Bulletin of the American Physical Society
APS April Meeting 2015
Volume 60, Number 4
Saturday–Tuesday, April 11–14, 2015; Baltimore, Maryland
Session T1: Poster Session III (14:00 - 17:00) |
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Sponsoring Units: APS Room: South Foyer |
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T1.00001: NUCLEAR PHYSICS |
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T1.00002: Development of a Neutron Detector for A1 at MAMI Zoe Pierce The Mainz A1 spectrometers perform high precision measurements to investigate the structure of the nucleus and its constituents. Previous knowledge of the neutron form factor (FF) is limited due to poor detection efficiencies. Our goal is to create a neutron detector with an efficiency better than 80{\%}, leading to the improvement of the measurements of the neutron electric FF and reducing systematic uncertainties. This new detector would also open up the possibility to study non-mesonic two-body weak decays. ~The neutron detector should have a large active detector volume, a high detection efficiency (\textgreater 80{\%}), a good resolution (\textless .5 ns), and must be low in cost. The proposed design of the detector follows a modular concept with an active detector volume of approximately one cubic meter. In order to allow high beam currents and their resulting high rates, this detector will be highly segmented using 32 crossed layers consisting of 64 bars, utilizing solid and liquid organic scintillators, with dimensions (15 x 30 x 960) mm$^{\mathrm{3}}$. In total 4096 channels have to be read out via WLS fibers using silicon multi pixel photon counters (MPPC). [Preview Abstract] |
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T1.00003: Optimization of the Efficiency of a Neutron Detector to Measure ($\alpha $, n) Reaction Cross-Section Jesus Perello, Fernando Montes, Tony Ahn, Zach Meisel Nucleosynthesis, the origin of elements, is one of the greatest mysteries in physics. A recent particular nucleosynthesis process of interest is the charge-particle process (cpp). In the cpp, elements form by nuclear fusion reactions during supernovae. This process of nuclear fusion, ($\alpha $,n), will be studied by colliding beam elements produced and accelerated at the National Superconducting Cyclotron Laboratory (NSCL) to a helium-filled cell target. The elements will fuse with $\alpha $ (helium nuclei) and emit neutrons during the reaction. The neutrons will be detected for a count of fused-elements, thus providing us the probability of such reactions. The neutrons will be detected using the Neutron Emission Ratio Observer (NERO). Currently, NERO's efficiency varies for neutrons at the expected energy range (0-12MeV). To study ($\alpha $,n), NERO's efficiency must be near-constant at these energies. Monte-Carlo N-Particle Transport Code (MCNP6), a software package that simulates nuclear processes, was used to optimize NERO configuration for the experiment. MCNP6 was used to simulate neutron interaction with different NERO configurations at the expected neutron energies. By adding additional 3He detectors and polyethylene, a near-constant efficiency at these energies was obtained in the simulations. With the new NERO configuration, study of the ($\alpha $,n) reactions can begin, which may explain how elements are formed in the cpp. [Preview Abstract] |
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T1.00004: Parity violation measurement of neutron density Zidu Lin, Charles Horowitz Parity-violating electron scattering can measure neutron densities in a model independent fashion because the weak charge of a neutron is much larger than that of a proton. At Jefferson laboratory, the neutron radius of $^{208}$Pb has already been measured by PREX, and a future project CREX aims to measure the neutron radius of $^{48}$Ca. In this work, we propose to measure not only the neutron radius, but the full radial structure of the neutron density distribution in $^{48}$Ca, by measuring the parity violating asymmetry at a number of different momentum transforms and using a Fourier Bessel expansion to fit the neutron density directly. Finally, we estimate the statistical error in the Fourier Bessel coefficients that can be determined for a realistic experimental beam time. [Preview Abstract] |
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T1.00005: Spectrometers for Beta Decay Electrons Yong Jiang, Jay Hirshfield Inspired by the neutrino mass direct measurement experiment Project 8, precision spectrometers are proposed to simultaneously measure energy and momentum of beta-decay electrons produced in rare nuclear events with improved energy resolution. For detecting single beta decay electrons near the end-point from a gaseous source such as tritium, one type of spectrometer is proposed to utilize stimulated cyclotron resonance interaction of microwaves with electrons in a waveguide immersed in a magnetic mirror. In the external RF fields, on-resonance electrons will satisfy both the cyclotron resonance condition and waveguide dispersion relationship. By correlating the resonances at two waveguide modes, one can associate the frequencies with both the energy and longitudinal momentum of an on-resonance electron to account for the Doppler shifts. For detecting neutrino-less double-beta decay, another spectrometer is proposed with thin foil of double-beta-allowed material immersed in a magnetic field, and RF antenna array for detection of synchrotron radiation from electrons. It utilizes the correlation between the antenna signals including higher harmonics of radiation to reconstruct the total energy distribution. [Preview Abstract] |
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T1.00006: Dipole Radiation Interference Patterns Kanan Grosklos, Xin Li, Henk Arnoldus When two particles are placed near each other and irradiated by a laser beam, the emitted radiation from each particle will interfere. Dipole radiation is the most elementary radiation and is the focus of our study. We observed the interference pattern of two linear dipoles, at different separations and phase angles in the near and far fields. In particular, the energy flow pattern in the near field between the two dipoles can be complicated and contain singularities and vortices. [Preview Abstract] |
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T1.00007: Radiative corrections to the elastic e-p and mu-p scattering in Monte Carlo simulation approach Oleksandr Koshchii, Andrei Afanasev In this paper, we calculated exactly lepton mass corrections for the elastic e-p and mu-p scatterings using the ELRADGEN 2.1 Monte Carlo generator. These estimations are essential to be used in the MUSE experiment that is designed to solve the proton radius puzzle. This puzzle is due to the fact that two methods of measuring proton radius (the spectroscopy method, which measures proton energy levels in hydrogen, and the electron scattering experiment) predicted the radius to be 0.8768$\pm$0.0069 fm, whereas the experiment that used muonic hydrogen provided the value that is 5\% smaller. Since the radiative corrections are different for electrons and muons due to their mass difference, these corrections are extremely important for analysis and interpretation of upcoming MUSE data. [Preview Abstract] |
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T1.00008: Low-energy $^{9}$Be + $^{208}$Pb scattering, breakup and fusion within a four-body model Mahir Hussein, Pierre Descouvemont, T. Druet, L. Felipe Canto We investigate the $^{9}$Be elastic scattering, breakup and fusion at energies around the Coulomb barrier. The three processes are described simultaneously, with identical conditions of calculations. The $^9$Be nucleus is defined in an $\alpha$ + $\alpha$ + n three-body model, using the hyperspherical coordinate method. We first analyze spectroscopic properties of $^9$Be, and show that the model provides a fairly good description of the low-lying states. The scattering with $^{208}$Pb is then studied with the Continuum Discretized Coupled Channel (CDCC) method, where the $\alpha$ + $\alpha$ + n continuum is approximated by a discrete number of pseudostates. The use of a three-body model for $^9$Be improves previous theoretical works, where $^9$Be is assumed to have a two-body structure ($^{9}$Be +n or $\alpha$ + $^{5}$He), although neither $^8$Be nor $^5$He are bound. Optical potentials for the $\alpha+^{208}$Pb and $n+^{208}$Pb systems are taken from the literature. Scattering, breakup and fusion cross sections are calculated. In general, a good agreement with experiment is obtained, considering that there is no parameter fitting. We show that continuum effects increase at low energies, and confirm that breakup channels enhance the fusion cross [Preview Abstract] |
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T1.00009: Minimizing Residual Pressure within a Windowless Gas Target System - JENSA Orlando Gomez, Justin Browne, Antonios Kontos, Fernando Montes Nuclear reactions between light gases and radioactive isotope beams are essential to address open questions in nuclear structure and astrophysics. Pure light gas targets are critical for the measurements of proton- and alpha-induced reactions. \underline {J}et \underline {E}xperiments in \underline {N}uclear \underline {S}tructure and \underline {A}strophysics (JENSA) is the world's most dense ($\sim$ 10$^{19}$ atoms/cm$^{2}$) windowless gas target system. Most of the gas flow is localized; however, escaping gas creates a pressure gradient which degrades experimental measurements and contaminates the beam line. JENSA contains a differential pumping system to maintain a vacuum. The previous design configuration was not optimized for experiments (pressure measurements 70 cm downstream from the jet were $\sim$ 10$^{-3}$ torr; optimal is less than 10$^{-4}$ torr). We have altered the current differential pumping system to minimize the residual pressure profile. Several configurations of two gas-receiving catchers were tested, and the most efficient ones identified using Enhanced Pirani and Cold Cathode gauges. We have determined the 30 mm outer and 20 mm inner gas-receiving cones minimize JENSA central chamber pressure to 200 millitorr at 16,000 torr of discharge pressure. Altering the tubing configuration has additionally lowered the pressure 70 cm downstream to 10$^{-5}$ torr. The new residual pressure allows operation of JENSA with planned expansion of a recoil mass separator SECAR. [Preview Abstract] |
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T1.00010: New Levels in \textsuperscript{157}Pm J. Ranger, E.H. Wang, J.H. Hamilton, A.V. Ramayya, J.K. Hwang, A. Navin, M. Rejmund, A. Lemasson, S. Bhattacharyya, Y.X. Luo, J.O. Rasmussen, S.J. Zhu, G.M. Ter-Akopian, Yu. Oganessian Gamma rays in coincidence with isotopically-identified fission fragments using VAMOS++ and EXOGAM, produced using \textsuperscript{238}U on a \textsuperscript{9}Be target, at an energy near the Coulomb barrier have been observed, as reported by Navin \emph{et al.}. In the present work, we have combined data from the in-beam mass- and Z-gated spectra with the $\gamma$-$\gamma$-$\gamma$-$\gamma$ data from \textsuperscript{252}Cf (SF) to assign transitions and levels in \textsuperscript{157}Pm. In contrast to Hwang (2009), the transitions previously assigned to \textsuperscript{156}Pm are all seen in the M-Z gated spectra of \textsuperscript{157}Pm and are not seen in the M-Z gated spectra of \textsuperscript{156}Pm. The new expanded levels of \textsuperscript{157}Pm are remarkably similar to those of the levels in \textsuperscript{155}Pm, which have been assigned as a well-deformed rotational band built on $\pi$ 5/2 [532], as in \textsuperscript{155}Pm. New level schemes in \textsuperscript{147}Ce are also verified and elaborated upon. [Preview Abstract] |
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T1.00011: Nuclear shells, sub-shells and shell evolution Ian Bentley Shell structure in nuclei is seen in transition rates, binding energies and the energetics of excited states. The robustness of shells have been tested using extrema and differential observables. The shell and sub-shell closures between $8 \leq N,Z \leq 50$, and missing signatures of shells will be a primary focus, as will the migration of shells in energies of $6^+_1,8^+_1,$ and $10^+_1$ states. Pairing correlations have been determined across the chart of the nuclides using linear fits as a function of $I(I+1)$ for $I\geq 20$ yrast states. These correlations occur at roughly the same locations as binging energy based correlations, but are noticeably larger in magnitude. A discussion of the comparison of experimentally determined pairing correlations and pairing calculations using the BCS formalism for gadolinium nuclei will be included. [Preview Abstract] |
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T1.00012: ABSTRACT WITHDRAWN |
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T1.00013: Selection Rules for M1 and Gamow Teller transitions with a J=0 T=1 pairing interaction Matthew Harper, Larry Zamick We consider selection rules for M1 transtions in a single j shell with a J=0 T=1 pairing interaction. We use J=1$^{+}$ to J=2$^{+}$ in $^{46}$Ti as an example.The states are classified as (v,T,t)-seniority- isospin and reduced isospin. We obtain vanishing B(M1)'s for 3 reasons. a.$\Delta$T=2 b. $\Delta$v=4 or 6 c. The final state differs from the initial state in both v and t. The first case a. is obvious because the M1 operator is of rank 1 in isospin.For case b. we note that the M1 operator acting on a J=0 v=0 pair can only change v by 2 units. In c. the M1 operator cannot change both v and t at the same time. Examples af a. are (411) to $(231),$$(231)$. Examples of b. are (611) $to(221)$, (211) Examples of c. are (611) to (412), (422); (220) to (412), (411),$(422)$, (421). Transitons in which the seniority changes by 2 units and the reduced isospin does not change are allowed.These selection rules also apply to corresponding Gamow-Teller transiitons. [Preview Abstract] |
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T1.00014: A triplet polarimeter for use in the Jefferson Lab GlueX experiment Brianna Thorpe, M. Dugger, B.G. Ritchie The GlueX experiment in Hall D at Jefferson Lab will utilize a polarized photon beam to help identify exotic meson states. Knowledge of the degree of polarization of the photon beam is critical for identifying those states. The use of the triplet production process (pair creation off atomic electrons) could allow for determination of polarization with high precision. A newly-constructed polarimeter will be described, preliminary results of the detector's response to alpha and electron sources will be presented, and estimates of potential performance with the Jefferson Lab Hall D photon beam will be discussed. [Preview Abstract] |
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T1.00015: FEW BODY SYSTEMS |
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T1.00016: Double photoionization of Be-like (Be-F$^{5+}$) ions Shahin Abdel Naby, Michael Pindzola, James Colgan The time-dependent close-coupling method is used to study the single photon double ionization of Be-like (Be - F$^{5+}$) ions. Energy and angle differential cross sections are calculated to fully investigate the correlated motion of the two photoelectrons. Symmetric and antisymmetric amplitudes are presented along the isoelectronic sequence for different energy sharing of the emitted electrons. Our total double photoionization cross sections are in good agreement with available theoretical results and experimental measurements along the Be-like ions. [Preview Abstract] |
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T1.00017: Electron Impact ionization of H, He and Li isoelectronic series B.C. Saha, A.K. Basak, M.A. Uddin, A.K.F. Haque, M.A.R. Patoary Electron impact ionization cross-sections for Hydrogen (H), Helium (He) and Lithium (Li) isoelectronic series are presented for $E\le 2.0keV$. A few simple models [1] suitable for rapid generation of accurate results as needed for various modeling codes are used to calculate cross sections. Our results describe reasonably well the experimental findings. Details will be presented at the conference. \\[4pt] [1] A. K. F. Haque, M. A. Uddin, M. Shahjahan, M. R Talukder, A. K. Basak and B. C. Saha,`` Electron impact inner-shell ionization of atoms'', in \textit{Advances in Quantum Chemistry}, \textbf{61},309-373 (2011). [Preview Abstract] |
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T1.00018: Configuration space Faddeev formalism: $\Lambda+n+n$ bound state search Vladimir Suslov, Igor Filikhin, Branislav Vlahovic The HypHI Collaboration has recently reported the evidence for bound state of $\Lambda+n+n$ system (Phys. Rev. C88, 041001(R) (2013)). However, the theoretical analysis did not find $^3_\Lambda n$ bound state (see, for instance, Phys. Lett. B 736, 93 (2014)). In the present work we will describe our attempt to construct a phenomenological three-body $\Lambda NN$ force with the spin-isospin dependence that is attractive in the channel T=1, S=1/2. This dependence was tested to reproduce the value of ground state energy for $^3_\Lambda $H hypernuclei. The formalism of the configuration-space Faddeev equations is applied for $\Lambda+n+n$ and $\Lambda+n+p$ systems. As $\Lambda+n$ interaction the s-wave potential simulating model NSC97f is used. This potential reproduces well the hyperon binding energy for $^3_\Lambda $H nuclei (J. Phys. G: 31, 389 (2005)). The details of the model and obtained results will be presented. [Preview Abstract] |
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T1.00019: Quantum dissipative dynamics of two-level atoms in hyperbolic metamaterials Cristian Cortes, Giacomo Torlai, Zubin Jacob Hyperbolic metamaterials (HMMs) represent a class of artificial nanostructured media that have garnered a lot of attention over the past few years due their broadband singularity in the photonic density of states. This unique property has led to many research directions ranging from subwavelength light manipulation to the control of radiative decay rates of quantum emitters in HMMs. Here, we apply a second quantization approach, first developed by Dekker (1975), to study the quantum dissipative dynamics of a two-level atom coupled to a hyperbolic medium. The Dekker quantization approach provides a framework that allows for non-Hermitian Hamiltonians whose imaginary part represents the dissipation of the quantum system. We calculate the resonance fluorescence spectrum and steady-state dynamics of a two-level atom in an HMM. Our results take into account non-idealities of the medium such as loss and finite unit-cell size and should be experimentally observable using current nanofabrication technology. [Preview Abstract] |
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T1.00020: Quantized friction force: Lindbladian model satisfying Ehrenfest theorems Denys Bondar, Renan Cabrera, Andre Campos, Herschel Rabitz We construct a quantum counterpart of classical friction, a dissipative force acting against the direction of motion with the magnitude proportional to particle's velocity. In particular, a Lindblad master equation is derived satisfying the appropriate dynamical relations for observables (i.e., the Ehrenfest theorems). Numerical illustrations as well as theoretical investigations are presented. These findings significantly advance a long search for a universal valid Lindbladian model of quantum friction. [Preview Abstract] |
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T1.00021: NEW DIRECTIONS IN ASTROPHYSICS |
(Author Not Attending)
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T1.00022: The vacuum's dark particles behave like dark matter and dark energy John Haller Building on the governing hypothesis that self-information is equal to action, I solve for the time step of the vacuum. The resulting equations (both quantum diffusion and Friedmann's equations) argue that a dark particle, or special black hole, exists at hbar or twice the reduced Planck mass where the Hawking temperature breaks down. It is hypothesized that if neutral hydrogen is nearby the dark particles are able to couple with the background field and thus have a density that looks like dark matter. If hydrogen is not around, the dark particles become frozen leading to a constant density of black body radiation similar to dark energy. If the Universe's dark particles (away from neutral hydrogen) became frozen during the re-ionization of the Universe's history, its BBR density is well within confidence ranges for the cosmological constant. This hypothesis can also explain the recent observations that dark matter decays into dark energy. [Preview Abstract] |
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T1.00023: Dark matter possibilities Orvin Wagner In my research I observe signals that penetrate dense matter and I hypothesize that they are due to waves in dark matter. Since they readily penetrate thick matter I hypothesize that they are due to small dark matter particles instead of the usual hypothesized Wimps. For example I observed signals that penetrate my local hill at near 77 m/s. In addition the solar cycle appears to be due to to dark matter oscillating in the sun producing standing waves that have to due with planet placement and stability of the solar system. Dozens of experiments, over the past 20 years, confirm the penetrating waves. Examples of the experiments are presented on my website darkmatterwaves.com and US patent number 8,669,917 B1. [Preview Abstract] |
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T1.00024: MEST-Do the ``rubble-pile'' asteroid-1950 DA, with low 1700 kg/m$^3$ density, has a structure with spacetime center? Dayong Cao According to Einstein's equation and observation of flat universe, the paper gives new ideas both of dark massenergy and spacetime center, and supporses that some asteroids were comets which have spacetime center, and some comets were wraped up by rock in 2012. It explains of a observation about low density of the asteroid-1950 DA by spacetime center of the asteroid. (see Ben Rozitis, ``Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075) 1950 DA,'' http://www.nature.com/nature/journal/v512/n7513/full/nature13632.html) It also can explain of a rock hull of 67P/Churyumov-Gerasimenko. (see Jonathan O'Callaghan, ``Comets are like deep fried ICE CREAM: Nasa ice-box experiment confirms 67P is hard on the outside but fluffy on the inside,'' http://www.dailymail.co.uk/sciencetech/article-2949020/Comets-like-deep-fried-ICE-CREAM-Nasa-ice-box-experiment-confirms-67P-hard-outside-fluffy-inside.html) (See Dayong Cao, ``MEST-The dark hole, dark comet and dark matter are the space-time center'' and ``MEST- avoid next extinction by a space-time effect'') http://meetings.aps.org/link/BAPS.2014.APR.L1.3 http://meetings.aps.org/link/BAPS.2014.APR.L1.2 http://meetings.aps.org/link/BAPS.2015.APR.L1.2 http://meeting.aps.org/Meeting/CAL12/Session/H1.8 http://meetings.aps.org/link/BAPS.2012.APR.K1.79 [Preview Abstract] |
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T1.00025: Stellar, Planetary, Satellite, and Galactic Rotation Origin as Tangential Accretion of Decaying Relevant Orbital Material Sections Transfering Their Orbital Momentum Into Rotational Motion of the Accreted Body Stewart Brekke Planets and stars began as cores orbited by sections of relevant material which decayed and tangentially accreted to the slowly rotating cores causing the resultant formed planet or star to rotate faster due to addition of their angular momentums. If $I\omega_{pre-planetary or stellar core}$ is the angular momentum of the pre-planetary or pre-stellar core and $I\omega_{orbitingsection}$, then the equation for the origins of stellar and planetary rotation is $ (I\omega)_{core} + (I\omega)_{section1} + ... + (I\omega)_{sectionn} = (I\omega)_{newlyformedplanetorstar}$. Galaxies began as sets of pre-formed galactic arms orbiting each other. Due to gravitation the orbits of the arms decayed tangentially colliding and accreting in their fore sections forming spiral galaxies which began to rotate. The origin of galactic rotation results from the angular momentum of the pre formed arms adding together to result in the rotation of the newly formed galaxy. If $I\omega$ is the angular momentum of each of the pre-galactic arms, the equation for the origin of galactic rotation is $(I\omega)_{arm1} + ...+ (I\omega)_{armn} = (I\omega)_{newgalaxy}$. [Preview Abstract] |
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T1.00026: Fluid dynamics nature of supernova remnant (Crab Nebula) Ahmad Reza Estakhr Supernova remnant (at early phase) is a high temperature fluid of gas and dust. after the explosion of a star in a supernova, the viscousity of supernova remnant changes with temperature. as supernova expand by time its temperature decreases and the viscousity increases, (or alternatively, the fluidity of supernova remnant tends to decreases) and leb to resistance phase of supernova remnant fluid to flow. $U^{\mu}=\gamma (c,u(\vec {r}, t))$ denotes four-velocity vector field of supernova. $J^ {\mu}=\rho U^{\mu}$ denotes four-current density of supernova fluid of gas and dust. Estakhr's Material-Geodesic equation is developed analogy of Navier Stokes equation and Einstein Geodesic equation to describe Fluid dynamics nature of supernova remnant (Crab Nebula): $\frac{DJ^ {\mu}}{D\tau}=\frac{dJ^{\mu}}{D \tau}+\Gamma^{\mu}_{\alpha \beta}J^{\alpha}U^{\beta}=J_ {\nu}\Omega^{\mu\nu}+\partial_ {\nu}T^{\mu\nu}+\Gamma^{\mu} _{\alpha\beta}J^{\alpha}U^ {\beta}$ Covariant formulation of Fluid dynamics nature of supernova remnant, describe the motion of fluid substances of supernova. [Preview Abstract] |
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T1.00027: Strong-field tidal distortions of rotating black holes Scott Hughes, Stephen O'Sullivan We describe how to compute the geometry of an event horizon that is distorted by a binary companion using black hole perturbation theory. The techniques we use are good for fast orbital motion and rapid black hole spin, but are limited to large binary mass ratios. We sketch the formalism that we use and show results for a variety of interesting binary orbits, including embeddings that illustrate the dynamical response of the horizon to a time-varying applied tide. These results illustrate some interesting consequences of the teleological nature of a black hole's event horizon. [Preview Abstract] |
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T1.00028: PARTICLES AND FIELDS |
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T1.00029: Monte Carlo studies of the CoGeNT detector for a variety of dark matter candidates Ronnie Rera, Matthew Bellis, Juan Collar, Nicole Fields, Chris Kelso Since December 2009, the CoGeNT experiment has recorded interactions in the detector with the goal of either detecting dark matter or setting stringent limits on the mass and cross-section of these particles, assuming that dark matter is a form of WIMP (Weakly Interacting Massive Particle). The collaboration has made public this dataset to the broader community and this analysis is based on that dataset. and we have a set of analysis tools that performs an unbinned, maximum likelihood fit to the data, accounting for known backgrounds and systematic effects. Here we present a set of studies using Monte Carlo datasets which mimic these backgrounds and can add an arbitrary amount of WIMP signal, parametrized by energy deposition and time of year, mass, cross-section, and choice of local WIMP velocity distribution. We use these tools to check the robustness of our fitting approach and to test for sensitivity and bias. The current status of this analysis will be presented. [Preview Abstract] |
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T1.00030: Measurement of the double-differential cross section $d\sigma/d\phi^{*}$ of $Z\rightarrow\mu\mu$ events at CMS Nicholas Mucia We present a measurement of the double-differential cross section $d\sigma/d\phi^{*}$ using $Z\rightarrow\mu\mu$ events produced in pp collisions recorded with the CMS detector in 2012. The observable $\phi^{*}$ depends only on the angular variables of the two leptons. This variable is closely related to the transverse momentum of the $Z$ boson but suffers less from experimental resolution. Theoretical predictions are compared to the measured cross sections. [Preview Abstract] |
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T1.00031: On the Anomalous Structures of the Vector Leptonic Currents Rasulkhozha S. Sharafiddinov According to a mass-charge duality [1], any type of charge says about the existence in nature of a kind of inertial mass. Therefore, the steadiness of the electric charge distribution in leptons $(l=e,$ $\mu,$ $\tau, ...)$ can be explained by the intralepton interratio of forces of different nature. From its point of view, we not only must present the Dirac $(i=1)$ and Pauli $(i=2)$ form factors $F_{il}$ in the form $$F_{il}(q^{2})=f_{il}(0)+R_{il}(q^{2})+A_{il}(\vec{q^{2}})+..., \eqno(1)$$ but we also need to conclude that each type of charge comes forward as the source of a kind of dipole moment. Herewith the independent components $f_{il}$ coincide with normal sizes of the electric charge and magnetic moment. The functions $R_{il}$ describe the interaction between the lepton electromagnetic radius and the field of emission. The terms $A_{il}$ characterize the dependence of form factors $F_{il}$ on the square of three-dimensional momentum transfer $\vec{q^{2}}$ and at $\vec{q^{2}}=0$ are reduced to their anomalous values. They show that the electron similarly to all other the leptons possesses as well as the anomalous electric charge. To such a type of charge corresponds a kind of inertial mass. 1. R.S. Sharafiddinov, Bull. Am. Phys. Soc. 59(5), T1.00009 (2014). [Preview Abstract] |
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T1.00032: Anomalous Electric Charge of a Neutrino of True Neutrality Rasulkhozha S. Sharafiddinov Any dipole arises as a result of a kind of charge. Therefore, if each neutrino having a C-even or a C-odd charge possesses a mass of a vector $(V)$ or an axial-vector $(A)$ nature, from the point of view of mass-charge duality [1], the steadiness of an axial-vector electric charge distribution in all C-noninvariant leptons $(l^{A}=e^{A},$ $\mu^{A},$ $\tau^{A}, ...)$ must be accepted as the intralepton harmony of axial-vector types of forces. Then it is possible, for example, to present the anapole $(i=1)$ and electric dipole $(i=2)$ form factors $G_{il^{A}}$ depending on the momentum transfer square $q^{2}$ in the form $$G_{il^{A}}(q^{2})=g_{il^{A}}(0)+R_{il^{A}}(q^{2})+\Phi_{il^{A}}(\vec{q^{2}})+..., \eqno(1)$$ where $g_{il^{A}}$ define the static anapole and electric dipole, $R_{il^{A}}$ characterize the dependence of form factors $G_{il^{A}}$ on the lepton axial-vector radius. The functions $\Phi_{il^{A}}$ describe the anomalous behavior of axial-vector currents. Thus, a neutrino of true neutrality similarly to all other the axial-vector leptons must possess the anomalous electric charge of C-noninvariant nature. Such a type of charge says about the existence in neutrino of a kind of inertial mass.\\[4pt] [1] R.S. Sharafiddinov, Bull. Am. Phys. Soc. 59(5), T1.00009 (2014). [Preview Abstract] |
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T1.00033: Simulations of Prototype Photon Detection Technologies for ELBNF Johnathon Lowery, Jon Urheim, Stuart Mufson, Denver Whittington, Bruce Howard Efficient detection of 128-nm scintillation light from particle interactions in large liquid argon Time Projection Chambers, such as those foreseen for the proposed ``Experiments at the Long Baseline Neutrino Facility,'' poses significant challenges. Many different prototype photon detection technologies are currently under evaluation for ELBNF. Each technology has been tested at the TallBo dewar at Fermilab in two modes. They were studied with self-triggered cosmic rays and with tracks selected with a hodoscope array. In this work, I present the results of several simulations which seek to compare the performance of these technologies. In these simulations, line source generators are used to create photons which are propagated using ray-tracing. By comparing the results of the simulations to data taken in the runs at TallBo, it is possible to compute the photon detection efficiencies for these technologies. In addition, simulations of the propagation of light through coated acrylic bars are discussed. [Preview Abstract] |
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T1.00034: Generation of the sedimentation potential by rapid deceleration of a fluid jet Han Jung Park, Ziyao Tang, Gerald Diebold The sedimentation potential refers to the generation of a voltage in an ionic or colloidal solution as a result of motion of the ions or colloidal particles relative to the surrounding fluid. In the case of colloidal suspensions, where the density of the colloidal particles differs from that of the fluid, the effect of a body force on the suspension, generated typically either in a centrifuge or the earth's gravitational field, is to give different motion to the charged particles and the fluid, producing a distortion of the normally spherical counter charge distribution around the colloidal particles. As a result of the opposing charges attached to the particles and in the double layer in the surrounding fluid, dipoles are generated at the sites of the particles, which add to give a macroscopic voltage in the fluid. Experiments reported here show that the sedimentation potential can be generated by the rapid deceleration of a jet of colloid at a rigid surface where, again, the differential acceleration of the particles and fluid gives rise to a voltage. The voltages between a conducting surface and a metallic tube used to form the jet are found to have large signal-to-noise ratios. Park \textit{et al.} \textit{JOURNAL OF APPLIED PHYSICS} 116, 104908 (2014) [Preview Abstract] |
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T1.00035: Mass? What Mass? --Inertial Forces In Massless Systems John Johnson Inertial forces in massless systems are possible due to, of all things, simple propagation delays of the binding forces. Analysis at the classical level shows that in addition to intrinsic masses there are effective inertial mass contributions due to the interaction forces themselves. For 1/r potentials the effective mass is E/c$^{\mathrm{2}}$, but for more complex potentials this is not true. The general form of the effective mass term is shown, and in addition the inertial force density of an electromagnetic field is derived. While these analytical results are in the classical regime, it is argued that the retardation mechanism must apply to any interacting system of finite spatial extension. [Preview Abstract] |
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T1.00036: Fermion Pairing and the Scalar Boson of the 2D Conformal Anomaly Emil Mottola, Daniel Blaschke, Raul Carballo-Rubio We analyze the phenomenon of fermion pairing into an effective boson associated with anomalies and the anomalous commutators of currents, bilinear in the fermion fields. In 2D the chiral bosonization of the Schwinger model is determined by the chiral current anomaly of massless Dirac fermions. A similar bosonized description applies to the 2D conformal trace anomaly of the fermion stress tensor. For both the chiral and conformal anomalies, correlation functions involving anomalous currents, $j^{m}_5$ or $T^{mn}$ of massless fermions exhibit a massless boson $1/k^2$ pole, and the associated spectral functions obey a UV finite sum rule, becoming $d$-functions in the massless limit. In both cases the effective action of the anomaly is non-local, but may be expressed in a local form by the introduction of a new bosonic field, which becomes a bona fide propagating quantum field in its own right. In both cases this is expressed in Fock space by the anomalous Schwinger commutators of currents becoming the canonical commutation relations of the corresponding boson. The Casimir energy of fermions on a finite interval can also be described as a coherent scalar condensation of pairs, and the one-loop correlation function of stress tensors can be expressed as tree diagrams [Preview Abstract] |
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T1.00037: Developing a Webcam-Based Data Logger to Analyze Cosmic Rays in a Cloud Chamber Kelly Nealon, Matt Bellis Muons from secondary cosmic rays provide students with an opportunity to interact with a natural phenomenon that relies both on special relativity and fairly sophisticated particle physics knowledge. In many physics departments, undergraduate students set up a pair of scintillators in coincidence to measure the rate of these muons and in some cases, measure their angular dependence, but this requires specialized and potentially expensive equipment. We have spent the past year formalizing a design of a cloud chamber that relies not on dry ice, but Peltier thermoelectric coolers, that can be built for about one hundred dollars worth of equipment. With this design we can see the tracks left by cosmic rays, however to turn it into a useful undergraduate physics lab requires some sort of data logger. This poster details our efforts to use an off-the-shelf webcam to trigger on the change in image when a cosmic ray track appears in the chamber. We use this to estimate the rate and angular dependence and compare our results to other measurements. The successes and limitations of this approach will be discussed. [Preview Abstract] |
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T1.00038: Wire Bond Encapsulation for the CMS Forward Pixel Upgrade Sam Higginbotham The Phase 1 upgrade of the pixel tracker for the CMS experiment will require the assembly of approximately 1000 modules consisting of pixel sensors bump bonded to readout chips. Electrical connections between the custom readout chips and support ASIC's that constitute the front-end of the pixel data acquisition system are made via wire bonds to a thin printed circuit board. Part of the assembly process carried out at Purdue University includes the partial encapsulation of the wire bonds for mechanical protection, prevention of electrolytic corrosion, and to damp oscillations due to Lorentz forces from transient current pulses in large magnetic fields. We present the details of the robotic assembly process which allows the deposition of the viscous encapsulant compound with 100 micron precision. [Preview Abstract] |
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T1.00039: Radiation Hard Active Media R{\&}D for CMS Hadron Endcap Calorimetry Emrah Tiras The High Luminosity LHC era imposes unprecedented radiation conditions on the CMS detectors targeting a factor of 5-10 higher than the LHC design luminosity. The CMS detectors will need to be upgraded in order to withstand these conditions yet maintain/improve the physics measurement capabilities. One of the upgrade options is reconstructing the CMS Endcap Calorimeters with a shashlik design electromagnetic section and replacing active media of the hadronic section with radiation-hard scintillation materials. In this context, we have studied various radiation-hard materials such as Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), HEM and quartz plates coated with various organic materials such as p-Terphenyl (pTp), Gallium doped Zinc Oxide (ZnO:Ga) and Anthracene. Here we discuss the related test beam activities, laboratory measurements and recent developments. [Preview Abstract] |
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T1.00040: TESTS OF PHYSICS LAWS |
(Author Not Attending)
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T1.00041: Critical Analysis of the Mathematical Formalism of Theoretical Physics. IV. Foundations of Trigonometry Temur Z. Kalanov Analysis of the foundations of standard trigonometry is proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. It is shown that the foundations of trigonometry contradict to the principles of system approach and contain formal-logical errors. The principal logical error is that the definitions of trigonometric functions represent quantitative relationships between the different qualities: between qualitative determinacy of angle and qualitative determinacy of rectilinear segments (legs) in rectangular triangle. These relationships do not satisfy the standard definition of mathematical function because there are no mathematical operations that should be carry out on qualitative determinacy of angle to obtain qualitative determinacy of legs. Therefore, the left-hand and right-hand sides of the standard mathematical definitions have no the identical sense. The logical errors determine the essence of trigonometry: standard trigonometry is a false theory. [Preview Abstract] |
(Author Not Attending)
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T1.00042: Critical Analysis of the Mathematical Formalism of Theoretical Physics. V. Foundations of the Theory of Negative Numbers Temur Z. Kalanov Analysis of the foundations of the theory of negative numbers is proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. Statement of the problem is as follows. As is known, point $O$ in the Cartesian coordinate system $XOY$ determines the position of zero on the scale. The number ``zero'' belongs to both the scale of positive numbers and the scale of negative numbers. In this case, the following formallogical contradiction arises: the number $0$ is both positive number and negative number; or, equivalently, the number $0$ is neither positive number nor negative number, i.e. number $0$ has no sign. Then the following question arises: Do negative numbers exist in science and practice? A detailed analysis of the problem shows that negative numbers do not exist because the foundations of the theory of negative numbers contrary to the formal-logical laws. It is proved that: (a) all numbers have no signs; (b) the concepts ``negative number'' and ``negative sign of number'' represent a formallogical error; (c) signs ``plus'' and ``minus'' are only symbols of mathematical operations. The logical errors determine the essence of the theory of negative numbers: the theory of negative number is a false theory. [Preview Abstract] |
(Author Not Attending)
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T1.00043: Where Are the Logical Errors in the Theory of Big Bang? Temur Z. Kalanov The critical analysis of the foundations of the theory of Big Bang is proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. It is argued that the starting point of the theory of Big Bang contains three fundamental logical errors. The first error is the assumption that a macroscopic object (having qualitative determinacy) can have an arbitrarily small size and can be in the singular state (i.e., in the state that has no qualitative determinacy). This assumption implies that the transition, \textit{(macroscopic object having the qualitative determinacy) }$\to $ \textit{(singular state of matter that has no qualitative determinacy),} leads to loss of information contained in the macroscopic object. The second error is the assumption that there are the void and the boundary between matter and void. But if such boundary existed, then it would mean that the void has dimensions and can be measured. The third error is the assumption that the singular state of matter can make a transition into the normal state without the existence of the program of qualitative and quantitative development of the matter, without controlling influence of other (independent) object. However, these assumptions conflict with the practice and, consequently, formal logic, rational dialectics, and cybernetics. Indeed, from the point of view of cybernetics, the transition, \textit{(singular state of the Universe) }$\to $\textit{ (normal state of the Universe), }would be possible only in the case if there was the Managed Object that is outside the Universe and have full, complete, and detailed information about the Universe. Thus, the theory of Big Bang is a scientific fiction. [Preview Abstract] |
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T1.00044: The Substitution of a Super Black Fixed Micro-Object for an Optical Microcavity in a Delayed Choice Experiment to Send Information Immediately Between 2 Paired Particles: Simplifying the Experiment Douglas Snyder An experiment has been described that relies on a delayed choice for an idler photon that immediately affects the signal photon with which it is at least initially entangled and for which the idler photon provides which-way information. The delayed choice concerns whether to maintain or eliminate the entanglement before any measurements are made. In one option of the delayed choice, the entanglement can be eliminated because the relevant state of the idler photon related to its entanglement is eliminated when the idler photon enters an optical microcavity filled with photons with the same mode as the incoming idler photon. The microcavity is located at the crossroads of two possible idler photon paths. The relevant state of the idler photon characterizes the particular path taken by the photon and this information is eliminated when the particle enters the cavity. Over a number of runs with this choice, the distribution of the paired signal photons shows interference. If the entanglement is maintained, the distribution of the paired signal photons shows which-way information. This experiment can be simplified by using a super black material (e.g., Vantablack) affixed to a fixed micro-object located at the crossroads of the two possible idler photon paths instead of the optical microcavity. The photon would be absorbed by the material and there would be no way to detect from which direction it came. Objects such as fixed mirrors in a Mach Zehnder interferometer do not provide ww information. The super black fixed micro-object should not either. [Preview Abstract] |
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T1.00045: Large Fixed Objects, Such as Fixed Mirrors, Impacted by Photons Do Not Provide Which-Way Information Due to Momentum Transfer: Implications for A Delayed Choice Experiment to Send Information Immediately Between 2 Paired Particles Douglas Snyder If a photon impacts a much larger fixed object, the momentum transfer from the photon to the fixed object is essentially undetectable. This principle is the basis for a Mach Zehnder interferometer where fixed full-silvered and half-silvered mirrors do not provide which way information when impacted by an incoming photon. Kim relied on fixed mirrors impacted by photons to demonstrate quantum erasure. If the principle did not work, Kim would not have obtained symmetric and anti-symmetric interference. The present experiment relies on delayed choices for idler photons which initially possess ww information that immediately affect the distribution of signal photons initially entangled with the idler photons and for which the idler photons provide ww information. It relies on the principle noted. In the case of the present experiment, one of those fixed objects is an optical microcavity that is situated at the crossroads of two possible paths for the idler photon. The delayed choice concerns whether to maintain or eliminate the entanglement before any measurements are made. If the idler photon enters the microcavity filled with photons in the same mode as the idler photon, the entanglement is eliminated. The resulting distribution of the paired signal photons with this choice shows interference. If the choice is not to send the idler photon toward the microcavity and preserve the which-way information of the idler photons, the resulting distribution of the paired signal photons shows ww information. [Preview Abstract] |
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T1.00046: Single Photon diffraction and interference John Hodge A previous paper based on the Scalar Theory of Everything studied photon diffraction and interference (IntellectualArchive, Vol.1, No. 3, P. 20, Toronto, Canada July 2012. http://intellectualarchive.com/?link$=$item{\&}id$=$597). Several photons were required in the experiment at the same time. Interference experiments with one photon in the experiment at a time also showed interference patterns. The previous paper with the Bohm Interpretation, models of the screen and mask, and the Transaction Interpretation of Quantum Mechanics were combined. The reverse wave required by the Transaction Interpretation was provided by a reflected plenum wave rather than a reverse time wave. The speed of the plenum wave was assumed to be much faster than the speed of photons/light. Using the assumptions of Fraunhofer diffraction resulted in the same equation for the photon distribution on a screen as the intensity pattern of the Fraunhofer diffraction. ( http://myplace.frontier.com/$\sim$jchodge/ ) [Preview Abstract] |
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T1.00047: Adomian Decomposition approach to solve the simple harmonic quantum oscillator Adnan Jaradat The simple harmonic quantum oscillator problem has been solved using two methods namely, the algebraic method where the raising and lower operators used and the Frobenius method. Here, we will adopt the Adomian decomposition method to solve this problem and derive the Hermite polynomials in much easier way than the above mentioned methods. [Preview Abstract] |
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T1.00048: Experimental Observation of Temperature Variation of Surface Magnetization on a Nanostructured Co/Pt Thin Film Chidubem Nwokoye, Edward Della Torre, Lawrence Bennett, Abid Siddique, Frank A. Narducci Magneto-optic Kerr effect, MOKE, is used to observe the complex rotation of the polarization plane of linearly polarized incident light reflected from the surface of a magnetic material. The rotation is directly related to the surface magnetization of the material [1]. We report work that extends the experiments in [2] that studied Bose-Einstein Condensation (BEC) of magnons in confined nanostructures. We report the MOKE experimental results of an investigation of surface magnetic remanence and coercivity on a Co/Pt ferromagnetic thin film at low-temperatures. Our findings are explained and are attributed to the BEC of confined magnons in the Co/Pt thin film.\\[4pt] [1] Z. Q. Qiu and S. D. Bader, Surface magneto-optic Kerr effect, Review of Scientific Instruments, 71, 31, 1243-1255 (2000).\\[0pt] [2] Bennett, L.H. and Della Torre, E. (2014) Bose-Einstein Condensation of Confined Magnons in Nanostructures. Journal of Modern Physics, 5, 693-705. [Preview Abstract] |
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T1.00049: RADIATION |
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T1.00050: Universality and Kirchhoff's Law of Thermal Emission Pierre-Marie Robitaille, Stephen J. Crothers Kirchhoff's law is derived in `The Theory of Heat Radiation', by Max Planck, but without properly addressing reflection. This is rectified in part by modifying his equation in \S 25 to $dt\cdot \nu\cdot 8\pi\int_0^\infty\left({\bf\epsilon}_\nu+\rho_\nu{\bf K}_\nu\right)d\nu$, and \S 26 (i.e. Eq. 25) to $dt\cdot \nu\cdot 8\pi\int_0^\infty\left(\alpha_\nu+\rho_\nu\right){\bf K}_\nu d\nu$, respectively. When these are equated, solutions are either $\bf K_\nu=\epsilon_\nu/\alpha_\nu$ (Eq. 27), or $\epsilon_\nu={\bf K}_\nu-\rho_\nu {\bf K}_\nu$. The former, which leads to Kirchhoff's law, is undefined when $\alpha_\nu=0$. Planck tries to prove Kirchhoff's law by placing two separate media in contact. Each medium is characterized by its own emission, for which Planck uses the notation ($\epsilon_\nu$), absorptivity ($\alpha_\nu$), and reflectivity ($\rho_\nu$). The critical step in the derivation involves Planck's need to set $\left(1-\rho_\nu\right)$=$\left(1-\rho_\nu'\right)$, which he astonishingly achieves by initially deducing that $\rho_\nu$=$\rho_\nu'$=0 and then, in Eq. 40, setting $\rho_\nu$=$\rho_\nu'$ (see \S 37). This is a contradiction of known physics for frequency dependent reflectivities in differing materials. Kirchhoff's law and universality are invalid concepts. [Preview Abstract] |
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T1.00051: Generation of strong terahertz field from two-color laser filamentation and optical rectification Donghoon Kuk, Yungjun Yoo, Taek Il Oh, Yong Sing You, Ki-Yong Kim We have demonstrated strong-field (\textgreater 8 MV/cm), high-peak-power (12 MW) THz generation with a bandwidth of \textgreater 20 THz via two-color laser filamentation. Moderate average power (1.4 mW) is also achieved by using a cryogenically-cooled Ti:sapphire amplifier capable of producing 30 fs, 15 mJ pulses at a 1 kHz repetition rate. For maximal THz generation and transmission, we have used a combination of a thin dichroic waveplate and a large Brewster-angled silicon filter. Here we have used a thin BBO crystal for frequency doubling (800 nm to 400 nm) and observed strong terahertz emission from the crystal itself. We also find that this type of terahertz emission can be optimized to yield more output power compared to two-color photoionization. In both cases, we have used a microbolometer camera for real-time THz beam profiling. This cost-effective THz camera along with our intense THz sources can be a useful tool for nonlinear THz studies including broadband THz spectroscopy and imaging. [Preview Abstract] |
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T1.00052: Intense laser interaction with argon cluster/fiber targets and radiation generation at 1 kHz repetition rates Yan Tay, Donghoon Kuk, Howard Milchberg, Ki-Yong Kim We have investigated the interaction of intense femtosecond laser pulses with two types of targets, a gas of clusters and argon solid fibers ($\sim$ 50 micron diameter), at 1 kHz repetition rates for high-flux X-ray and terahertz radiation generation. Here we have used capillary nozzles (50 $\sim$ 500 microns in diameter) to produce argon or nitrogen clusters in high-density (10$^{19}$ - 10$^{21}$ cm$^{-3})$ gas jets at high backing pressure ($\sim$ 1000 psi) and cryogenic temperature (100 K). All optical methods including optical interferometry and Rayleigh/Mie scattering are used to characterize the atomic gas densities, cluster sizes, and clustering ratios in continuous gas jets. We have also produced continuous argon fiber targets with a thin cryogenically cooled capillary nozzle. These cluster and fiber targets can be utilized to produce enhanced X-ray and terahertz generation, as well as energetic electrons and ions, with intense, high-repetition-rate (\textgreater kHz) laser interaction. [Preview Abstract] |
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T1.00053: A Synchrotron Radiation Research Facility for Africa Kenneth Evans-Lutterodt, Sekazi Mtingwa, Ahmadou Wague, Guebre Tessema, Herman Winick Africa is the only habitable continent without a synchrotron light source. Dozens of African scientists use facilities abroad. Even though South Africa has become a member of ESRF, the number of users is limited by distance and travel cost. A light source in Africa would give many more African scientists access to this tool. Momentum is now building for an African light source, as a collaboration involving several African countries. An interim Steering Committee has been formed, with a mandate to plan a conference. SESAME, now nearing completion in Jordan, is a collaboration of 9 countries in the Middle East (www.sesame.org.jo) is an example to follow. UNESCO became the umbrella organization for SESAME at its Executive Board 164th session, May 2002, as it did in the case of CERN in the 1950s. UNESCO's Executive Board described SESAME as ``a quintessential UNESCO project combining capacity building with vital peace-building through science'' and ``a model project for other regions.'' It is likely that UNESCO, if asked, would play a similar role as a facilitator for an African light source. [Preview Abstract] |
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T1.00054: Characterization of neutron yield and x-ray spectra of a High Flux Neutron Generator (HFNG) Nnaemeka Nnamani The High Flux Neutron Generator (HFNG) is a DD plasma-based source, with a self-loading target intended for fundamental science and engineering applications, including $^{\mathrm{40}}$Ar/$^{\mathrm{39}}$Ar geochronology, neutron cross section measurements, and radiation hardness testing of electronics. Our first estimate of the neutron yield, based on the population of the 4.486 hour $^{\mathrm{115}}$In isomer gave a neutron yield of the order 10$^{\mathrm{8}}$ n/sec; optimization is ongoing to achieve the design target of 10$^{\mathrm{11}}$ n/sec. Preliminary x-ray spectra showed prominent energy peaks which are likely due to atomic line-emission from back-streaming electrons accelerated up to 100 keV impinging on various components of the HFNG chamber. Our x-ray and neutron diagnostics will aid us as we continue to evolve the design to suppress back-streaming electrons, necessary to achieve higher plasma beam currents, and thus higher neutron flux. This talk will focus on the characterization of the neutron yield and x-ray spectra during our tests. A collimation system is being installed near one of the chamber ports for improved observation of the x-ray spectra. This work is supported by NSF Grant No. EAR-0960138, U.S. DOE LBNL Contract No. DE-AC02-05CH11231, U.S. DOE LLNL Contract No. DE-AC52-07NA27344, and the UC Office of the President Award 12-LR-238745. [Preview Abstract] |
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T1.00055: ABSTRACT WITHDRAWN |
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T1.00056: ACCELERATORS AND STORAGE RINGS |
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T1.00057: Plasma simulation in a hybrid ion electric propulsion system Manish Jugroot, Alex Christou An exciting possibility for the next generation of satellite technology is the microsatellite. These satellites, ranging from 10-500 kg, can offer advantages in cost, reduced risk, and increased functionality for a variety of missions. For station keeping and control of these satellites, a suitable compact and high efficiency thruster is required. Electrostatic propulsion provides a promising solution for microsatellite thrust due to their high specific impulse. The rare gas propellant is ionized into plasma and generates a beam of high speed ions by electrostatic processes. A concept explored in this work is a hybrid combination of dc ion engines and hall thrusters to overcome space-charge and lifetime limitations of current ion thruster technologies. A multiphysics space and time-dependent formulation was used to investigate and understand the underlying physical phenomena. Several regions and time scales of the plasma have been observed and will be discussed. [Preview Abstract] |
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