromatic radiation that should induce continuum photons emitted by the OB star near 2175A to be strongly absorbed as ``second steps'' in resonantlyenhanced H2 twophoton transitions to two well known doublyexcited dissociative states of H2. Archival UV and VUV spectra of 185 OB stars strongly support our nonlinear model for the 2175A band. [Preview Abstract] 

S1.00039: Areal foliation and asymptotically velocityterm dominated behavior in T$^2$ symmetric spacetimes with positive cosmological constant Adam Clausen, James Isenberg We prove a global foliation result, using areal time, for $T^2$ symmetric spacetimes with a positive cosmological constant. We then find a class of solutions that exhibit asymptotically velocityterm dominated behavior near the singularity. [Preview Abstract] 

S1.00040: 6D Antide Sitter Space Solutions to Einstein's Equation with Scalar Fields Jordan Kehrer We study a scalar field in sixdimensional Antide Sitter space by extending the RandallSundrum model. The model includes a single scalar field and two compactified extra dimensions. Using perturbation methods, we simultaneously solve the Einstein Field equation and the KleinGordon equation to find the back reaction on the Antide Sitter space metric. Following the methods of Golberger and Wise, we minimize the scalar field potential to find the compactification length of the warped extra dimension. We study whether this solution has the properties to solve the hierarchy problem. [Preview Abstract] 

S1.00041: The Iron Project and the RMAX Project: Transitions in Fe~XV, Fe~XVI, and Astrophysical Applications Maximiliano Montenegro, Sultana Nahar, Anil Pradhan, Chiranjib Sur, Justin Oelgoetz While the Iron Project is involved in scattering and radiative atomic processes of iron and ironpeak elements, the Rmax Project aims at the Xray spectroscopy of astrophysical objects. Under the Iron Project, the oscillator strengths and radiative decay rates for fine structure transitions going up to n=10 and l=9 are obtained for magenesium like Fe~XV and sodium like Fe~XVI. They correspond to 98 levels for Fe~XVI and 504 levels for Fe~XV. We have employed relativistic BreitPauli Rmatrix method for the allowed electric dipole (E1) transitions and BreitPauli atomic structure calculations for forbidden (E2, E3, M1, M2) transitions for these ions. The results have been benchmarked against the ab initio coupled cluster method which includes relativistic effects. Very good agreement is found for Fe~XVI. The application of the Iron Project and the RmaX Project data to laboratory and astrophysical sources is demonstrated for timeresolved spectroscopy of Xray lines of Helike Fe and Ni, especially for the astrophysical diagnostic lines. [Preview Abstract] 

S1.00042: Redesigning problem solving component in General Physics course. Jerry Shakov, Jim McGuire Problembased learning has been widely used in teaching introductory/general physics courses for a long time. The role of problemsolving sessions in the learning process is absolutely critical: they give the students an opportunity to learn how to apply both newly and previously acquired knowledge to practical situations, how to put together different strategies and portions of material, and much more. Unfortunately, the traditional format used for the problem solving sessions is not very accommodative for the goal: large class sizes and limited time often force instructors to spend most of the time solving sample problems in front of the class, which leaves the students with the role of passive observers. In this work, we will discuss how one can involve the students in the process of active learning using collaborative strategies and principles of cognitive apprenticeship. [Preview Abstract] 

S1.00043: ABSTRACT WITHDRAWN 

S1.00044: Computational techniques for quantitative characterization of critical fluctuations in binary fluids Ana Oprisan, Sorinel Oprisan, John Hegseth The observation and analysis of fluctuations near the critical point in real time and space is an important issue in the critical point phenomena. This important aspect is related to statistical physics and to microscopic image formation. Using three different techniques, bright field (BF), phase contrast (PC), and dark field (DF), we investigated a liquid mixture system of methanol and partially deuterated cylcohexane. The recorded images corresponding to BF, PC, and DF exhibit intensity variation in the spatial domain. Image analysis finds similarities in the image formation for BF and PC, but differences for DF. Using different image analysis techniques, we found that the gray level probability distribution functions are Gaussian for both bright field and phase contrast, and that the distribution is different not only in amplitude but also in the tail of the distribution for the dark field. The power spectra corresponding to images recorded with these techniques show the existence of large fluctuations in these images and their connection to generalized nucleation. Fluctuations recorded in these images are evidence of selfsimilarity in real space. [Preview Abstract] 

S1.00045: ABSTRACT WITHDRAWN 

S1.00046: Cosmic Ray Composition Measurements by the HiRes Detector. Yulia Fedorova Composition of the ultra high energy cosmic rays (UHECR) along with energy spectrum plays an important part in solving the mystery of the cosmic rays  their origin and acceleration mechanisms. Both, composition and energy spectrum, can be measured by observing extensive air showers (EAS) produced by high energy cosmic particles in the Earth's atmosphere. High Resolution Fly's Eye (HiRes) fluorescence detector is capable to measure the UV light emitted by EAS in stereo. The stereo observations significantly improve the resolution of such measurements and, hence, the resolution of the particle energy and shower maximum (Xmax) reconstruction. The latter is usually serves as an indicator of the chemical composition of the incident cosmic ray particle. We present a study of the detector sensitivity to the CR characteristics (charge, mass, energy, arrival direction) based on the different hadronic interaction models and some real data analysis. [Preview Abstract] 

S1.00047: Predicting neural network firing pattern from phase resetting curve Sorinel Oprisan, Ana Oprisan Autonomous neural networks called central pattern generators (CPG) are composed of endogenously bursting neurons and produce rhythmic activities, such as flying, swimming, walking, chewing, etc. Simplified CPGs for quadrupedal locomotion and swimming are modeled by a ring of neural oscillators such that the output of one oscillator constitutes the input for the subsequent neural oscillator. The phase response curve (PRC) theory discards the detailed conductancebased description of the component neurons of a network and reduces them to ``black boxes'' characterized by a transfer function, which tabulates the transient change in the intrinsic period of a neural oscillator subject to external stimuli. Based on openloop PRC, we were able to successfully predict the phaselocked period and relative phase between neurons in a halfcenter network. We derived existence and stability criteria for heterogeneous ring neural networks that are in good agreement with experimental data. [Preview Abstract] 

S1.00048: Monitoring the Ultraluminous Supernova SN 1978K in NGC 1313 Ian Smith, Stuart Ryder, Markus Boettcher, Manfred Pakull, Athena Stacy We present our radio (Australia Telescope Compact Array) and Xray (XMMNewton) monitoring observations of the unusual ultraluminous supernova SN 1978K in NGC 1313 at $\sim 25$ years after the explosion. [Preview Abstract] 

S1.00049: The Meanings of Einstein's Principle of Constancy of the Velocity of Light, 19051929. Felix T. Smith Within 4 months in 1905, Einstein published his fundamental papers on both the photon phenomenology of lighta particulate description, and on special relativity, a development based entirely on the wave theory. On the wave side, to establish Lorentz invariance Einstein used the postulate $P_1 $, that the observed velocity of light is independent of the velocity of the source. He also drew on the accepted doctrine of electromagnetism and optics that $c$ was a ``universal constant'' (not further defined) and combined that with $P_1 $ as his strongly affirmed Principle of Constancy of the Velocity of Light ($P_{\mbox{CVL}} )$. This principle has been thought of as combining the postulate $P_1 $ with a subpostulate $P_2 $, that $c$ is strictly invariant in space and time. The successes of special relativity made reliance on postulate $P_1 $ less important over time, and deSitter's analysis of the light curves of double stars (1912) converted its physical content from an axiom to an experimental fact. Despite Pauli's reminder (1921) that a slowly timedependent $c\left( t \right)$ is still compatible with Lorentz invariance, the Principle $P_{\mbox{CVL}} $ rapidly became identified entirely with $P_2 $ and $c$ became dogmatically invariant. In 1929 this greatly influenced the interpretation of the Hubble redshift distance relationship. [Preview Abstract] 

S1.00050: ABSTRACT WITHDRAWN 

S1.00051: Allorder calculation of spindependent PNC amplitude in Cs and a revised value of Cs anapole moment Marianna Safronova, W. R. Johnson The precise measurements of the $6s_{1/2}[F=4]  7s_{1/2}[F=3]$ and $6s_{1/2}[F=3]  7s_{1/2} [F=4]$ paritynonconserving (PNC) amplitudes in $^{133}$Cs [1] gave an experimental value of the nuclear spindependent PNC interaction accurate to about 15\%. The resulting nuclear anapole moment extracted from this experiment was, in turn, used to place constraints on PNC meson coupling constants. The constraints obtained from the Cs experiment were found to be inconsistent with constraints from other nuclear PNC measurements, which favor a smaller value of the Cs anapole moment. Motivated by this disagreement, we reexamined the atomic physics calculation of the PNC amplitude used in this analysis. Our calculations are based on the relativistic allorder singledouble method where all single and double excitations of the DiracHartreeFock wave function are included to all orders of perturbation theory. The resulting PNC amplitudes are used to reevaluate the value of Cs anapole moment. Detailed investigation of the theoretical uncertainties is carried out. \\ \nonumber [1] C.\ S.\ Wood, S.\ C.\ Bennett, D.\ Cho, B. P. Masterson, J. L. Roberts, C. E. Tanner, and C. E. Wieman, Science 275, 1759 (1997) [Preview Abstract] 
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