Dobson, Ken
2000-11-01
On Sunday 7 October 1900 Herr Doktor Heinrich Rubens and his wife dropped in on the Planck's Berlin household for tea and some (inevitable) shop-talk. Rubens and his colleague Ferdinand Kurlbaum had been working on an experimental project dear to Max Planck's heart: the variation of intensity with frequency of the radiation from hot objects. They had developed state-of-the-art techniques for taking measurements in the infrared, and Rubens outlined their latest results, due to be presented to the Prussian Academy on 25 October. Between teatime and suppertime Planck had deduced the final version of the radiation law. He was able to work so quickly because he had been working on the problem of reconciling the obviously incomplete Rayleigh law - and various other versions - for many years. The new data confirmed his fairly ad hoc reconciliation of electromagnetic theory and statistical thermodynamics and he sent the outline of his new relationship to Rubens by postcard the same evening. Almost as quick as an e-mail. This itself was a highly important step forward in physics - but what was really outstanding and original was yet to follow, after `a few weeks of the most strenuous work of my life', said the 42 year-old Planck. He realized the significance of his work: `Today I have made a discovery as important as that of Newton,' he confided to his son. This was his based on his determination to find a physical meaning for what had started off as `fictional' mathematical aids to help him derive his formula. The logic compelled him, somewhat reluctantly it appears, to accept that the vibrating objects in a hot body responsible for the oscillating electromagnetic waves they emitted could change in energy only by small discrete amounts: energy packets (quanta) of a size linked to frequency by the relationship E = hf. Not many people took a lot of notice of all this. One did - the obscure Albert Einstein who generalized it in his annus mirabilis 1905 to show that the
Quanta of Geometry: Noncommutative Aspects
Chamseddine, Ali H.; Connes, Alain; Mukhanov, Viatcheslav
2015-03-01
In the construction of spectral manifolds in noncommutative geometry, a higher degree Heisenberg commutation relation involving the Dirac operator and the Feynman slash of real scalar fields naturally appears and implies, by equality with the index formula, the quantization of the volume. We first show that this condition implies that the manifold decomposes into disconnected spheres, which will represent quanta of geometry. We then refine the condition by involving the real structure and two types of geometric quanta, and show that connected spin manifolds with large quantized volume are then obtained as solutions. The two algebras M2(H ) and M4(C ) are obtained, which are the exact constituents of the standard model. Using the two maps from M4 to S4 the four-manifold is built out of a very large number of the two kinds of spheres of Planckian volume. We give several physical applications of this scheme such as quantization of the cosmological constant, mimetic dark matter, and area quantization of black holes.
Monochromatic gamma emitter for low energy quanta
Tomova, Z R; Mironova, S A
2004-01-01
The possibility of creating of a monochromatic gamma emitter of low energy quanta is analyzed. The idea is based on Daning's scheme. Except for purely scientific problems the monochromator is actual for therapy of wide range of diseases.
Boudenot, Jean-Claude
2016-01-01
« Les atomes, dit Jean Perrin en 1913, ne sont pas ces éléments éternels et insécables dont l'irréductible simplicité donnait au possible une borne, et, dans leur inimaginable petitesse, nous commençons à pressentir un fourmillement prodigieux de mondes nouveaux ». C'est bien dans un monde totalement nouveau, le monde quantique, que nous a fait pénétrer la découverte des quanta par Max Planck. Son article de 1900 est le déclencheur de l'une des plus grandes révolutions scientifiques de tous les temps. Les trente années qui suivent sont les plus riches de la physique ; Planck, Einstein, Bohr, Sommerfeld, de Broglie, Schrödinger, Heisenberg, Dirac, Born, Pauli… reconstruisent la physique sur de nouvelles bases sur fond de conflit des générations. Le monde est par ailleurs secoué par la guerre, Max Planck est tourmenté et vit des épreuves personnelles dramatiques. C'est l'homme, aussi bien que l'oeuvre, que les auteurs ont tenté de dépeindre dans cet ouvrage. Ils ont également souhait�...
The propagation of gamma quanta in matter
Lejpunskij, Ovsej Ilich; Sakharov, Vsevolod Nikolaevich
1965-01-01
The Propagation of Gamma Quanta in Matter deals with various problems of the propagation and absorption of gamma quanta in matter, particularly the occurrence of multiple scattering of radiation. The ultimate objective is to determine the material, size, and configuration that will ensure the safe absorption of nuclear radiation. Shield design problems are given, the solution of which is achieved using numerical data presented in graphs and tables. This volume is comprised of three chapters and begins with an overview of the interaction of gamma radiation with matter and multiple scattering of
Flip-Flopping Fractional Flux Quanta
Ortlepp, T.; Ariando,; Mielke, O.; Verwijs, C.J.M.; Foo, K.F.K.; Rogalla, H.; Uhlmann, F.H.; Hilgenkamp, H.
2006-01-01
The d-wave pairing symmetry in high–critical temperature superconductors makes it possible to realize superconducting rings with built-in phase shifts. Such rings have a twofold degenerate ground state that is characterized by the spontaneous generation of fractional magnetic flux quanta with eithe
QUANTA: An Interdisciplinary Learning Community (Four Studies).
Avens, Cynthia; Zelley, Richard
QUANTA is a year-long interdisciplinary program at Daytona Beach Community College (Florida) that seeks to establish a learning community of students and teachers. Three courses (English, Pyschology, and Humanities) are integrated around a common theme each semester of the freshman year, and are taught using a collaborative teaching model. This…
Fractional flux quanta in superconducting solenoids
Sá de Melo, C. A. R.
1996-03-01
The quantization of flux quanta in superconductors is revisited and analyzed in a new topology. The topology is that of a superconducting wire that winds N times around a fixed axis and has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. In this case, fractional flux quanta can be measured through the center of the solenoid, provided that its cross-section radius is small enough. The Little-Parks experiment for an identical topology is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0.
Do sympathetic nerves release noradrenaline in "quanta"?
Stjärne, L
2000-07-01
The discovery of excitatory junction potentials (EJPs) in guinea-pig vas deferens by Burnstock and Holman (1960) showed for the first time that a sympathetic transmitter, now known to be ATP, is secreted in "quanta". As it was assumed at the time that EJPS are triggered by noradrenaline, this discovery led to attempts to use the fractional overflow of noradrenaline from sympathetically innervated tissues to assess, indirectly, the number of noradrenaline molecules in the average "quantum". The basic finding was that each pulse released 1/50000 of the tissue content of noradrenaline, when reuptake was blocked and prejunctional alpha(2)-adrenoceptors were intact. This provided the constraints, two extreme alternatives: (i) each pulse releases 0.2-3% of the content of a vesicle from all varicosities, or (ii) each pulse releases the whole content of a vesicle from 0.2 to 3% of the varicosities. New techniques have made it possible to address questions about the release probability in individual sites, or the "quantal" size, more directly. Results by optical (comparison of the labelling of SV2 and synaptotagmin, proteins in the membrane of transmitter vesicles), electrophysiological (excitatory junction currents, EJCs, at single visualized varicosities) and amperometric (the noradrenaline oxidation current at a carbon fibre electrode) methods reveal that transmitter exocytosis in varicosities is intermittent. The EJC and noradrenaline oxidation current responses (in rat arteries) to a train of single pulses were observed to be similar in intermittency and amplitude fluctuation. This suggests that they are caused by exocytosis of single or very few "quanta" of ATP and noradrenaline, respectively, equal to the contents of single vesicles, from a small population of release sites. These findings support, but do not conclusively prove the validity of the "intermittent" model of noradrenaline release. The question if noradrenaline is always secreted in packets of preset size
Local quanta, unitary inequivalence, and vacuum entanglement
Vázquez, Matías R.; del Rey, Marco; Westman, Hans; León, Juan
2014-12-01
In this work we develop a formalism for describing localised quanta for a real-valued Klein-Gordon field in a one-dimensional box [ 0 , R ] . We quantise the field using non-stationary local modes which, at some arbitrarily chosen initial time, are completely localised within the left or the right side of the box. In this concrete set-up we directly face the problems inherent to a notion of local field excitations, usually thought of as elementary particles. Specifically, by computing the Bogoliubov coefficients relating local and standard (global) quantisations, we show that the local quantisation yields a Fock representation of the Canonical Commutation Relations (CCR) which is unitarily inequivalent to the standard one. In spite of this, we find that the local creators and annihilators remain well defined in the global Fock space FG, and so do the local number operators associated to the left and right partitions of the box. We end up with a useful mathematical toolbox to analyse and characterise local features of quantum states in FG. Specifically, an analysis of the global vacuum state |0G > ∈FG in terms of local number operators shows, as expected, the existence of entanglement between the left and right regions of the box. The local vacuum |0L > ∈FL, on the contrary, has a very different character. It is neither cyclic (with respect to any local algebra of operators) nor separating and displays no entanglement between left and right partitions. Further analysis shows that the global vacuum also exhibits a distribution of local excitations reminiscent, in some respects, of a thermal bath. We discuss how the mathematical tools developed herein may open new ways for the analysis of fundamental problems in local quantum field theory.
The Quanta Image Sensor: Every Photon Counts
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Eric R. Fossum
2016-08-01
Full Text Available The Quanta Image Sensor (QIS was conceived when contemplating shrinking pixel sizes and storage capacities, and the steady increase in digital processing power. In the single-bit QIS, the output of each field is a binary bit plane, where each bit represents the presence or absence of at least one photoelectron in a photodetector. A series of bit planes is generated through high-speed readout, and a kernel or “cubicle” of bits (x, y, t is used to create a single output image pixel. The size of the cubicle can be adjusted post-acquisition to optimize image quality. The specialized sub-diffraction-limit photodetectors in the QIS are referred to as “jots” and a QIS may have a gigajot or more, read out at 1000 fps, for a data rate exceeding 1 Tb/s. Basically, we are trying to count photons as they arrive at the sensor. This paper reviews the QIS concept and its imaging characteristics. Recent progress towards realizing the QIS for commercial and scientific purposes is discussed. This includes implementation of a pump-gate jot device in a 65 nm CIS BSI process yielding read noise as low as 0.22 e− r.m.s. and conversion gain as high as 420 µV/e−, power efficient readout electronics, currently as low as 0.4 pJ/b in the same process, creating high dynamic range images from jot data, and understanding the imaging characteristics of single-bit and multi-bit QIS devices. The QIS represents a possible major paradigm shift in image capture.
Proving Light Quanta Exist in an Undergraduate Laboratory
Neel, M. S.; Thorn, J. J.; Davies, R. E.; Beck, M.
2003-05-01
While well known experiments involving phenomena such as the photoelectric effect and Compton scattering strongly suggest the existence of photons, they do not prove the existence of light quanta. For example, it is possible to explain both of the aforementioned effects using a semiclassical treatment in which the electromagnetic field is not quantized, and is instead treated as a classical wave. To prove the existence of light quanta one must perform an experiment whose results cannot be explained using classical waves. Here we have performed an experiment that cannot be explained with a classical wave theory, and which demonstrates the localization of light quanta. Namely, we prove that a single photon can only go one way when it leaves a beamsplitter. (P. Grangier, G. Roger and A. Aspect, Europhys. Lett. 1, 173 (1986).) The experimental apparatus is appropriate for an undergraduate teaching laboratory.
On the number of soft quanta in classical field configurations
Mueck, Wolfgang
2013-01-01
A central point in the large-N portrait of black holes proposed by Dvali and Gomez is the estimate of the number of soft quanta that make up the classical gravitational field. It is shown here that the coherent state formalism provides a way to calculate that number directly. As a consequence, the average energy of the quanta is such that the typical geometric size of the field source can be roughly interpreted as their de Broglie wavelength. The calculation is done for the electromagnetic field and for Newtonian gravity, and it is argued that the number of soft quanta should be unchanged in General Relativity due to the long range nature of gravity.
Nota (polemica) sobre la representación de la guerra en Quanta, quanta guerra ...de Merce Rodored
Łuczak, Barbara
2003-01-01
The objective of the article is to describe the structure of the narrative world in Mercć Rodoreda’s Quanta, ąuanta guerra... and to analyse representation of the war as one of the most important elements of this universe.
Bistability and chaos at low levels of quanta.
Gevorgyan, T V; Shahinyan, A R; Chew, Lock Yue; Kryuchkyan, G Yu
2013-08-01
We study nonlinear phenomena of bistability and chaos at a level of few quanta. For this purpose, we consider a single-mode dissipative oscillator with strong Kerr nonlinearity with respect to the dissipation rate driven by a monochromatic force as well as by a train of Gaussian pulses. The quantum effects and decoherence in the oscillatory mode are investigated in the framework of the purity of states and the Wigner functions calculated from the master equation. We demonstrate the quantum chaotic regime by means of a comparison between the contour plots of the Wigner functions and the strange attractors on the classical Poincaré section. Considering bistability at a low limit of quanta, we analyze the minimal level of excitation numbers at which the bistable regime of the system is displayed. We also discuss the formation of an oscillatory chaotic regime by varying oscillatory excitation numbers at ranges of a few quanta. We demonstrate quantum-interference phenomena that are assisted hysteresis-cycle behavior and quantum chaos for the oscillator driven by a train of Gaussian pulses. We establish the border of quantum-classical correspondence for chaotic regimes in the case of strong nonlinearities.
Quantum Random Number Generation Using a Quanta Image Sensor
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Emna Amri
2016-06-01
Full Text Available A new quantum random number generation method is proposed. The method is based on the randomness of the photon emission process and the single photon counting capability of the Quanta Image Sensor (QIS. It has the potential to generate high-quality random numbers with remarkable data output rate. In this paper, the principle of photon statistics and theory of entropy are discussed. Sample data were collected with QIS jot device, and its randomness quality was analyzed. The randomness assessment method and results are discussed.
Quantum Random Number Generation Using a Quanta Image Sensor
Amri, Emna; Felk, Yacine; Stucki, Damien; Ma, Jiaju; Fossum, Eric R.
2016-01-01
A new quantum random number generation method is proposed. The method is based on the randomness of the photon emission process and the single photon counting capability of the Quanta Image Sensor (QIS). It has the potential to generate high-quality random numbers with remarkable data output rate. In this paper, the principle of photon statistics and theory of entropy are discussed. Sample data were collected with QIS jot device, and its randomness quality was analyzed. The randomness assessment method and results are discussed. PMID:27367698
Outstanding Antibiofilm Features of Quanta-CuO Film on Glass Surface.
Tripathy, Nirmalya; Ahmad, Rafiq; Bang, Seung Hyuck; Khang, Gilson; Min, Jiho; Hahn, Yoon-Bong
2016-06-22
Intelligently designed surface nanoarchitecture provides defined control over the behavior of cells and biomolecules at the solid-liquid interface. In this study, CuO quantum dots (quanta-CuO; ∼3-5 nm) were synthesized by a simple, low-temperature solution process and further formulated as paint to construct quanta-CuO thin film on glass. Surface morphological characterizations of the as-coated glass surface reveal a uniform film thickness (∼120 ± 10 nm) with homogeneous distribution of quanta-CuO. The antibiofilm assay showed a very high contact bacteria-killing capacity of as-coated quanta-CuO glass surfaces toward Staphylococcus aureus and Escherichia coli. This efficient antibacterial/antibiofilm activity was ascribed to the intracellular reactive oxygen species (ROS) generated by the quanta-CuO attached to the bacterial cells, which leads to an oxidative assault and finally results in bacterial cell death. Although there is a significant debate regarding the CuO nanostructure's antibacterial mode of action, we propose both contact killing and/or copper ion release killing mechanisms for the antibiofilm activity of quanta-CuO paint. Moreover, synergism of quanta-CuO with conventional antibiotics was also found to further enhance the antibacterial efficacy of commonly used antibiotics. Collectively, this state-of-the-art design of quanta-CuO coated glass can be envisioned as promising candidates for various biomedical and environmental device coatings.
How likely are constituent quanta to initiate inflation?
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Lasha Berezhiani
2015-10-01
Full Text Available We propose an intuitive framework for studying the problem of initial conditions in slow-roll inflation. In particular, we consider a universe at high, but sub-Planckian energy density and analyze the circumstances under which it is plausible for it to become dominated by inflated patches at late times, without appealing to the idea of self-reproduction. Our approach is based on defining a prior probability distribution for the constituent quanta of the pre-inflationary universe. To test the idea that inflation can begin under very generic circumstances, we make specific – yet quite general and well grounded – assumptions on the prior distribution. As a result, we are led to the conclusion that the probability for a given region to ignite inflation at sub-Planckian densities is extremely small. Furthermore, if one chooses to use the enormous volume factor that inflation yields as an appropriate measure, we find that the regions of the universe which started inflating at densities below the self-reproductive threshold nevertheless occupy a negligible physical volume in the present universe as compared to those domains that have never inflated.
Integration of sensory quanta in cuneate nucleus neurons in vivo.
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Fredrik Bengtsson
Full Text Available Discriminative touch relies on afferent information carried to the central nervous system by action potentials (spikes in ensembles of primary afferents bundled in peripheral nerves. These sensory quanta are first processed by the cuneate nucleus before the afferent information is transmitted to brain networks serving specific perceptual and sensorimotor functions. Here we report data on the integration of primary afferent synaptic inputs obtained with in vivo whole cell patch clamp recordings from the neurons of this nucleus. We find that the synaptic integration in individual cuneate neurons is dominated by 4-8 primary afferent inputs with large synaptic weights. In a simulation we show that the arrangement with a low number of primary afferent inputs can maximize transfer over the cuneate nucleus of information encoded in the spatiotemporal patterns of spikes generated when a human fingertip contact objects. Hence, the observed distributions of synaptic weights support high fidelity transfer of signals from ensembles of tactile afferents. Various anatomical estimates suggest that a cuneate neuron may receive hundreds of primary afferents rather than 4-8. Therefore, we discuss the possibility that adaptation of synaptic weight distribution, possibly involving silent synapses, may function to maximize information transfer in somatosensory pathways.
Major Gravitational Phenomena Explained by the Micro-Quanta Paradigm
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Michelini M.
2010-01-01
Full Text Available Some major problems of physics, which remained unsolved within classical and rel- ativistic gravitation theories, are explained adopting the quantum gravity interaction descending from the micro-quanta paradigm. The energy source of the gravitational power P g r , which heats and contracts the Bok’s gas globules harbouring the future stars, is identified and defined as well as the gravitational power generated on the solid / fluid planets. Calculations are carried out to make the comparison between P g r predicted for the solar giant planets and the measured infrared radiation power P int coming from the interior. The case of planets with solid crust (Earth, etc. requires a particular attention due to the threat to stability produced by the thermal dilatation. An analysis is done of the Earth’s planetary equilibrium which may be attained eliminating the temperature rise through the migration of hot internal magma across the crust fractured by earth- quakes. The temperatures observed up to 420,000 years ago in Antartica through Vostok and Epica ice cores suggest the possibility that the Earth gravitational power P g r may be radiated in space through these temperature cycles (Glacial Eras. In this general frame the Earth’s high seismicity and the dynamics of Plate tectonics may find their origin.
Major Gravitational Phenomena Explained by the Micro-Quanta Paradigm
Directory of Open Access Journals (Sweden)
Michelini M.
2010-01-01
Full Text Available Some major problems of physics, which remained unsolved within classical and relativistic gravitation theories, are explained adopting the quantum gravity interaction descending from the micro-quanta paradigm. The energy source of the gravitational power $P_{gr}$, which heats and contracts the Bok's gas globules harbouring the future stars, is identified and defined as well as the gravitational power generated on the solid/fluid planets. Calculations are carried out to make the comparison between $P_{gr}$ predicted for the solar giant planets and the measured infrared radiation power $P_{int}$ coming from the interior. The case of planets with solid crust (Earth, etc. requires a particular attention due to the threat to stability produced by the thermal dilatation. An analysis is done of the Earth's planetary equilibrium which may be attained eliminating the temperature rise through the migration of hot internal magma across the crust fractured by earthquakes. The temperatures observed up to 420,000 years ago in Antartica through Vostok and Epica ice cores suggest the possibility that the Earth gravitational power $P_{gr}$ may be radiated in space through these temperature cycles (Glacial Eras. In this general frame the Earth's high seismicity and the dynamics of Plate tectonics may find their origin.
I quanta acustici e la teoria dell’udito
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Dennis Gabor
2016-06-01
Full Text Available Writing in 1946 and 1947, the author considers the possibility to describe acoustical phenomena with quantum methods, and emphasizes that such an approach on sound analysis connects very neatly with issues in the psychophysiology of hearing. Central to Gabor’s paper is a representation of sound signals including the explicit determination of both frequency and time variables (different from the classic Fourier analysis, where sound is analysed in terms of perfectly periodical oscillations, i.e. oscillations of indeterminate duration. The author illustrates an «information diagram» that splits the sound signal in «logons» or acoustical quanta, e.g. rectangular units of minimal time/frequency area. These latter are formally described as functions or «elementary signals» consisting of a real part (oscillation and an imaginary part (a pseudo-Gaussian pulse. The author shows that the time/frequency unit area in the information diagram are subject to quantum uncertainty. And that the definition of such unit area of acoustical energy might definitely converge with a number of (then accepted empirical measurements in the psychophysiology of hearing.
Contextual essay for integrated thematic unit: Kids, Quarks, and Quanta
Draeger, Vicki Lee
This essay provides the research and rationale to support the theory that early adolescence is the best time to present an introduction to quantum mechanics. It supports the creation of an integrated thematic unit to be used with students ages 11--14 in an inclusion classroom without limiting the unit to only an inclusion setting. The first section sets forth five problems the unit was written to address. Citing The National Center for Education Statistics 2000 version of The Nation's Report Card, the problems with current practices in science education resulting in poor student performance are presented. References to Project 2061: Science for All Americans help to demonstrate that students with disabilities are seldom considered when physical science curriculum is being developed, supporting the position that equity in science education is necessary, while maintaining challenging subject matter. The problem of the poor quality of many physical science texts is addressed, with an emphasis on the importance of curricular connections. The poor quality of physical science teacher training in many university teacher training courses is discussed, and the nature of the integrated thematic unit as a curriculum design is examined with reference to what is considered the over-emphasis on "reality-based" content to the exclusion of abstract subject matter. Having presented the problems and supporting their validity, the essay then demonstrated how Kids, Quarks, and Quanta specifically addresses each problem. The two and a half year study of Dr. John Hubisz and the committee he formed under The David and Lucille Packard Foundation grant to review and critique the physical science textbooks currently used with early adolescents is often referenced to support both the problems of teacher training and the poor quality of many texts. Recent brain research conducted by researchers of the National Institute of Mental Health is used to support the presentation of more abstract
What heavy quanta bounds could be inferred from a Higgs discovery?
Díaz-Cruz, J L
2001-01-01
The Higgs couplings can receive non-decoupling corrections due to heavy quanta, and deviations from the SM can be used to test its presence. The possible Higgs signal recently reported at LEP, with mh=115 GeV, severely constrains the presence of heavy quanta, such as a heavy fourth family. At Tevatron, the Higgs production by gluon fusion, followed by the decay h -> WW*, can also be used to probe the existence of heavy colored particles, including additional families, chiral sextet and octet quarks. Within the MSSM, we also find that gluon fusion is a sensitive probe for the squark spectrum.
The physics of atoms and quanta introduction to experiments and theory
Haken, Hermann; Brewer, William D
2000-01-01
The Physics of Atoms and Quanta is a thorough introduction to experiments and theory in this field. Every classical and modern aspect is included and discussed in detail. The new edition is completely revised, new sections on atoms in strong electric fields and high magnetic fields complete the comprehensive coverage of all topics related to atoms and quanta. All new developments, such as new experiments on quantum entanglement, the quantum computer, quantum information, the Einstein-Podolsky-Rosen paradoxon, Bell's inequality, Schrödinger's cat, decoherence, Bose-Einstein-Condensation and the atom laser are discussed. Over 170 problems and their solutions help deepen the insight in this subject area and make this book a real study text. The second and more advanced book by the same authors entitled "Molecular Physics and Elements of Quantum Chemistry" is the completion of this unique textbook.
Stability of the GaAs based Hall sensors irradiated by gamma quanta
Gradoboev, Aleksandr Vasilyevich; Karlova, G. F.
2015-01-01
The present work is aimed at investigation of the stability of the GaAsbased Hall sensors (pickups) to irradiation by gamma quanta. The examined objects are the gallium arsenide based Hall sensors manufactured on thin active layers by the methods of vaporphase epitaxy (VPE), molecular beam epitaxy, and ion implantation. Our research methodology involves measurements of the volt-ampere characteristics (VACs) of all sensors for different values of the supply voltage polarity and electron concen...
Quantum-mechanical derivation of the Davydov equations for multi-quanta states
Energy Technology Data Exchange (ETDEWEB)
Kerr, W.C.; Lomdahl, P.S.
1989-01-01
Our purpose here is to present a derivation of the Davydov equations which employs only quantum-mechanical techniques. The derivation here is more general than our previous treatment of this problem because we use an Ansatz which has present several quanta of the high frequency oscillator system rather than just one quantum. Since some steps of the calculation are the same as those in our paper which treats the single quantum case, reference will be made to that paper for some of the those details. 9 refs.
Are there Mega Quanta of Action Playing a Part in Hubble Spheres?
Kostro, Ludwik
Quanta of action (Planck's, Stoney's, Kittel's etc.) are related to the so-called units determined by universal constants: c - speed of light in vacuum, G - Newtonian gravitational constant and by the respective constant connected with the respective interaction. If we introduce Λ - units determined by c, G and Λ we obtain also the Λ- mega quantum of action. It will be shown that this quantum of action can be disclosed in the Lagrangian used to express the stationary action in General Relativity applied in cosmology in which the cosmological constant Λ appears. It will be discussed if this mega quantum is connected with the causally bounded zones in our universe, i.e. with the Hubble spheres. If we introduce Kittel's gravitational units determined by c, G and MG, where MG means the gravitational mass (of ordinary + and dark matter), embedded and causally bounded in a Hubble' sphere then we obtain also a Kittel mega quantum of action. The meaning of both mega quanta will be discussed.
Excitation of vibrational quanta in furfural by intermediate-energy electrons
Energy Technology Data Exchange (ETDEWEB)
Jones, D. B. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Neves, R. F. C. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Instituto Federal do Sul de Minas Gerais, Campus Poços de Caldas, Minas Gerais (Brazil); Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, MG (Brazil); Lopes, M. C. A. [Departamento de Física, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, MG (Brazil); Costa, R. F. da [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo (Brazil); Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, 09210-580 São Paulo (Brazil); Varella, M. T. do N. [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, São Paulo (Brazil); Bettega, M. H. F. [Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná (Brazil); Lima, M. A. P. [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo (Brazil); García, G. [Instituto de Física Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); and others
2015-12-14
We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°–90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.
La teoría de los quanta en España
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Moreno González, Antonio
2000-12-01
Full Text Available Not available
En España la incorporación de la teoría de los cuantos de Planck a las revistas y otras publicaciones de difusión de la actividad científica, a las enseñanzas secundaria y universitaria, así como a los ámbitos de información y debate donde tuvieron eco las noticias sobre el panorama científico internacional, fue desigual y en algunos casos tardía. De cómo se produjo este proceso de actualización científica y el atisbo de algunas razones que pudieran justificar la tardanza en dar por buena la novedad de los quanta, me ocuparé en las páginas que siguen.
Non-gaussianities and the Stimulated creation of quanta in the inflationary universe
Agullo, Ivan
2010-01-01
Cosmological inflation generates a spectrum of density perturbations that can seed the cosmic structures we observe today. These perturbations are usually computed as the result of the gravitationally-induced spontaneous creation of perturbations from an initial vacuum state. In this paper, we compute the perturbations arising from gravitationally-induced stimulated creation when perturbations are already present in the initial state. The effect of these initial perturbations is not diluted by inflation and survives to its end, and beyond. We consider a generic statistical density operator $\\rho$ describing an initial mixed state that includes probabilities for nonzero numbers of scalar perturbations to be present at early times during inflation. We analyze the primordial bispectrum for general configurations of the three different momentum vectors in its arguments. We find that the initial presence of quanta can significantly enhance non-gaussianities in the so-called squeezed limit. Our results show that an...
Images from Bits: Non-Iterative Image Reconstruction for Quanta Image Sensors
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Stanley H. Chan
2016-11-01
Full Text Available A quanta image sensor (QIS is a class of single-photon imaging devices that measure light intensity using oversampled binary observations. Because of the stochastic nature of the photon arrivals, data acquired by QIS is a massive stream of random binary bits. The goal of image reconstruction is to recover the underlying image from these bits. In this paper, we present a non-iterative image reconstruction algorithm for QIS. Unlike existing reconstruction methods that formulate the problem from an optimization perspective, the new algorithm directly recovers the images through a pair of nonlinear transformations and an off-the-shelf image denoising algorithm. By skipping the usual optimization procedure, we achieve orders of magnitude improvement in speed and even better image reconstruction quality. We validate the new algorithm on synthetic datasets, as well as real videos collected by one-bit single-photon avalanche diode (SPAD cameras.
Korshunov, V M; Kissina, E V; Ikonnikova, T B; Mal'tsev, V N; Goncharova, G I
1980-06-01
Lactobacilli (strain B12G) and bifidobacteria (strain 75-41), administered orally in a dose of 5 x 10 cells to CBA mice on days 1, 3, 5 and 10 after irradiation with gamma quanta in a dose of 700 rad, restored the "eubiosis" of the intestinal tract, specifically suppressing opportunistic bacteria and facilitating the normalization of the quantitative and qualitative correlation between microbial associations constituting the obligatory intestinal flora. For one thing, the preparations of lactobacilli and bifidobacteria, used for treatment, restored the amount of lactobacilli in the intestinal tract of the irradiated animals to the level, characteristic of the intact animals; for another, these preparations prevented the dissemination of Escherichia, Proteus, Enterococcus in the small intestine and considerably decreased the amount of these microorganisms, as well as Clostridium, in the large intestine.
Images from Bits: Non-Iterative Image Reconstruction for Quanta Image Sensors.
Chan, Stanley H; Elgendy, Omar A; Wang, Xiran
2016-11-22
A quanta image sensor (QIS) is a class of single-photon imaging devices that measure light intensity using oversampled binary observations. Because of the stochastic nature of the photon arrivals, data acquired by QIS is a massive stream of random binary bits. The goal of image reconstruction is to recover the underlying image from these bits. In this paper, we present a non-iterative image reconstruction algorithm for QIS. Unlike existing reconstruction methods that formulate the problem from an optimization perspective, the new algorithm directly recovers the images through a pair of nonlinear transformations and an off-the-shelf image denoising algorithm. By skipping the usual optimization procedure, we achieve orders of magnitude improvement in speed and even better image reconstruction quality. We validate the new algorithm on synthetic datasets, as well as real videos collected by one-bit single-photon avalanche diode (SPAD) cameras.
Simulations of gamma quanta scattering in a single module of the J-PET detector
Szymański, K; Bednarski, T; Białas, P; Czerwiński, E; Giergiel, K; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Molenda, M; Moskal, I; Niedźwiecki, Sz; Pałka, M; Pawlik, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Witkowski, P; Wiślicki, W; Zieliński, M; Zoń, N
2013-01-01
This article describes simulations of scattering of annihilation gamma quanta in a strip of plastic scintillator. Such strips constitute basic detection modules in a newly proposed Positron Emission Tomography which utilizes plastic scintillators instead of inorganic crystals. An algorithm simulating chain of Compton scatterings was elaborated and series of simulations have been conducted for the scintillator strip with the cross section of 5 mm x 19 mm. Obtained results indicate that secondary interactions occur only in the case of about 8% of events and out of them only 25$\\%$ take place in the distance larger than 0.5 cm from the primary interaction. It was also established that light signals produced at primary and secondary interactions overlap with the delay which distribution is characterized by FWHM of about 40 ps.
Excitation of vibrational quanta in furfural by intermediate-energy electrons
Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; Blanco, F.; Brunger, M. J.
2015-12-01
We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.
Directory of Open Access Journals (Sweden)
A. A. Zolotin
2015-07-01
Full Text Available Posteriori inference is one of the three kinds of probabilistic-logic inferences in the probabilistic graphical models theory and the base for processing of knowledge patterns with probabilistic uncertainty using Bayesian networks. The paper deals with a task of local posteriori inference description in algebraic Bayesian networks that represent a class of probabilistic graphical models by means of matrix-vector equations. The latter are essentially based on the use of tensor product of matrices, Kronecker degree and Hadamard product. Matrix equations for calculating posteriori probabilities vectors within posteriori inference in knowledge patterns with quanta propositions are obtained. Similar equations of the same type have already been discussed within the confines of the theory of algebraic Bayesian networks, but they were built only for the case of posteriori inference in the knowledge patterns on the ideals of conjuncts. During synthesis and development of matrix-vector equations on quanta propositions probability vectors, a number of earlier results concerning normalizing factors in posteriori inference and assignment of linear projective operator with a selector vector was adapted. We consider all three types of incoming evidences - deterministic, stochastic and inaccurate - combined with scalar and interval estimation of probability truth of propositional formulas in the knowledge patterns. Linear programming problems are formed. Their solution gives the desired interval values of posterior probabilities in the case of inaccurate evidence or interval estimates in a knowledge pattern. That sort of description of a posteriori inference gives the possibility to extend the set of knowledge pattern types that we can use in the local and global posteriori inference, as well as simplify complex software implementation by use of existing third-party libraries, effectively supporting submission and processing of matrices and vectors when
Go Pink! The Effect of Secondary Quanta on Detective Quantum Efficiency
Energy Technology Data Exchange (ETDEWEB)
Watson, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-09-05
Photons are never directly observable. Consequently, we often use photoelectric detectors (eg CCDs) to record associated photoelectrons statistically. Nonetheless, it is an implicit goal of radiographic detector designers to achieve the maximum possible detector efficiency1. In part the desire for ever higher efficiency has been due to the fact that detectors are far less expensive than associated accelerator facilities (e.g. DARHT and PHERMEX2). In addition, higher efficiency detectors often have better spatial resolution. Consequently, the optimization of the detector, not the accelerator, is the system component with the highest leverage per dollar. In recent years, imaging scientists have adopted the so-called Detective Quantum Efficiency, or DQE as a summary measure of detector performance. Unfortunately, owing to the complex nature of the trade-space associated with detector components, and the natural desire for simplicity and low(er) cost, there has been a recent trend in Los Alamos to focus only on the zerofrequency efficiency, or DQE(0), when designing such systems. This narrow focus leads to system designs that neglect or even ignore the importance of high-spatial-frequency image components. In this paper we demonstrate the significant negative impact of these design choices on the Noise Power Spectrum1 (NPS) and recommend a more holistic approach to detector design. Here we present a statistical argument which indicates that a very large number (>20) of secondary quanta (typically visible light and/or recorded photo-electrons) are needed to take maximum advantage of the primary quanta (typically x-rays or protons) which are available to form an image. Since secondary particles come in bursts, they are not independent. In short, we want to maximize the pink nature of detector noise at DARHT.
Obol, Mahmut
2013-01-01
Ferrites are distinct material for electromagnetic applications due to its unique spin precession. In this paper, Casimir pressure effect by deploying magnetically tunable surface plasmon quanta in stratified structure of using ferrite and metal wires is presented. Previously, oscillating surface plasmon quanta were successfully included to modify first reflection and first transmission characteristics. The oscillating surface plasmon quanta in the modified reflection in such a system, not only does resolve in a typical matter in metamaterial, but also provide new applications such as creating Casimir pressure effects through the metamaterial composite shown in this paper. The Casimir pressure flips from attractive state to repulsive state is referred to actual cause mechanism of radiation from surface plasmon quanta. Both Casimir force analysis and the measured data of radiations indicate us the system develops quantized states by electric flux induced by ferromagnetic resonance, so we also carried quantum a...
Kotkin, G L
1996-01-01
The elastic light-light scattering below the threshold of the $e^+e^-$ pair production leads to a variation in polarization of hard $\\gamma$-quanta traversing without loss a region where the laser light is focused. Equations are obtained which determine the variation of Stokes parameters of that this effect can be observed in the experiment E-144 at SLAC. It should be taken into account (and, perhaps, it can be used) in experiments at future
Detectors for selective registration of charged particles and gamma-quanta
Ryzhikov, V; Katrunov, K
2002-01-01
A new design is proposed and described of a combined detector (CD) for simultaneous detection of charged particles and gamma-quanta. The CD comprises a single crystalline plate of ZnSe(Te) placed onto the output window of a scintillating transparent light transducer made of CsI(Ti) and Al sub 2 O sub 3 (Ti) in the shape of truncated pyramid. The CsI(Ti) light transducer is used to create an additional channel for detection of gamma-radiation,as well as for protecting the photodiode from the penetrating radiation.It is shown that introduction of such light transducer does not worsen the energy characteristics of ZnSe(Te). Separate detection of alpha- and gamma-radiation has been achieved under simultaneous excitation by sup 2 sup 3 sup 9 Pu (ZnSe(Te), R sub a =6%) and sup 2 sup 4 sup 1 Am (CsI(Tl), R subgamma = 20 %). The use of selective optical filters allows separation of the peaks of total absorption (p.t.a.) in the case of their superposition.
Fast quantum control and light-matter interactions at the 10,000 quanta level
Alonso, J; Soler, Z U; Fadel, M; Marinelli, M; Keitch, B C; Negnevitsky, V; Home, J P
2015-01-01
Fast control of quantum systems is essential in order to make use of quantum properties before they are degraded by decoherence. This is important for quantum-enhanced information processing, as well as for pushing quantum systems into macroscopic regimes at the boundary between quantum and classical physics. Bang-bang control attains the ultimate speed limit by making large changes to control fields on timescales much faster than the system can respond, however these methods are often challenging to implement experimentally. Here we demonstrate bang-bang control of a trapped-ion oscillator using nano-second switching of the trapping potentials. We perform controlled displacements which allow us to realize quantum states with up to 10,000 quanta of energy. We use these displaced states to verify the form of the ion-light interaction at high excitations which are far outside the usual regime of operation. These methods provide new possibilities for quantum-state manipulation and generation, alongside the poten...
On the integration of fields and quanta in time dependent backgrounds
Castillo, Esteban; Palma, Gonzalo
2013-01-01
Field theories with global continuous symmetries may admit configurations in which time translation invariance is broken by the movement of homogeneous background fields evolving along the flat directions implied by the symmetries. In this context, the field fluctuations along the broken symmetry are well parametrized by a Goldstone boson field that may non-trivially interact with other fields present in the theory. These interactions violate Lorentz invariance as a result of the broken time translation invariance of the background, producing a mixing between the field content and the particle spectrum of the theory. In this article we study the effects of such interactions on the low energy dynamics of the Goldstone boson quanta, paying special attention to the role of the particle spectrum of the theory. By studying the particular case of a canonical two-field model with a mexican-hat potential, we analyze the derivation of the low energy effective field theory for the Goldstone boson, and discuss in detail...
I quanta acustici di Gabor nelle tecnologie del suono e della musica
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Agostino Di Scipio
2016-06-01
Full Text Available Through a series of brillant paper publications dating from the late 1940s, Dennis Gabor developed a new conceptual and operational framework for the analysis of sound signals, based on a quantum-oriented view of acoustical phenomena. In the present essay, I try to illustrate the shaping up of Gabor’s quantum analysis of sound, especially as delineated in two papers from 1946 (Theory of communication and 1947 (Acoustical quanta and the theory of hearing, and to overview its legacy in scientific research as well as in audio and musical applications. After some introductory remarks, I follow a hybrid path, between history of science and history of audio technology, sketching a “genealogy” of Gabor’s quantum view of sound (i.e. as connected to Heisenberg’s indeterminacy principle, to Mach’s analysis of sensation, etc., and relating it to an empiricist tradition of modern science. I eventually situate his research in the context of contemporary research preoccupations shared by other, at the time, and I finally discuss some of the earliest audio devices that seem to tie back to Gabor’s own practical experiments (beside his theoretical framework and that revealed of primary interest to pioneers in analog and digital music technologies and related creative practices.
Yamauchi, Megumi S; Shingaki, Naohiko; Yamane, Nobuhisa
2012-05-01
We evaluated QUANTA Lite reagent series (INOVA Diagnostics, CA, USA) to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded (ds) DNA, SS-A and SS-B, in parallel with MESACUP (Medical & Biological Laboratories, Nagoya). Overall agreements between two reagents for qualitative interpretation ranged from 77.5% (ANA) to 99.0%(anti-SS-B antibodies). When we compared to the results by indirect fluorescent antibody (IFA) test on HEp-2 cells, QUANTA Lite ANA demonstrated better sensitivity and specificity; 92.2% versus 76.5% in sensitivity and 92.1% versus 86.8% in specificity. Also, determining anti-chromatin antibodies and IFA test onto Chrithidia luciliae demonstrated greater interpretive correlation to detect anti-ds DNA by QUANTA Lite than by MESACUP. All the discrepant sera to which QUANTA Lite SS-A gave positive interpretations were confirmed to contain the antibodies specific to SS-A 52kDa antigen, which is supplemented to QUANTA Lite capture-probes. With these results, we can conclude that QUANTA Lite has superiorities over MESACUP; (1) to detect a variety of autoantibodies consisting of ANA, (2) to have a better correlation with confirmatory tests to detect anti-ds DNA antibodies, (3)to detect additional autoantibodies specific to SS-A 52kDa antigen, and (4) to have an enough compatibility in determining anti-SS-B antibodies.
Cyclotron resonance of composite fermions with two and four flux quanta
Kukushkin, I. V.; Smet, J. H.; von Klitzing, K.; Wegscheider, W.
2003-12-01
The application of quantum field theoretical methods to strongly interacting many-body problems has reaped rich rewards. Foremost, it has nurtured the quasi-particle notion. The introduction of suitable fictitious entities permits to cast otherwise notoriously difficult many-body systems in a single-particle form. We can then take the customary physical approach, using concepts and representations which formerly could only be applied to systems with weak interactions, and still capture the essential physics. A most notable recent example occurs in the conduction properties of a two-dimensional electron system, when exposed to a strong perpendicular magnetic field B. They are governed by electron-electron interactions, that bring about the Nobel prize winning fractional quantum Hall effect (FQHE) (Perspectives on Quantum Hall effects, Wiley, New York, 1996). Composite fermions (CFs), that do not experience the external magnetic field but a drastically reduced effective magnetic field B ∗, were identified as opposite quasi-particles that simplify enormously the understanding of the FQHE (Phys. Today (2000) 39; Phys. Rev. Lett. 63 (1989) 199). They behave as legitimate particles with well-defined charge, spin and statistics (Phys. Rev. B 47 (1993) 7312; Composite Fermions, World Scientific, Singapore, 1998; Phys. Rev. Lett. 70 (1993) 2944; 75 (1995) 3926; 71 (1993) 3846; 72 (1994) 2065; 77 (1996) 2272). They precess, like electrons, along circular orbits, with a diameter determined by B ∗ rather than B, and with a frequency that is hard to predict, since the effective mass remains enigmatic. Ever since their prediction, the demonstration of enhanced absorption of a microwave field that resonates with the frequency of their circular motion was considered the ultimate experiment to unravel this issue. Here, we report the observation of this cyclotron resonance of CFs with two and four flux quanta and extract their effective mass.
Siegel, Edward Carl-Ludwig; Newcomb, Simon; Strutt-Rayleigh, John William; Poincare, Henri; Weyl, Hermann; Benford, Frederick; Antonoff, Marvin
2015-03-01
DIGIT-PHYSICS: DIGITS?: For a Very Long Time Giving Us All The FINGER!!!: CONTRA Wigner,``On the Unreasonable Effectiveness of Physics in Mathematics!'' A Surprise in Theoretical/Experimental Physics and/or Ostensibly Pure-Mathematics: PHYSICS: Quantum-Mechanics/Statistical-.Mechanics. DIGITS-LAW(S); DIGITS' ostensibly ``pure-mathematics' 1:1-map onto the QUANTUM!!! [Google:''http://www.benfordonline.net/ list/ chronological'']: Newcomb[Am.J.Math.4,39(1881)]-Poincare[Calcul des Probabilité(1912)]-Weyl[Math.Ann., 77, 313(1916)-Benford[J.Am.Phil Soc,78,115 (1938)]-..-Antonoff/Siegel[AMS Joint-Mtg.,San Diego(2002)-abs.# 973-60-124] empirical inter-digit{on-ANY/ALL averageS) = log[base =10] (1 + 1/d) = log[base =10] ([d +1]/d) upon algebraic-inversion is d = 1/[10⌃[ ] -1] 1/[2.303..e⌃[ ] -1] 1/[2.303..e⌃[] -1] 1/[2.303..e⌃[ ω] -1]: Digits Are Bosons Are Quanta Because (On Average) Quanta and Bosons Are and Always Were Digits!!! (Ex: atom energy-levels numbering: 0,...,9) ANY/ALL QUANTUM-physics[Planck(1901)-Einstein(1905)-Bose(1924)-Einstein(1925)-vs.Fermi(1927)-Dirac(1927)-...] is and always was Newcomb(1881) DIGIT-physics!!!
Tang, Xiangyang; Yang, Yi; Tang, Shaojie
2012-03-01
The grating-based x-ray differential phase contrast (DPC) CT is emerging as a new technology with the potential for extensive preclinical and clinical applications. In general, the performance of an imaging system is jointly determined by its signal property (modulation transfer function-MTF(k)) and noise property (noise power spectrum-NPS(k)), which is characterized by its spectrum of noise equivalent quanta. As reported by us previously, owing to an adoption of the Hilbert filtering for image reconstruction in the fashion of filtered backprojection (FBP), the noise property of DPC-CT characterized by its NPS(k) differs drastically from that of the conventional attenuation-based CT (1/|k| trait vs. |k| trait). In this work, via system analysis, modeling and simulated phantom study, we initially investigate the signal property of DPC-CT characterized by its MTF(k) and compare it with that of the conventional CT. In addition, we investigate the DPC-CT's spectrum of noise equivalent quanta NEQ(k) - the most important figure of merit (FOM) in the assessment of an imaging system's performance - by taking the MTF(k) and NPS(k) jointly into account. Through such a thorough investigation into both the signal and noise properties, the imaging performance of DPC-CT and its potential over the conventional attenuation-based CT can be fully understood and appreciated.
Energy Technology Data Exchange (ETDEWEB)
Akimenko, S.A.; Belousov, V.I.; Blik, A.M.; Kolosov, V.N.; Kut' in, V.M.; Palinov, A.I.; Solov' ev, A.S. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Serpukhov. Inst. Fiziki Vysokikh Ehnergij); Bannikov, A.V.; Krumshtejn, Z.V. (Joint Inst. for Nuclear Research, Dubna (USSR))
Shower hodoscope detector, containing 49 units of lead glass with total volume of 1.4x1.4x0.35 m/sup 3/ has been described and the method of the detector calibration based on the use of ..pi.. deg (eta) ..-->.. 2 ..gamma.. decays has been considered. The calibration is aimed at the setting of counting spacing of amplitude transducer epsilon sub(i). In the suggested way of calibration according to resonances the attribution of the coefficients epsilon sub(i) directly to the values of table masses of neutral mesons is realized, whereas after the calibration on electron beam the account of certain difference between e- and ..gamma..-showers, effects of incomplete absorption etc. is necessary. Similar algorithms can be developed for resonances in the system of more than two ..gamma..-quanta.
Directory of Open Access Journals (Sweden)
R. A. Treumann
2011-06-01
Full Text Available We clarify the notion of magnetic field lines in plasma by referring to sub-microscale (quantum mechanical particle dynamics. It is demonstrated that magnetic field lines in a field of strength B carry single magnetic flux quanta Φ_{0}=h/e. The radius of a field line in the given magnetic field B is calculated. It is shown that such field lines can merge and annihilate only over the length ℓ_{∥} of their strictly anti-parallel sections, for which case we estimate the power generated. The length ℓ_{∥} becomes a function of the inclination angle θ of the two merging magnetic flux tubes (field lines. Merging is possible only in the interval 12πθ≤π. This provides a sub-microscopic basis for "component reconnection" in classical macro-scale reconnection. We also find that the magnetic diffusion coefficient in plasma appears in quanta D_{0}^{m}=eΦ_{0}/m_{e}=h/m_{e}. This lets us conclude that the bulk perpendicular plasma resistivity is limited and cannot be less than η_{0⊥}=μ_{0}eΦ_{0}/m_{e}=μ_{0}h/m_{e}~10^{−9} Ohm m. This resistance is an invariant.
Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Chasovikov, E. N.; Galper, A. M.; Kheymits, M. D.; Murchenko, A. E.; Yurkin, Y. T.
2016-02-01
GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be the new generation satellite gamma-observatory. Gamma-telescope GAMMA-400 consists of anticoincidence system (top and lateral sections - ACtop and AClat), the converter-tracker (C), time-of-flight system (2 sections S1 and S2), position-sensitive calorimeter CC1 makes of 2 strips layers and 2 layers of CsI(Tl) detectors, electromagnetic calorimeter CC2 composed of CsI(Tl) crystals, neutron detector ND, scintillation detectors of the calorimeter (S3 and S4) and lateral detectors of the calorimeter (LD). All detector systems ACtop, AClat, S1-S4, LD consist of two BC-408 based sensitive layers of 1 cm thickness each. Three apertures provide events registration both from upper and lateral directions. The main aperture provides the best angular (all strip layers information analysis) and energy (energy deposition in the all detectors studying) resolution. Gamma-telescope GAMMA-400 is optimized for the gamma-quanta and charged particles with energy 100 GeV detection with the best parameters in the main aperture. Triggers in the main aperture will be formed using information about particle direction provided by time of flight system and presence of charged particle or backsplash signal formed according to analysis of energy deposition in combination of both layers anticoincidence systems ACtop and AClat individual detectors. For double-layer ACtop taking into account both amplitude and temporal trigger marker onboard analysis only 2.8% photons will be wrongly recognized as electrons or protons for 100 GeV particles. The part of charged particles mistakenly identified as gammas is ∼10-5 using described algorithms. For E∼3 GeV less than 3% photons will be wrongly recognized as charged particles and fraction of wrongly identified charged particles will be also ∼10-5. In the additional aperture the particles identification is provided by analysis of signals corresponding to energy deposition in the
Sinitsyna, V. G.; Arsov, T. P.; Borisov, S. S.; Musin, F. I.; Nikolsky, S. I.; Mirzafatikhov, R. M.; Kasparov, G. M.; Sinitsyna, V. Y.; Platonov, G. F.
2003-07-01
Basic science: nuclear physics, physics of elementary particles and connected with them astrophysics and cosmology, has studied the structure of matter on micro and macro scales. Gamma-astronomy and neutrino-astronomy, are unique experimental possibilities to search for high-energy cosmic ray sources (1012 - 1014 eV). Evidence has already been obtained of metagalactic sources exceeding by 106 - 1012 times the power of gamma-quanta galactic sources. This data puts into doubt the assumption about the galactic origin of the observed very high energy cosmic radiation. The energy spectrum of the majority of known gamma-sources with energy 1012 - 1014 eV is harder than the proton and cosmic ray nuclei spectrum. The problem of observing extensive air showers generated by neutrinos is connected with the extremely small effective cross-section of inelastic collisions of neutrinos with nuclei. However, two facts allow a search for showers generated by neutrinos. The hadron cascade with primary energy of more than 1012 eV leaves the ground to atmosphere from depth of ~ 300 g/cm2 without essential loss of total energy in the hadron cascade. The Cherenkov radiation in the atmosphere from such hadron cascades will be observed at distances from the telescope of 7.5 km over an area more than 7 . 105 m2. This partially compensates for the small cross-section of inelastic neutrino collisions. RFBR, FNP, GNTP
Delgado, C F; Mielnik, Bogdan
1998-01-01
The Zeldovich hypothesis is revised and the meaning of quasi energy spectra is discussed. The observation of Floquet resonance for microobjects in quickly oscillating external fields might bring a new information about the time scale of hypothetical quantum jumps.
Vibrations, Quanta and Biology
Huelga, S F
2013-01-01
Quantum biology is an emerging field of research that concerns itself with the experimental and theoretical exploration of non-trivial quantum phenomena in biological systems. In this tutorial overview we aim to bring out fundamental assumptions and questions in the field, identify basic design principles and develop a key underlying theme -- the dynamics of quantum dynamical networks in the presence of an environment and the fruitful interplay that the two may enter. At the hand of three biological phenomena whose understanding is held to require quantum mechanical processes, namely excitation and charge transfer in photosynthetic complexes, magneto-reception in birds and the olfactory sense, we demonstrate that this underlying theme encompasses them all, thus suggesting its wider relevance as an archetypical framework for quantum biology.
Ekert, Artur; Kay, Alastair; Pope, James
2012-07-28
Alan Turing has certainly contributed to a widespread belief that the quest for a perfect, unbreakable, cipher is a futile pursuit. The ancient art of concealing information has, in the past, been matched by the ingenuity of code-breakers, but no longer! With the advent of quantum cryptography, the hopes of would-be eavesdroppers have been dashed, perhaps for good. Moreover, recent research, building on schemes that were invented decades ago to perform quantum cryptography, shows that secure communication certified by a sufficient violation of a Bell inequality makes a seemingly insane scenario possible-devices of unknown or dubious provenance, even those that are manufactured by our enemies, can be safely used for secure communication, including key distribution. All that is needed to implement this bizarre and powerful form of cryptography is a loophole-free test of a Bell inequality, which is on the cusp of technological feasibility. We provide a brief overview of the intriguing connections between Bell inequalities and cryptography and describe how studies of quantum entanglement and the foundations of quantum theory influence the way we may protect information in the future.
Kent, Adrian
2016-01-01
I sketch a line of thought about consciousness and physics that gives some motivation for the hypothesis that conscious observers deviate - perhaps only very subtly and slightly - from quantum dynamics. Although it is hard to know just how much credence to give this line of thought, it does motivate a stronger and more comprehensive programme of quantum experiments involving quantum observers.
Davidson, M P
2001-01-01
It is shown using numerical simulation that classical charged tachyons have several features normally thought to be unique to quantum mechanics. Spin-like self-orbiting helical motions are shown to exist at discrete values for the velocity of the tachyon in Feynman-Wheeler electrodynamics and in normal causal electrodynamics more complex closed orbits also appear to exist. Tunneling behavior of the classical tachyon is observed at classical turning points depending on the angle of incidence. The equations of motion appear to be chaotic and effectively indeterministic when the tachyon crosses its own past light cone. It is argued that self-interacting tachyons moving in a tight helix would behave causally, and that they could be a basis for a hidden variable description of quantum mechanics. A procedure is proposed which could determine the fine structure constant.
Essex, David W
2015-01-01
A new model for space and matter is obtained by joining every pair of point charges in the observable universe by an ethereal string. Positive gravitational potential energy in each string gives an attractive gravitational force due to the action of an energy conservation constraint. Newton's laws of motion are derived and inertia is explained in accordance with Mach's principle. The Machian string model gives a surprisingly simple way to understand the expansion history of the Universe. The decelerating expansion in the radiation era and the matter era is explained without using General Relativity and the transition from deceleration to acceleration is explained without the need to introduce a separate 'dark energy' component. The interaction between Machian strings gives a physical model for modified Newtonian dynamics (MOND) and is therefore an alternative to 'dark matter'.
Nikolsky, S. I.; Sinitsyna, V. G.
2003-07-01
The experimental data about gamma-quanta sources with energy > 1 TeV are characterised by the fact that the observed metagalactic sources (active galactic nuclei) are 106 - 107 times more powerful than the galactic ones, but they do not differ in energy spectrum (F(> Eγ)~Eγ-1.3+/-0.15). The power of metagalactic sources and their unlimited number puts into doubt the assumption about the galactic origin of the observable cosmic ray flux. It is possible to assume, that the uniform cosmic ray spectrum is formed (by ``braking'') in an ``infinite'' number of elastic (or inelastic) collisions with relict photons in intergalactic space. Thus, the observable spectral distribution of protons and cosmic ray nuclei with index of (2.72+/-0.02) = 2.718... (the Nipper's number) is the consequence of such ``braking'' warming up the relict photons. RFBR, FNP, GNTP
Energy Technology Data Exchange (ETDEWEB)
Gradoboev, Alexander V.; Simonova, Anastasiia V.; Orlova, Ksenia N. [National Research Tomsk Polytechnic University, Lenina avenue 30, 634050 Tomsk (Russian Federation)
2016-12-15
We consider the influence of preliminary irradiation by {sup 60}Co gamma quanta on emission power decrease during the operating time of IR-LEDs based upon AlGaAs double heterostructures. Irradiation was realized in passive power mode of the LEDs prior to aging. Aging under long operating time conditions was simulated by a step-stress approach. We have determined that the emissive power decrease of LED during operating time has two stages. On the first stage, decrease of LED emissive power is due to rearrangement of original defect structure. On the second stage, emissive power goes down as the result of inducing new structural defects. We have shown identical multistage mechanisms of emissive power drop are observed during both operating time and influence of ionizing radiation. We have established that preliminary irradiation has increased reliability and operating time of LEDs. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Didyk, A. Yu.; Wisniewski, R.
2014-03-01
Specimens of a number of metal were placed successively along the length in a deuterium high-pressure chamber of the "finger type" (DHPC-FT). The specimens were: two aluminum rods, a copper rod, two YMn2 alloy specimens, and stainless steel. The molecular deuterium pressure in the DHPC-FT chamber was 2 kbar. The specimens were irradiated by braking γ-quanta with boundary energy 23 MeV. After irradiation, all specimens were investigated on scanning electron microscopes (SEM) with electron probe X-ray microelement analysis (XMA). Considerable changes in the structure of the surfaces and elemental composition of the measured aluminum, destruction of the homogeneous YMn2 alloy specimen, and the "formation of monocrystalline specimens" of the YMn2 type and structures resembling manganese-based "crystals" were observed. A phenomenological explanation of the observed phenomena and effects based on nuclear reactions is proposed with consideration of certain new approaches, which are examined.
Didyk, A. Yu.; Wiśniewski, R.
2012-12-01
Studies have been carried out into the element composition of Pd and brass with associated materials and synthesized novel structure, placed in dense deuterium gas in a deuterium high-pressure chamber (DHPC) under the pressure 3 kbar and irradiated with γ-quanta of energy up to 8.8 MeV. Using the methods of scanning electron microscopy, microelement chemical analysis and X-ray diffraction, it was determined that in the absence in the chamber volume and walls of all HPC-forming materials the synthesized structure is largely composed of alumosilicates and Al and Si oxides with high content of Ti compounds as rutile TiO2. Pd1.5D2. Considerable anomalies in the chemical composition were found both in the surface and at large depth in a Pd specimen. The entire Pd surface turned into a structure comprised of Pd clusters, Cu and Zn compounds, with a notable content of Mg, Al, S, Si, K, Ca, Ti and Fe compounds. Results of evaluative calculations, including computation of the Q-value, are presented for nuclear reactions produced in a saturated with deuterium Pd specimen and dense deuterium gas under the action of γ-quanta, neutrons and protons of energies up to E n + E p ≈ E γ - E D MeV generated by deuteron fission. The obtained results can be explained by "collective effects" as chain reactions caused by deuteron fission induced by protons ( E p > 3.39 MeV) and neutrons ( E n > 2.25 MeV), as well as by thermonuclear synthesis of deuterium atoms elastically scattered by protons of energies up to E P < E γ - E D MeV.
Energy Technology Data Exchange (ETDEWEB)
Tang Xiangyang; Yang Yi; Tang Shaojie [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Drive, C-5018, Atlanta, Georgia 30322 (United States)
2012-07-15
Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360 Degree-Sign full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G{sub 1} and G{sub 2} with periods 8 and 4 {mu}m, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 Multiplication-Sign 32, 64 Multiplication-Sign 64, 96 Multiplication-Sign 96, and 128 Multiplication-Sign 128 {mu}m{sup 2}, respectively, corresponding to a 40.96 Multiplication-Sign 40.96 mm{sup 2} field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(k), spectrum of noise equivalent quanta NEQ(k), and detective quantum efficiency DQE(k). A cylindrical water phantom at 5.1 mm diameter and complex refraction coefficient n= 1 -{delta}+i{beta}= 1 -2.5604 Multiplication-Sign 10{sup -7}+i1.2353 Multiplication-Sign 10{sup -10} is placed in air to measure the edge transfer function, line spread function
Tang, Xiangyang; Yang, Yi; Tang, Shaojie
2012-01-01
Purpose: Differential phase contrast CT (DPC-CT) is emerging as a new technology to improve the contrast sensitivity of conventional attenuation-based CT. The noise equivalent quanta as a function over spatial frequency, i.e., the spectrum of noise equivalent quanta NEQ(k), is a decisive indicator of the signal and noise transfer properties of an imaging system. In this work, we derive the functional form of NEQ(k) in DPC-CT. Via system modeling, analysis, and computer simulation, we evaluate and verify the derived NEQ(k) and compare it with that of the conventional attenuation-based CT. Methods: The DPC-CT is implemented with x-ray tube and gratings. The x-ray propagation and data acquisition are modeled and simulated through Fresnel and Fourier analysis. A monochromatic x-ray source (30 keV) is assumed to exclude any system imperfection and interference caused by scatter and beam hardening, while a 360° full scan is carried out in data acquisition to avoid any weighting scheme that may disrupt noise randomness. Adequate upsampling is implemented to simulate the x-ray beam's propagation through the gratings G1 and G2 with periods 8 and 4 μm, respectively, while the intergrating distance is 193.6 mm (1/16 of the Talbot distance). The dimensions of the detector cell for data acquisition are 32 × 32, 64 × 64, 96 × 96, and 128 × 128 μm2, respectively, corresponding to a 40.96 × 40.96 mm2 field of view in data acquisition. An air phantom is employed to obtain the noise power spectrum NPS(k), spectrum of noise equivalent quanta NEQ(k), and detective quantum efficiency DQE(k). A cylindrical water phantom at 5.1 mm diameter and complex refraction coefficient n = 1 − δ + iβ = 1 −2.5604 × 10−7 + i1.2353 × 10−10 is placed in air to measure the edge transfer function, line spread function and then modulation transfer function MTF(k), of both DPC-CT and the conventional attenuation-based CT. The x-ray flux is set at 5 × 106 photon/cm2 per projection and
Energy Technology Data Exchange (ETDEWEB)
Sinitsyna, V.G. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Arsov, T.P. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Alaverdian, A.Y. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Borisov, S.S. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Musin, F.I. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Nikolsky, S.I. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Sinitsyna, V.Y. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Platonov, G.F. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation)
2006-01-15
The gamma-quantum emitting objects in our Galaxy are supernova remnants and binary. The observed results of gamma-quantum sources Tycho Brahe and Geminga by the SHALON gamma-telescope are presented. The integral spectra of events from the source - k{sub on} and background events, observing simultaneously with source's events - k{sub off}, and the source image are presented. The energy spectra of Tycho's SNR and Geminga supernova remnant F(E{sub 0}>0.8TeV){approx}E{sup k} are harder than the Crab Nebula spectrum. Tycho's SNR has long been considered as a candidate cosmic ray source in Northern Hemisphere. A non-linear kinetic model of cosmic ray acceleration in supernova remnants was used for Tycho's SNR. The expected {pi}{sup o}-decay gamma-quanta flux F{sub {gamma}}{approx}E{sub {gamma}}{sup -1} extends up to {approx}30TeV, whereas the Inverse Compton gamma-ray flux has a cut-off above a few TeV. So, the detection of gamma-rays at energies of {approx}10-30TeV by SHALON is evidence for hadron origin.
Sinitsyna, V. G.; Arsov, T. P.; Alaverdian, A. Y.; Borisov, S. S.; Musin, F. I.; Nikolsky, S. I.; Sinitsyna, V. Y.; Platonov, G. F.
2006-01-01
The gamma-quantum emitting objects in our Galaxy are supernova remnants and binary. The observed results of gamma-quantum sources Tycho Brahe and Geminga by the SHALON gamma-telescope are presented. The integral spectra of events from the source - k and background events, observing simultaneously with source's events - k, and the source image are presented. The energy spectra of Tycho's SNR and Geminga supernova remnant F(E>0.8TeV)˜E are harder than the Crab Nebula spectrum. Tycho's SNR has long been considered as a candidate cosmic ray source in Northern Hemisphere. A non-linear kinetic model of cosmic ray acceleration in supernova remnants was used for Tycho's SNR. The expected π°-decay gamma-quanta flux F˜Eγ-1 extends up to ˜30TeV, whereas the Inverse Compton gamma-ray flux has a cut-off above a few TeV. So, the detection of gamma-rays at energies of ˜10-30TeV by SHALON is evidence for hadron origin.
Energy Technology Data Exchange (ETDEWEB)
Auffray, E. [CERN, Geneva (Switzerland); Borisevitch, A. [Institute for Nuclear Problems, Minsk (Belarus); Gektin, A.; Gerasymov, Ia. [Institute for Scintillation Materials NASU, Kharkiv (Ukraine); Korjik, M.; Kozlov, D. [Institute for Nuclear Problems, Minsk (Belarus); Kurtsev, D. [Institute for Scintillation Materials NASU, Kharkiv (Ukraine); Mechinsky, V. [Institute for Nuclear Problems, Minsk (Belarus); Sidletskiy, O., E-mail: sidletskiy@isma.kharkov.com [Institute for Scintillation Materials NASU, Kharkiv (Ukraine); Zoueyski, R. [Institute for Nuclear Problems, Minsk (Belarus)
2015-05-21
This work focuses on the study of changes in the optical transmission of Y{sub 2}SiO{sub 5}:Ce crystals caused by ionizing radiation from γ-quanta and high energy protons. Radioisotope content of proton-irradiated crystals, transmission and induced absorption spectra, and scintillation characteristics are measured after irradiation with protons. In contrast to crystals of heavy complex oxides, Y{sub 2}SiO{sub 5}:Ce crystals do not demonstrate significant deterioration of transmission in the luminescence range (400–600 nm) under irradiation. Such crystals can be considered as a material for construction of detecting cells of the calorimetric detectors at LHC with high luminosity. The feasibility of growing large crackless Y{sub 2}SiO{sub 5}:Ce crystals with a diameter up to 50 mm and length up to 250 mm is demonstrated. - Highlights: • Large YSO:Ce single crystals are obtained. • YSO:Ce demonstrates improved radiation hardness compared to heavy scintillators. • YSO:Ce is a promising crystal for LHC detectors upgrade.
Quanta of geometry and unification
Chamseddine, Ali H.
2016-11-01
This is a tribute to Abdus Salam’s memory whose insight and creative thinking set for me a role model to follow. In this contribution I show that the simple requirement of volume quantization in spacetime (with Euclidean signature) uniquely determines the geometry to be that of a noncommutative space whose finite part is based on an algebra that leads to Pati-Salam grand unified models. The Standard Model corresponds to a special case where a mathematical constraint (order one condition) is satisfied. This provides evidence that Salam was a visionary who was generations ahead of his time.
Quanta of Geometry and Unification
Chamseddine, Ali H
2016-01-01
This is a tribute to Abdus Salam's memory whose insight and creative thinking set for me a role model to follow. In this contribution I show that the simple requirement of volume quantization in space-time (with Euclidean signature) uniquely determines the geometry to be that of a noncommutative space whose finite part is based on an algebra that leads to Pati-Salam grand unified models. The Standard Model corresponds to a special case where a mathematical constraint (order one condition) is satisfied. This provides evidence that Salam was a visionary who was generations ahead of his time.
Didyk, A. Yu.; Wisniewski, R.
2014-05-01
Metal samples were arranged inside a "finger-type" high-pressure chamber (DHPC-FT) filled by deuterium. They were two aluminum rods, a copper rod, two specimens of homogeneous YMn2 alloy, and a stainless steel wire. The pressure of molecular deuterium in DHPC-FT was about 2 kbar. The samples were irradiated by braking γ-quanta at a threshold energy of 23 MeV. All the samples were studied using scanning electron microscopy (SEM) and X-ray (roentgen) microelement probe analysis (RMPA). Considerable changes in the surface structure and elemental composition were found for the samples of copper, aluminum, YMn2 alloy, and stainless steel. Unusual results were analyzed in detail and compared with the earlier data.
Didyk, A. Yu.; Wisniewski, R. S.
2013-08-01
A high-pressure chamber with a Pd-rod inside was filled up with 1.2 kbar molecular deuterium (DHPC). Then the saturated by deuterium palladium rod was irradiated during 18 hours by 11 MeV braking γ-quanta at 11-13 μA electron beam using the MT-25 electron accelerator. The element compositions of all the DHPC surfaces which had been in contact with dense deuterium gas were studied using scanning electronic microscopes with Roentgen microprobe analysis. It was determined that all the surfaces, including surfaces of the high-purity Pd-rod (99.995%), were covered either by a partially homogeneous layer or large microparticles of lead. Also, light elements as C, O, Na, Mg, Al, Si, Ti, Mn, Fe, Cu, Zn and heavy metals as Ag, Ta, W, Pt, Au and Pb were observed on the chambers inner surfaces.
Didyk, A. Yu.; Wiśniewski, R.; Wilczynska-Kitowska, T.
2013-12-01
This work is a continuation and addition to Ref. [1], which presents results on studies of the surface and elemental compositions of a Pd rod and brass screw for the collection of nuclear and chemical reaction products in a deuterium high-pressure chamber (DHPC) under irradiation with γ-quanta with an energy of 10 MeV for 18 h at the MT-25 electron accelerator at a beam current of 11-13 μA. The DHPC is filled with 1.2-kbar molecular deuterium in which a Pd rod saturated with deuterium is loaded. After irradiation, the elemental compositions of other surfaces of all DHPC elements, which are inside the DHPC in dense deuterium, are studied using an electron scanning microscope and X-ray microprobe analysis. It is established that all surfaces, including the surface of a high-purity palladium rod (99.995%), are covered with a partly homogeneous layer of large microparticles of lead. Also, light elements such as 6C, 8O, 11Na, 12Mg, 13Al, 14Si, 22Ti, 25Mn, 26Fe, 29Cu, and 30Zn and heavy metals such as 47Ag, 73Ta, 74W, 78Pt, 79Au, and 82Pb are observed. Possible processes that can cause the anomalies observed in the new synthesized elements are briefly discussed.
Didyk, A. Yu.; Wiśniewski, R.; Wilczynska-Kitowska, T.
2013-12-01
A high-pressure chamber is filled with 1.2 kbar molecular deuterium (DHPC). The palladium rod saturated with deuterium is loaded inside the DHPC and irradiated with 10-MeV bremsstrahlung γ-quanta for 18 h with a 11-13 μA electron beam using the MT-25 electron accelerator. The elemental compositions of all surfaces of the DHPC element inside the dense deuterium gas were studied using scanning electronic microscopes with X-ray microelement microprobe analysis. It is found that all surfaces, including the surface of a high-purity palladium rod (99.995%), are covered with a partly homogeneous layer or large microparticles of lead. Also, light elements such as 6C, 8O, 11Na, 12Mg, 13Al, 14Si, 22Ti, 25Mn, 26Fe, 29Cu, and 30Zn and heavy metals such as 47Ag, 73Ta, 74W, 78Pt, 79Au, and 82Pb are observed. Possible processes that can cause the anomalies observed in the newly formed chemical elements are briefly discussed.
Loos, C; Buhr, H; Blendl, C
2013-07-01
The purpose of this study was to determine the values for noise equivalent quanta, detective quantum efficiency, modulation transfer function, noise power spectrum, and the values for the parameters for automated CDMAM test phantom analyses required to achieve satisfactory quality of digital mammograms. During the course of tests according to PAS 1054 (8 CR and 12 DR systems), test images were made with a test phantom insertion plate containing two lead edges in nearly horizontal and vertical directions. Only original data were processed with a program that was developed at the Cologne University of Applied Sciences (FH-Köln). All equipment systems complied with the requirements regarding visual recognition of gold-plated mammo detail test objects. CDMAM test images were also evaluated using the CDIC (CUAS) and CDCOM (EUREF) programs. CDMAM test images show comparable values for the parameters, precision, sensitivity and specificity. DR systems require about half the dose used for CR systems for similar results. The NEQ values achieved with the dose used for the CDMAM test images show larger scatter ranges. The MTF of the different equipment system types differ significantly from each other. Visual evaluation of CDMAM test images can be replaced by automated evaluation. Limiting values were determined for each parameter. Automated evaluation of CDMAM test phantom images should be used to determine the physical parameter NEQQC. This method is much more sensitive to noise and sharpness influences and has a higher validity than diagnostic methods. Automated evaluation objectivizes testing. © Georg Thieme Verlag KG Stuttgart · New York.
Key distribution in PKC through Quantas
Goel, Aditya
2010-01-01
Cryptography literally means "The art & science of secret writing & sending a message between two parties in such a way that its contents cannot be understood by someone other than the intended recipient". and Quantum word is related with "Light". Thus, Quantum Cryptography is a way of descripting any information in the form of quantum particles. There are no classical cryptographic systems which are perfectly secure. In contrast to Classical cryptography which depends upon Mathematics, Quantum Cryptography utilizes the concepts of Quantum Physics which provides us the security against the cleverest marauders of the present age. In the view of increasing need of Network and Information Security, we do require methods to overcome the Molecular Computing technologies (A future technology) and other techniques of the various codebrakers. Both the parts i.e. Quantum Key distribution and Information transference from Sender to Receiver are much efficient and secure. It is based upon BB84 protocol. It can b...
Quantum mechanics and computation; Quanta y Computacion
Energy Technology Data Exchange (ETDEWEB)
Cirac Sasturain, J. I.
2000-07-01
We review how some of the basic principles of Quantum Mechanics can be used in the field of computation. In particular, we explain why a quantum computer can perform certain tasks in a much more efficient way than the computers we have available nowadays. We give the requirements for a quantum system to be able to implement a quantum computer and illustrate these requirements in some particular physical situations. (Author) 16 refs.
Optical Manipulation of Single Flux Quanta
Veshchunov, I S; Mironov, S V; Godin, A G; Trebbia, J -B; Buzdin, A I; Tamarat, Ph; Lounis, B
2016-01-01
Magnetic field can penetrate into type-II superconductors in the form of Abrikosov vortices, which are magnetic flux tubes surrounded by circulating supercurrents often trapped at defects referred to as pinning sites. Although the average properties of the vortex matter can be tuned with magnetic fields, temperature or electric currents, handling of individual vortices remains challenging and has been demonstrated only with sophisticated magnetic force, superconducting quantum interference device or strain-induced scanning local probe microscopies. Here, we introduce a far-field optical method based on local heating of the superconductor with a focused laser beam to realize a fast, precise and non-invasive manipulation of individual Abrikosov vortices, in the same way as with optical tweezers. This simple approach provides the perfect basis for sculpting the magnetic flux profile in superconducting devices like a vortex lens or a vortex cleaner, without resorting to static pinning or ratchet effects. Since a ...
Conceptual Unification of Gravity and Quanta
Heller, M; Sasin, W
2006-01-01
We present a model unifying general relativity and quantum mechanics. It is based on the (noncommutative) algebra ${\\cal A}$ on the groupoid $\\Gamma = E \\times G$, where $E$ is the total space of the frame bundle over spacetime, and $G$ the Lorentz group. The differential geometry, based on derivations of ${\\cal A}$, is constructed. The eigenvalue equation for the Einstein operator plays the role of a generalized Einstein's equation. The algebra ${\\cal A}$, when suitably represented in a bundle of Hilbert spaces, is a von Neumann algebra $\\mathcal{M}$ of random operators representing the quantum sector of the model. The Tomita-Takesaki theorem allows us to define the dynamics of random operators which depends on the state $\\phi $. The same state defines the noncommutative probability measure (in the sense of free probability theory). The state $\\phi $ satisfies the Kubo-Martin-Schwinger (KMS) condition, and can be interpreted as describing a generalized equilibrium state. By suitably averaging elements of the...
Gravity Quanta, Entropy and Black Holes
Alfonso-Faus, A
1999-01-01
We propose the use of a gravitational uncertainty principle for gravitation.We define the corresponding gravitational Planck's constant and thegravitational quantum of mass. We define entropy in terms of the quantum ofgravity with the property of having an extensive quality. The equivalent 2ndlaw of thermodynamics is derived, the entropy increasing linearly withcosmological time. These concepts are applied to the case of black holes,finding their entropy and discussing their radiation.
Energy Technology Data Exchange (ETDEWEB)
Hartje, Udo Albert Juergen
2009-07-01
The internationally favored direction of the physics sciences looks for the solution of the basic problems in higher and higher energies at impressive research constructions - mockingly mentioned as 'cognition machines' - which surpass itself with its financial efforts each the other. If in this wise shall be found: 'The elementariest bit of all elements' and 'the unity of the whole physics as well as the whole nature sciences at all', then this is a thought aberration. The prognosticated HIGGS-particles may have an exceptional quality; however, they would be very complex objects which integrate an enormous number of effect-quanta h (Planck constants) in their structure: They are with safety not simplicity. They will also not bring a better understanding about the simplicity of the last elements for us. We know since Planck, Poincare, Einstein, Bohr, Heisenberg, Schroedinger, DeBrogue and other well-known physicists that the 'atomos' can have only a diminutiveness discrete not measurable energy. The search with gigantic machines is at all especially nonsensical than it pumps still energy into the processes. However, the elementary consists of fractions from that energy what have well-known smallest particles or weakest radiation in itself puts. The work in hand follows another approach. It grasps nature on a deductive way. I start out from a most general analysis and synthesis of scientific and everyday-language concepts; and I combine that with a principle of 'general physical field' which after Einstein must exist. The dynamic space-time processes of the fields are depicted by graphic means in mathematical spatial coordinate-systems. Through it arises a consistent view over all areas of the knowledge from the most simply over simple structures until to the most complicated phenomena and things: that one are the cognition remained secretive till now obstinately. In the foreground will be originate as important the
Energy Technology Data Exchange (ETDEWEB)
Loos, C.; Buhr, H.; Blendl, C. [Fachhochschule Koeln (Germany). Inst. of Media and Imaging Technology
2013-07-15
Purpose: The purpose of this study was to determine the values for noise equivalent quanta, detective quantum efficiency, modulation transfer function, noise power spectrum, and the values for the parameters for automated CDMAM test phantom analyses required to achieve satisfactory quality of digital mammograms. Materials and Methods: During the course of tests according to PAS 1054 (8 CR and 12 DR systems), test images were made with a test phantom insertion plate containing two lead edges in nearly horizontal and vertical directions. Only original data were processed with a program that was developed at the Cologne University of Applied Sciences (FH-Koeln). All equipment systems complied with the requirements regarding visual recognition of gold-plated mammo detail test objects. CDMAM test images were also evaluated using the CDIC (CUAS) and CDCOM (EUREF) programs. Results: CDMAM test images show comparable values for the parameters, precision, sensitivity and specificity. DR systems require about half the dose used for CR systems for similar results. The NEQ values achieved with the dose used for the CDMAM test images show larger scatter ranges. The MTF of the different equipment system types differ significantly from each other. Conclusion: Visual evaluation of CDMAM test images can be replaced by automated evaluation. Limiting values were determined for each parameter. Automated evaluation of CDMAM test phantom images should be used to determine the physical parameter NEQ{sub QC}. This method is much more sensitive to noise and sharpness influences and has a higher validity than diagnostic methods. Automated evaluation objectivizes testing. (orig.)
Einstein's physics atoms, quanta, and relativity : derived, explained, and appraised
Cheng, Ta-Pei
2013-01-01
Many regard Albert Einstein as the greatest physicist since Newton. What exactly did he do that is so important in physics? We provide an introduction to his physics at a level accessible to an undergraduate physics student. All equations are worked out in detail from the beginning. Einstein's doctoral thesis and his Brownian motion paper were decisive contributions to our understanding of matter as composed of molecules and atoms. Einstein was one of the founding fathers of quantum theory: his photon proposal through the investigation of blackbody radiation, his quantum theory of photoelectri
From Quanta to the Continuum: Opportunities for Mesoscale Science
Energy Technology Data Exchange (ETDEWEB)
Crabtree, George [Argonne National Lab. (ANL), Argonne, IL (United States); Sarrao, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alivisatos, Paul [Univ. of California, Berkeley, CA (United States); Barletta, William [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Bates, Frank [Univ. of Minnesota, Minneapolis, MN (United States); Brown, Gordon [Stanford Univ., CA (United States); French, Roger [Case Western Reserve Univ., Cleveland, OH (United States); Greene, Laura [Univ. of Illinois, Urbana, IL (United States); Hemminger, John [Univ. of California, Irvine, CA (United States); Kastner, Marc [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Kay, Bruce [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lewis, Jennifer [Univ. of Illinois, Urbana, IL (United States); Ratner, Mark [Northwestern Univ., Evanston, IL (United States); Anthony, Rollett [Carnegie Mellon Univ., Pittsburgh, PA (United States); Rubloff, Gary [University of Maryland, College Park, MD (United States); Spence, John [Arizona State Univ., Mesa, AZ (United States); Tobias, Douglas [Univ. of California, Irvine, CA (United States); Tranquada, John [Brookhaven National Lab. (BNL), Upton, NY (United States)
2012-09-01
This report explores the opportunity and defines the research agenda for mesoscale science—discovering, understanding, and controlling interactions among disparate systems and phenomena to reach the full potential of materials complexity and functionality. The ability to predict and control mesoscale phenomena and architectures is essential if atomic and molecular knowledge is to blossom into a next generation of technology opportunities, societal benefits, and scientific advances.. The body of this report outlines the need, the opportunities, the challenges, and the benefits of mastering mesoscale science.
Space, time, and quanta an introduction to contemporary physics
Mills, Robert
1994-01-01
This is the ideal supplement for courses emphasizing modern physics. Part I covers special relativity and the meaning of time, Part II discusses quantum physics, Part III looks at elementary particles and force fields. The three self-contained parts can be used separately or in combination. Familiarity with calculus and classical physics, while helpful, is not necessary as the pertinent ideas of these fields are introduced as needed.
On Einstein, Light Quanta, Radiation, and Relativity in 1905
Miller, Arthur I.
1976-01-01
Analyzes section 8 of Einstein's relativity paper of 1905, "On the Electrodynamics of Moving Bodies," in its historical context. Relates this section to the rest of the relativity paper, to the genesis of relativity theory, and to contemporaneous work on radiation theory. (Author/MLH)
Rabi-vibronic resonance with large number of vibrational quanta
Glenn, R.; Raikh, M. E.
2011-01-01
We study theoretically the Rabi oscillations of a resonantly driven two-level system linearly coupled to a harmonic oscillator (vibrational mode) with frequency, \\omega_0. We show that for weak coupling, \\omega_p \\ll \\omega_0, where \\omega_p is the polaronic shift, Rabi oscillations are strongly modified in the vicinity of the Rabi-vibronic resonance \\Omega_R = \\omega_0, where \\Omega_R is the Rabi frequency. The width of the resonance is (\\Omega_R-\\omega_0) \\sim \\omega_p^{2/3} \\omega_0^{1/3} ...
Relativité et quanta une nouvelle révolution scientifique
Cohen-Tannoudji, Gilles
2017-01-01
Ces trois dernières années, les moissons scientifiques ont été exceptionnellement fructueuses, de la découverte du boson de Higgs à celles des ondes gravitationnelles émises lors de la coalescence de deux trous noirs massifs, et aux observations du fond cosmologique par le satellite Planck. L'humanité vient alors d'atteindre un nouveau palier dans la compréhension du monde quantique et du monde de la gravitation : nos bases théoriques, expérimentales et technologiques forment un socle scientifique solide pour aller plus loin et tenter de répondre aux nouvelles questions qui surgissent suite à ces découvertes... Enquête et mise au point sur une révolution en cours.
Introdução à mecânica dos "quanta" Parte I
Directory of Open Access Journals (Sweden)
Ramos Theodoro A.
2003-01-01
Full Text Available Este artigo consiste nas notas da primeira conferência publicado originalmente no número de Novembro de 1931 no Boletim do Instituto de Engenharia, pp. 157-166. Aqui os conceitos básicos da física ondulatoria e da óptica geométrica são discutidos e a analogia entre a mecânica clássica e a óptica geométrica é explorada com vistas a introdução da mecânica ondulatória de Schrödinger.
Pomeranchuk instability and Bose condensation of scalar quanta in a Fermi liquid
Kolomeitsev, E E
2015-01-01
We study excitations in a normal Fermi liquid with a local scalar interaction. Spectrum of bosonic scalar-mode excitations is investigated for various values and momentum dependence of the scalar Landau parameter $f_0$ in the particle-hole channel. For $f_0 >0$ the conditions are found when the phase velocity on the spectrum of the zero sound acquires a minimum at a non-zero momentum. For $-10$.
Regards sur la matière des quantas et des choses
D'Espagnat, Bernard
1993-01-01
La physique quantique n'est pas seulement à la base de nombreuses inventions de pointe. Elle constitue aussi une révolution conceptuelle de grande ampleur.Bien que ses implications pratiques comme ses conséquences philosophiques soient immenses, la physique quantique est encore mal connue des non-spécialistes, en partie à cause des difficultés qu'il y a à exposer ses fondements.Or c'est justement la gageure réussie de cet ouvrage. En un style clair, enjoué et dépourvu d'équations, Etienne Klein nous guide dans les profondeurs de la matière. Nous découvrons avec lui des expériences aussi étranges que celle des fentes de Young ", qui montre que la matière est à la fois onde et corpuscule et que ses caractéristiques sont en partie liées... à notre propre existence en tant qu'observateur humain! Après avoir pris connaissance de paradoxes surprenants comme celui du chat de Schrödinger _ un chat à la fois mort et vivant! _ nous abordons la mystérieuse question de la " non-séparabilité ", s...
Zeltzer, Gabriel
In condensed matter systems the spatial limit is given by the fundamental atomic and molecular interactions. Controlling matter at these length scales hold promise in both fundamental scientific research as well as applications in nanotechnology and related fields such as electronics, biochemistry and medicine. Atomic and molecular manipulation on surfaces has opened a new realm of possibilities where materials can be engineered at the spatial limit and artificial structures can be constructed with a bottom-up approach, one building block at a time. This thesis describes nanostructures assembled from CO molecules on Cu(111) using a custom-built low-temperature ultra-high vacuum (UHV) scanning tunneling microscope (STM). The design and performance of the atom-manipulation apparatus that has enabled these experiments is presented. The control of electronic and vibronic states is demonstrated in several coherent quantum geometries and interactions between these two degrees of freedom are investigated. This work has revealed a virtual vibron process where non-local vibrons are synthesized and focused using a two-dimensional electron gas as a propagation medium and molecular oscillators as a source. Analysis of higher order harmonic modes of quartz tuning fork sensors is presented in the context of high frequency optical homodyne interferometric detection of subnanometer oscillatory motion. Further developments which could expand upon the work presented herein, in which STM may be combined with quantum force sensing through the use of quartz tuning forks, are suggested.
Void formation in pure aluminium irradiated with high-energetic electron beams and gamma-quanta
DEFF Research Database (Denmark)
Gan, V. V.; Ozhigou, L. S.; Yamnitsky, V. A.
1983-01-01
The spatial distribution of displaced atoms and helium atoms and also the spectra of damaging energies of primary displaced atoms in a thick aluminium target irradiated with electrons of 225 MeV energy were calculated. Pure aluminium (99.9999%) irradiated up to 0.04 dose was studied by electron-m......-microscopy. Voids of size 5 to 40 nm were obtained and their vacancy nature was estimated. The dislocation structure of the material was studied...
Quanta, quarks, and families: implications of quantum physics for family research.
Doherty, W J
1986-06-01
This paper offers recommendations for family research in light of the scientific paradigm ushered in by quantum physics in the early twentieth century. After summarizing the basic discoveries of quantum physics, the author discusses philosophical implications of these discoveries, and then presents implications for conducting scientific research about families within a post-Newtonian paradigm that emphasizes relations, process, and dynamic causation. The author argues for using complementary research models, including linear and systemic, because no one theory or methodology can illuminate fully the inscrutable nature of family processes.
Korshunov, V M; Pinegin, B V; Mal'tsev, V N; Kissina, E V; Ikonnikova, T B
1980-07-01
The treatment of CBA mice, irradiated in a dose of 700 Gy with antibiotics (penicillin V, oxytetracycline, streptomycin) in combination with bacterial therapy (B. bifidum, strain 75-41) or with antibiotics alone led to the increased percentage of survivors among them in comparison with the control animals. At the same time the medical prognosis was better in cases of the combined treatment with antibiotics and bifidobacteria. This circumstance was due to the fact that the combined treatment with antibiotics and bifidobacteria, considerably facilitated the normalization of the microbial picture of the intestine; in this case the "eubiosis" of the intestinal tract was almost completely restored by the 22nd day after the irradiation, whereas in the treatment with antibiotics alone the inhibitory effect on the development of the opportunistic flora at a later period of the development of dysbacteriosis was less pronounced, while the number of lactic acid bacteria remained at the same low level as in the untreated mice.
Of Cats and Quanta: Paradoxes of Knowing and Knowability of Reality
Shkliarevsky, Gennady
2010-01-01
The legacy of Post-Modernism is renewed attention to the issues of knowledge production. Now that post-modernism is out of fashion, the emphasis is no longer on the "cursed" questions formulated by its adepts. The main issue is no longer whether it is possible to attain knowledge which corresponds to reality. Rather, the new set of questions addresses the issue of how we attain such knowledge. The discourse on knowability has also broadened and now involves a variety of disciplines that span the traditionally separate domains of sciences and humanities. The article focuses on the problem of paradox as it relates to the broader issue of knowledge production and the process of construction in general. It examines paradoxes in contemporary physics as they relate to how knowledge is produced and sees the resolution of the problem of paradox in a better understanding of the construction of knowledge. Viewed from this perspective, paradoxes no longer appear as structural limitations of human capacity to know, but r...
Bieniek, Ronald J.
1996-01-01
Collision-induced transitions can significantly affect molecular vibrational-rotational populations and energy transfer in atmospheres and gaseous systems. This, in turn. can strongly influence convective heat transfer through dissociation and recombination of diatomics. and radiative heat transfer due to strong vibrational coupling. It is necessary to know state-to-state rates to predict engine performance and aerothermodynamic behavior of hypersonic flows, to analyze diagnostic radiative data obtained from experimental test facilities, and to design heat shields and other thermal protective systems. Furthermore, transfer rates between vibrational and translational modes can strongly influence energy flow in various 'disturbed' environments, particularly where the vibrational and translational temperatures are not equilibrated.
Energy Technology Data Exchange (ETDEWEB)
Paty, M. [Paris-7 Univ., 75 (France)
1999-05-01
This article is a short biography of the French physicist Paul Langevin. P.Langevin epitomizes the whole physics of the first half of the last century. His formation made him both an experimenter and a theorist of a great value. His fields of interest were: ionized gas, electron physics, radiation physics and the electrodynamics of moving bodies. P.Langevin was one of the first to fully understand the implications of the relativity theory set up by A.Einstein and he became a fervent supporter of new ideas in physics, he discussed and analysed the interpretations of quantum physics since the very beginning of this new branch of physics. (A.C.)
Egorov, Vladimir V.
The concept of a dozy chaos in the theory of quantum transitions and its applications are discussed in a historical context. Conjectured that dozy chaos is of primary importance to the dynamic self-organization of any living organism and concentrated in its brain. A hypothesis of the physical origin of cancer is put forward. Surmised that dozy chaos is the physical origin of life and driving force of its evolution.
Bunao, Joseph
2016-01-01
This study considers the operator $\\hat{T}$ corresponding to the classical spacetime four-volume $T$ of a finite patch of spacetime in the context of Unimodular Loop Quantum Cosmology for the homogeneous and isotropic model with flat spatial sections and without matter sources. Since $T$ is canonically conjugate to the cosmological "constant" $\\Lambda$, the operator $\\hat{T}$ is constructed by solving its canonical commutation relation with $\\hat{\\Lambda}$ - the operator corresponding to $\\Lambda$. %This is done by expanding $\\hat{T}$ in terms of Bender-Dunne-like basis operators $\\hat{T}_{m,n}$ and solving for the expansion coefficients. This conjugacy, along with the action of $\\hat{T}$ on definite volume states reducing to $T$, allows us to interpret that $\\hat{T}$ is indeed a quantum spacetime four-volume operator. The eigenstates $\\Phi_{\\tau}$ are calculated and, considering $\\tau\\in\\mathbb{R}$, we find that the $\\Phi_{\\tau}$'s are normalizable suggesting that the real line $\\mathbb{R}$ is in the discret...
Bunao, J.
2017-02-01
This study considers the operator \\hat{T} corresponding to the classical spacetime four-volume \\tilde{T} (on-shell) of a finite patch of spacetime in the context of unimodular loop quantum cosmology for the homogeneous and isotropic model with flat spatial sections and without matter sources. Since the spacetime four-volume is canonically conjugate to the cosmological ‘constant’, the operator \\hat{T} is constructed by solving its canonical commutation relation with {\\hat Λ } —the operator corresponding to the classical cosmological constant on-shell {\\tilde Λ } . This conjugacy, along with the action of \\hat{T} on definite volume states reducing to \\tilde{T} , allows us to interpret that \\hat{T} is indeed a quantum spacetime four-volume operator. The discrete spectrum of \\hat{T} is calculated by considering the set of all τ’s where the eigenvalue equation has a solution {{ Φ }τ} in the domain of \\hat{T} . It turns out that, upon assigning the maximal domain D≤ft(\\hat{T}\\right) to \\hat{T} , we have {{ Φ }τ}\\in D≤ft(\\hat{T}\\right) for all τ \\in {C} so that the spectrum of \\hat{T} is purely discrete and is the entire complex plane. A family of operators {{\\hat{T}}≤ft({{b0},{φ0}\\right)}} was also considered as possible self-adjoint versions of \\hat{T} . They represent the restrictions of \\hat{T} on their respective domains D≤ft({{\\hat{T}}≤ft({{b0},{φ0}\\right)}}\\right) which are just the maximal domain with additional quasi-periodic conditions. Their possible self-adjointness is motivated by their discrete spectra only containing real and discrete numbers {τm} for m=0,+/- 1,+/- 2,... .
Application of fast-moving magnetic-flux-quanta in constructing an AND gate and an OR gate
Energy Technology Data Exchange (ETDEWEB)
Jung, K. R. [Korea Photonics Technology Institute, Gwangju (Korea, Republic of); Kang, J. H. [University of Incheon, Incheon (Korea, Republic of)
2004-08-15
In developing an arithmetic logic unit (ALU) with new electronic devices, constructing an OR gate and an AND gate is crucial. In this work, we have designed, fabricated, and tested an OR gate and an AND gate by using rapid single flux quantum (RSFQ) logic. We constructed an AND gate with two D flip-flops and an OR gate with the combination of a confluence buffer and a D flip-flop. The role of the D flip-flop in an OR gate is to output the data when clocked. DC/SFQ circuits were used to generate data and clock pulses in testing the gates. Outputs were read with RS flip-flop type readout circuits and displayed on an oscilloscope. Input frequencies of 10 kHz and 1 MHz were used in this work. We observed correct operations of the gates. The bandwidth of the oscilloscope limited the maximum frequency of our measurements. The logic gates themselves could operate at tens of GHz. We measured the bias margins of the D flip-flop and the confluence buffer of the OR gate, and their values were +-39% and +-23 %, respectively. We also measured the operation margin of the AND gate to be +-25 %. The circuit was measured at liquid-helium temperature.
Kolomeitsev, E. E.; Voskresensky, D. N.
2016-12-01
The spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter f0 in the particle-hole channel. For f0 > 0 the conditions are found when the phase velocity on the spectrum of zero sound acquires a minimum at non-zero momentum. For -1 excitations, and for f0 excitations. An effective Lagrangian for the scalar excitation modes is derived after performing a bosonization procedure. We demonstrate that the instability may be tamed by the formation of a static Bose condensate of the scalar modes. The condensation may occur in a homogeneous or inhomogeneous state relying on the momentum dependence of the scalar Landau parameter. We show that in the isospin-symmetric nuclear matter there may appear a metastable state at subsaturation nuclear density owing to the condensate. Then we consider a possibility of the condensation of the zero-sound-like excitations in a state with a non-zero momentum in Fermi liquids moving with overcritical velocities, provided an appropriate momentum dependence of the Landau parameter f0(k) > 0. We also argue that in peripheral heavy-ion collisions the Pomeranchuk instability may occur already for f0 > -1.
Directory of Open Access Journals (Sweden)
Sharma Neha Gupta
2015-12-01
Full Text Available The J-PET detector being developed at the Jagiellonian University is a positron emission tomograph composed of the long strips of polymer scintillators. At the same time, it is a detector system that will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit time and hit position of the gamma quantum. In order to take advantage of this fact, a dedicated sampling front-end electronics that enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity, we use the Mahalanobis distance. The achievable position and time resolution depend on the number and values of the threshold levels at which the signal is sampled. A reconstruction method as well as preliminary results are presented and discussed.
Energy Technology Data Exchange (ETDEWEB)
Eidemueller, Dirk
2017-02-01
The first part gives a survey about the surprising properties of quantum physics and their most important interpretations. We contrast the new quantum-physical principles of the description of nature with those of classical physics. In the second part we perform in the framework of the reductionism debate an extensive analysis of the understanding of reality represented by the evolutionary theory of knowledge and subject this a critique by means of several central points. A special point of view lies hereby beside the results of quantum philosophy on the relation of physics, chemistry, and biology as well as on the body-soul problem. in the third part we deal with the mutual theories, which follow from the evolution theory and the quantum philosophy for our picture of world.
Even-odd flux quanta effect in the Fraunhofer oscillations of an edge-channel Josephson junction
Baxevanis, B.; Ostroukh, V. P.; Beenakker, C. W. J.
2015-01-01
We calculate the beating of h /2 e and h /e periodic oscillations of the flux-dependent critical supercurrent Ic(Φ ) through a quantum spin-Hall insulator between two superconducting electrodes. A conducting pathway along the superconductor connects the helical edge channels via a nonhelical channel, allowing an electron incident on the superconductor along one edge to be Andreev reflected along the opposite edge. In the limit of small Andreev reflection probability the resulting even-odd effect is described by Ic∝|cos(e Φ /ℏ ) +f | , with |f |≪1 proportional to the probability for phase-coherent interedge transmission. Because the sign of f depends on microscopic details, a sample-dependent inversion of the alternation of large and small peaks is a distinctive feature of the beating mechanism for the even-odd effect.
Kolomeitsev, E E
2016-01-01
Spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with a local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter $f_0$ in the particle-hole channel. For $f_0 >0$ the conditions are found when the phase velocity on the spectrum of the zero sound acquires a minimum at a non-zero momentum. For $-10$. We also argue that in peripheral heavy-ion collisions the Pomeranchuk instability may occur already for $f_0 >-1$.
Plotnitsky, Arkady
2016-01-01
The book considers foundational thinking in quantum theory, focusing on the role the fundamental principles and principle thinking there, including thinking that leads to the invention of new principles, which is, the book contends, one of the ultimate achievements of theoretical thinking in physics and beyond. The focus on principles, prominent during the rise and in the immediate aftermath of quantum theory, has been uncommon in more recent discussions and debates concerning it. The book argues, however, that exploring the fundamental principles and principle thinking is exceptionally helpful in addressing the key issues at stake in quantum foundations and the seemingly interminable debates concerning them. Principle thinking led to major breakthroughs throughout the history of quantum theory, beginning with the old quantum theory and quantum mechanics, the first definitive quantum theory, which it remains within its proper (nonrelativistic) scope. It has, the book also argues, been equally important in qua...
Directory of Open Access Journals (Sweden)
Helen Rose C. Pereira
2013-06-01
Full Text Available OBJETIVO: Revisar os principais artigos referentes ao tema desequilíbrio energético e obesidade, a fim de quantificar o excedente energético diário associado ao ganho de peso em crianças e adolescentes. FONTES DE DADOS: Artigos publicados nos últimos dez anos, indexados nas bases de dados eletrônicas Medline (Pubmed e SciELO-Br. Na base de dados Medline, utilizou-se o descritor "energy gap", termo que descreve os valores energéticos associados às modificações no peso corporal em indivíduos ou populações. Na base de dados SciELO-Br, utilizaram-se os descritores "obesidade", "metabolismo energético", "balanço energético" e "desequilíbrio energético", devido ao fato de não terem sido encontrados artigos nacionais que discutissem o assunto "energy gap". SÍNTESE DOS DADOS: Na população infantil, quatro estudos foram realizados e indicam que crianças e adolescentes estão gradualmente ganhando peso devido a um pequeno, mas persistente, balanço energético positivo diário, 70 a 160kcal acima do total calórico adequado para o crescimento. Os valores encontrados sugerem que pequenas modificações nos hábitos diários de alimentação e de atividade física seriam suficientes para evitar futuros ganhos de peso nessa população. CONCLUSÕES: O ganho gradual de peso pode ser explicado por pequena média diária de balanço energético positivo, de 70 a 160kcal acima do total calórico adequado para o crescimento. O incentivo às pequenas modificações nos hábitos alimentares e de atividades físicas que promovam a redução de 160kcal diárias pode ser uma prática acessível, a fim de barrar o ganho de peso nessa população.
Kudin, A M; Vydaj, Y T; Gres, V Y
2001-01-01
The dependence on the response (L/E) from energy (E) in the range of 5.9...60 keV has been investigated for CsI(Na) during the aging and for CsI(Tl) crystals with different activator concentrations and light collection conditions. On the contrast to data on increasing of L/E in the range of approx 15 keV (so called the response non-proportionality up to + 245), we have shown that value and sign of non-proportionality are determined by light collection conditions, mainly and scintillation material (luminescence centers concentration) in the minor. The distinct correlation is observed between non-proportionality and energy resolution in the low energy range even where is supposed the non-proportionality contribution is insignificant. The main conclusion is the response non-proportionality is not fundamental property of the scintillator. It (and energy resolution) rise from light collection conditions for the quantum with different penetration depth and scintillation long.
Directory of Open Access Journals (Sweden)
Francesco Zanchini di Castiglionchio
2014-07-01
Full Text Available "A CHIARE LETTERE" - CONFRONTI (di Francesco Zanchini di CastiglionchioSi sa che la nomina del card. Levada a Prefetto della Congregazione dottrinale va fatta risalire a una scelta personale di Benedetto XVI, che già l’aveva apprezzato come collaboratore durante la sua lunga presidenza del Dicastero, per poi nomiarlo suo successore, superando i dubbi insorti in Curia a proposito della mancanza, in lui, di una solida formazione accademico-teologica e canonistica. Ma perseverare diabolicum, se è vero che la sua figura ha poi inevitabilmente percorso l’intero cursus honorum della preminenza dottrinale, attraverso il meccanismo automatico, che porta l’investito anche alla presidenza della pontificia Commissione biblica, e poi della Commissione Teologica internazionale; ipoteca delicata, questa, su enti di ricerca per sé liberi, e comunque rispondenti a finalità non riconducibili a quella del controllo dottrinale.
Zh, Aslanyan P
2010-01-01
The designed 2m propane bubble chambers(PBC) with modern power technologies for PC and high precision digital photographic methods is a unique multi-propose, competitive capable and higher-informative 4$\\pi$ detector for study of exotic multi-strange events with $V^0$($\\Lambda,K^0_s$ and $\\gamma$) particles, light hyper-nucleus, ($V^0, V^0$) interactions and other correlations (P02 J-PARC LOI). First from all of unbeatable privilege for PBC are registration of multi-vertex or complex decay modes(with 10-50$\\mu$m space resolution), where is included of the beam area too. The acceptance of beam area for detectors is crucial important for $\\Lambda$ hyperon physics, because more than 70% from $\\Lambda$ hyperons are emitted in the beam area with azimuth $\\beta$ or polar angles $< 15^0$ in p+C reaction at 10 GeV/c. The observed well-known resonances $\\Sigma^{0}$, $\\Sigma^{*\\pm}$(1385) and $K^{*\\pm}$(892) from PDG are good tests of this method. The subject of proposed P02 project allow to explore of multi-strange...
Sharma, N G; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Gorgol, M; Jasińska, B; Kamińska, D; Kapłon, Ł; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Rundel, O; Słomski, A; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zieliński, M; Zgardzińska, B; Moskal, P
2015-01-01
The J-PET detector being developed at Jagiellonian University, is a Positron Emission Tomograph composed of the long strips of polymer scintillators. At the same time it is a detector system which will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit-time and hit-position of the gamma quantum. In order to take advantage of this fact a dedicated sampling front-end electronics which enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity we use the Mahalanobis distance. The achievable position and time-resolution depends on number and values of the threshold levels at which the signal is sampled. A reconstruction method, as well as preliminary results are presented and discussed.
Directory of Open Access Journals (Sweden)
Rony Carlos Preti
2007-01-01
Full Text Available OBJECTIVE: The objective of this study was to use a questionnaire to evaluate knowledge concerning diabetic retinopathy among the physicians present at the 12th Latin American Congress on Diabetes held in São Paulo, Brazil, September 2004. METHODS: A questionnaire about their experience and management of patients with diabetes mellitus and the ophthalmologic examination was administered to 168 endocrinologists attending the meeting. RESULTS: Among the 168 physicians, only 36.9% correctly referred patients with diabetes type 1 to an ophthalmologist, whereas 86.9% referred patients with the type 2 disorder as recommended by the American Academy of Ophthalmology. Regarding the correct indication for screening for diabetic retinopathy, more physicians who had received their degree less than 5 years previously implemented this practice (54.8%, as opposed to those who had received their MD 20 years or more ago (22.6%. Regarding their experience in funduscopy during their specialty training, 52.4% claimed to have experience, but only 21.4% of those interviewed performed this examination on their patients. According to 84.5% of the interviewees, the fundus examination influenced their clinical treatment program. CONCLUSION: Our study demonstrates that medical knowledge among medical practitioners and endocrinologists on preventive measures and periodicity of diabetic retinopathy examinations appears to be far from ideal for diabetes type 1, but satisfactory for diabetes type 2. Therefore, refresher courses emphasizing the correct management of diabetic patients are necessary, because the social and economic impact of retinopathy is significant.OBJETIVO: O objetivo deste estudo foi avaliar através de questionário o conhecimento dos médicos presentes no 12º Congresso Latino Americano de Diabetes Realizado em São Paulo Brasil, Setembro de 2004. MATERIAIS E MÉTODOS: Através de um questionário aplicado a 168 especialistas em endocrinologia presentes no 12º Congresso Latino Americano de Diabetes realizado São Paulo - Brasil em Setembro de 2004, os autores interrogaram sobre a experiência e conduta em relação à Retinopatia Diabética e ao exame oftalmológico. RESULTADOS: Dos 168 médicos, apenas 36,9% encaminhavam corretamente ao oftalmologista os pacientes com diabetes do tipo 1, enquanto 86,9% o faziam de acordo com a Academia Americana de Oftalmologia para os diabéticos do tipo 2. Quanto ao correto encaminhamento dos pacientes para exame de fundo de olho: os médicos com tempo de formação inferior a cinco anos foram os que mais realizam esta prática (54,8%, comparados àqueles com 20 ou mais anos (22,1%. Quanto à experiência em fundoscopia durante a especialização, embora 52,40% afirmassem possuir experiência, apenas 21,4% dos entrevistados realizavam fundo de olho em seus pacientes. Para 84,5% dos entrevistados, o exame de fundo de olho influenciava o tratamento clínico sistemico. CONCLUSÃO: O estudo demonstra que o conhecimento médico das medidas preventivas e de periodicidade do exame da Retinopatia Diabética apresenta-se distante do ideal, para diabéticos tipo 1 e satisfatória para diabéticos tipo 2. Médicos graduados ate 5 anos apresentaram maior porcentagem de correto encaminhamento. A presença de retinopatia diabética no exame de fundo de olho influencia o tratamento clinico sistêmico da maioria dos médicos entrevistados.
Asatiani, T. L.; Genina, L. E.; Zatsepin, G. T.
1985-01-01
A systematic analysis of large gamma families, detected in X-ray emulsion chambers, cases of multicore halos have been observed, and among them five events in which the halo is divided into three of four separate cores with their alignment observed in the target diagram (coplanarity of axes of corresponding electron photon cascades). The halo alignment (tendency to the straight line) leads to the aximuthal asymmetry (thrust). The analysis of lateral and momentum distributions of particles in these families shows that they also have thrust that correlates with the direction of the halo core alignment.
Halvorson, Hans
This book consists of a collection of 18 articles by students, colleagues, and friends of the theoretical chemist/philosopher of science, Hans Primas. Although the articles are written in honor of Primas, the editors state that the collection is not a Festschrift, but that it simply 'takes up some of the discussions that Primas has initiated or inspired' (p. 2). Due to the breadth of Primas' intellectual interests, the result is a highly eclectic collection of articles, whose topics range through (i) the historical development of experimental NMR spectroscopy, (ii) Jungian psychology, (iii) a defense of determinism in the rationalistic tradition of Leibniz, to (iv) a mathematical exposition of 'operator trigonometry.' However, since our space-and my expertise-is limited, the following comments will be restricted to those articles that deal with the mathematical and conceptual foundations of physics, a subject to which Primas has made a large contribution.
Delhôtel, Jean-Michel
'Information is physical': the popular slogan (Landauer, 1991) recalls the fact that information, if it is to be stored, processed or communicated, must have a physical embodiment. Until recently, the physical systems used for representing information were all within the jurisdiction of classical laws. Since the early 1980s however, a growing band of theorists have been toying with the idea of extending such representations to the quantum realm. The computational or cryptographical advantages afforded by linear combinations of quantum states have been unveiled and quantified. Renewed interest in Hilbert space structure and properties of 'entangled' quantum systems have become cornerstones of a new discipline: 'quantum information theory' (QIT), to which we owe some of the most significant and intriguing results in mathematical physics over the last decade.
Directory of Open Access Journals (Sweden)
Ricardo Schaffeln Dorigueto
2005-12-01
Full Text Available OBJETIVO: Avaliar o número de manobras necessárias para abolir o nistagmo posicional em pacientes com Vertigem Posicional Paroxística Benigna e verificar possíveis influências do substrato fisiopatológico e/ou canal semicircular acometido. FORMA DE ESTUDO: clínico prospectivo com coorte transversal. MATERIAL E MÉTODO: Sessenta pacientes com Vertigem Posicional Paroxística Benigna foram tratados por meio das manobras de reposicionamento de estatocônios, repetidas semanalmente até a abolição do nistagmo. A Análise de Variância foi aplicada para verificar diferenças entre as variáveis dos fatores "substrato fisiopatológico" e "canal semicircular acometido". RESULTADOS: Foram necessárias de 1 a 8 manobras, em média 2,13 para abolir o nistagmo posicional. A cupulolitíase necessitou de um número maior de manobras que a ductolitíase (p=0,0002* e não houve diferença entre os canais semicirculares (p=0,5213. Nos canais anterior e posterior, a ductolitíase precisou em média de uma a duas manobras e a cupulolitíase precisou em média de três manobras. No canal lateral, tanto a ductolitíase quanto a cupulolitíase precisaram de duas manobras, em média. CONCLUSÕES: São necessárias de uma a oito manobras semanais de reposicionamento de estatocônios, em média duas, para eliminar o nistagmo posicional na Vertigem Posicional Paroxística Benigna. A cupulolitíase necessita de maior número de manobras que a ductolitíase. O canal semicircular acometido não influencia o número de manobras terapêuticas.AIM: To evaluate the number of weekly canalith repositioning procedures needed to eliminate positioning nystagmus in patients with benign paroxysmal positional vertigo and to verify influences of canalithiasis or cupulolithiasis and/or semicircular canal involvement. STUDY DESIGN: clinical prospective with transversal cohort. MATERIAL AND METHOD: Sixty patients with benign paroxysmal positional vertigo were consecutively selected according to each combination of canalithiasis or cupulolithiasis with semicircular canal involvement. Patients were treated by means of canalith repositioning procedures repeated weekly until the elimination of the positioning nystagmus. Analysis of Variance was used to verify differences between the variables. RESULTS: An average of 2.13 procedures (from 1 to 8 was needed to eliminate the positioning nystagmus. Canalithiasis required an average of 1.53 procedures, while cupulolithiasis needed 2.92 procedures (p=0.0002. An average of two procedures was needed to eliminate the positioning nystagmus in cases with posterior canal involvement, 2.39 procedures in cases with anterior canal involvement and 2.07 procedures in cases with lateral canal involvement (p=0.5213. CONCLUSIONS: From one to eight weekly canalith repositioning procedures were needed, with an average of two, to eliminate positioning nystagmus in benign paroxysmal positional vertigo. Cupulolithiasis requires a greater number of procedures than canalithiasis to eliminate positioning nystagmus. Semicircular canal involvement didn't influence the number of therapeutic maneuvers.
Institute of Scientific and Technical Information of China (English)
曹志华; 郑传发; 张桥
2005-01-01
分析了复合酸化剂对艾维因肉鸡空肠内Eschericha coli和Salmonella typhi定植定量的影响.结果表明,日粮中添加复合酸化剂后,肉鸡空肠内ESscherichia coli和Salmonella typhi数量显著减少,肉鸡生长速度显著提高,死亡率降低13.3%.
Directory of Open Access Journals (Sweden)
Maria João Freitas
2015-06-01
Full Text Available The current study discusses the type of linguistic information assessed during the performance of tasks designed to test phonological awareness: (i phonological knowledge, stored in the phonological representations in the mental lexicon; (ii phonetic detail, available in the acoustic stimuli. We therefore evaluated 23 Portuguese children (mean age: 5;04, all preschoolers, in order to avoid the effect of orthographic representations. All children were submitted to a word segmentation task, which included 19 distractor stimuli and 7 target stimuli controlled for the presence/absence of unstressed vowels, based on the possible phonetic formats of these words in spontaneous speech. The results showed that children do not process the stimuli on the basis of one single type of linguistic information (phonological information in the lexical representations or acoustic properties of the stimuli. The children’s answers, namely the ones coded as segmentation errors, lead us to the formulate an hypothesis according to which several strategies may be activated during performance of tasks designed to assess phonological awareness: processing the word’s phonological representation; processing the phonetic detail in the acoustic stimulus; processing representations of different phonetic formats of a single word in European Portuguese, which seem to be part of the children’s awareness of their language.
Energy Technology Data Exchange (ETDEWEB)
Burck, Andreas
2008-11-04
This thesis describes the development of large-area magnetic calorimeters which could for example be used for the investigation of the dissociative recombination or the measurement of the Lamb-shift for hydrogenlike heavy ions. The detectors consist of two meandershaped niobium thin film pickup coils and a paramagnetic sensor. The deposition of energy in the sensor results in a temperature change and therefore in a change of magnetisation of the sensor, which can be measured by a SQUID-magnetometer with high precision. As sensormaterials a dilute alloy of gold-erbium (Au:Er) as well as silver-erbium (Ag:Er) were used. Whereas the Ag:Er-sensor was glued on the pickup coil the Au:Er-sensor was for the first time microstructured by a novel microstructuring process established in this thesis. For the characterisation of the detectors and the sensormaterials a fluorescence source and a {sup 55}Fe source were used. The thermodynamic properties of the Au:Er-sensors thereby show promising results, as the magnetisation shows bulk properties down to 20 mK. The measurements of the signalize and the magnetisation with the detector which was equipped with a Ag:Er-sensor showed that the thermodynamic properties of the Ag:Eralloy could be fully described. Furthermore the shape of the pulses, the noise and the energy resolution of both detectors will be discussed. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Kuzin, A.M.; Bagabova, M.E.
1978-01-01
It was demonstrated that developmental processes activated in plants by quanta of red light (sprouting of dormant salad seeds, anthocyan synthesis) are very sensitive to ..gamma.. quanta, and that the combined effect of these two factors is important to expression of stimulated development after presowing exposure of seeds to ..gamma.. radiation.
Moessbauer optics of synchrotron radiation at an isotope interface
Belyakov, V A
2000-01-01
Coherent inelastic Moessbauer scattering (CIMS) of synchrotron radiation (SR) at an isotope interface (plane interface between two regions differing only in the concentration of the Moessbauer isotope) is investigated theoretically. Main attention is paid to the CIMS component resulting from SR quanta absorption by Moessbauer nuclei accompanied by creation or annihilation of the phonons in sample and following recoilless reemission of Moessbauer quanta.
On the Local Equilibrium Principle
Hessling, H
2001-01-01
A physical system should be in a local equilibrium if it cannot be distinguished from a global equilibrium by ``infinitesimally localized measurements''. This seems to be a natural characterization of local equilibrium, however the problem is to give a precise meaning to the qualitative phrase ``infinitesimally localized measurements''. A solution is suggested in form of a {\\em Local Equilibrium Condition} (LEC) which can be applied to non-interacting quanta. The Unruh temperature of massless quanta is derived by applying LEC to an arbitrary point inside the Rindler Wedge. Massless quanta outside a hot sphere are analyzed. A stationary spherically symmetric local equilibrium does only exist according to LEC if the temperature is globally constant. Using LEC a non-trivial stationary local equilibrium is found for rotating massless quanta between two concentric cylinders of different temperatures. This shows that quanta may behave like a fluid with a B\\'enard instability.
Bachilova, R. N.; Bloch, G. M.; Pankov, V. M.; Prohin, V. L.; Rutkovsky, A. I.; Rumin, S. P.
1988-07-01
Gamma-quanta flux measurements were carried out during February-October 1987 in a search for radiation from SN 1987A. The time dependence of the mean monthly gamma-quanta flux measured with the Nega telescope at an altitude of 500 km in the equatorial region is analyzed. The upper limit of the gamma-quanta flux is determined to be 1.5 x 10 to the -6th/sq cm s keV on the 3-sigma level for the 1.5-4.4 MeV energy interval.
Ada Clarice Gastaldi; Getúlio Antonio de Freitas Filho; Ana Paula Manfio Pereira; Janne Marques Silveira
2010-01-01
INTRODUÇÃO: pressões inspiratórias (PImax) ou expiratórias (PEmax) máximas constituem um método simples e não-invasivo para avaliação da força de músculos respiratórios e auxiliam na identificação de fraqueza dos músculos respiratórios, presente em diversas doenças e situações clínicas, como a tetraplegia. OBJETIVO: avaliar o número de manobras necessárias para atingir as pressões máximas em pacientes com tetraplegia. MÉTODOS: oito pacientes com tetraplegia (sete homens), média de idade de 37...
Directory of Open Access Journals (Sweden)
Ada Clarice Gastaldi
2010-06-01
Full Text Available INTRODUÇÃO: pressões inspiratórias (PImax ou expiratórias (PEmax máximas constituem um método simples e não-invasivo para avaliação da força de músculos respiratórios e auxiliam na identificação de fraqueza dos músculos respiratórios, presente em diversas doenças e situações clínicas, como a tetraplegia. OBJETIVO: avaliar o número de manobras necessárias para atingir as pressões máximas em pacientes com tetraplegia. MÉTODOS: oito pacientes com tetraplegia (sete homens, média de idade de 37,8±11,96 anos, com diagnóstico de lesão raquimedular cervical completa realizaram 10 medidas de PImax e PEmax nas posições sentada e deitada, totalizando 320 medidas. Os dados foram comparados pelo teste de Wilcoxon (pINTRODUCCIÓN: las presiones inspiratorias (PImax y espiratorias (PEmax máximas constituyen un método simple y no invasivo para evaluar la fuerza de los músculos respiratorios, y ayudan a identificar la debilidad de los músculos respiratorios presente en diferentes enfermedades y situaciones clínicas, como la tetraplejía. OBJETIVO: evaluar el número de maniobras necesarias para llegar a las presiones máximas en pacientes con tetraplejía. MÉTODOS: fueron incluidos ocho pacientes con tetraplejía (siete hombres, con edad media de 37,8±11,96 años y diagnóstico de lesión cervical raquis medular completa, a lo que se le realizaron 10 mediciones de PImax y PEmax en posición sentado y acostado, totalizando 320 mediciones. Los datos fueron comparados por el test de Wilcoxon (pINTRODUCTION: maximum inspiratory (IPmax and expiratory (EPmax pressures constitute a simple noninvasive method for evaluation of respiratory muscle strength which helps in the identification of muscle weakness usually present in several diseases and clinical situations, such as quadriplegia. OBJECTIVE: to assess the number of maneuvers needed to achieve maximum pressures in patients with quadriplegia. METHODS: eight quadriplegic patients (seven men with mean age of 37.8 ± 11.96 years old and presenting with diagnosis of complete spinal cord lesion were submitted to 10 measurements of IPmax and EPmax in both seated and supine positions, totalizing 320 measurements. Data were compared by using the Wilcoxon's test (p<0.05. RESULTS: the 1st and 10th measurements of IPmax and EPmax for seated position ranged from 74.1±15.1 to 74.8±19.8 cmH2O and 32.4±6.8 to 32.4±9.0 cmH2O, respectively; whereas for supine position such measurements ranged from 76.5±18.6 to 91.1±13.3 cmH2O (p<0.05 and 32.5±5.8 to 32.9±5.1 cmH2O, respectively. The results regarding the 3rd and 5th measurements of IPmax for seated position were 81.1±19.5, 81.5±18.8, and 83.0±18.9 cmH2O; whereas EPmax had 35.0±8.2; 35.3±7.9, and 36.8±8.0 cmH2O. IPmax values for seated position were 90.3±17.8, 94.6±16.0, and 97.4±17.8 cmH2O (p<0.05, whereas EPmax had 33.3±5.8, 35.6±5.4, and 36.9±4.9 cmH2O. The highest value occurred from the 6th measurement in 40% of the tests. CONCLUSIONS: To obtain maximum values for respiratory pressures in quadriplegic patients, it is necessary to repeat the measurements at least 10 times for each evaluation.
Directory of Open Access Journals (Sweden)
Ada Clarice Gastaldi
2009-12-01
Full Text Available INTRODUÇÃO: pressões inspiratórias (PImax ou expiratórias (PEmax máximas constituem um método simples e não-invasivo para avaliação da força de músculos respiratórios e auxiliam a identificação de fraqueza dos músculos respiratórios, presente em diversas doenças e situações clínicas, como a tetraplegia. OBJETIVO: avaliar o número de manobras necessárias para atingir as pressões máximas em pacientes com tetraplegia. MÉTODOS: oito pacientes com tetraplegia (sete homens, média de idade de 37,8±11,96 anos, com diagnóstico de lesão raquimedular cervical completa realizaram 10 medidas de PImax e PEmax nas posições sentada e deitada, totalizando 320 medidas. Os dados foram comparados pelo teste de Wilcoxon (pINTRODUCCIÓN: las presiones inspiratorias (PImáx y espiratorias (PEmáx máximas constituyen un método simple y no invasivo para evaluar la fuerza de los músculos respiratorios, y ayudan a identificar la debilidad de los músculos respiratorios presente en diferentes enfermedades y situaciones clínicas, como la tetraplejía. Objetivo: evaluar el número de maniobras necesarias para llegar a las presiones máximas en pacientes con tetraplejía. MÉTODOS: fueron incluidos ocho pacientes con tetraplejía (siete hombres, con edad media de 37,8±11,96 años y diagnóstico de lesión cervical raquis medular completa, a lo que se le realizo diez mediciones de PImáx y PEmáx en posición sentado y acostado, totalizando 320 mediciones. Los datos fueron comparados por el test de Wilcoxon (pINTRODUCTION: maximum inspiratory (PImax and expiratory (PEmax pressures are a simple non-invasive method for evaluation of respiratory muscle strength that helps in the identification of muscle weakness, usually present in several diseases and clinical situations, such as quadriplegia. Objective: to assess the number of maneuvers needed to achieve maximum pressures in patients with quadriplegia. METHODS: eight quadriplegic patients (seven men with mean age range of 37.8±11.96 years old and diagnosed with complete spinal cord lesion were submitted to ten measurements of PImax and PEmax in both seated and supine positions, totalizing 320 measurements. Data were compared by using the Wilcoxon's test (p<0.05. RESULTS: the 1st and 10th measurements of PImax and PEmax for seated position ranged from 74.1±15.1 to 74.8±19.8 cmH2O and 32.4±6.8 to 32.4±9.0 cmH2O, respectively; whereas for supine position these measurements ranged from 76.5±18.6 to 91.1±13.3 cmH2O (p<0.05 and 32.5±5.8 to 32.9±5.1 cmH2O, respectively. The results regarding the 3rd and 5th measurements of PImax for seated position were 81.1±19.5 cmH2O, 81.5±18.8 cmH2O, and 83.0±18.9 cmH2O; whereas PEmax had 35.0±8.2 cmH2O; 35.3±7.9 cmH2O, and 36.8±8.0 cmH2O. PImax values for seated position were 90.3±17.8 cmH2O, 94.6±16.0 cmH2O, and 97.4±17.8 cmH2O (p<0.05, whereas PEmax resulted in 33.3±5.8 cmH2O, 35.6±5.4 cmH2O, and 36.9±4.9 cmH2O. The highest value occurred from the sixth measurement in 40% of the tests. CONCLUSION: as to obtain maximum values for respiratory pressures in quadriplegic patients, it is necessary to repeat each measurement at least ten times.
Energy Technology Data Exchange (ETDEWEB)
Beetz, Juergen
2016-07-01
In this essential can be found the structure and the general properties of atoms, the precise interior of atoms and the special behaviour resulting from it, and the mysterious world of ''quanta'' and their behaviour.
Quantum-matter physics: Quasiparticles on a collision course
van der Marel, Dirk
2016-05-01
Emergent quanta of momentum and charge, called quasiparticles, govern many of the properties of materials. The development of a quasiparticle collider promises to reveal fundamental insights into these peculiar entities. See Letter p.225
National Research Council Canada - National Science Library
Corda, Christian
2013-01-01
Introducing a black hole (BH) effective temperature, which takes into account both the non-strictly thermal character of Hawking radiation and the countable behavior of emissions of subsequent Hawking quanta, we recently re...
High-Flux Ultracold-Atom Chip Interferometers Project
National Aeronautics and Space Administration — ColdQuanta's ultimate objective is to produce a compact, turnkey, ultracold-atom system specifically designed for performing interferometry with Bose-Einstein...
Staging quantum cryptography with chocolate ballsa)
Svozil, Karl
2006-09-01
Moderated by a director, laypeople and students assume the role of quanta and enact a quantum cryptographic protocol. The performance is based on a generalized urn model capable of reproducing complementarity even for classical chocolate balls.
Wheeler-Feynman Absorber Theory Viewed by Model of Expansive Nondecelerative Universe
Sukenik, Miroslav; Sima, Jozef
2001-01-01
The present contribution documents the harmony of postulates and conclusions of Wheeler-Feynman absorber theory and the model of Expansive Nondecelerative Universe. A relationship connecting advanced electromagnetic waves and gravitational field quanta is rationalized.
Castell, Stephen
2012-06-01
In the wake of Stephen Hawking's appearance on the TV show The Big Bang Theory, last month's "Quanta" page (May p3), included a request: "If you think Hawking should appear in any other TV shows, then let us know".
Reflexive measurements, self-inspection and self-representation
Svozil, Karl
2016-01-01
There exist limits of self-inspection due to self-referential paradoxes, incompleteness and fixed point theorems. As quantum mechanics dictates the exchange of discrete quanta, measurements and self-inspection of quantized systems are fundamentally limited.
Quantum nonlinear optics with single photons enabled by strongly interacting atoms
DEFF Research Database (Denmark)
Peyronel, Thibault; Firstenberg, Ofer; Liang, Qi Yu
2012-01-01
The realization of strong nonlinear interactions between individual light quanta (photons) is a long-standing goal in optical science and engineering, being of both fundamental and technological significance. In conventional optical materials, the nonlinearity at light powers corresponding...
76 FR 39070 - Application(s) for Duty-Free Entry of Scientific Instruments
2011-07-05
... Expertise (IMAGE) Center, 750 Communications Drive--Mailcode 4402, Carbondale, IL 62901. Instrument: Quanta 450 scanning electron microscope. Manufacturer: FEI Company, Czech Republic. Intended Use: The...: FEI Company, the Netherlands. Intended Use: The instrument will enhance the research...
FastLane: An Agile Congestion Signaling Mechanism for Improving Datacenter Performance
2013-05-20
Cloudera, Ericsson, Facebook, General Electric, Hortonworks, Huawei , Intel, Microsoft, NetApp, Oracle, Quanta, Samsung, Splunk, VMware and Yahoo...Web Services, Google, SAP, Blue Goji, Cisco, Clearstory Data, Cloud- era, Ericsson, Facebook, General Electric, Hortonworks, Huawei , Intel, Microsoft
Radiative Processes of the DeWitt-Takagi Detector
Díaz, D E
2003-01-01
We examine the excitation of a uniformly accelerated DeWitt-Takagi detector coupled quadratically to a Majorana-Dirac field. We obtain the transition probability from the ground state of the detector and the vacuum state of the field to an excited state with the emission of a Minkowski pair of quanta, in terms of elementary processes of absorption and scattering of Rindler quanta from the Fulling-Davies-Unruh thermal bath in the co-accelerated frame.
Gestrina, G N
2005-01-01
The relativistic effect of energy increase in a particle freely moving in vacuum is discussed on the basis of quantum field theory and probability theory using some ideas of super-symmetrical theories. The particle is assumed to consist of a "seed" whose energy is equal to the particle rest energy and whose pulse is equal to the product of the particle mass by its velocity and of a "fur coat" - the system of virtual quanta of the material field - vacuum. Each of these quanta possesses the same energy and pulse as the "seed" but have no mass. The system of the quanta is in a state being the superposition of quantum states with energies and pulses multiple of the "seed" energy and pulse. The virtual quanta is created (or destroyed) in of such states. The probability of creating a quanta in any state is the inverse of the relativistic factor, and the average number of the quanta making up the "fur coat" with a "seed" is equal to this particular factor. The kinetic energy and the relativistic addition to the part...
Detection of dark-matter-radiation of stars during visible sun eclipses
Energy Technology Data Exchange (ETDEWEB)
Volkamer, Klaus E-mail: dr.volkamer@t-online.de
2003-07-01
Recently a so-far unknown form of quantized, cold dark matter was detected on a laboratory scale which shows a complementary structure as compared to known forms of matter. From the experiments results that the observed quanta of the new type of matter as integer multiples of the Planck mass (mp = n {center_dot} {radical}((h{center_dot}c)/((2 {center_dot} {pi} {center_dot} G))) = n 0 21.77 {mu}g, with n = 1, 2, 3 etc.) exhibit a spatially extended 'field-like' structure ranging over distances of centimetres or more, opposite to the 'point-like' structure of the known elementary particles of the standard model. Association of quanta of the new form of 'soft' (or subtle) matter to clusters was observed, as well as re-clustering after absorption. Thus, between such quanta a physical interaction must exist. In addition, the new form of matter shows at least two interactions with normal matter, a gravitational one due to its real mass content and a so-far unknown 'topological', i.e. form-specific, interaction at phase borders. Additional indications for a weak electromagnetic interaction exist. Furthermore, the experimental results reveal that some types of quanta of the new form of 'field-like' matter exhibit positive mass, as normal matter, but others exhibit a negative mass content, both in the order of magnitude of the Planck mass. Memory effects in normal matter were detected after absorption of quanta of the new form of soft matter. In general, the findings characterize the quanta of 'fieldlike' matter as WIMP candidates of a cosmic background radiation of cold dark matter (quanta with positive mass) as well as of a cosmic background radiation of dark energy (quanta with negative mass). During visible sun eclipses in 1989, 1996 and. 1999, as well as during full moon of 6 January 2001, a so-far unknown form of dark-matter-radiation ('dark radiation') was detected. The quanta of this &apos
Black holes and the butterfly effect
Energy Technology Data Exchange (ETDEWEB)
Shenker, Stephen H.; Stanford, Douglas [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University,Stanford, CA 94305 (United States); Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States)
2014-03-13
We use holography to study sensitive dependence on initial conditions in strongly coupled field theories. Specifically, we mildly perturb a thermofield double state by adding a small number of quanta on one side. If these quanta are released a scrambling time in the past, they destroy the local two-sided correlations present in the unperturbed state. The corresponding bulk geometry is a two-sided AdS black hole, and the key effect is the blueshift of the early infalling quanta relative to the t=0 slice, creating a shock wave. We comment on string- and Planck-scale corrections to this setup, and discuss points that may be relevant to the firewall controversy.
Experiments with Individual Photons
Beck, Mark
2004-05-01
I describe several different experiments we have performed with individual photons. For example, while well known experiments involving phenomena such as the photoelectric effect and Compton scattering strongly suggest the existence of photons, they do not prove the existence of light quanta. To prove the existence of light quanta one must perform an experiment whose results cannot be explained using classical waves. We have performed such an experiment--it demonstrates the localization of light quanta by showing that a single photon only goes one way when it leaves a beamsplitter [1]. In a second experiment we demonstrate that this single photon will interfere with itself when it transits an interferometer. The experiments have been performed by undergraduates, and the goal of this project is to develop a series of experiments exploring fundamental aspects of quantum mechanics for an undergraduate teaching lab. [1] P. Grangier, G. Roger and A. Aspect, Europhys. Lett. 1, 173 (1986).
Black holes and the butterfly effect
Shenker, Stephen H
2013-01-01
We use holography to study sensitive dependence on initial conditions in strongly coupled field theories. Specifically, we mildly perturb a thermofield double state by adding a small number of quanta on one side. If these quanta are released a scrambling time in the past, they destroy the local two-sided correlations present in the unperturbed state. The corresponding bulk geometry is a two-sided AdS black hole, and the key effect is the blueshift of the early infalling quanta relative to the $t = 0$ slice, creating a shock wave. We comment on string- and Planck-scale corrections to this setup, and discuss points that may be relevant to the firewall controversy.
The Possibilist Transactional Interpretation and Relativity
Kastner, Ruth E
2012-01-01
A recent ontological variant of Cramer's Transactional Interpretation, called "Possibilist Transactional Interpretation" or PTI, is extended to the relativistic domain. The present interpretation clarifies the concept of 'absorption,' which plays a crucial role in TI (and in PTI). In particular, in the relativistic domain, coupling amplitudes between fields are interpreted as amplitudes for the generation of confirmation waves (CW) by a potential absorber in response to offer waves (OW), whereas in the nonrelativistic context CW are taken as generated with certainty. It is pointed out that solving the measurement problem requires venturing into the relativistic domain in which emissions and absorptions take place; nonrelativistic quantum mechanics only applies to quanta considered as 'already in existence' (i.e., 'free quanta'), and therefore cannot fully account for the phenomenon of measurement, in which quanta are tied to sources and sinks.
Dressed Hard States and Black Hole Soft Hair.
Mirbabayi, Mehrdad; Porrati, Massimo
2016-11-18
A recent, intriguing Letter by Hawking, Perry, and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this Letter we make use of factorization theorems for infrared divergences of the S matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.
Vergeles, S N
2015-01-01
It is shown that the Wilson fermion doubling phenomenon on irregular lattices (simplicial complexes) does exist. This means that the irregular (not smooth) zero or soft modes exist. The statement is proved on 4 Dimensional lattice by means of the Atiyah-Singer index theorem, then it is extended easily into the cases $D<4$. But there is a fundamental difference between doubled quanta on regular and irregular lattices: in the latter case the propagator decreases exponentially. This means that the doubled quanta on irregular lattice are "bad" quasiparticles.
Energy Technology Data Exchange (ETDEWEB)
Orlov, Y.; Netecha, M.E.; Vasiliev, A.P.; Avaev, V.N.; Vasiliev, G.A. [Research and Development Institute of Power Engineering, Moscow (Russian Federation); Zelensky, D.I.; Istomin, Y.L.; Cherepnin, Y.S. [Institute of Atomic Energy of the National Nuclear Center of the Republic of Kazakhstan, Semipalatinsk-21 (Kazakhstan); Nomura, Y. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2000-03-01
A set of measurements on skyshine radiation was conducted at two special research reactors. A broad range of detectors was used in the measurements to record neutron and gamma radiations. Dosimetric and radiometric field measurements of the neutrons and gamma quanta of the radiation scattered in the air were performed at distances of 50 to 1000 m from the reactor during different weather conditions. The neutron spectra in the energy range of 1 eV to 10 MeV and the gamma quanta spectra in the range of 0.1-10 MeV were measured. (author)
Dressed Hard States and Black Hole Soft Hair
Mirbabayi, Mehrdad; Porrati, Massimo
2016-11-01
A recent, intriguing Letter by Hawking, Perry, and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this Letter we make use of factorization theorems for infrared divergences of the S matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.
Shaving off Black Hole Soft Hair
Mirbabayi, Mehrdad
2016-01-01
A recent, intriguing paper by Hawking, Perry and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this note we make use of factorization theorems for infrared divergences of the S-matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S-matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.
Alekseev, V M; Verbitskij, V S; Verbitskij, S S; Lapik, M A; Tselebrovskij, A N; Lapik, A M; Rusakov, A V; Savopulo, M L; Smirnov, V V; Chubarov, M N
2002-01-01
Paper describes algorithm to calculate scintillation coordinates elaborated for a coordinate-sensitive large detector based on liquid scintillator with radial arrangement of nine FEU-174 photomultipliers. Paper contains the simulation results of coordinate resolution dependence in detector centre on energy of gamma-quanta within 0.2-8 MeV range. Using this algorithm one processed the experimental data obtained with application of sup 6 sup 0 Co gamma-radiation source and the results of determination of scintillation coordinates for gamma-quanta beam. The accuracy of coordinate determination in detector centre when applying the descried algorithm constitutes approx 10 mm
Decay of 5H in a microscopic three-cluster model
Lashko, Yu. A.; Filippov, G. F.
2008-12-01
The Pauli-allowed states of a three-cluster model are shown to be orthonormal polynomials of a discrete variable, which become the Kravchuk polynomials as the number of oscillator quanta increases. Such asymptotic behavior corresponds to the subsequent decay of the 5H into the 4H and a neutron.
LETTER TO THE EDITOR: Remarks on the construction of a Hermitian phase operator
Roy, P.; Roy, B.
1997-12-01
We consider an oscillator system (whose states are realized in the space of Kravchuk polynomials) in a finite-dimensional Hilbert space. A Hermitian phase operator and the phase quanta raising and lowering operator are constructed using this framework. Also, we have constructed phase coherent states and examined their squeezing property.
Reducing Motional Decoherence in Ion Traps with Surface Science Methods
Haeffner, Hartmut
2014-03-01
Many trapped ions experiments ask for low motional heating rates while trapping the ions close to trapping electrodes. However, in practice small ion-electrode distances lead to unexpected high heating rates. While the mechanisms for the heating is still unclear, it is now evident that surface contamination of the metallic electrodes is at least partially responsible for the elevated heating rates. I will discuss heating rate measurements in a microfabricated surface trap complemented with basic surface science studies. We monitor the elemental surface composition of the Cu-Al alloy trap with an Auger spectrometer. After bake-out, we find a strong Carbon and Oxygen contamination and heating rates of 200 quanta/s at 1 MHz trap frequency. After removing most of the Carbon and Oxygen with Ar-Ion sputtering, the heating rates drop to 4 quanta/s. Interestingly, we still measure the decreased heating rate even after the surface oxidized from the background gas throughout a 40-day waiting time in UHV.
Teaching Quantum Physics without Paradoxes
Hobson, Art
2007-01-01
Although the resolution to the wave-particle paradox has been known for 80 years, it is seldom presented. Briefly, the resolution is that material particles and photons are the quanta of extended spatially continuous but energetically quantized fields. But because the resolution resides in quantum field theory and is not usually spelled out in…
Energy Technology Data Exchange (ETDEWEB)
Kicinska-Habior, M. [Warsaw Univ., Inst. of Experimental Physics, Warsaw (Poland)]|[University of Washington, Nuclear Physics Laboratory, Seattle (United States); Snover, K.A.; Drebi, Z.; Ye, D.; Kelly, M. [University of Washington, Nuclear Physics Laboratory, Seattle (United States); Maj, A. [University of Washington, Nuclear Physics Laboratory, Seattle (United States)]|[Institute of Nuclear Physics, Cracow (Poland); Trznadel, Z. [Warsaw Univ., Inst. of Experimental Physics, Warsaw (Poland)
1996-12-31
The gamma spectra from the giant dipole resonance (GDR) decay have been investigated. It was assumed that the gamma quanta emitted from GDR origin from statistical emission and Bremsstrahlung. The calculation results are compared with the experimental data from {sup 12}C + {sup 26}Mg and {sup 12}C + {sup 24}Mg reactions. 9 refs, 1 fig., 1 tab.
Controlled contact to a C-60 molecule
DEFF Research Database (Denmark)
Neel, N.; Kröger, J.; Limot, L.;
2007-01-01
The tip of a low-temperature scanning tunneling microscope is approached towards a C-60 molecule adsorbed at a pentagon-hexagon bond on Cu(100) to form a tip-molecule contact. The conductance rapidly increases to approximate to 0.25 conductance quanta in the transition region from tunneling...
Energy Technology Data Exchange (ETDEWEB)
Pinto Rengifo, Ricardo Alberto
2008-02-15
We address the excitation of quantum breathers in small nonlinear networks of two and three degrees of freedom, in order to study their properties. The invariance under permutation of two sites of these networks substitutes the translation invariance that is present in nonlinear lattices, where (classical) discrete breathers are time periodic space localized solutions of the underlying classical equations of motion. We do a systematic analysis of the spectrum and eigenstates of such small systems, characterizing quantum breather states by their tunneling rate (energy splitting), site correlations, fluctuations of the number of quanta, and entanglement. We observe how these properties are reflected in the time evolution of initially localized excitations. Quantum breathers manifest as pairs of nearly degenerate eigenstates that show strong site correlation of quanta, and are characterized by a strong excitation of quanta on one site of the network which perform slow coherent tunneling motion from one site to another. They enhance the fluctuations of quanta, and are the least entangled states among the group of eigenstates in the same range of the energy spectrum. We use our analysis methods to consider the excitation of quantum breathers in a cell of two coupled Josephson junctions, and study their properties as compared with those in the previous cases. We describe how quantum breathers could be experimentally observed by employing the already developed techniques for quantum information processing with Josephson junctions. (orig.)
IMPACT RANGE ESTIMATION OF POLLUTED SOIL AREA FOR RADIATION MONITORINGBY «IN SITU» METHOD
Directory of Open Access Journals (Sweden)
A. Zhukouski
2014-01-01
Full Text Available Intensity of «direct» gamma-quanta absorbed in cylindrical detector has been determined for the detector placed over soil uniformly contaminated in depth. The dependence of impact range radius for NaI(Tl detector to cesium depth contamination is established for soil from Tohoku region, Japan.
A pinhole gamma camera with optical depth-of-interaction elimination
Korevaar, M.A.N.; Heemskerk, J.W.T.; Beekman, F.J.
2009-01-01
The performance of pinhole single photon emission computed tomography (SPECT) depends on the spatial resolution of the gamma-ray detectors used. Pinhole cameras suffer from strong resolution loss due to the varying depth-of-interaction (DOI) of gamma quanta that enter the detector material at an ang
Energy Technology Data Exchange (ETDEWEB)
Zhang Hongwei; Zhang Lili; Zhang Canbang; Zhou Lingyun [Department of Physics, Honghe University, Mengzi, 661100 (China); Xu Lin, E-mail: zhhw7272@126.com [Department of Physics, Yunnan Normal University, Kunming, 650092 (China)
2011-02-01
In this paper, a lethal effect experiment was carried out, in which the biological cells of suspension-industrial saccharomyces cervisiac Sachromyce 2.1189 in liquid was irradiated by CO{sub 2} laser. The experiment results were analyzed by means of quanta theory and thermotics theory. The theoretic analysis results can explain well the experimental results of the lethal effect.
Tales of the quantum understanding physics' most fundamental theory
Hobson, Art
2016-01-01
This is a book about the quanta that make up our universe--the highly unified bundles of energy of which everything is made. It explains wave-particle duality, randomness, quantum states, non-locality, Schrodinger's cat, quantum jumps, and more, in everyday language for non-scientists and scientists who wish to fathom science's most fundamental theory.
Problems in the Science and Mathematics of 'The Logic of Scientific Discovery'
Directory of Open Access Journals (Sweden)
Alan B. Whiting
2012-11-01
Full Text Available Professor Sir Karl Popper (1902-1994 was one of the most influential philosophers of science of the twentieth century. However, in his most famous work 'The Logic of Scientific Discovery' he displays troubling misunderstandings of science and mathematics at a basic level. These call into question his conclusions concerning the philosophy of science.Quanta 2012; 1: 13–18.
The multiplicity and the spectra of secondaries correlated with the leading particle energy
Kruglov, N. A.; Proskuryakov, A. S.; Sarycheva, L. I.; Smirnova, L. N.
1985-01-01
The spectra of leading particles of different nature in pp-collisions at E sub 0 = 33 GeV are obtained. The multiplicities and the spectra of secondaries, mesons, gamma-quanta, lambda and lambda-hyperons and protons for different leading particle energy ranges are determined.
Belfkir, Mohamed
2017-01-01
The strong CP violation and Dark matter are two important and theoretically compelling issues in modern particle physics and cosmology and the concept of axion-like particle (ALPs) is an elegant solution to both. To solve the CP violation problem we introduce a scalar field. The quanta associated to this field is the ALP.
Digital SQUIDs based on Smart DROS
Podt, M.; Keizer, D.; Flokstra, J.; Rogalla, H.
1999-01-01
A Double Relaxation Oscillation SQUID (DROS) with the complete flux locked loop (FLL) circuitry on one single chip, a Smart DROS, has been realized. A superconducting storage loop interrupted by two write gates to add or extract flux quanta acts as an integrator that supplies the feedback flux to th
Teaching Quantum Physics without Paradoxes
Hobson, Art
2007-01-01
Although the resolution to the wave-particle paradox has been known for 80 years, it is seldom presented. Briefly, the resolution is that material particles and photons are the quanta of extended spatially continuous but energetically quantized fields. But because the resolution resides in quantum field theory and is not usually spelled out in…
Terahertz Generation & Vortex Motion Control in Superconductors
Nori, Franco
2005-03-01
A grand challenge is to controllably generate electromagnetic waves in layered superconducting compounds because of its Terahertz frequency range. We propose [1] four experimentally realizable devices for generating continuous and pulsed THz radiation in a controllable frequency range. We also describe [2-4] several novel devices for controlling the motion of vortices in superconductors, including a reversible rectifier made of a magnetic-superconducting hybrid structure [4]. Finally, we summarize a study [5] of the friction force felt by moving vortices. 1) S. Savel'ev, V. Yampol'skii, A. Rakhmanov, F. Nori, Tunable Terahertz radiation from Josephson vortices, preprint 2) S. Savel'ev and F. Nori, Experimentally realizable devices for controlling the motion of magnetic flux quanta, Nature Mat. 1, 179 (2002) 3) S. Savel'ev, F. Marchesoni, F. Nori, Manipulating small particles, PRL 92, 160602 (2004); B. Zhu, F. Marchesoni, F. Nori, Controlling the motion of magnetic flux quanta, PRL 92, 180602 (2004) 4) J.E. Villegas, et al., Reversible Rectifier that Controls the Motion of Magnetic Flux Quanta, Science 302, 1188 (2003) 5) A. Maeda, et al., Nano-scale friction: kinetic friction of magnetic flux quanta and charge density waves, preprint
AN ELECTROPHYSIOLOGICAL INVESTIGATION OF NEUROMUSCULAR TRANSMISSION IN MYASTHENIA GRAVIS,
with myasthenia gravis . With repetitive nerve stimulation at frequencies above 2/sec, only the first few stimuli elicited muscle contractions in most...It is tentatively concluded that in myasthenia gravis there is a deficiency in the amount of ACh in the quanta of transmitter released from the motor nerve terminals. (Author)
Murdin, P.
2000-11-01
British engineer and archaeo-astronomer, born in Scotland, became professor of engineering science at Oxford University. Accurately surveyed the megalithic sites in Britain and the megalithic lunar observatories, identifying their shapes and astronomical alignments. He claimed to have discovered in the dimensions of the circles, as apparently used by the megalithic constructors, quanta of length ...
Electric fields and quantum wormholes
Engelhardt, D.; Freivogel, B.; Iqbal, N.
2015-01-01
Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum version of an Einstein-Rosen bridge between the particles, or a
The Hawking cascade from a black hole is extremely sparse
Gray, Finnian; Van-Brunt, Alexander; Visser, Matt
2015-01-01
The Hawking flux from a black hole, (at least as seen from large distances), is extremely sparse and thin, with the average time between emission of successive Hawking quanta being hundreds of times larger than the natural timescale set by the energies of the emitted quanta. Some aspects of this result have been known for over 30 years, but have been largely forgotten, possibly because authors focussed mainly on the late-time high-temperature regime. We shall instead focus on the early-stage low-temperature regime, and shall both quantify and significantly extend these observations in a number of different ways. First we shall identify several natural dimensionless figures of merit, and thereby compare the mean time between emission of successive Hawking quanta to several quite natural timescales that can be associated with the emitted quanta, demonstrating that ratios of 300 or more are typical for emission of photons or gravitons from a Schwarzschild black hole. Furthermore these ratios are independent of t...
National Research Council Canada - National Science Library
Kamińska, D; Gajos, A; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Curceanu, C; Dulski, K; Głowacz, B; Gupta-Sharma, N; Gorgol, M; Hiesmayr, B C; Jasińska, B; Korcyl, G; Kowalski, P; Krzemień, W; Krawczyk, N; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Silarski, M; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P
2016-01-01
...) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals...
Observable Effects of Quantum Gravity
Chang, Lay Nam; Sun, Chen; Takeuchi, Tatsu
2016-01-01
We discuss the generic phenomenology of quantum gravity and, in particular, argue that the observable effects of quantum gravity, associated with new, extended, non-local, non-particle-like quanta, and accompanied by a dynamical energy-momentum space, are not necessarily Planckian and that they could be observed at much lower and experimentally accessible energy scales.
Imaging of the dynamic magnetic structure in a parallel array of shunted Josephson junctions
DEFF Research Database (Denmark)
Doderer, T.; Kaplunenko, V. K.; Mygind, Jesper
1994-01-01
is applied to the edge junction of the array. This effect was found to be due to the self-induced magnetic field produced by the edge current. This nonuniform field divides the array into domains each spanning several unit cells and each containing the same number of flux quanta. We report on experimental...
Bothe's 1925 heuristic assumption in the dawn of quantum field theory
Fick, D.
2013-01-01
In an unpublished manuscript filed at the Archive of the Max-Planck Society in Berlin, Walther Bothe (1891-1957) put, with one heuristic assumption, the spontaneous and induced transitions of light quanta, on an equal footing, probably as early as 1925. In modern terms, he assumed that the probability for the creation of a light quantum in a phase space cell already containing s light quanta is proportional to s + 1 and not, as assumed at that time, proportional to s; that is proportional to the fraction of the total radiation density which belongs to s light quanta. For Bothe, the added +1 somehow replaced the spontaneous decay and allowed him to treat empty phase space cells in a black body as thermodynamically consistent. We describe in some detail Bothe's route to this heuristic trick. Finally we discuss why, both Bose's and Bothe's heuristic assumptions lead to an identical distribution law for light quanta in a black body and thus to Planck's law and Einstein's fluctuation formula.
Gravitation radiation observations
Glass, E. N.
2017-01-01
The notion of gravitational radiation begins with electromagnetic radiation. In 1887 Heinrich Hertz, working in one room, generated and received electromagnetic radiation. Maxwell's equations describe the electromagnetic field. The quanta of electromagnetic radiation are spin 1 photons. They are fundamental to atomic physics and quantum electrodynamics.
TOF-PET detector concept based on organic scintillators
Moskal, P; Białas, P; Ciszewska, M; Czerwiński, E; Heczko, A; Kajetanowicz, M; Kapłon, Ł; Kochanowski, A; Konopka-Cupiał, G; Korcyl, G; Krzemień, W; Łojek, K; Majewski, J; Migdał, W; Molenda, M; Niedźwiecki, Sz; Pałka, M; Rudy, Z; Salabura, P; Silarski, M; Słomski, A; Smyrski, J; Zdebik, J; Zieliński, M
2013-01-01
In this contribution we present a new concept of the large acceptance detector systems based on organic scintillators which may allow for simultaneous diagnostic of large fraction of the human body. Novelty of the concept lies in employing large blocks of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes.
Multiple scattering and accidental coincidences in the J-PET detector simulated using GATE package
Kowalski, P; Wiślicki, W; Raczyński, L; Bednarski, T; Białas, P; Bułka, J; Czerwiński, E; Gajos, A; Gruntowski, A; Kamińska, D; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wochlik, I; Zieliński, M; Zoń, N
2015-01-01
Novel Positron Emission Tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta.
Gravitational Quantum Foam and Supersymmetric Gauge Theories
Maeda, T; Noma, Y; Tamakoshi, T; Maeda, Takashi; Nakatsu, Toshio; Noma, Yui; Tamakoshi, Takeshi
2005-01-01
We study K\\"{a}hler gravity on local SU(N) geometry and describe precise correspondence with certain supersymmetric gauge theories and random plane partitions. The local geometry is discretized, via the geometric quantization, to a foam of an infinite number of gravitational quanta. We count these quanta in a relative manner by measuring a deviation of the local geometry from a singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over \\mathbb{P}^1. With such a regularization prescription, the number of the gravitational quanta becomes finite and turns to be the perturbative prepotential for five-dimensional \\mathcal{N}=1 supersymmetric SU(N) Yang-Mills. These quanta are labelled by lattice points in a certain convex polyhedron on \\mathbb{R}^3. The polyhedron becomes obtainable from a plane partition which is the ground state of a statistical model of random plane partition that describes the exact partition function for the gauge theory. Each gravitational quantum of the local geometry is shown...
Dialogo tra arte e tecnologia in una mostra al Vittoriano
Greco, Anna Maria
2001-01-01
The connection between art and science is the subject of a unique exhibition: art has tried to understand nature and to interpret the laws of physics; matter and antimatter, relativity and quanta, protons and neutrons became tools of a new creativity (1 page)
Self-breaking in planar few-atom Au constrictions for nanometer-spaced electrodes
O'Neill, K.; Osorio, E.A.; Van der Zant, H.S.J.
2007-01-01
The authors present results on electromigrated Au nanojunctions broken near the conductance quantum of 77.5 μS. At room temperature it is found that wires, initially narrowed by an actively-controlled electromigration technique down to a few conductance quanta, continue to narrow after removing the
The submm wave Josephson flux flow oscillator; Linewidth measurements and simple theory
DEFF Research Database (Denmark)
Mygind, Jesper; Koshelets, V. P.; Samuelsen, Mogens Rugholm
2005-01-01
The Flux Flow Oscillator (FFO) is a long Josephson junction in which a DC bias current and a DC magnetic field maintain a unidirectional viscous flow of magnetic flux quanta. The theoretical linewidth of the electromagnetic radiation generated at the end boundary is due to internal current...
HIGHLY ACTIVE CaO FOR THE TRANSESTERIFICATION TO ...
African Journals Online (AJOL)
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same properties as diesel, to supply or replace such fossil fuel[1, 2]. ... fats with short-chain alcohols (generally methanol) in the presence of catalysts. ... waste water used to clean the catalysts, and the opportunity to operate a ... photograph was taken by Quanta 200 scanning electron microscope equipped with an energy.
Hawking radiation is corpuscular
Mück, Wolfgang
2016-01-01
The total number of Hawking quanta emitted during the evaporation of a Schwarzschild black hole is proportional to the square of the initial mass and proportional to the Bekenstein entropy. This simple, but seemingly unnoticed, fact is interpreted in terms of the recent discovery of black hole soft hair.
Tales of the quantum understanding physics' most fundamental theory
Hobson, Art
2017-01-01
Everybody has heard that we live in a world made of atoms. But far more fundamentally, we live in a universe made of quanta. Many things are not made of atoms: light, radio waves, electric current, magnetic fields, Earth's gravitational field, not to mention exotica such a neutron stars, black holes, dark energy, and dark matter. But everything, including atoms, is made of highly unified or "coherent" bundles of energy called "quanta" that (like everything else) obey certain rules. In the case of the quantum, these rules are called "quantum physics." This is a book about quanta and their unexpected, some would say peculiar, behavior--tales, if you will, of the quantum. The quantum has developed the reputation of being capricious, bewildering, even impossible to understand. The peculiar habits of quanta are certainly not what we would have expected to find at the foundation of physical reality, but these habits are not necessarily bewildering and not at all impossible or paradoxical. This book explains those h...
Ionizing Emissions and Electronics,
1984-05-22
Sternheimer [12]. Protons are emitted by atomic nuclei as a result of the bombardment with their charged/loaded particles, by neutrons,[" gamma-quanta...different energies of protons was conducted according to the method of Sternheimer [221. When proton passes at the distances from a nucleus less than the
Geopolymers for Structural Ceramic Applications
2006-08-31
possibly of leucite, were found precipitating out 0 of the geopolymer matrix in regions near the pour zone. The sheath -like morphology of * the crystallites...determined from the best fit of seven datum points using the BET method with an Autosorb- 1 Surface Area and Pore Size Analyzer (Quanta chrome
Multi-Resource Fair Queueing for Packet Processing
2012-06-19
Huawei , Intel, MarkLogic, Microsoft, NetApp, Oracle, Quanta, Splunk, VMware and by DARPA (contract #FA8650-11-C-7136). Multi-Resource Fair Queueing for...Google PhD Fellowship, gifts from Amazon Web Services, Google, SAP, Blue Goji, Cisco, Cloud- era, Ericsson, General Electric, Hewlett Packard, Huawei
Electric fields and quantum wormholes
Engelhardt, D.; Freivogel, B.; Iqbal, N.
2015-01-01
Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum version of an Einstein-Rosen bridge between the particles, or a "
Energy Technology Data Exchange (ETDEWEB)
Koenneker, Carsten (comp.)
2012-11-01
The following topics are dealt with: Reality in the test facility, quantum teleportation, the reality of quanta, interaction-free quantum measurement, rules for quantum computers, quantum computers with ions, spintronics with diamond, the limits of the quantum computers, a view in the future of quantum optics. (HSI)
Correlation between quantal secretion and vesicle loss at the frog neuromuscular junction.
Hurlbut, W P; Iezzi, N; Fesce, R; Ceccarelli, B
1990-01-01
1. We measured the rate of occurrence of miniature endplate potentials (MEPPs) at identified endplates in frog cutaneous pectoris muscles treated with crude black widow spider venom (BWSV) or purified alpha-latrotoxin (alpha-LTX) in calcium-free solutions, and we examined the relationship between the length of the nerve terminal and the total number of quanta secreted, and the relationship between the number of quanta secreted and the number of vesicles remaining at different times. 2. The venom, or toxin, was applied in a modified Ringer solution with tetrodotoxin, 1 mM-EGTA and no divalent cations, and quantal secretion was started by applying Ca2(+)-free solutions with Mg2+. This was done to synchronize the quantal discharge at the various junctions in a muscle. Ringer solution was applied after the MEPP rate had declined to low levels, and then the muscle fibre was injected with Lucifer Yellow, the endplate stained for acetylcholinesterase and the length of the nerve terminal and the length of a sarcomere were measured on the fluorescent fibre. 3. The total number of quanta secreted by a terminal was measured under a wide variety of experimental conditions: the weights of the frogs ranged from 13 to 68 g, the temperature from 9 to 28 degrees C, and the concentration of Mg2+ from 2 to 10 mM. In one series of experiments the Mg2+ was withdrawn after 3-4 min and reapplied 35-40 min later in order to divide the total output of quanta into two approximately equal bouts of secretion that were well separated in time. 4. The total number of MEPPs recorded at a junction was loosely correlated with the length of its nerve terminal, but it was not affected by the temperature, the concentration of Mg2+ or the division of secretion into well-separated bouts of quantal release. The average total secretion per unit length was about 3700 quanta/sarcomere or about 1200 quanta/microns. 5. The average time course of quantal secretion per micrometre of terminal was determined at
Andreevsky, S. E.; Kuznetsov, V. D.; Sinelnikov, V. M.
2017-03-01
The paper describes the complex of scientific instruments and the algorithm of the "Molniya-Gamma" experiment on measuring gamma-ray fluxes in the energy range of 32-750 keV carried out in 2011 on board the Russian Segment (RS) of the International Space Station (ISS). About 500 thousand energy spectra with a time resolution of 1 min were obtained in 512 energy channels during 232 days. One-second variations in the number of gamma quanta in four energy channels and the triggered fluxes of gamma quanta lasting less than 100 ms were recorded simultaneously. The data obtained allow us to study temporal and spatial variation of gamma-ray radiation to detect terrestrial gamma flashes (TGFs). Data on very large number of gamma-ray spikes were acquired through a trigger data mode with a low threshold.
DEFF Research Database (Denmark)
Georg, Birgitte; Rask, Lene; Hannibal, Jens;
2014-01-01
and FOS and qPCR to quantify FOS mRNA responses. The magnitude of the FOS response was found to correlate with the amount of melanopsin expressed by the cells, and a transient FOS mRNA induction followed by FOS protein still elevated after 24 h of illumination was revealed. Exposing the cells to darkness...... after light resulted in reduction of the response compared to exposure to light solely showing dependency on continuous light. Increasing irradiances of blue light (480 nm) up to 10(11) quanta cm(-2) s(-1) elicited steep increases in FOS mRNA, while increases between 10(12) and 5 × 10(13) quanta cm(-2...
Nonlinear Phonon Effects in Protein Molecular System%蛋白质分子系统中的非线性声子效应（英）
Institute of Scientific and Technical Information of China (English)
韩定安; 史小川; 周光辉
2002-01-01
We study the effects of quantum fluctuations in the improved Pang model with two quanta and with an added cubic nonlinear phonon term. The equations of motion for the model with a quasicoherent two - quanta state in the Hamiltonian is given by soliton mechanism.Some elementary properties of the soliton, including the greatly increased binding energy and the deformation al energy of the soliton, are also given.%研究具有两个量子态的蛋白质模型中的量子涨落和非线性声子效应,从模型哈密顿与运动方程出发,得到了系统中的孤子结合能及形宽能等相对于线性系统不同的一些基本性质.
Novel detector systems for the Positron Emission Tomography
Moskal, P; Silarski, M; Smyrski, J; Zdebik, J; Zieliński, M
2013-01-01
In this contribution we describe a novel solution for the construction of Positron Emission Tomograph. We present the device allowing for determination of the impact position as well as time and deph of interaction of the annihilation gamma quanta. The device is comprised of scintillation chamber consisting of organic scintillators surrounding the body of the patient. We discuss two possible solutions: (i) the tomograph built out of scintillator strips, and (ii) the tomograph built out of the scintillator plates. The application of the fast scintillators will enable to take advantage of the difference between time of the registration of the annihilation quanta. The invented method will permit to use a thick layers of detector material with the possibility of measuring the depth of the gamma quantum interaction (DOI) and the determination of their time of flight (TOF), and will allow for increasing the size of the diagnostic chamber without a significant increase of costs. The method is a subject of two patent...
An FEL based high-intensity gamma source at the TESLA Test Facility at DESY
Pagani, C; Schneidmiller, E A; Yurkov, M V
1999-01-01
One possible extension of the FEL activity at DESY is connected with the installation of an additional FEL beamline providing tunable UV radiation with peak and average power of 220 GW and 7 kW, respectively. This report presents the feasibility study of a high-intensity, polarized, monochromatic gamma source at the TESLA Test Facility. Gamma quanta are produced in the process of Compton backscattering of the UV FEL radiation on 1 GeV electrons of the TTF accelerator. The ultimate intensity of the gamma source can reach a value up to 10 sup 1 sup 2 gamma quanta per second with a maximum energy of about 100 MeV. The energy resolution of the gamma source can be reduced down to a value of about 0.2%. Potential applications of the intense gamma source at the TESLA Test Facility are discussed as well.
Einstein today; Einstein aujourd'hui
Energy Technology Data Exchange (ETDEWEB)
Aspect, A.; Grangier, Ph. [Centre National de la Recherche Scientifique (CNRS), Lab. Charles Fabry de l' Institut d' Optique a Orsay, 91 - Orsay (France); Bouchet, F.R. [Institut d' Astrophysique de Paris, CNRS, 75 - Paris (France); Brunet, E.; Derrida, B. [Universite Pierre et Marie Curie, Ecole Normale Superieure, 75 - Paris (France); Cohen-Tannoudji, C. [Academie des Sciences, 75 - Paris (France); Dalibard, J.; Laloe, F. [Laboratoire Kastler Brossel. UMR 8552 (ENS, UPMC, CNRS), 75 - Paris (France); Damour, Th. [Institut des Hautes Etudes Scientifiques, 91 - Bures sur Yvette (France); Darrigol, O. [Centre National de la Recherche Scientifique (CNRS), Groupe Histoire des Sciences Rehseis, 75 - Paris (France); Pocholle, J.P. [Thales Research et Technology France, 91 - Palaiseau (France)
2005-07-01
The most important contributions of Einstein involve 5 fields of physics : the existence of quanta (light quanta, stimulated radiation emission and Bose-Einstein condensation), relativity, fluctuations (Brownian motion and thermodynamical fluctuations), the basis of quantum physics and cosmology (cosmological constant and the expansion of the universe). Diverse and renowned physicists have appreciated the development of modern physics from Einstein's ideas to the knowledge of today. This book is a collective book that gathers their work under 7 chapters: 1) 1905, a new beginning; 2) from the Einstein, Podolsky and Rosen's article to quantum information (cryptography and quantum computers); 3) the Bose-Einstein condensation in gases; 4) from stimulated emission to the today's lasers; 5) Brownian motion and the fluctuation-dissipation theory; 6) general relativity; and 7) cosmology. (A.C.)
Superconducting wires and fractional flux
Sá de Melo, C. A. R.
1996-05-01
The quantization of flux quanta in superconductors is revisited and analyzed in a new geometry. The system analyzed is a superconducting wire. The geometry is such that the superconducting wire winds N times around an insulating cylinder and that the wire has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. The winding number N acts as a topological index that controls flux quantization. In this case, fractional flux quanta can be measured through the center of the insulating cylinder, provided that the cylinder radius is small enough. The Little-Parks experiment for an identical geometry is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0. When a SQUID is made in such a geometry the maximal current through the SQUID varies with period Φ0/N.
Directory of Open Access Journals (Sweden)
Alkhimova Mariya A.
2015-06-01
Full Text Available The source of X-ray radiation with the energy of quanta that may vary in the range hν = 1÷12 keV was developed for studies in X-ray interaction with matter and modification of solid surfaces. It was based on a vacuum spark discharge with the laser triggering. It was shown in our experiments that there is a possibility to adjust X-ray radiation spectrum by changing the configuration of the electrode system when the energy stored in the capacitor is varied within the range of 1÷17 J. A comprehensive study of X-ray imaging and quanta energy was carried out. These experiments were carried out for the case of both direct and reverse polarity of the voltage on the electrodes. Additionally, ion composition of plasma created in a laser-triggered vacuum discharge was analyzed. Highly charged ions Zn(+21, Cu(+20 and Fe(+18 were observed.
Gorbunov, Dmitry
2016-01-01
A classical evolution in chaotic inflationary models starts at high energy densities with semi-classical initial conditions presumably consistent with universal quantum nature of all the fundamental forces. That is each quantum contributes the same amount to the energy density. We point out the upper limit on this amount inherent in this approach, so that all the quanta are inside the weak-coupling domain. We discuss this issue in realistic models with modified gravity, $R^2$- and Higgs-inflations, emphasizing the specific change of the initial conditions with metric frame, while all the quanta still contribute equal parts. The analysis can be performed straightforwardly in any model with modified gravity ($F(R)$-gravity, scalars with non-minimal couplings to gravity, etc).
Protocols and prospects for building a quantum repeater
Energy Technology Data Exchange (ETDEWEB)
Loock, Peter van [Institute of Physics, Johannes Gutenberg Universitaet Mainz (Germany)
2014-07-01
An overview will be given of various approaches to implementing a quantum repeater for quantum communication over large distances. This includes a discussion of systems and protocols that are experimentally feasible and thus realizable in the midterm in order to go beyond the current limit of a few hundred km given by direct quantum-state transmissions. At the same time, these schemes should be, in principle, scalable to arbitrary distances. In this context, the influence of various elements and strategies in a quantum repeater protocol on the final fidelities and rates are addressed: initial entanglement distribution, Bell measurements, multiplexing, postselection, quantum memories, and quantum error detection/correction. Solely on the hardware side, the differences in using just single quanta or instead employing many quanta for the flying (photons) and the stationary (atoms) qubits are pointed out.
Quantized conductance in atom-sized wires between two metals
DEFF Research Database (Denmark)
Brandbyge, Mads; Schiøtz, Jakob; Sørensen, Mads Reinholdt
1995-01-01
We present experimental and theoretical results for the conductance and mechanical properties of atom-sized wires between two metals. The experimental part is based on measurements with a scanning tunneling microscope (STM) where a point contact is created by indenting the tip into a gold surface...... to observe more than up to four quanta in these experiments. A detailed discussion is given of the statistical methods used in the analysis of the experimental data. The theoretical part of the paper addresses some questions posed by the experiment: Why can conductance quantization be observed, what...... is the origin of the scatter in the experimental data, and what is the origin of the scaling of the scattering with the number of conductance quanta? The theoretical discussion is based on a free-electron-like model where scattering from the boundary of the nanowire is included. The configurations...
Characterization of SLUG microwave amplifiers
Hoi, I.-C.; Zhu, S.; Thorbeck, T.; McDermott, R.; Mutus, J.; Jeffrey, E.; Barends, R.; Chen, Y.; Roushan, P.; Fowler, A.; Sank, D.; White, T.; Campbell, B.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Kelly, J.; Megrant, A.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Vainsencher, A.; Wenner, J.; Martinis, J. M.
2015-03-01
With the rapid growth of superconducting circuits quantum technology, a near quantum-limited amplifier at GHz frequency is needed to enable high fidelity measurements. We describe such an amplifier, the SQUID based, superconducting low inductance undulatory galvanometer (SLUG) amplifier. We measure the full scattering matrix of the SLUG. In particular, we measure both forward and reverse gain, as well as reflection. We see 15dB forward gain with added noise from one quanta to several quanta. The -1 dB compression point is around -95 dBm, about two orders of magnitude higher than that of typical Josephson parametric amplifiers. With these properties, SLUG is well suited for the high fidelity, simultaneous multiplexed readout of superconducting qubits.
Selective measurement of quantronium qubit states by using of mesoscopic non-linear oscillator
Denisenko, M. V.; Satanin, A. M.
2016-12-01
We study the process of selective measurements of states of individual quantum systems - Josephson qubit - using nonlinear oscillator, working in the mesoscopic regime, when the number of quanta in the measuring process varies from a few dozen to a few hundred. Quantum Monte-Carlo method simulated dissipative dynamics of the system "qubit - oscillator" and the measurement process of a qubit state to modify the number of quanta of the oscillator. It is shown that for different Rabi-pulses of the recording state of a qubit the discrimination of states is possible, as well as the measurement of the effect of back-action of the measuring device, including separation of the prepared superposition state - carrying out statistical projective measurements.
Duarte, F. J.
2016-12-01
The history of the probability amplitude equation |ψ>=(|x ,y >-|y ,x >) applicable to quanta pairs, propagating in different directions with entangled polarizations, is reviewed and traced back to the 1947-1949 period. The interferometric Dirac foundations common to |ψ>=(|x ,y >-|y ,x >) and the generalized N-slit interferometric equation, for indistinguishable quanta, are also described. The results from a series of experiments on N-slit laser interferometers, with intra interferometric propagation paths up to 527 m, are reviewed. Particular attention is given to explain the generation of interferometric characters, for secure space-to-space communications, which immediately collapse on attempts of interception. The design of a low divergence N-slit laser interferometer for low Earth orbit-low Earth orbit (LEO-LEO), and LEO-geostationary Earth orbit (LEO-GEO), secure interferometric communications is described and a weight assessment is provided.
X-ray quantum-eraser setup for time-energy complementarity
Gunst, Jonas; Pálffy, Adriana
2016-12-01
A quantum-eraser setup exploiting the time-energy complementarity relation in the x-ray regime is investigated theoretically. The starting point is the interference process between x-ray quanta driving two nuclear hyperfine transitions in a nuclear forward-scattering setup. We show that which-way information can be obtained by marking the scattering paths with orthogonal polarization states, thus leading to the disappearance of the interference pattern. In turn, erasure of the which-way information leads to the reappearance of the interference fringes. We put forward two schemes using resonant scattering off nuclear targets and design which-way marking procedures to realize the quantum-eraser setup for x-ray quanta.
Energy sources, self-organization, and the origin of life.
Boiteau, Laurent; Pascal, Robert
2011-02-01
The emergence and early developments of life are considered from the point of view that contingent events that inevitably marked evolution were accompanied by deterministic driving forces governing the selection between different alternatives. Accordingly, potential energy sources are considered for their propensity to induce self-organization within the scope of the chemical approach to the origin of life. Requirements in terms of quality of energy locate thermal or photochemical activation in the atmosphere as highly likely processes for the formation of activated low-molecular weight organic compounds prone to induce biomolecular self-organization through their ability to deliver quanta of energy matching the needs of early biochemical pathways or the reproduction of self-replicating entities. These lines of reasoning suggest the existence of a direct connection between the free energy content of intermediates of early pathways and the quanta of energy delivered by available sources of energy.
Precision Measurement in Biology
Quake, Stephen
Is biology a quantitative science like physics? I will discuss the role of precision measurement in both physics and biology, and argue that in fact both fields can be tied together by the use and consequences of precision measurement. The elementary quanta of biology are twofold: the macromolecule and the cell. Cells are the fundamental unit of life, and macromolecules are the fundamental elements of the cell. I will describe how precision measurements have been used to explore the basic properties of these quanta, and more generally how the quest for higher precision almost inevitably leads to the development of new technologies, which in turn catalyze further scientific discovery. In the 21st century, there are no remaining experimental barriers to biology becoming a truly quantitative and mathematical science.
Flyby Anomaly via Least Action
Annila, A.
2017-04-01
The observed but unexpected changes in velocity during spacecraft flybys of Earth are examined using the principle of least action in its original dissipative form. In general, the spacecraft's momentum will change when it travels through an energy density gradient of space that is enfolding a gravitating, orbiting and rotating body. When space is understood as a physical substance that embodies quanta of actions, rather than being modeled by a mere metric, it becomes apparent that the changes in momentum couple with flux of quanta from the local system of bodies to the universal surroundings or vice versa. In this way the original least-action principle accounts also for the 'anomalous' change in velocity by an equation of motion which complies with the empirical relation that has been deduced from Earth-flybys.
On Counterfactuals and Contextuality
Svozil, K
2005-01-01
Although by definition a nonoperational, untestable method, counterfactual reasoning abounds in quantum mechanics. Many mind-boggling features such as contextuality are consequences of the assumption that elements of physical reality exist irrespective of their actual measurement. Yet quantum mechanically any operational, experimental existence is limited to a single maximal operator; i.e., to a single complete context. Quanta can only be prepared and measured in a single context. If quanta are measured in a context different from what they have been prepared for, the measurement device may or may not be capable of translating one context into the other. Counterfactual reasoning and contextuality is defined and critically evaluated with regard to its nonempirical content. To this end, a uniqueness property of states, explosion views and link observables are introduced. If only a single context associated with a particular maximum set of observables can be operationalized, then a context translation principle ...
Energy Technology Data Exchange (ETDEWEB)
Borisov, A. Yu., E-mail: borissov@belozersky.msu.ru [Moscow State University, Belozersky Institute of Physicochemical Biology (Russian Federation)
2011-11-15
The authors of a number of experimental works detected nonresonance biphoton excitation of bacteriochlorophyll molecules, which represent the main pigment in the light-absorbing natural 'antenna' complexes of photosynthesizing purple bacteria, by femtosecond IR pulses (1250-1500 nm). They believe that IR quanta excite hypothetic forbidden levels of the pigments of these bacteria in the double frequency range 625-750 nm. We propose and ground an alternative triplet mechanism to describe this phenomenon. According to our hypothesis, the mechanism of biphoton excitation of molecules by IR quanta can manifest itself specifically, through high triplet levels of molecules in the high fields induced by femtosecond-picosecond laser pulses.
Degrees of freedom in discrete geometry
Ariwahjoedi, Seramika; Rovelli, Carlo; Zen, Freddy P
2016-01-01
Following recent developments in discrete gravity, we study geometrical variables (angles and forms) of simplices in the discrete geometry point of view. Some of our relatively new results include: new ways of writing a set of simplices using vectorial (differential form) and coordinate-free pictures, and a consistent procedure to couple particles of space, together with a method to calculate the degrees of freedom of the system of 'quanta' of space in the classical framework.
2000-01-01
The physical characteristics of a clinical prototype amorphous silicon-based flat panel imager for full-breast digital mammography have been investigated. The imager employs a thin thallium doped CsI scintillator on an amorphous silicon matrix of detector elements with a pixel pitch of 100 μm. Objective criteria such as modulation transfer function (MTF), noise power spectrum, detective quantum efficiency (DQE), and noise equivalent quanta were employed for this evaluation. The presampling MT...
Linearized supergravity from Matrix theory
Kabat, D; Kabat, Daniel; Taylor, Washington
1998-01-01
We show that the linearized supergravity potential between two objects arising from the exchange of quanta with zero longitudinal momentum is reproduced to all orders in 1/r by terms in the one-loop Matrix theory potential. The essential ingredient in the proof is the identification of the Matrix theory quantities corresponding to moments of the stress tensor and membrane current. We also point out that finite-N Matrix theory violates the Equivalence Principle.
Collisional metastability of high rotational states of CN(X 2Σ +, ? = 0)
Hay, S.; Shokoohi, F.; Callister, S.; Wittig, C.
1985-07-01
CN(X 2Σ +, v'' = 0) high rotational states relax slowly via 300 K collisions with Ar and Kr. Relaxation decreases with increasing rotation, and the partially relaxed distributions are bimodal, with low N'' thermalized (300 K), and N'' = 80 unrelaxed after 1000 collisions. Relaxation by N 2, CO, and Xe is similar to Ar and Kr, but more efficient. He and NO remove many quanta in a single collision.
Project of the underwater system for chemical threat detection
Silarski, M; Moskal, P; Smolis, M; Tadeja, S
2015-01-01
In this article we describe a novel method for the detection of explosives and other hazardous substances in the marine environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides forneutron and gamma quanta which speeds up and simplifies identification. Moreover, it may provide a determination of the density distribution of a dangerous substance. First preliminary results of Monte Carlo simulations dedicated for design of a device exploiting this method are also presented.
Design of the SABAT system for underwater detection of dangerous substances
Silarski, M; Smolis, M; Tadeja, S; Moskal, P
2016-01-01
We present status of simulations used to design a novel device for the detection of hazardous substances in the aquatic environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides for neutron and gamma quanta which speeds up and simplifies identification. First preliminary results show that both the neutron guide and the $\\gamma$ ray guide increase the performance of underwater threats detection.
Energy Technology Data Exchange (ETDEWEB)
Kuzelev, M. V., E-mail: kuzelev@mail.ru [Moscow State University (Russian Federation)
2011-02-15
A nonlinear theory of interaction of two electromagnetic waves with a beam or a gas of spinless charged particles is developed. The effects of stimulated Compton scattering of electromagnetic waves and stimulated particle pair production (annihilation) during a collision of two electromagnetic quanta are investigated. Other stimulated processes that can occur only in a medium and decelerate electromagnetic waves are also considered. The relation between stimulated processes and various types of instabilities considered in classical electrodynamics of plasmas and plasmalike media is demonstrated.
On-chip optical trapping for atomic applications
Perez, Maximillian A.; Salim, Evan; Farkas, Daniel; Duggan, Janet; Ivory, Megan; Anderson, Dana
2014-09-01
To simplify applications that rely on optical trapping of cold and ultracold atoms, ColdQuanta is developing techniques to incorporate miniature optical components onto in-vacuum atom chips. The result is a hybrid atom chip that combines an in-vacuum micro-optical bench for optical control with an atom chip for magnetic control. Placing optical components on a chip inside of the vacuum system produces a compact system that can be targeted to specific experiments, in this case the generation of optical lattices. Applications that can benefit from this technology include timekeeping, inertial sensing, gravimetry, quantum information, and emulation of quantum many-body systems. ColdQuanta's GlasSi atom chip technology incorporates glass windows in the plane of a silicon atom chip. In conjunction with the in-vacuum micro-optical bench, optical lattices can be generated within a few hundred microns of an atom chip window through which single atomic lattice sites can be imaged with sub-micron spatial resolution. The result is a quantum gas microscope that allows optical lattices to be studied at the level of single lattice sites. Similar to what ColdQuanta has achieved with magneto-optical traps (MOTs) in its miniMOT system and with Bose- Einstein condensates (BECs) in its RuBECi(R) system, ColdQuanta seeks to apply the on-chip optical bench technology to studies of optical lattices in a commercially available, turnkey system. These techniques are currently being considered for lattice experiments in NASA's Cold Atom Laboratory (CAL) slated for flight on the International Space Station.
Antimatter in the Direct-Action Theory of Fields
Directory of Open Access Journals (Sweden)
Ruth E. Kastner
2016-01-01
Full Text Available One of Feynman's greatest contributions to physics was the interpretation of negative energies as antimatter in quantum field theory. A key component of this interpretation is the Feynman propagator, which seeks to describe the behavior of antimatter at the virtual particle level. Ironically, it turns out that one can dispense with the Feynman propagator in a direct-action theory of fields, while still retaining the interpretation of negative energy solutions as antiparticles. Quanta 2016; 5: 12–18.
Extraction of information from a single quantum
Paraoanu, G. S.
2011-01-01
We investigate the possibility of performing quantum tomography on a single qubit with generalized partial measurements and the technique of measurement reversal. Using concepts from statistical decision theory, we prove that, somewhat surprisingly, no information can be obtained using this scheme. It is shown that, irrespective of the measurement technique used, extraction of information from single quanta is at odds with other general principles of quantum physics.
Optical magnetic ﬂux generation in superconductor
Indian Academy of Sciences (India)
Masayoshi Tonouchi
2002-05-01
The generation of the magnetic ﬂux quanta inside the superconductors is studied as a new effect to destroy superconductivity using femtosecond (fs) laser. The vortices are successfully generated in the YBa2Cu3O7- thin ﬁlm striplines by the fs laser. It is revealed that the vortex distribution in the strip reﬂects the fs laser beam proﬁle.
2008-05-01
Makanchy, Urdzhar and Taskesken districts. The comparison group included the population from the Kokpekty district of the Semipalatinsk Province who, for...calibrated and the effectiveness curve for recording gamma quanta by the peak total absorption was drawn with the help of a set of OSGI reference...0.744 ZhanaMa 0.078±0.024 0.718±0.221 For comparison , we can state that the annual absorbed dose from gamma radiation of naturally radioactive
S Matrix Proof of Consistency Condition Derived from Mixed Anomaly
Bhansali, Vineer
For a confining quantum field theory with conserved current J and stress tensor T, the JJJ> and anomalies computed in terms of elementary quanta must be precisely equal to the same anomalies computed in terms of the exact physical spectrum if the conservation law corresponding to J is unbroken. These strongly constrain the allowed representations of the low energy spectrum. We present a proof of the latter consistency condition based on the proof by Coleman and Grossman of the former consistency condition.
How accurately can we measure the hydrogen 2S->1S transition rate from the cosmological data?
Mukhanov, Viatcheslav; Naselsky, Pavel; Trombetti, Tiziana; Burigana, Carlo
2012-01-01
Recent progress in observational cosmology, and especially the forthcoming PLANCK mission data, open new directions in so-called precision cosmology. In this paper we illustrate this statement considering the accuracy of cosmological determination of the two-quanta decay rate of 2s hydrogen atom state. We show that the PLANCK data will allow us to measure this decay rate significantly better than in the laboratory experiments.
Comment on "Thermal propagation in two-dimensional Josephson junction arrays"
De Leo, Cinzia
2009-01-01
In a recent paper, Filatrella et al. [Phys. Rev. B 75, 54510 (2007)] report results of numerical calculations of energy barriers for flux quanta propagation in two-dimensional arrays of Josephson junctions with finite self and mutual inductances. To avoid complex numerical calculations, they use an approximated inductance model to address the effects of the mutual couplings. Using a full inductance matrix model, we show that this approximated model cannot be used to calculate the energy barri...
Is the Galactic Cosmic Ray Spectrum Constant in Time?
Eichler, David; Pohl, Martin
2013-01-01
The hypothesis is considered that the present Galactic cosmic ray spectrum is at present softer than its time average due to source intermittency. Measurements of muogenic nuclides underground could provide an independent measurement of the time averaged spectrum. Source intermittency could also account for the surprising low anisotropy reported by the IceCube collaboration. Predictions for Galactic emission of ultrahigh-energy quanta, such as UHE gamma rays and neutrinos, might be higher or lower than previously estimated.
The detective quantum efficiency of an imaging detector
Energy Technology Data Exchange (ETDEWEB)
Zanella, G. [Padova Univ. (Italy). Dipartimento di Fisica and INFN; Zannoni, R. [Padova Univ. (Italy). Dipartimento di Fisica and INFN
1995-05-15
The efficiency of an imaging detector is a more extensive parameter than the quantum efficiency of a track detector or of a counter, as an image is created by the summation of many responses due to the single incoming quanta. This efficiency parameter is the so-called detective quantum efficiency (DQE). The paper illustrates the general meaning of DQE and the procedure to measure it. (orig.).
On the theory of electromagnetic cascades in thin targets and photon multiplicity measurements
Energy Technology Data Exchange (ETDEWEB)
Khokonov, M.Kh.
2015-02-01
The partial probabilities of different scenarios of electromagnetic shower processes are calculated in analytical form. It has been shown that these results are important for measurements of the photon multiplicities which occur during above 100 GeV electron radiation in oriented crystals or in the case of interaction of relativistic electrons with powerful Petawatt laser beams. Quantitative analysis of optimal experimental conditions has been performed. The results are applicable for above few GeV electrons and gamma quanta.
On the possible thermal tachyons
Kozlowski, Miroslaw; Marciak-Kozlowska, Janina
2006-01-01
In this paper the existence of the thermal tachyons i.e. quanta of temperature field, with is described in the theoretical frame of hyperbolic thermal equation. The modified Lorentz transformation are developed. It is argued that thermal tachyons can exist in accordance with modified Lorentz transformation after change . The thermal tachyons fulfill the hyperbolic heat transport equation and in principle can be created by attosecond laser pulses. Key words: Tachyons; Thermal processes; Attose...
Development of a reference liquid scintillation cocktail
CSIR Research Space (South Africa)
Van Wyn Gaardt, WM
2006-02-01
Full Text Available of a scintillator dissolved in an organic solvent. The so-called scintillator solute is a material which emits a weak light flash or scintillation upon interaction with a certain quanta of radiation – the intensity of this scintillation being a... to prepare preliminary liquid scintillation cocktails. Figure 3: Maximum deviations observed between repeat measurements of the same source, displayed in red for Ultima Gold, green for XP, yellow for XI and blue for XPI. Figure 4: The counting...
STRIP-PET: a novel detector concept for the TOF-PET scanner
Moskal, P; Białas, P; Ciszewska, M; Czerwiński, E; Heczko, A; Kajetanowicz, M; Kapłon, Ł; Kochanowski, A; Konopka-Cupiał, G; Korcyl, G; Krzemień, W; Łojek, K; Majewski, J; Migdał, W; Molenda, M; Niedźwiecki, Sz; Pałka, M; Rudy, Z; Salabura, P; Silarski, M; Słomski, A; Smyrski, J; Zdebik, J; Zieliński, M
2013-01-01
We briefly present a design of a new PET scanner based on strips of polymer scintillators arranged in a barrel constituting a large acceptance detector. The solution proposed is based on the superior timing properties of the polymer scintillators. The position and time of the reaction of the gamma quanta in the detector material will be determined based on the time of arrival of light signals to the edges of the scintillator strips.
Jauregui, Luis A.; Pettes, Michael T.; Shi, Li; Rokhinson, Leonid P.; Chen, Yong P.
2014-03-01
Topological superconductivity can be proximity induced by coupling s-wave superconductors with spin-helical electron systems, such as the surface of 3D topological insulators (TIs), where the energy bands follow Dirac dispersion and the electronic states possess helical spin-momentum locking. We have grown Bi2Te3 nanoribbons (NRs) by vapor liquid solid method and characterized their crystalline structure by TEM and Raman spectroscopy. We fabricate backgated field effect devices where the chemical potential (μ) can be tuned from bulk bands to surface states and ambipolar field effect has been observed. The temperature dependence of the resistance and Shubnikov de Haas oscillations show suppressed bulk conduction with surface conduction dominating and a pi-Berry's phase. The Aharonov-Bohm oscillations (ABO), measured with a magnetic field parallel to the NR axis, have a period equal to one flux quanta with conductance maxima at half flux quanta (pi-ABO), for μ close to the charge neutrality point. Such pi-ABO is a direct evidence of the existence of 1D helical modes at half flux quanta. We have also fabricated Josephson junctions on our TI NR devices with inter-electrode separations up to 200 nm, and measured supercurrent with a proximity induced gap of 0.5meV at 0.25K.
Coherent Diabatic Ion Transport and Separation in a Multi-Zone Trap Array
Bowler, R; Lin, Y; Tan, T R; Hanneke, D; Jost, J D; Home, J P; Leibfried, D; Wineland, D J
2015-01-01
We investigate the motional dynamics of single and multiple ions during transport between and separation into spatially distinct locations in a multi-zone linear Paul trap. A single 9Be+ ion in a 2 MHz harmonic well located in one zone was laser-cooled to near its ground state of motion and transported 370 micrometers by moving the well to another zone. This was accomplished in 8 microseconds, corresponding to 16 periods of oscillation. Starting from a state with n=0.1 quanta, during transport the ion was excited to a displaced coherent state with n=1.6 quanta but on completion was returned close to its motional ground state with n=0.2. Similar results were achieved for the transport of two ions. We also separated chains of up to 9 ions from one potential well to two distinct potential wells. With two ions this was accomplished in 55 microseconds, with final excitations of about 2 quanta for each ion. Fast coherent transport and separation can significantly reduce the time overhead in certain architectures fo...
CDOM Sources and Photobleaching Control Quantum Yields for Oceanic DMS Photolysis
Galí, Martí
2016-11-14
Photolysis is a major removal pathway for the biogenic gas dimethylsulfide (DMS) in the surface ocean. Here we tested the hypothesis that apparent quantum yields (AQY) for DMS photolysis varied according to the quantity and quality of its photosensitizers, chiefly chromophoric dissolved organic matter (CDOM) and nitrate. AQY compiled from the literature and unpublished studies ranged across 3 orders of magnitude at the 330 nm reference wavelength. The smallest AQY(330) were observed in coastal waters receiving major riverine inputs of terrestrial CDOM (0.06-0.5 m3 (mol quanta)-1). In open-ocean waters, AQY(330) generally ranged between 1 and 10 m3 (mol quanta)-1. The largest AQY(330), up to 34 m3 (mol quanta)-1), were seen in the Southern Ocean potentially associated with upwelling. Despite the large AQY variability, daily photolysis rate constants at the sea surface spanned a smaller range (0.04-3.7 d-1), mainly because of the inverse relationship between CDOM absorption and AQY. Comparison of AQY(330) with CDOM spectral signatures suggests there is an interplay between CDOM origin (terrestrial versus marine) and photobleaching that controls variations in AQYs, with a secondary role for nitrate. Our results can be used for regional or large-scale assessment of DMS photolysis rates in future studies.
Test of a single module of the J-PET scanner based on plastic scintillators
Moskal, P; Bednarski, T; Czerwiński, E; Kapłon, Ł; Kubicz, E; Moskal, I; Pawlik-Niedźwiecka, M; Sharma, N G; Silarski, M; Zieliński, M; Zoń, N; Białas, P; Gajos, A; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Molenda, M; Pałka, M; Raczyński, L; Rudy, Z; Salabura, P; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wiślicki, W
2014-01-01
Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this article we report on tests of a single detection module built out from BC-420 plastic scintillator strip (with dimensions of 5x19x300mm^3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50ps intervals. The time resolution of the prototype module was established to be better than 80ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93cm (sigma) for the annihilation quanta...
The flaw in the firewall argument
Mathur, Samir D
2014-01-01
A lot of confusion surrounds the issue of black hole complementarity, because the question has been considered without discussing the mechanism which guarantees unitarity. Considering such a mechanism leads to the following: (1) The Hawking quanta with energy E of order the black hole temperature T carry information, and so only appropriate processes involving E>>T quanta can have any possible complementary description with an information-free horizon; (2) The stretched horizon describes all possible black hole states with a given mass M, and it must expand out to a distance s_{bubble} before it can accept additional infalling bits; (3) The Hawking radiation has a very particular low temperature T, and infalling quanta interact significantly with it only within a distance s_{alpha} of the horizon. One finds s_{alpha} >T, and this removes the argument against complementarity recently made by Almheiri et al. In particular, the condition E>>T leads to the notion of 'fuzzball complementarity', where the modes aro...
The flaw in the firewall argument
Energy Technology Data Exchange (ETDEWEB)
Mathur, Samir D., E-mail: mathur.16@osu.edu; Turton, David, E-mail: turton.7@osu.edu
2014-07-15
A lot of confusion surrounds the issue of black hole complementarity, because the question has been considered without discussing the mechanism which guarantees unitarity. Considering such a mechanism leads to the following: (1) The Hawking quanta with energy E of order the black hole temperature T carry information, and so only appropriate processes involving E≫T quanta can have any possible complementary description with an information-free horizon; (2) The stretched horizon describes all possible black hole states with a given mass M, and it must expand out to a distance s{sub bubble} before it can accept additional infalling bits; (3) The Hawking radiation has a specific low temperature T, and infalling quanta interact significantly with it only within a distance s{sub α} of the horizon. One finds s{sub α}≪s{sub bubble} for E≫T, and this removes the argument against complementarity recently made by Almheiri et al. In particular, the condition E≫T leads to the notion of ‘fuzzball complementarity’, where the modes around the horizon are indeed correctly entangled in the complementary picture to give the vacuum.
A quantum biological hypothesis of human secondary dentinogenesis.
Moss, M L; Moss-Salentijn, L; Hasselgren, G; Ling, H
2005-01-01
It is hypothesized that human coronal secondary dentin (SD) is a final classical mechanical (CM) response to a chain of prior quantum mechanical (QM) transductions of the information of initial CM occlusal loadings of enamel. Such CM energy is transduced into QM quanta (as protons) that are translocated centripetally via clustered water (CW), (as "proton wires"), that is structurally related to both enamel prism sheath and hydroxyapatite crystal hydration shells. These quanta pass into odontoblastic cell processes (OP), lying within dentinal tubules (DT). OP's contain abundant parallel arrays of cylindrical microtubules (MT). These are the sites of two further CW-related QM events: (i) proton translocation associated with conformal changes of MT tubulin protein dimers; and (ii) coherent energetic oscillations within the CW filling the MT's hollow cores. Finally, these quanta pass into the odontoblastic soma, where QM wave function collapse transduces this information into a final CM state that initiates the processes of SD formation. A critical portion of this hypothesis may be experimentally tested.
Strong Coupling and Classicalization
Dvali, Gia
2016-01-01
Classicalization is a phenomenon in which a theory prevents itself from entering into a strong-coupling regime, by redistributing the energy among many weakly-interacting soft quanta. In this way, the scattering process of some initial hard quanta splits into a large number of soft elementary processes. In short, the theory trades the strong coupling for a high-multiplicity of quanta. At very high energies, the outcome of such a scattering experiment is a production of soft states of high occupation number that are approximately classical. It is evident that black hole creation in particle collision at super-Planckian energies is a result of classicalization, but there is no a priory reason why this phenomenon must be limited to gravity. If the hierarchy problem is solved by classicalization, the LHC has a chance of detecting a tower of new resonances. The lowest-lying resonances must appear right at the strong coupling scale in form of short-lived elementary particles. The heavier members of the tower must b...
Cascaded-Systems Analysis of Flat-Panel Sandwich Detectors for Single-Shot Dual-Energy X-ray Imaging
Energy Technology Data Exchange (ETDEWEB)
Kim, Ho Kyung; Kim, Dong Woon; Kim, Junwoo; Youn, Hanbean [Pusan National University, Busan (Korea, Republic of)
2015-05-15
We have developed the cascaded-systems model to investigate the signal and noise characteristics in the flat-panel sandwich detector which was developed for the preclinical single-shot dual-energy x-ray imaging. The model incorporates parallel branches to include direct interaction of x-rays in photodiode that is unavoidable in the sandwich structure with a corresponding potential increase in image noise. The model has been validated in comparison with the experimental. The cascaded-systems analysis shows that direct x-ray interaction noise behaves as additive electronic noise that is white in the frequency domain; hence it is harmful to the DQE at higher frequencies where the number of secondary quanta lessens. Even at zero frequency, the direct x-ray interaction noise can reduce the DQE of the detectors investigated in this study by ∼20% for the 60 kV x-ray spectrum. The DQE of rear detector in the sandwich structure is sensitive to additive electronic noise because of the enhancement in the number of electronic noise quanta relative to that of x-ray quanta that are attenuated through the front layers including the intermediate filter layer (i.e. incident photon fluence times transmission factor)
Pulse-shape discrimination with Cs2HfCl6 crystal scintillator
Cardenas, C.; Burger, A.; Goodwin, B.; Groza, M.; Laubenstein, M.; Nagorny, S.; Rowe, E.
2017-10-01
The results of investigation into cesium hafnium chloride (Cs2HfCl6) scintillating crystals as a promising detector to search for rare nuclear processes occurring in Hf isotopes is reported. The light output, quenching factor, and pulse-shape characteristics have been investigated at room temperature. The scintillation response of the crystal induced by α-particles and γ-quanta were studied to determine possibility of particle discrimination. Using the optimal filter method we obtained clear separation between signals with a factor of merit (FOM) = 9.3. This indicates that we are able to fully separate signals originating from α-particles and γ-quanta. Similar fruitful discrimination power was obtained by applying the mean time method (FOM = 7) and charge integration method (FOM = 7.5). The quenching factor for collimated 4 MeV α-particles is found to be 0.36, showing that α-particles generate more than a third of the light compared to γ-quanta at the same energy.
Evidence of TeV gamma-ray radiation in supernova remnant Cygnus X-3
Energy Technology Data Exchange (ETDEWEB)
Sinitsyna, V.G.; Arsov, T.P.; Alaverdyan, A.Y.; Ivanov, I.A.; Nikolsky, S.I.; Musin, F.M.; Mirzafatihov, R.M.; Platonov, G.F.; Sinitsyna, V.Y.; Galitskov, A.N.; Oblakov, I.V.; Capdevielle, J.N
2001-04-01
Since 1994 the telescope SHALON, at SHALON-ALATOO mountain observatory (height 3338 m) detected very high energy gamma-rays from galactic objects Crab Nebula, Cygnus X-3, Geminga and Tycho Brahe. Time analysis shows that the contribution of protons of cosmic rays in observed gamma-quanta with energies higher than 0.8 TeV from the point sources of very high energy gamma-quanta does not exceed 10% - 15% (Fig. 6). The fluxes at energies above 0.8 TeV observed from the Crab Nebula are (1.10 {+-} 0.30) x 10{sup -12} cm{sup -2}s{sup -1}, from Cygnus X-3 are (4.20 {+-} 0.70) x 10{sup -13}cm{sup -2}s{sup -1}, from Geminga are (0.48 {+-} 0.17) x 10{sup -12}cm{sup -2}s{sup -1} and from Tycho Brahe are (1.89 {+-} 0.90) x 10{sup -13}cm{sup -2}s{sup -1} (Fig. 5, 6, 7). Observed gamma-quanta fluxes from detected galactic and extragalactic sources are approximately equal (this is connected to the fact that the best gamma-telescopes of today are very flexible to the flux intensity). That means that for distances differing by a factor of 10{sup 4}, the radiating power of extragalactic objects is 10{sup 8} higher. Taking into consideration a limited number of sources in our Galaxy in comparison to Methagalaxy, one can propose that cosmic rays of energies higher than 10{sup 12} eV are mainly of an extragalactic origin.
Einstein's Revolutionary Light-Quantum Hypothesis
Stuewer, Roger H.
2005-05-01
The paper in which Albert Einstein proposed his light-quantum hypothesis was the only one of his great papers of 1905 that he himself termed ``revolutionary.'' Contrary to widespread belief, Einstein did not propose his light-quantum hypothesis ``to explain the photoelectric effect.'' Instead, he based his argument for light quanta on the statistical interpretation of the second law of thermodynamics, with the photoelectric effect being only one of three phenomena that he offered as possible experimental support for it. I will discuss Einstein's light-quantum hypothesis of 1905 and his introduction of the wave-particle duality in 1909 and then turn to the reception of his work on light quanta by his contemporaries. We will examine the reasons that prominent physicists advanced to reject Einstein's light-quantum hypothesis in succeeding years. Those physicists included Robert A. Millikan, even though he provided convincing experimental proof of the validity of Einstein's equation of the photoelectric effect in 1915. The turning point came after Arthur Holly Compton discovered the Compton effect in late 1922, but even then Compton's discovery was contested both on experimental and on theoretical grounds. Niels Bohr, in particular, had never accepted the reality of light quanta and now, in 1924, proposed a theory, the Bohr-Kramers-Slater theory, which assumed that energy and momentum were conserved only statistically in microscopic interactions. Only after that theory was disproved experimentally in 1925 was Einstein's revolutionary light-quantum hypothesis generally accepted by physicists---a full two decades after Einstein had proposed it.
La explicación de Einstein del efecto fotoeléctrico: un análisis histórico-epistemológico
Directory of Open Access Journals (Sweden)
Alejandro Cassini
2008-05-01
Full Text Available Mostramos que la explicación de Einstein del efecto fotoeléctrico es una explicación causal que posee claras ventajas epistemológicas sobre otras explicaciones rivales. Señalamos la fertilidad heurística de esta hipótesis y los problemas que suscitó la aceptación de la realidad de los cuantos de luz. Concluimos que la realidad de los cuantos de luz ha resultado históricamente afectada por el problema general de la realidad de las entidades cuánticas y no ha podido resolverse independientemente de él. Por ello el componente causal de la explicación de Einstein no ha logrado mantenerse en el contexto de una teoría cuántica referida al movimiento de partículas. No obstante, el valor heurístico original de la hipótesis del cuanto de luz de Einstein ha mantenido su vigencia.We show that Einstein's explanation of photoelectric effect is a causal explanation that has clear epistemological advantages with respect to other rival explanations. We point out the heuristic fertility of this hypothesis and the problems brought about by the acceptance of the reality of light-quanta. We conclude that the reality of light-quanta has been historically affected by the general problem of the reality of quantum entities and that the former cannot be solved independently of the latter. For that reason, the causal component of Einstein's explanation cannot be retained in the context of quantum theory of particle motion. In any case, the original heuristic value of Einstein's hypothesis of light-quanta is not affected by the aforementioned considerations.
Cyclic-AMP levels in the lichen Evernia prunastri are modulated by light quantity and quality.
Segovia, María; Gordillo, Francisco J L; Figueroa, Félix L
2003-07-01
Changes in the accumulation of cAMP levels were measured by the isotope dilution assay using protein kinase A in the lichen Evernia prunastri at varying light conditions. cAMP levels decreased following exposure to low irradiance (20 micromol quanta m(-2) s(-1), and below the compensation point for photosynthesis) of red light (600-710-nm wave length) and increased by 50% after far-red light illumination (15 micromol quanta m(-2) s(-1), 710-800-nm wavelength). Far-red partially reverted the effect of red light when the former was supplied after the latter. cAMP increased to its maximum level under high irradiance supplied by a non-photomorphogenic yellow light source (400 micromol quanta m(-2) s(-1), reaching photosynthetic saturation). The addition of small quantities of red and far-red light, however, had profound restricting effects on cAMP accumulation. The addition of inhibitors of electron transport chains did not promote any significant change in cAMP levels in any of the treatments, indicating that cAMP accumulation could not depend on ATP synthesis. We propose that the response of cAMP accumulation at low irradiance comprises the activation of a morphogenic pathway through a red/far-red photoreceptor. In addition, at high irradiance the response would occur most likely through photosystems II and I acting as sensors of light quantity, that can be strongly modified by the red/far-red photomorphogenic system. Thus, cAMP would be involved in sensing the overall light environment.
Count response model for the CMB spots
Giovannini, Massimo
2010-01-01
The statistics of the curvature quanta generated during a stage of inflationary expansion is used to derive a count response model for the large-scale phonons determining, in the concordance lore, the warmer and the cooler spots of the large-scale temperature inhomogeneities. The multiplicity distributions for the counting statistics are shown to be generically overdispersed in comparison with conventional Poissonian regressions. The generalized count response model deduced hereunder accommodates an excess of correlations in the regime of high multiplicities and prompts dedicated analyses with forthcoming data collected by instruments of high angular resolution and high sensitivity to temperature variations per pixel.
Role of fluctuations in the quantal description of damped motion
Energy Technology Data Exchange (ETDEWEB)
Hernandez, E.S.
1980-01-01
The construction of a frictional time-dependent Schroedinger equation is reviewed for harmonic motion in a restricted framework, i.e., demanding the conservation of the Gaussian shape of wave packets. The evolution of the quanta fluctuations is discussed in a time-independent model, and it is shown that such a situation does not correspond to damped harmonic oscillations. The role of fluctuations in providing dissipative behavior is discussed and the time evolution of arbitrary wave functions subject to damped motion as described by Schroedinger-Kostin equation is analyzed in detail.
Random matrices and Riemann hypothesis
Pierre, Christian
2011-01-01
The curious connection between the spacings of the eigenvalues of random matrices and the corresponding spacings of the non trivial zeros of the Riemann zeta function is analyzed on the basis of the geometric dynamical global program of Langlands whose fundamental structures are shifted quantized conjugacy class representatives of bilinear algebraic semigroups.The considered symmetry behind this phenomenology is the differential bilinear Galois semigroup shifting the product,right by left,of automorphism semigroups of cofunctions and functions on compact transcendental quanta.
Propensities toward C2H(Ã 2Π) in acetylene photodissociation
Zhang, J.; Riehn, C. W.; Dulligan, M.; Wittig, C.
1995-10-01
When expansion-cooled acetylene is excited to the ν″1+3ν″3 vibrational level (4 quanta of CH-stretch) and then photodissociated at 248.3 nm, the dominant product channel is C2H(Ã 2Π). This differs markedly from one-photon 193.3 nm photodissociation, which provides 1200 cm-1 less energy and yields C2H(X˜ 2Σ+) as the primary product. Photodissociation at 121.6 nm yields C2H(Ã 2Π) exclusively.
Classical Physics and the Bounds of Quantum Correlations.
Frustaglia, Diego; Baltanás, José P; Velázquez-Ahumada, María C; Fernández-Prieto, Armando; Lujambio, Aintzane; Losada, Vicente; Freire, Manuel J; Cabello, Adán
2016-06-24
A unifying principle explaining the numerical bounds of quantum correlations remains elusive, despite the efforts devoted to identifying it. Here, we show that these bounds are indeed not exclusive to quantum theory: for any abstract correlation scenario with compatible measurements, models based on classical waves produce probability distributions indistinguishable from those of quantum theory and, therefore, share the same bounds. We demonstrate this finding by implementing classical microwaves that propagate along meter-size transmission-line circuits and reproduce the probabilities of three emblematic quantum experiments. Our results show that the "quantum" bounds would also occur in a classical universe without quanta. The implications of this observation are discussed.
ESR of E' centres in unstrained geological quartz grains
Energy Technology Data Exchange (ETDEWEB)
Bartoll, J. E-mail: jens.bartoll@charite.de; Schwarcz, H.P.; Rink, W.J
2002-10-01
E{sub 1}' centres are detectable by ESR spectroscopy in unstrained quartz extracted from weathered rock of Cretaceous age. These centres completely disappear when the samples are irradiated with an artificial {gamma}-dose of about 200 Gy. The concentration of E{sub 1}' centres thermally (re)generated at 310 deg. C can be reduced drastically under the influence of {gamma}-quanta, too. The {gamma}-radiation induces thermally unstable components in the quartz matrices that start to decay at around 100 deg. C.
Cavity sideband cooling of a single trapped ion.
Leibrandt, David R; Labaziewicz, Jaroslaw; Vuletić, Vladan; Chuang, Isaac L
2009-09-04
We report a demonstration and quantitative characterization of one-dimensional cavity cooling of a single trapped (88)Sr(+) ion in the resolved-sideband regime. We measure the spectrum of cavity transitions, the rates of cavity heating and cooling, and the steady-state cooling limit. The cavity cooling dynamics and cooling limit of 22.5(3) motional quanta, limited by the moderate coupling between the ion and the cavity, are consistent with a simple model [Phys. Rev. A 64, 033405 (2001)] without any free parameters, validating the rate equation model for cavity cooling.
Multiphonon resonances in the Debye-Waller factor of atom surface scattering.
Brenig, W
2004-02-06
He atom surface scattering by dispersionless phonons is treated employing coupled channel (CC) calculations. At low energies, they predict a behavior opposite to perturbative Born or "exponentiated" Born approximation: strong resonant phonon stimulated elastic and inhibited inelastic scattering. The corresponding resonances have not been observed in earlier CC results since these have considered only the temperature dependence of the Debye-Waller factor at higher energy or omitted the attractive well. The resonances can be interpreted in terms of bound states in the attractive well with several excited vibrational quanta. They may be observable for, e.g., He scattering by a cold Xe/Cu surface.
The information paradox: Conflicts and resolutions
Indian Academy of Sciences (India)
Samir D Mathur
2012-11-01
Many relativists have been long convinced that black hole evaporation leads to information loss or remnants. String theorists have however not been too worried about the issue, largely due to a belief that the Hawking argument for information loss is flawed in its details. A recently derived inequality shows that the Hawking argument for black holes with horizon can in fact be made rigorous. What happens instead is that in string theory, black hole microstates have no horizons. Thus the evolution of radiation quanta with $E ∼ kT$ is modified by order unity at the horizon, and we resolve the information paradox.
Skrypnyk, A I; Khazhmuradov, M A
2011-01-01
We considered GEANT4 version 4.9.4 with different Electromagnetic Physics Package for calculation of response functions of detectors based on semi-insulating materials. Computer simulations with GEANT4 packages were run in order to determine the energy deposition of gamma-quanta in detectors of specified composition (Mercuric (II) Iodide and Thallium Bromide) at various energies from 0.026 to 3 MeV. The uncertainty in these predictions is estimated by comparison of their results with EGSnrc simulations. A general good agreement is found for EGSnrc and GEANT4 with Penelope 2008 model of LowEnergy Electromagnetic package.
L'homme qui ne portait pas de chaussettes, ou Quel Einstein célébrons-nous ?
Marage, Pierre
2007-01-01
2005 est l’Année internationale de la Physique. Elle marque le centième anniversaire des fameux articles d’Einstein de 1905 :la description du mouvement des corpuscules en suspension dans un liquide (le « mouvement brownien »), qui permit enfin de confirmer l’existence des atomes et qui formera sa thèse de doctorat ;l’article sur les quanta et l’effet photoélectrique qui, reprenant et élargissant l’hypothèse de Planck sur le rayonnement, fait d’Einstein l’un des pères de la mécanique quantiqu...
Splash, pop, sizzle: Information processing with phononic computing
Directory of Open Access Journals (Sweden)
Sophia R. Sklan
2015-05-01
Full Text Available Phonons, the quanta of mechanical vibration, are important to the transport of heat and sound in solid materials. Recent advances in the fundamental control of phonons (phononics have brought into prominence the potential role of phonons in information processing. In this review, the many directions of realizing phononic computing and information processing are examined. Given the relative similarity of vibrational transport at different length scales, the related fields of acoustic, phononic, and thermal information processing are all included, as are quantum and classical computer implementations. Connections are made between the fundamental questions in phonon transport and phononic control and the device level approach to diodes, transistors, memory, and logic.
Kirpichnikov, I. V.
2010-01-01
Heidelberg-Moscow Collaboration experimental data [1-4] with the claim for the observation of the neutrinoless double beta-decay of Ge-76 has been carefully analyzed. The analysis gave an evidence that the observed 2039 kev line in the full spectrum was produced by overlapping of three unresolved peaks: ~2035.5 kev, ~2037.5 kev and ~2039.5 kev. It was indicated that the 2035.5 kev and 2039.5 kev peaks were produced by the double-coincidences of gamma-quanta in the detectors. Existence of the ...
Kinetics of light-assisted physical ageing in S-rich arsenic sulphide glasses
Indian Academy of Sciences (India)
A KOZDRAS
2016-08-01
The obtained results show that kinetics of light-assisted physical ageing in S-rich glasses can be well fitted with stretch-exponential Kohlrausch-type function, in which exponent $\\beta$-values and the effective time relaxationconstant τ depend on the wavelength of incident photons. The obtained $\\beta$-values exhibit well-expressedminimum for the structural relaxation stimulated by light with energy of quanta comparable with the optical gap of the material. This effect is found to be similar to Se-rich glasses.
Khitrov, V A
2001-01-01
The new, model-independent method to estimate simultaneously the level densities excited in the (n,gamma) reaction and the radiative strength functions of dipole transitions is developed. The method can be applied for any nucleus and reaction followed by cascade gamma-emission. It is just necessary to measure the intensities of two-step gamma-cascades depopulating one or several high-excited states and determine the quanta ordering in the main portion of the observed cascades. The method provides a sufficiently narrow interval of most probable densities of levels with given J suppi and radiative strength functions of dipole transitions populating them.
[Quantum processes in evolution of regulation of living system (mathematical modelling)].
Menshutkin, V V; Natochin, Iu V
2011-01-01
We have developed an imitation model of the appearance of regulation of physiological functions of protocell at the initial stages of evolution of living system. It is based on suggestion of the appearance of signal function in spontaneously formed products of partial hydrolysis of the protocell polypeptides, based on which there appear the regulatory molecules--quanta of regulation. For construction of the model, the mathematical apparatus of final automats and of genetic algorithm is used. The model has demonstrated the positive role of involvement of regulatory peptides in the system of regulation of protocell functions to provide its viability under the changing envelopment conditions.
Custodio, P S
2003-01-01
We apply the Generalized Uncertainty Principle (GUP) to the problem of maximum entropy and evaporation/absorption of energy of black holes near the Planck scale. We find within this general approach corrections to the maximum entropy, and indications for quenching of the evaporation because not only the evaporation term goes to a finite limit, but also because absorption of quanta seems to help the balance for black holes in a thermal bath. Then, residual masses around the Planck scale may be the final outcome of primordial black hole evaporation.
J-PET detector system for studies of the electron-positron annihilations
Directory of Open Access Journals (Sweden)
Pawlik-Niedźwiecka M.
2016-01-01
Full Text Available Jagiellonian Positron Emission Tomograph (J-PET has been recently constructed at the Jagiellonian University as a prototype of a cost-effective scanner for the metabolic imaging of the whole human body. J-PET detector is optimized for the measurement of momentum and polarization of photons from the electron-positron annihilations. It is built out of strips of plastic scintillators, forming three cylindrical layers. As detector of gamma quanta it will be used for studies of discrete symmetries and multiparticle entanglement of photons originating from the decays of ortho-positronium atoms.
Erwin Schrödinger and Quantum Wave Mechanics
Directory of Open Access Journals (Sweden)
John J. O'Connor
2017-08-01
Full Text Available The fathers of matrix quantum mechanics believed that the quantum particles are unanschaulich (unvisualizable and that quantum particles pop into existence only when we measure them. Challenging the orthodoxy, in 1926 Erwin Schrödinger developed his wave equation that describes the quantum particles as a packet of quantum probability amplitudes evolving in space and time. Thus, Schrödinger visualized the unvisualizable and lifted the veil that has been obscuring the wonders of the quantum world. Quanta 2017; 6: 48–52.
The Phase Space Formulation of Time-Symmetric Quantum Mechanics
Directory of Open Access Journals (Sweden)
Charlyne de Gosson
2015-11-01
Full Text Available Time-symmetric quantum mechanics can be described in the Weyl–Wigner–Moyal phase space formalism by using the properties of the cross-terms appearing in the Wigner distribution of a sum of states. These properties show the appearance of a strongly oscillating interference between the pre-selected and post-selected states. It is interesting to note that the knowledge of this interference term is sufficient to reconstruct both states.Quanta 2015; 4: 27–34.
Finite Size Corrections to the Excitation Energy Transfer in a Massless Scalar Interaction Model
Maeda, N; Tobita, Y; Ishikawa, K
2016-01-01
We study the excitation energy transfer (EET) for a simple model in which a virtual massless scalar particle is exchanged between two molecules. If the time interval is finite, then the finite size effect generally appears in a transition amplitude through the regions where the wave nature of quanta remains. We calculated the transition amplitude for EET and obtained finite size corrections to the standard formula derived by using Fermi's golden rule. These corrections for the transition amplitude appear outside the resonance energy region. The estimation in a photosynthesis system indicates that the finite size correction could reduce the EET time considerably.
Relação entre income smoohing e ratings em companhias brasileiras de capital aberto
Tonin, Joyce Menezes da Fonseca
2013-01-01
Resumo: Este estudo teve como objetivo geral analisar a associação entre rating e gerenciamento de resultados contábeis decorrente do income smoothing em companhias de capital aberto com ações negociadas na BM&FBovespa no período de 2005 a 2011. Com a abordagem da informação contábil de Watts e Zimmerman (1986), a Teoria das Escolhas Contábeis de Fiels, Lys e Vicent (2001) e Francis (2001) e as contribuições de Martinez (2001) quantas as modalidades de Gerenciamento de Resultado, avaliou-se o...
Momentum entanglement in relativistic quantum mechanics
Smilga, Walter
2015-01-01
I present a new group-theoretical approach to the interaction mechanism of elementary particle physics. Within an irreducible unitary two-particle representation of the Poincare group, the commutation relations of the Poincare group require that the two-particle states be momentum entangled. As in gauge theories, momentum entanglement defines a correlation between two particles that can be described as an interaction provided by the exchange of virtual (gauge) quanta. The coupling constant of this interaction is uniquely determined by the structure of the irreducible two-particle state space. For two massive spin one-half particles, the coupling constant matches the empirical value of the electromagnetic coupling constant.
Are the Weak Measurements Really Measurements?
Directory of Open Access Journals (Sweden)
Dmitri Sokolovski
2013-05-01
Full Text Available Weak measurements can be seen as an attempt at answering the Which way? question without destroying interference between the pathways involved. Unusual mean values obtained in such measurements represent the response of a quantum system to this forbidden question, in which the true composition of virtual pathways is hidden from the observer. Such values indicate a failure of a measurement where the uncertainty principle says it must fail, rather than provide an additional insight into physical reality.Quanta 2013; 2: 50–57.
Phase locking and quantum statistics in a parametrically driven nonlinear resonator
Hovsepyan, G. H.; Shahinyan, A. R.; Chew, Lock Yue; Kryuchkyan, G. Yu.
2016-04-01
We discuss phase-locking phenomenon at low-level of quanta and quantum statistics for parametrically driven nonlinear Kerr resonator (PDNR). Oscillatory mode of PDNR is created in the process of a degenerate down-conversion of photons under interaction with a train of external Gaussian pulses. We calculate the distribution of photon-number states, the second-order correlation function of photons, the Wigner functions of cavity mode showing two-fold symmetry in phase space, and we analyze formation of phase-locked states in the regular as well as the quantum chaotic regime of the PDNR.
Recent results on hadron physics at KLOE
Babusci, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bossi, F; Branchini, P; Budano, A; Balkest, L Caldeira; Capon, G; Ceradini, F; Ciambrone, P; Curciarello, F; Czerwinski, E; Dane, E; De Leo, V; De Lucia, E; De Robertis, G; De Santis, A; Di Domenico, A; Di Donato, C; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gajos, A; Gauzzi, P; Giardina, G; Giovannella, S; Graziani, E; Happacher, F; Heijkenskjold, L; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kacprzak, K; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Palladino, A; Passeri, A; Patera, V; Longhi, I Prado; Ranieri, A; Redmer, C F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Wislicki, W; Wolke, M; Zdebik, J
2013-01-01
One of the basic motivations of the KLOE and KLOE-2 collaborations is the test of fundamental symmetries and the search for phenomena beyond the Standard Model via the hadronic and leptonic decays of ground-state mesons and via their production in the fusion of virtual gamma quanta exchanged between colliding electrons and positrons. This contribution includes brief description of results of recent analysis of the KLOE data aimed at (i) the search for the dark matter boson, (ii) determination of the hadronic and light-by-light contributions to the g-2 muon anomaly and (iii) tests of QCD anomalies.
Roldán-Molina, A; Nunez, Alvaro S; Duine, R A
2017-02-10
We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons-the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.
Single Photon Counting Performance and Noise Analysis of CMOS SPAD-Based Image Sensors.
Dutton, Neale A W; Gyongy, Istvan; Parmesan, Luca; Henderson, Robert K
2016-07-20
SPAD-based solid state CMOS image sensors utilising analogue integrators have attained deep sub-electron read noise (DSERN) permitting single photon counting (SPC) imaging. A new method is proposed to determine the read noise in DSERN image sensors by evaluating the peak separation and width (PSW) of single photon peaks in a photon counting histogram (PCH). The technique is used to identify and analyse cumulative noise in analogue integrating SPC SPAD-based pixels. The DSERN of our SPAD image sensor is exploited to confirm recent multi-photon threshold quanta image sensor (QIS) theory. Finally, various single and multiple photon spatio-temporal oversampling techniques are reviewed.
Low Temperature Superplasticity of Ti-6Al-4V Processed by Warm Multidirectional Forging (Preprint)
2012-07-01
using a JEOL JEM-2100FX transmission electron microscope (TEM) and a Quanta 600 field-emission-gun scanning-electron microscope (SEM). Results and...factor of three compared to the initial condition (Fig. 2b). A backscattered electron ( BSE ) image revealed the distribution of the phase in the...a) BSE image of Ti-6Al-4V after annealing at Т=550С for 0.5 hour and (b) grain size as a function of soak time at 550C. Superplastic Behavior
Kotanjyan, A S
2007-01-01
We investigate the electromagnetic field generated by a point charge moving along a helical trajectory inside a circular waveguide with conducting walls filled by homogeneous dielectric. The parts corresponding to the radiation field are separated and the formulae for the radiation intensity are derived for both TE and TM waves. It is shown that the main part of the radiated quanta is emitted in the form of the TE waves. Various limiting cases are considered. The results of the numerical calculations show that the insertion of the waveguide provides an additional mechanism for tuning the characteristics of the emitted radiation by choosing the parameters of the waveguide and filling medium.
Communication strategies for two models of discrete energy harvesting
DEFF Research Database (Denmark)
Trillingsgaard, Kasper Fløe; Popovski, Petar
2014-01-01
in a battery and transmissions are interrupted if the battery runs out of energy. We address communication in slot-based energy harvesting systems, where the transmitter communicates with ON-OFF signaling: in each slot it can either choose to transmit (ON) or stay silent (OFF). Two different models...... of harvesting and communication are addressed. In the first model an energy quantum can arrive, with a certain probability, in each slot. The second model is based on a frame of size F: energy arrives periodically over F slots, in batches containing a random number of energy quanta. We devise achievable...
Waiting for the W - and the Higgs
Tannenbaum, M. J.
2016-10-01
The search for the left-handed W ± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.
High-fidelity transport of trapped-ion qubits through an X-junction trap array.
Blakestad, R B; Ospelkaus, C; VanDevender, A P; Amini, J M; Britton, J; Leibfried, D; Wineland, D J
2009-04-17
We report reliable transport of (9)Be(+) ions through an "X junction" in a 2D trap array that includes a separate loading and reservoir zone. During transport the ion's kinetic energy in its local well increases by only a few motional quanta and internal-state coherences are preserved. We also examine two sources of energy gain during transport: a particular radio-frequency noise heating mechanism and digital sampling noise. Such studies are important to achieve scaling in a trapped-ion quantum information processor.
Perspectives on Einstein's scientific works in Milan
Bracco, Christian
2015-01-01
The Milanese period in Albert Einstein's life is a key one for the understanding of the development of his scientific questioning. While being a student in Z\\"urich from 1896, Einstein returned regularly to Milan to meet his family for the holidays. There, he could work on the most recent articles in physics at the rich library of the Lombardo Institute, Academy of Sciences and Letters. Hopefully, this new perspective will help to trace back more accurately a few of Einstein's scientific ideas, such as the need to expand his first doctoral work on molecular forces to weakly compressed gases or as to conceive a first idea of light quanta.
Dual-Energy Semiconductor Detector of X-rays and Gamma Radiation
Directory of Open Access Journals (Sweden)
Brodyn, M.S.
2014-03-01
Full Text Available Analysis of the major types of ionizing radiation detectors, their advantages and disadvantages are presented. Application of ZnSe-based semiconductor detector in high temperature environment is substantiated. Different forms of ZnSe-based detector samples and double-crystal scheme for registration of X- and gamma rays in a broad energy range were used . Based on the manufactured simulator device, the study sustains the feasibility of the gamma quanta recording by a high-resistance ZnSe-based detector operating in a perpulse mode.
Popper's Experiment: A Modern Perspective
Directory of Open Access Journals (Sweden)
Tabish Qureshi
2012-11-01
Full Text Available Karl Popper had proposed an experiment to test the standard interpretation of quantum mechanics. The proposal survived for many year in the midst of no clear consensus on what results it would yield. The experiment was realized by Kim and Shih in 1999, and the apparently surprising result led to lot of debate. We review Popper's proposal and its realization in the light of current era when entanglement has been well studied, both theoretically and experimentally. We show that the "ghost-diffraction" experiment, carried out in a different context, conclusively resolves the controversy surrounding Popper's experiment.Quanta 2012; 1: 19–32.
Superconducting microfabricated ion traps
Wang, Shannon X; Labaziewicz, Jaroslaw; Dauler, Eric; Berggren, Karl; Chuang, Isaac L
2010-01-01
We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.
Energy Technology Data Exchange (ETDEWEB)
Beardsmore, D.J.; Pearman, G.I. [Commonwealth Scientific Industrial Research Organization (CSIRO), Victoria (Australia). Division of Atmospheric Research
1984-09-01
Atmospheric CO{sub 2} concentrations were measured in the troposphere and lower stratosphere over the Australia-New Zealand region and as far south as Antarctica for the period 1972-1981. The samples were collected from aircraft over a large range of latitudes and altitudes. The sampling program has been based on the cooperation of the Australia Department of Transport, Quantas Airways, Trans Australia Airlines, the United States, New Zealand and Australian Air Forces and occasional chartering of light aircraft for special purposes.
Quantum field theory of classically unstable Hamiltonian dynamics
Energy Technology Data Exchange (ETDEWEB)
Strauss, Y., E-mail: ystrauss@cs.bgu.ac.il [Department of Mathematics, Ben-Gurion University of the Negev, Be’er Sheva 8410501 (Israel); Department of Physics, Ariel University, Ariel 4070000 (Israel); Horwitz, L. P. [Department of Physics, Ariel University, Ariel 4070000 (Israel); School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv university, Tel-Aviv 6997801 (Israel); Department of Physics, Bar-Ilan University, Ramat-Gan 5290002 (Israel); Levitan, J. [Department of Physics, Ariel University, Ariel 4070000 (Israel); Yahalom, A. [Department of Electrical and Electronic Engineering, Ariel 4070000 (Israel)
2015-07-15
We study a class of dynamical systems for which the motions can be described in terms of geodesics on a manifold (ordinary potential models can be cast into this form by means of a conformal map). It is rigorously proven that the geodesic deviation equation of Jacobi, constructed with a second covariant derivative, is unitarily equivalent to that of a parametric harmonic oscillator, and we study the second quantization of this oscillator. The excitations of the Fock space modes correspond to the emission and absorption of quanta into the dynamical medium, thus associating unstable behavior of the dynamical system with calculable fluctuations in an ensemble with possible thermodynamic consequences.
Thirty years that shook physics the story of quantum theory
Gamow, George A
1966-01-01
""Dr. Gamow, physicist and gifted writer, has sketched an intriguing portrait of the scientists and clashing ideas that made the quantum revolution."" - Christian Science MonitorIn 1900, German physicist Max Planck postulated that light, or radiant energy, can exist only in the form of discrete packages or quanta. This profound insight, along with Einstein's equally momentous theories of relativity, completely revolutionized man's view of matter, energy, and the nature of physics itself.In this lucid layman's introduction to quantum theory, an eminent physicist and noted popularizer of scien
A Nuclear Polariton with Two Entangled Counter-Propagating Branches
Liao, Wen-Te
2014-01-01
A setup for generating the special superposition of a simultaneously forward- and backward-propagating collective excitation in a nuclear sample is studied. We show that by actively manipulating the scattering channels of single x-ray quanta with the help of a normal incidence x-ray mirror, a nuclear polariton which propagates in two opposite directions can be generated. The two counter-propagating polariton branches are entangled by a single x-ray photon. The quantum nature of the nuclear excitation entanglement gives rise to a sub-angstrom wavelength standing wave excitation pattern that can be used as a flexible tool to probe matter dynamically on the atomic scale.
Quantised transistor response to ion channels revealed by nonstationary noise analysis
Becker-Freyseng, C.; Fromherz, P.
2011-11-01
We report on the quantised response of a field-effect transistor to molecular ion channels in a biomembrane. HEK293-type cells overexpressing the Shaker B potassium channel were cultured on a silicon chip. An enhanced noise of the transistor is observed when the ion channels are activated. The analysis of the fluctuations in terms of binomial statistics identifies voltage quanta of about 1 μV on the gate. They are attributed to the channel currents that affect the gate voltage according to the Green's function of the cell-chip junction.
Spectral linewidth of autonomous and injection-locked flux-flow oscillators
DEFF Research Database (Denmark)
Koshelets, V. P.; Shchukin, A.; Lapytskaya, I. L.;
1995-01-01
-flow oscillators (FFO) as low as 750 kHz was found at 280 GHz. Presently no theory exists for the linewidth of the FFO. Above a few MHz the experimental linewidth scales with the square of the dynamic resistance of the dc I-V curve as found for short Josephson junctions and oscillators based on resonant motion......Oscillators based on unidirectional viscous flow of magnetic flux quanta in long Josephson tunnel junctions with high damping have been experimentally investigated by harmonic mixing and frequency multiplication at frequencies up to 450 GHz. An integral spectral linewidth of two flux...
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emek Hefer (Israel); The Hadassah Institute, Jerusalem (Israel)
2015-07-15
It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio τ{sub gap}/τ{sub emission} = O(1), where τ{sub gap} is the average time gap between the emissions of successive Hawking quanta and τ{sub emission} is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process. (orig.)
Roldán-Molina, A.; Nunez, Alvaro S.; Duine, R. A.
2017-02-01
We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons—the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.
Surface acoustic wave modulation of a coherently driven quantum dot in a pillar microcavity
Villa, B.; Bennett, A. J.; Ellis, D. J. P.; Lee, J. P.; Skiba-Szymanska, J.; Mitchell, T. A.; Griffiths, J. P.; Farrer, I.; Ritchie, D. A.; Ford, C. J. B.; Shields, A. J.
2017-07-01
We report the efficient coherent photon scattering from a semiconductor quantum dot embedded in a pillar microcavity. We show that a surface acoustic wave can periodically modulate the energy levels of the quantum dot but has a negligible effect on the cavity mode. The scattered narrow-band laser is converted into a pulsed single-photon stream, displaying an anti-bunching dip characteristic of single-photon emission. Multiple phonon sidebands are resolved in the emission spectrum, due to the absorption and emission of vibrational quanta in each scattering event.
Magnonics From Fundamentals to Applications
Slavin, Andrei
2013-01-01
Spin waves (and their quanta magnons) can effectively carry and process information in magnetic nanostructures. By analogy to photonics, this research field is labelled magnonics. It comprises the study of excitation, detection, and manipulation of magnons. From the practical point of view, the most attractive feature of magnonic devices is the controllability of their functioning by an external magnetic field. This book has been designed for students and researchers working in magnetism. Here the readers will find review articles written by leading experts working on realization of magnonic devices.
Bardelli, L; Bizzeti, P G; Carraresi, L; Danevich, F A; Fazzini, T F; Grinyov, B V; Ivannikova, N V; Kobychev, V V; Kropivyansky, B N; Maurenzig, P R; Nagornaya, L L; Nagorny, S S; Nikolaiko, A S; Pavlyuk, A A; Poda, D V; Solsky, I M; Sopinskyy, M V; Stenin, Y G; Taccetti, F; Tretyak, V I; Vasiliev, Y V; Yurchenko, S S; Stenin, Yu. G.; Vasiliev, Ya. V.
2006-01-01
Energy resolution, light yield, non-proportionality in the scintillation response, alpha/beta ratio, pulse shape for gamma rays and alpha particles were studied with CdWO4 crystal scintillators. Some indication for a difference in the emission spectra for gamma rays and alpha particles was observed. No dependence of CdWO4 pulse shape on emission spectrum wavelengths under laser, alpha particles and gamma ray excitation was observed. Dependence of scintillation pulse shape for gamma quanta and alpha particles and pulse-shape discrimination ability on temperature was measured in the range of 0-24 degrees.
Energy Technology Data Exchange (ETDEWEB)
Bardelli, L. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Bini, M. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Bizzeti, P.G. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Carraresi, L. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Danevich, F.A. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine)]. E-mail: danevich@kinr.kiev.ua; Fazzini, T.F. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Grinyov, B.V. [Institute for Scintillation Materials, 61001 Kharkov (Ukraine); Ivannikova, N.V. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation); Kobychev, V.V. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Kropivyansky, B.N. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Maurenzig, P.R. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Nagornaya, L.L. [Institute for Scintillation Materials, 61001 Kharkov (Ukraine); Nagorny, S.S. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Nikolaiko, A.S. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Pavlyuk, A.A. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation); Poda, D.V. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Solsky, I.M. [Institute for Materials, 79031 Lviv (Ukraine); Sopinskyy, M.V. [Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine); Stenin, Yu.G. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation); Taccetti, F. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Tretyak, V.I.; Yurchenko, S.S. [Institute for Nuclear Research, MSP 03680 Kiev (Ukraine); Vasiliev, Ya.V. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation)
2006-12-21
Energy resolution, non-proportionality in the scintillation response, {alpha}/{beta} ratio, pulse shape for {gamma} rays and {alpha} particles were studied with CdWO{sub 4} crystal scintillators. Some indication for a difference in the emission spectra for {gamma} rays and {alpha} particles was observed. No dependence of CdWO{sub 4} pulse shape on emission spectrum wavelengths under laser, {alpha} particles and {gamma} ray excitation was observed. Dependence of scintillation pulse shape for {gamma} quanta and {alpha} particles and pulse-shape discrimination ability on temperature was measured in the range of 0-24{sup o}C.
Comment on the quantum modes of the scalar field on $AdS_{d+1}$ spacetime
Cotaescu, I I
1999-01-01
The problem of the quantum modes of the scalar free field on anti-de Sitter backgrounds with an arbitrary number of space dimensions is considered. It is shown that this problem can be solved by using the same quantum numbers as those of the nonrelativistic oscillator and two parameters which give the energy quanta and respectively the ground state energy. This last one is known to be just the conformal dimension of the boundary field theory of the AdS/CFT conjecture.
Waiting for the W. and the Higgs
Tannenbaum, M. J.
2016-12-01
The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.
Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations.
Ockeloen-Korppi, C F; Damskägg, E; Pirkkalainen, J-M; Heikkilä, T T; Massel, F; Sillanpää, M A
2017-03-10
A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.
Higgs production at hadron colliders as a probe of new physics
Díaz-Cruz, J L
2000-01-01
The coupling of Higgs with gauge bosons can receive non-decoupling corrections due to heavy quanta. Deviation from the SM predictions are described by a set of parameters e_V, which can be related to the parameters S,T. The Higgs production by gluon fusion can be used to probe e_g, whereas its decays into WW can probe e_W. The resulting bounds may imply the exclusion of heavy particles, such as additional standard or mirror families, chiral colored sextets and octet quarks. Within the MSSM, we also find that gluon fusion is a sensitive probe for the spectrum of squark masses.
J-PET detector system for studies of the electron-positron annihilations
Pawlik-Niedźwiecka, M.; Khreptak, O.; Gajos, A.; Wieczorek, A.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Czerwiński, E.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Kamińska, D.; Korcyl, G.; Kowalski, P.; Krzmień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.
2016-11-01
Jagiellonian Positron Emission Tomograph (J-PET) has been recently constructed at the Jagiellonian University as a prototype of a cost-effective scanner for the metabolic imaging of the whole human body. J-PET detector is optimized for the measurement of momentum and polarization of photons from the electron-positron annihilations. It is built out of strips of plastic scintillators, forming three cylindrical layers. As detector of gamma quanta it will be used for studies of discrete symmetries and multiparticle entanglement of photons originating from the decays of ortho-positronium atoms.
The Features of Infrared Absorption of the Protein Molecules in the Living System
Institute of Scientific and Technical Information of China (English)
PANG XiaoFeng
2001-01-01
We utilize a vibron-soliton model for amide-I vibrational quanta interacting with optical phonons to study the feature of infrared absorption of the protein molecules with finite temperature. The self-trapping of amide-I vibrational quantum results in red shift of the main peak and largely anomalous band to occur in the infrared absorption for the protein molecules. Utilizing the concise model of vibron and improved theory of color centers we have given theoretically the value of red shifts of the main peak and the intensity of anomalous band in infrared absorption,respectively, the latter reduces with increasing temperature which is consistent with the experimental result.``
Waiting for the W and the Higgs
Tannenbaum, M J
2016-01-01
The search for the left-handed $W^{\\pm}$ bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.
New Information Distance Measure and Its Application in Question Answering System
Institute of Scientific and Technical Information of China (English)
Xian Zhang; Yu Hao; Xiao-Yan Zhu; Ming Li
2008-01-01
In a question answering (QA) system, the fundamental problem is how to measure the distance between a question and an answer, hence ranking different answers. We demonstrate that such a distance can be precisely and mathematically defined. Not only such a definition is possible, it is actually provably better than any other feasible definitions.Not only such an ultimate definition is possible, but also it can be conveniently and fruitfully applied to construct a QA system. We have built such a system -- QUANTA. Extensive experiments are conducted to justify the new theory.
Multiplicity fluctuations in heavy-ion collisions using canonical and grand-canonical ensemble
Energy Technology Data Exchange (ETDEWEB)
Garg, P. [Indian Institute of Technology Indore, Discipline of Physics, School of Basic Science, Simrol (India); Mishra, D.K.; Netrakanti, P.K.; Mohanty, A.K. [Bhabha Atomic Research Center, Nuclear Physics Division, Mumbai (India)
2016-02-15
We report the higher-order cumulants and their ratios for baryon, charge and strangeness multiplicity in canonical and grand-canonical ensembles in ideal thermal model including all the resonances. When the number of conserved quanta is small, an explicit treatment of these conserved charges is required, which leads to a canonical description of the system and the fluctuations are significantly different from the grand-canonical ensemble. Cumulant ratios of total-charge and net-charge multiplicity as a function of collision energies are also compared in grand-canonical ensemble. (orig.)
Research Article. An introduction to the edition of two Lemaître’s original manuscripts
Directory of Open Access Journals (Sweden)
Maere Catherine de
2017-04-01
Full Text Available The aim of this paper is to explain the contributions of G. Lemaître to Spinor Theory. At the end of the paper, we edited also, for the first time two short manuscripts: Spineurs et Quanta and Les spineurs et la physique quantique, written by Lemaître in December 1955 and in January 1956. This edition is a way of honouring Professor Michael Heller because he was the first, with Professor Odon Godart, who discovered, classified and published unedited manuscripts of G. Lemaître.
Examples of the Zeroth Theorem of the History of Science
Energy Technology Data Exchange (ETDEWEB)
Jackson, J.D.
2007-08-24
The zeroth theorem of the history of science, enunciated byE. P. Fischer, states that a discovery (rule,regularity, insight) namedafter someone (often) did not originate with that person. I present fiveexamples from physics: the Lorentz condition partial muAmu = 0 definingthe Lorentz gauge of the electromagnetic potentials; the Dirac deltafunction, delta(x); the Schumann resonances of the earth-ionospherecavity; the Weizsacker-Williams method of virtual quanta; the BMTequation of spin dynamics. I give illustrated thumbnail sketches of boththe true and reputed discoverers and quote from their "discovery"publications.
Trojan horse attack free fault-tolerant quantum key distribution protocols
Yang, Chun-Wei; Hwang, Tzonelih
2013-11-01
This work proposes two quantum key distribution (QKD) protocols—each of which is robust under one kind of collective noises—collective-dephasing noise and collective-rotation noise. Due to the use of a new coding function which produces error-robust codewords allowing one-time transmission of quanta, the proposed QKD schemes are fault-tolerant and congenitally free from Trojan horse attacks without having to use any extra hardware. Moreover, by adopting two Bell state measurements instead of a 4-GHZ state joint measurement for decoding, the proposed protocols are practical in combating collective noises.
A two dimensional model for magnetic flux fractionalization in high Tc superconductors
Cristofano, G; Naddeo, A; Niccoli, G
2004-01-01
We show how the recently proposed effective theory for a Quantum Hall system at "paired states" filling nu=1 (Mod.Phys.Lett. A 15 (2000) 1679; Nucl. Phys. B 641(2002) 547), the twisted model (TM), well adapts to describe self-generated half-integer flux quanta observed near grain boundaries (GBs). We stress the key role of our theory in describing the phenomenology of linear Josephson Junction Arrays (JJAs) which have been proposed as a model of YBCO grain boundaries, in particular we focus on "closed" geometries which appear promising as "protected" qubits for the implementation of an ideal quantum computer.
Directory of Open Access Journals (Sweden)
Bischof Hans-Joachim
2007-02-01
Full Text Available Abstract Background The Radical Pair model proposes that magnetoreception is a light-dependent process. Under low monochromatic light from the short-wavelength part of the visual spectrum, migratory birds show orientation in their migratory direction. Under monochromatic light of higher intensity, however, they showed unusual preferences for other directions or axial preferences. To determine whether or not these responses are still controlled by the respective light regimes, European robins, Erithacus rubecula, were tested under UV, Blue, Turquoise and Green light at increasing intensities, with orientation in migratory direction serving as a criterion whether or not magnetoreception works in the normal way. Results The birds were well oriented in their seasonally appropriate migratory direction under 424 nm Blue, 502 nm Turquoise and 565 nm Green light of low intensity with a quantal flux of 8·1015 quanta s-1 m-2, indicating unimpaired magnetoreception. Under 373 nm UV of the same quantal flux, they were not oriented in migratory direction, showing a preference for the east-west axis instead, but they were well oriented in migratory direction under UV of lower intensity. Intensities of above 36·1015 quanta s-1 m-2 of Blue, Turquoise and Green light elicited a variety of responses: disorientation, headings along the east-west axis, headings along the north-south axis or 'fixed' direction tendencies. These responses changed as the intensity was increased from 36·1015 quanta s-1 m-2 to 54 and 72·1015 quanta s-1 m-2. Conclusion The specific manifestation of responses in directions other than the migratory direction clearly depends on the ambient light regime. This implies that even when the mechanisms normally providing magnetic compass information seem disrupted, processes that are activated by light still control the behavior. It suggests complex interactions between different types of receptors, magnetic and visual. The nature of the
Energy Technology Data Exchange (ETDEWEB)
Geitner, Uwe W.
2013-04-01
The series The Inner Life of the Elementary Particles attempts to develop the elementary particles along of a genealogical tree, which begins before the ''big bang''. The simple presentation without mathematics opens also for the interested layman a plastic understanding. Volume IX discusses the known puzzles of particle physics and cosmology and offers for many of them explanation models. Explanation approaches are among others the ''DNA'' of the elementary particles and the interpretation of the quanta and the spin.
Directory of Open Access Journals (Sweden)
Khalil Chamcham
2013-07-01
Full Text Available So far we can identify at least three concepts within modern cosmology that bring into debate the question of consciousness in the universe: 1 Fine Tuning; 2 The Anthropic Principle and 3 The Multiverse. This does not exclude the question of the role of observer (i.e. consciousness in cosmology as developed within Quantum Physics: we observe the universe through quanta and any breakthrough in understanding the origin and nature of the universe will come only through a quantum theory of gravity […
Separation Process of Polydisperse Particles in the Plasma of Radio-frequency Discharge
Directory of Open Access Journals (Sweden)
D.G. Batryshev
2014-07-01
Full Text Available Method of separation of polydisperse particles in the plasma of radio-frequency (RF discharge is considered. Investigation of plasma equipotential field gave conditions for separation. The purpose of this work was an obtaining of monodisperse particles in the plasma of RF discharge. Samples of monodisperse microparticles of silica and alumina were obtained. The size and chemical composition of samples were studied on a scanning electron microscope Quanta 3D 200i (SEM, USA FEI company. Average size of separated silica nanoparticles is 600 nm, silica and alumina microparticles is 5 mkm.
Thirty years that shook physics the story of quantum theory
Gamow, George
1985-01-01
""Dr. Gamow, physicist and gifted writer, has sketched an intriguing portrait of the scientists and clashing ideas that made the quantum revolution."" - Christian Science MonitorIn 1900, German physicist Max Planck postulated that light, or radiant energy, can exist only in the form of discrete packages or quanta. This profound insight, along with Einstein's equally momentous theories of relativity, completely revolutionized man's view of matter, energy, and the nature of physics itself.In this lucid layman's introduction to quantum theory, an eminent physicist and noted popularizer of scien
Calibration of photomultipliers gain used in the J-PET detector
Bednarski, T; Moskal, P; Białas, P; Giergiel, K; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Molenda, M; Moskal, I; Niedźwiecki, Sz; Pałka, M; Pawlik, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Szymański, K; Wiślicki, W; Witkowski, P; Zieliński, M; Zoń, N
2013-01-01
Photomultipliers are commonly used in commercial PET scanner as devices which convert light produced in scintillator by gamma quanta from positron-electron annihilation into electrical signal. For proper analysis of obtained electrical signal, a photomultiplier gain curve must be known, since gain can be significantly different even between photomultipliers of the same model. In this article we describe single photoelectron method used for photomultipliers calibration applied for J-PET scanner, a novel PET detector being developed at the Jagiellonian University. Description of calibration method, an example of calibration curve and gain of few R4998 Hamamatsu photomultipliers are presented.
Database and data structure for the novel TOF-PET detector developed for J-PET project
Czerwiński, E; Bednarski, T; Białas, P; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Molenda, M; Moskal, P; Niedźwiecki, Sz; Pałka, M; Pawlik, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zoń, N
2014-01-01
The complexity of the hardware and the amount of data collected during the PET imaging process require application of modern methods of efficient data organization and processing. In this article we will discuss the data structures and the flow of collected data from the novel TOF-PET medical scanner which is being developed at the Jagiellonian University. The developed data format reflects: registration process of the gamma quanta emitted from positron-electron annihilation, Front-End Electronic (FEE) structure and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.
Phononics in low-dimensional materials
Directory of Open Access Journals (Sweden)
Alexander A. Balandin
2012-06-01
Full Text Available Phonons – quanta of crystal lattice vibrations – reveal themselves in all electrical, thermal, and optical phenomena in materials. Nanostructures open exciting opportunities for tuning the phonon energy spectrum and related material properties for specific applications. The possibilities for controlled modification of the phonon interactions and transport – referred to as phonon engineering or phononics – increased even further with the advent of graphene and two-dimensional van der Waals materials. We describe methods for tuning the phonon spectrum and engineering the thermal properties of the low-dimensional materials via ribbon edges, grain boundaries, isotope composition, defect concentration, and atomic-plane orientation.
Baskov, V A; Kim, V; Polyansky, V V; Verdi, A; Verdi, A.
1999-01-01
99-014 In this article we propose to use a dedicated pile-up detector --- 180 degree Cherenkov calorimeter which measures energies of gamma-quanta being produced in ppinteractions by the Cherenkov radiation intensity --- to ensure the conditions which will allow LHCb to work with luminosity 4--5 10 32 cm -2 s -1 . The calorimeter consists of a multiplicator with the width corresponding to the maximum of particles in an electromagnetic shower, behind which a quartz plate is situated where shower particles produce Cherenkov radiation. The pile-up detector is situated at the 180 degree angle relative to the LHCb spectrometer.
Quasi-elastic reactions: an interplay of reaction dynamics and nuclear structure
Directory of Open Access Journals (Sweden)
Recchia F.
2011-10-01
Full Text Available Multinucleon transfer reactions have been investigated in 40Ar+208Pb with the Prisma+Clara set-up. The experimental differential cross sections of different neutron transfer channels have been obtained at three different angular settings taking into account the transmission through the spectrometer. The experimental yields of the excited states have been determined via particle-γ coincidences. In odd Ar isotopes, we reported a signif cant population of 11/2− states, reached via neutron transfer. Their structure matches a stretched conf guration of the valence neutron coupled to vibration quanta.
Haunted quantum contextuality versus value indefiniteness - a minority report
Svozil, Karl
2011-01-01
Physical entities are ultimately (re)constructed from elementary yes/no events, in particular clicks in detectors or measurement devices recording quanta. Recently, the interpretation of certain such clicks has given rise to unfounded claims which are neither necessary nor sufficient, although they are presented in that way. In particular, clicks can neither inductively support nor "(dis)prove" the Kochen-Specker theorem, which is a formal result that has a deductive proof by contradiction. More importantly, the alleged empirical evidence of quantum contextuality, which is "inferred" from violations of bounds of classical probabilities by quantum correlations, is based on highly nontrivial assumptions, in particular on physical omniscience.
Moessbauer absorption by thick ferromagnets in radio-frequency magnetic field
Dzyublik, A Y
2002-01-01
The dynamical scattering theory is developed for transmission of the Moessbauer radiation through a ferromagnetic absorber of arbitrary thickness whose magnetization periodically reverses under the influence of an external radio-frequency (RF) magnetic field. The thickness dependence of the Moessbauer absorption spectrum as well as the time dependence and energy distribution of the transmitted beam are analyzed. The transmitted spectrum as a function of the frequency of transmitted gamma-quanta, reveals a sideband structure separated by twice the frequency of the RF field, which collapses to a single line at high frequencies.
Thermal balance of the jet in the microquasar SS433
Bisnovatyi-Kogan, Gennady S
2012-01-01
Thermal balance of the jet in the source SS433 is considered with account of radiative and adiabatic cooling, and different heating mechanisms. We consider jet heating by the inverse Compton effect of coronal hard X-ray quanta on jet electrons, the influence of shock wave propagation along the jet, and jet kinetic energy transformation into heat via Coulomb collisions of jet and corona protons. The most important heating mechanism for the source SS433 turns out to be Coulomb collisions of jet particles with the surrounding medium.
Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide
Anpilov, A. M.; Barkhudarov, E. M.; Bark, Yu B.; Zadiraka, Yu V.; Christofi, M.; Kozlov, Yu N.; Kossyi, I. A.; Kop'ev, V. A.; Silakov, V. P.; Taktakishvili, M. I.; Temchin, S. M.
2001-03-01
Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190≤λ≤430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.
On the noise-resolution duality, Heisenberg uncertainty and Shannon's information
Gureyev, T E; Nesterets, Ya I; Paganin, D M
2015-01-01
Several variations of the Heisenberg uncertainty inequality are derived on the basis of "noise-resolution duality" recently proposed by the authors. The same approach leads to a related inequality that provides an upper limit for the information capacity of imaging systems in terms of the number of imaging quanta (particles) used in the experiment. These results can be useful in the context of biomedical imaging constrained by the radiation dose delivered to the sample, or in imaging (e.g. astronomical) problems under "low light" conditions.
Scatter fraction of the J-PET tomography scanner
Kowalski, P; Raczyński, L; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Głowacz, B; Jasińska, J; Kamińska, D; Korcyl, G; Kozik, T; Krzemień, W; Kubicz, E; Mohammad, M; Niedźwiecki, Sz; Pałka, M; Pawlik-Niedźwiecka, M; Rudy, Z; Silarski, M; Smyrski, J; Strzelecki, A; Wieczorek, A; Zgardzińska, B; Zieliński, M; Moskal, P
2016-01-01
A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET collaboration. In this article we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.
Calvin, M.
1983-01-01
As a result of the exhaustion of our supplies of ancient photosynthesis (oil and gas) it is necessary to develop renewable fuels for the future. The most immediate source of renewable fuel is, of course, the annually growing green plants, some of which produce hydrocarbon(s) directly. New plant sources can be selected for this purpose, plants which have high potential for production of chemicals and liquid fuels. Suggestions are made for modification of both the product character and the productivity of the plants. Ultimately, a totally synthetic device will be developed for the conversion of solar quanta into useful chemical form completely independent of the need for arable land.
3D Sisyphus Cooling of Trapped Ions
Ejtemaee, S
2016-01-01
Using a laser polarization gradient, we realize 3D Sisyphus cooling of $^{171}$Yb$^+$ ions confined in and near the Lamb-Dicke regime in a linear Paul trap. The cooling rate and final mean motional energy of a single ion are characterized as a function of laser intensity and compared to semiclassical and quantum simulations. Sisyphus cooling is also applied to a linear string of four ions to obtain a mean energy of 1-3 quanta for all vibrational modes, an approximately order-of-magnitude reduction below Doppler cooled energies. This is used to enable subsequent, efficient sideband laser cooling.
Knight, P L
1983-01-01
Concepts of Quantum Optics is a coherent and sequential coverage of some real insight into quantum physics. This book is divided into six chapters, and begins with an overview of the principles and concepts of radiation and quanta, with an emphasis on the significance of the Maxwell's electromagnetic theory of light. The next chapter describes first the properties of the radiation field in a bounded cavity, showing how each cavity field mode has the characteristics of a simple harmonic oscillator and how each can be quantized using known results for the quantum harmonic oscillator. This chapte
3D Sisyphus Cooling of Trapped Ions
Ejtemaee, S.; Haljan, P. C.
2017-07-01
Using a laser polarization gradient, we realize 3D Sisyphus cooling of Yb+ 171 ions confined in and near the Lamb-Dicke regime in a linear Paul trap. The cooling rate and final mean motional energy of a single ion are characterized as a function of laser intensity and compared to semiclassical and quantum simulations. Sisyphus cooling is also applied to a linear string of four ions to obtain a mean energy of 1-3 quanta for all vibrational modes, an approximately order of magnitude reduction below Doppler cooled energies. This is used to enable subsequent, efficient sideband laser cooling.
Spontaneous Symmetry Breaking and Higgs Field in Higher Derivative Gravity Theory
Naboulsi, R
2003-01-01
Spontaneous symetry breaking in the context of higher derivative gravity theory is studied. For 2Lambda = 3m^2, where Lambda is the cosmological constant and m is the mass of the Klein-Gordon field and at initial temperature of the massless spinless quanta, the physical gravitional constant is less than the Plank-Wheeler inverse square mass, but the physical cosmological constant turns to be equal to the classical Einstein-Hilbert one. The critical temperature is shown to be different from zero and depends on the scalar curvature via the higher order correction parameter.
Generation and Detection of Infrared Single Photons and their Applications
Institute of Scientific and Technical Information of China (English)
ZENG He-ping; WU Guang; WU E; PAN Hai-feng; ZHOU Chun-yuan; WU E.,F.Treussart; J.-F.Roch
2006-01-01
Unbreakable secret communication has been a dream from ancient time.It is quantum physics that gives us hope to turn this wizardly dream into reality.The rapid development of quantum cryptography may put an end to the history of eavesdropping.This will be largely due to the advanced techniques related to single quanta,especially infrared single photons.In this paper,we report on our research works on single-photon control for quantum cryptography,ranging from single-photon generation to single-photon detection and their applications.
Polaritons in periodic and quasiperiodic structures
Albuquerque, Eudenilson L
2004-01-01
In recent years there have been exciting developments in techniques for producing multilayered structures of different materials, often with thicknesses as small as only a few atomic layers. These artificial structures, known as superlattices, can either be grown with the layers stacked in an alternating fashion (the periodic case) or according to some other well-defined mathematical rule (the quasiperiodic case). This book describes research on the excitations (or wave-like behavior) of these materials, with emphasis on how the material properties are coupled to photons (the quanta of the l
A Scalable Microfabricated Ion Trap for Quantum Information Processing
Maunz, Peter; Haltli, Raymond; Hollowell, Andrew; Lobser, Daniel; Mizrahi, Jonathan; Rembetski, John; Resnick, Paul; Sterk, Jonathan D.; Stick, Daniel L.; Blain, Matthew G.
2016-05-01
Trapped Ion Quantum Information Processing (QIP) relies on complex microfabricated trap structures to enable scaling of the number of quantum bits. Building on previous demonstrations of surface-electrode ion traps, we have designed and characterized the Sandia high-optical-access (HOA-2) microfabricated ion trap. This trap features high optical access, high trap frequencies, low heating rates, and negligible charging of dielectric trap components. We have observed trap lifetimes of more than 100h, measured trap heating rates for ytterbium of less than 40quanta/s, and demonstrated shuttling of ions from a slotted to an above surface region and through a Y-junction. Furthermore, we summarize demonstrations of high-fidelity single and two-qubit gates realized in this trap. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA).
Energy Technology Data Exchange (ETDEWEB)
Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P. [Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science, Krakow (Poland); Curceanu, C.; Silarski, M. [INFN, Laboratori Nazionali di Frascati, CP 13, Frascati (Italy); Gorgol, M.; Jasinska, B.; Zgardzinska, B. [Maria Curie-Sklodowska University, Department of Nuclear Methods, Institute of Physics, Lublin (Poland); Hiesmayr, B.C. [University of Vienna, Faculty of Physics, Vienna (Austria); Kowalski, P.; Raczynski, L.; Wislicki, W. [Swierk Computing Centre, National Centre for Nuclear Research, Otwock-Swierk (Poland); Krzemien, W. [National Centre for Nuclear Research, High Energy Department, Otwock-Swierk (Poland)
2016-08-15
We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 {sup circle} and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)
Krioukov, Dmitri; Sinkovits, Robert S; Rideout, David; Meyer, David; Boguna, Marian
2012-01-01
Causal sets are an approach to quantum gravity in which the causal structure of spacetime plays a fundamental role. The causal set is a quantum network which underlies the fabric of spacetime. The nodes in this network are tiny quanta of spacetime, with two such quanta connected if they are causally related. Here we show that the structure of these networks in de Sitter spacetime, such as our accelerating universe, is remarkably similar to the structure of complex networks -- the brain or the Internet, for example. Specifically, we show that the node degree distribution of causal sets in de Sitter spacetime is described by a power law with exponent 2, similar to many complex networks. Quantifying the differences between the causal set structure in de Sitter spacetime and in the real universe, we find that since the universe today is relatively young, its power-law exponent is not 2 but 3/4, yet exponent 2 is currently emerging. Finally, we show that as a consequence of a simple geometric duality, the growth d...
A Possible SLq(2) Substructure of the Standard Model
Finkelstein, Robert J
2009-01-01
We examine a quantum group extension of the standard model with the symmetry $SU(3) \\times SU(2) \\times U(1)\\times $ global $SLq(2)$. The quantum fields of this extended model lie in the state space of the $SLq(2)$ algebra. The normal modes or field quanta carry the factors $D^j_{mm^\\prime} (q|abcd)$, which are irreducible representations of $SLq(2)$ (which is also the knot algebra). We describe these field quanta as quantum knots and set $(j,m,m^\\prime)= 1/2 (N,w, \\pm r+1)$ where the $(N,w,r)$ are restricted to be (the number of crossings, the writhe, the rotation) respectively, of a classical knot. There is an empirical one-to-one correspondence between the four quantum trefoils and the four families of elementary fermions, a correspondence that may be expressed as $(j,m,m^\\prime)=3(t,-t_3, -t_0)$, where the four quantum trefoils are labelled by $(j,m,m^\\prime)$ and where the four families are labelled in the standard model by the isotopic and hypercharge indices $(t,t_3,-t_0)$. We propose extending this co...
Emergence of a Low Spin Phase in Group Field Theory Condensates
Gielen, Steffen
2016-01-01
Recent years have seen great progress towards deriving quantum cosmology models from the effective dynamics of condensate states in group field theory (GFT), where 'cosmology is the hydrodynamics of quantum gravity'; the classical Friedmann dynamics for homogeneous, isotropic universes, as well as loop quantum cosmology (LQC) corrections to general relativity have been shown to emerge from fundamental quantum gravity. We take one further step towards strengthening the link with LQC and show, in a rather wide class of GFT models for gravity coupled to a free massless scalar field and for generic initial conditions, that GFT condensates dynamically reach a low spin phase of many quanta of geometry, in which all but an exponentially small number of quanta are characterised by a single spin $j_0$ (i.e. by a constant volume per quantum). In one particular simple and natural case, this spin is the lowest one, $j_0=1/2$. The type of quantum state usually assumed in the derivation of LQC is hence derived from the qua...
Origin of the Low Energy Structure in Above Threshold Ionization
Titi, Atef S
2015-01-01
We present an ab initio analytic theory to account for both the very low energy structure (VLES) [C. Y. Wu et al., Phys. Rev. Lett. 109, 043001 (2012); W. Quan et al., Phys. Rev. Lett. 103, 093001 (2009)], and the low energy structure (LES) [W. Quan et al. Phys. Rev. Lett. 103, 093001 (2009); C.I. Blaga et al., Nat. Phys. 5, 335 2009)] of above threshold ionization. The origin of both VLES and LES lies in a forward scattering mechanism by the Coulomb potential. We parameterize the S matrix in terms of ?, which is the displacement of the the classical motion of an electron in the laser field. When ? = 0, the S matrix is singular, which we attribute to be forward Coulomb scattering without absorption of light quanta. By devising a regularization scheme, the resulting S matrix is non-singular when ? = 0, and the origins of VLES and LES are revealed. We attribute VLES to multiple forward scattering of near-threshold electrons by the Coulomb potential, with no absorption of light quanta, signifying the role of the...
Bogoslovsky, George Yu
2007-01-01
The impact of local space anisotropy on the transverse Doppler effect is examined. Two types of laboratory experiments aimed at seeking and measuring the local space anisotropy are proposed. In terms of the conventional special relativity theory, which treats 3D space to be locally isotropic, the experiments are of the type of ``null-experiments''. In the first-type experiments, a feasible Doppler shift of frequency is measured by the M\\"ossbauer effect, with the M\\"ossbauer source and absorber being located at two identical and diametrically opposed distances from the center of a rapidly rotating rotor, while the $\\gamma$-quanta are recorded by two stationary and oppositely positioned proportional counters. Either of the counters records only those $\\gamma$-quanta that passed through the absorber at the moment of the passage of the latter near a counter. The second-type experiments are made using the latest radio physics techniques for generating monochromatic oscillations and for recording weak signals. The...
Polarization spectral synthesis for Type Ia supernova explosion models
Bulla, M.; Sim, S. A.; Kromer, M.
2015-06-01
We present a Monte Carlo radiative transfer technique for calculating synthetic spectropolarimetry for multidimensional supernova explosion models. The approach utilizes `virtual-packets' that are generated during the propagation of the Monte Carlo quanta and used to compute synthetic observables for specific observer orientations. Compared to extracting synthetic observables by direct binning of emergent Monte Carlo quanta, this virtual-packet approach leads to a substantial reduction in the Monte Carlo noise. This is not only vital for calculating synthetic spectropolarimetry (since the degree of polarization is typically very small) but also useful for calculations of light curves and spectra. We first validate our approach via application of an idealized test code to simple geometries. We then describe its implementation in the Monte Carlo radiative transfer code ARTIS and present test calculations for simple models for Type Ia supernovae. Specifically, we use the well-known one-dimensional W7 model to verify that our scheme can accurately recover zero polarization from a spherical model, and to demonstrate the reduction in Monte Carlo noise compared to a simple packet-binning approach. To investigate the impact of aspherical ejecta on the polarization spectra, we then use ARTIS to calculate synthetic observables for prolate and oblate ellipsoidal models with Type Ia supernova compositions.
Kamińska, D.; Gajos, A.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Korcyl, G.; Kowalski, P.; Krzemień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pawlik-Niedźwiecka, M.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.
2016-08-01
We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the { o-Ps }→ 3γ decays with angular and energy resolution equal to σ (θ ) ≈ {0.4°} and σ (E) ≈ 4.1 {keV}, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.
Viaggiu, Stefano
2016-01-01
In this paper we present a statistical description of the cosmological constant in terms of massless bosons (gravitons). To this purpose, we use our recent results implying a non vanishing temperature ${T_{\\Lambda}}$ for the cosmological constant. In particular, we found that a non vanishing $T_{\\Lambda}$ allows us to depict the cosmological constant $\\Lambda$ as composed of elementary oscillations of massless bosons of energy $\\hbar\\omega$ by means of the Bose-Einstein distribution. In this context, as happens for photons in a medium, the effective phase velocity $v_g$ of these massless excitations is not given by the speed of light $c$ but it is suppressed by a factor depending on the number of quanta present in the universe at the apparent horizon. We found interesting formulas relating the cosmological constant, the number of quanta $N$ and the mean value $\\overline{\\lambda}$ of the wavelength of the gravitons. In this context, we study the possibility to look to the gravitons system so obtained as being ...
The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose
Grebe, A; Lu, T; Mokhov, N; Pronskikh, V
2016-01-01
The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.
Beam profile investigation of the new collimator system for the J-PET detector
Kubicz, E; Wieczorek, A; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Głowacz, B; Jasińska, B; Kamińska, D; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Mohammed, M; Moskal, I; Niedźwiecki, S; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Strzelecki, A; Wiślicki, W; Zieliński, M; Zgardzińska, B; Moskal, P
2016-01-01
Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose detector which will be used for search for discrete symmetries violations in the decays of positronium atoms and for investigations with positronium atoms in life-sciences and medical diagnostics. In this article we present three methods for determination of the beam profile of collimated annihilation gamma quanta. Precise monitoring of this profile is essential for time and energy calibration of the J-PET detector and for the determination of the library of model signals used in the hit-time and hit-position reconstruction. We have we have shown that usage of two lead bricks with dimensions of 5x10x20 cm^3 enables to form a beam of annihilation quanta with Gaussian profile characterized by 1 mm FWHM. Determination of this characteristic is essential for designing and construction the collimator system for the 24-module J-PET prototype. Simulations of the beam profile for different collimator dimensions were performed. This allowed us to choo...
The MARS15-based FermiCORD Code System for Calculation of the Accelerator-Induced Residual Dose
Energy Technology Data Exchange (ETDEWEB)
Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.
2016-09-01
The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.
Selective control of HOD photodissociation using CW lasers
Indian Academy of Sciences (India)
Manabendra Sarma; S Adhikari; Manoj K Mishra
2007-09-01
Selective control of HOD photodissociation (H-O + D ← HOD → H + O-D) has been theoretically investigated using CW lasers with appropriate carrier frequency and |0, 0〉, |0, 1〉 and |0, 2〉 with zero quantum of excitation in the O-H bond and zero, one and two quanta of excitation in the O-D bond as the initial states. Results indicate that the O-H bond in HOD can be selectively dissociated with a maximum flux of 87% in the H + O-D channel from the ground vibrational state |0, 0〉. For the O-D bond dissociation, it requires two quanta of excitation (|0, 2〉) in the O-D mode to obtain 83% flux in the H-O + D channel. Use of a two colour laser set-up in conjunction with the field optimized initial state (FOIST) scheme to obtain an optimal linear combination of |0, 0〉 and |0, 1〉 vibrational states as the initial state provides an additional 7% improvement to flux in the H-O + D channel as compared to that from the pure |0, 1〉 state.
COMBINED EFFECTS OF TEMPERATURE, IRRADIANCE AND SALINITY ON GROWTH OF DIATOM SKELETONEMA COSTATUM
Institute of Scientific and Technical Information of China (English)
颜天; 周名江; 钱培元
2002-01-01
3-factor experiment was used to study the combined effects of temperature, irradiance and salinity on the growth of an HAB species diatom Skeletonema costatum (Grey.) Cleve. The results showed that temperature (12, 19, 25, 32℃ ), irradiance ((0.02, 0.08, 0.3, 1.6) × 1016 quanta/(s·cm2) ) and salinity (10, 18, 25, 30, 35) significantly influenced the growth of this species. There were interactive effects between any two of and among all three physical factors on the growth. In the experiment, the most optimal growth condition for S. costatum was temparature of 25℃, salinity of 18 - 35 and irradiance of 1.6 × 1016 quanta/(s·cm2). The results indicated S. costatum could divide at higher rate and were more likely to bloom under high temperature and high illumination from spring to fall. It was able to distribute widely in ocean and estuary due to its adaptation to a wide range of salinities.
Correction of emission spectra in microspectrofluorimetry using a reference lamp: computations.
Galassi, L
1992-01-01
Accurate correction of emission spectra in microspectrofluorimetry, using a reference lamp, may require that a factor for the emissivity of tungsten be introduced. This is only possible provided that the true temperature of the lamp filament is known. A method is given for obtaining the true temperature from the knowledge of the colour temperature. Also, the values of the spectral concentration of the radiance of the black body, either computed according to Planck's equation or taken from available published tables, have to be converted from energetic units to units of quanta since the photomultiplier is linear not to absorbed power but to units of quanta. When the fluorescence spectra to be corrected extend into the far red it is preferable to use a lower temperature (by lowering the supply voltage) than that for which the lamp is certified. It is possible to determine the new temperature (and then the corresponding spectral distribution) by taking a few pairs of measurements at different wavelengths both at the lower voltage and at the voltage for which the lamp is certified and then introducing these values in a non-linear regression soluble on a PC with a curve fitting program. The microscope tungsten halogen lamp can conveniently be used as a reference, thanks to its small size and its steady spectral characteristics. When high accuracy is required, however, the halogen lamp should be calibrated against a certified ribbon filament lamp.
Radioactive contamination of SrI2(Eu) crystal scintillator
Belli, P; Cerulli, R; Danevich, F A; Galenin, E; Gektin, A; Incicchitti, A; Isaienko, V; Kobychev, V V; Laubenstein, M; Nagorny, S S; Podviyanuk, R B; Tkachenko, S; Tretyak, V I
2011-01-01
A strontium iodide crystal doped by europium (SrI2(Eu)) was produced by using the Stockbarger growth technique. The crystal was subjected to characterisation that included relative photoelectron output and energy resolution for gamma quanta. The intrinsic radioactivity of SrI2(Eu) crystal scintillator was tested both in scintillation mode and by using ultra-low background HPGe gamma spectrometry deep underground. The response of the SrI2(Eu) detector to alpha particles (alpha/beta ratio and pulse shape) was estimated by analysing the 226Ra trace contamination internal to the crystal. We have found alpha/beta=0.55 and no difference in scintillation decay for alpha particles and gamma quanta. The application of the obtained results in the search for the double electron capture and electron capture with positron emission in 84Sr has been investigated at a level of sensitivity T_1/2 \\sim 10^15-10^16 yr. The results of these studies demonstrate the potentiality of this material for a variety of scintillation appli...
Fitzek, H; Schroettner, H; Wagner, J; Hofer, F; Rattenberger, J
2016-04-01
In environmental scanning electron microscopy applications in the kPa regime are of increasing interest for the investigation of wet and biological samples, because neither sample preparation nor extensive cooling are necessary. Unfortunately, the applications are limited by poor image quality. In this work the image quality at high pressures of a FEI Quanta 600 (field emission gun) and a FEI Quanta 200 (thermionic gun) is greatly improved by optimizing the pressure limiting system and the secondary electron (SE) detection system. The scattering of the primary electron beam strongly increases with pressure and thus the image quality vanishes. The key to high-image quality at high pressures is to reduce scattering as far as possible while maintaining ideal operation conditions for the SE-detector. The amount of scattering is reduced by reducing both the additional stagnation gas thickness (aSGT) and the environmental distance (ED). A new aperture holder is presented that significantly reduces the aSGT while maintaining the same field-of-view (FOV) as the original design. With this aperture holder it is also possible to make the aSGT even smaller at the expense of a smaller FOV. A new blade-shaped SE-detector is presented yielding better image quality than usual flat SE-detectors. The electrode of the new SE detector is positioned on the sample table, which allows the SE-detector to operate at ideal conditions regardless of pressure and ED.
Flux tubes and the type-I/type-II transition in a superconductor coupled to a superfluid
Alford, Mark G
2007-01-01
We analyze magnetic flux tubes at zero temperature in a superconductor that is coupled to a superfluid via both density and gradient (``entrainment'') interactions. The example we have in mind is high-density nuclear matter, which is a proton superconductor and a neutron superfluid, but our treatment is general and simple, modeling the interactions as a Ginzburg-Landau effective theory with four-fermion couplings, including only s-wave pairing. We numerically solve the field equations for flux tubes with an arbitrary number of flux quanta, and compare their energies. This allows us to map the type-I/type-II transition in the superconductor, which occurs at the conventional kappa = 1/sqrt(2) if the condensates are uncoupled. We find that a density coupling between the condensates raises the critical kappa and blurs the transition into a series of steps as the number of quanta in the favored flux tube varies between 1 and infinity. We find that a gradient coupling between the condensates lowers the critical kap...
Energy Technology Data Exchange (ETDEWEB)
Moon, C.K. [Korea Energy Economics Institute, Euiwang (Korea, Republic of)
1997-08-01
If the necessity of careful study on energy function is mentioned, it should be stressed that energy investment not only needs a long gestation period but also, acts as the bottleneck in the production capacity of an economy when investment is not enough. Thereby, the adverse effect of an energy supply shortage is very big. Especially, the replacement/supplemental relationship between energy and capital which corresponds to the movement on the iso-quanta curve is believed to have a direct relation with the answer as to whether long-term economic development would be possible under an energy crisis and its influence on technology selection. Furthermore, the advantages of technological advances which correspond to the movement on the iso-quanta curve has a direct relation with the question whether long-term economic development would be possible under an energy crisis depending on whether its direction is toward energy-saving or energy-consuming. This study tackles the main issues and outlines of the quantitative approach method based on the accounting approach method for modeling energy demand, quantitative economics approach method, and production model. In order to model energy demand of the Korean manufacturing industry, related data was established and a positive analytical model is completed and presented based on these. 122 refs., 10 tabs.
Directory of Open Access Journals (Sweden)
Enrique Valenzuela-Espinoza
2011-04-01
Full Text Available Population growth, macronutrient (, uptake and carotenoids/chlorophyll a ratio we determined in Amphidinium carteri Hulburt, cultured under conditions of continuous light (50, 150, 300 and 750 μmol quanta m-2 s-1 and three nutrient concentrations NaNO3/NaH2PO4 at 441.5/18.1 μM (low 883/36.3 μM (medium and 1766/72.6 μM (high. Both nutrient and irradiance had a significant effect (p 0.05. In cultures under low nutrient condition, NO- and PO4- were almost depleted by the fifth day and in cultures with medium nutrient this condition occurred in the sixth day; whereas, at high nutrient condition the nutrients were not depleted. We concluded that A. carteri had higher growth rates and nutrient consumption at 300 μmol quanta m-2 s-1 during the first five days and in general the effect of nutrients on the pigment ratios was not significant (p > 0.05. However, the average peridinin/Chla ratio decreased up to 72% from the lowest and the highest irradiance. The opposite was observed for the average of diadinoxanthin/Chla ratio that increased almost two-fold, and the averages dinoxanthin and diatoxanthin to Chla ratios that increased from low to high irradiances. The average diatoxanthin/Chla ratio at 750 μmol quanta m-2 s-1 increased up to 2.7-fold from the exponential to the stationary phase only in the low and medium nutrient concentration. Likewise, the average peridinin, dinoxanthin and diatoxanthin to Chla ratios were not significantly different at 50 and 150 μmol quanta m-2 s-1. These results indicate important changes in average carotenoids/Chla ratios in A. carteri cultured under different irradiances.Se evaluaron el crecimiento poblacional, consumo de macronutrientes (, y proporción de carotenoides/clorofila a en Amphidinium carteri Hulburt, cultivado durante 7 días, bajo condiciones de luz continua: 50, 150, 300 y 750 μmol quanta m-2 s-1 y tres concentraciones de nutrientes NaNO3/NaH2PO4 (441.5/18.1 μM (bajo; 883/36.3 μM (medio y 1766
Superluminal radiation by uniformly moving charges
Tomaschitz, Roman
2003-03-01
The emission of superluminal quanta (tachyons) by freely propagating particles is scrutinized. Estimates are derived for spontaneous superluminal radiation from electrons moving close to the speed of the Galaxy in the microwave background. This is the threshold velocity for tachyon radiation to occur, a lower bound. Quantitative estimates are also given for the opposite limit, tachyon radiation emitted by ultra-relativistic electrons in linear colliders and supernova shock waves. The superluminal energy flux is studied and the spectral energy density of the radiation is derived, classically as well as in second quantization. There is a transversal bosonic and a longitudinal fermionic component of the radiation. We calculate the power radiated, its angular dependence, the mean energy of the radiated quanta, absorption and emission rates, as well as tachyonic number counts. We explain how the symmetry of the Einstein /A-coefficients connects to time-symmetric wave propagation and to the Wheeler-Feynman absorber theory. A relation between the tachyon mass and the velocity of the Local Group of galaxies is suggested.
Pasquier, Jennifer; Rioult, Damien; Abu-Kaoud, Nadine; Hoarau-Véchot, Jessica; Marin, Matthieu; Le Foll, Frank
2015-06-24
The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD) where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp). The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading), we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.
Co-regulation of dark and light reactions in three biochemical subtypes of C(4) species.
Kiirats, Olavi; Kramer, David M; Edwards, Gerald E
2010-08-01
Regulation of light harvesting in response to changes in light intensity, CO(2) and O(2) concentration was studied in C(4) species representing three different metabolic subtypes: Sorghum bicolor (NADP-malic enzyme), Amaranthus edulis (NAD-malic enzyme), and Panicum texanum (PEP-carboxykinase). Several photosynthetic parameters were measured on the intact leaf level including CO(2) assimilation rates, O(2) evolution, photosystem II activities, thylakoid proton circuit and dissipation of excitation energy. Gross rates of O(2) evolution (J(O)₂'), measured by analysis of chlorophyll fluorescence), net rates of O(2) evolution and CO(2) assimilation responded in parallel to changes in light and CO(2) levels. The C(4) subtypes had similar energy requirements for photosynthesis since there were no significant differences in maximal quantum efficiencies for gross rates of O(2) evolution (average value = 0.072 O(2)/quanta absorbed, approximately 14 quanta per O(2) evolved). At saturating actinic light intensities, when photosynthesis was suppressed by decreasing CO(2), ATP synthase proton conductivity (g (H) (+)) responded strongly to changes in electron flow, decreasing linearly with J(O)₂', which was previously observed in C(3) plants. It is proposed that g (H) (+) is controlled at the substrate level by inorganic phosphate availability. The results suggest development of nonphotochemical quenching in C(4) plants is controlled by a decrease in g (H) (+), which causes an increase in proton motive force by restricting proton efflux from the lumen, rather than by cyclic or pseudocyclic electron flow.
Quantum entanglement of angular momentum states with quantum numbers up to 10,010.
Fickler, Robert; Campbell, Geoff; Buchler, Ben; Lam, Ping Koy; Zeilinger, Anton
2016-11-29
Photons with a twisted phase front carry a quantized amount of orbital angular momentum (OAM) and have become important in various fields of optics, such as quantum and classical information science or optical tweezers. Because no upper limit on the OAM content per photon is known, they are also interesting systems to experimentally challenge quantum mechanical prediction for high quantum numbers. Here, we take advantage of a recently developed technique to imprint unprecedented high values of OAM, namely spiral phase mirrors, to generate photons with more than 10,000 quanta of OAM. Moreover, we demonstrate quantum entanglement between these large OAM quanta of one photon and the polarization of its partner photon. To our knowledge, this corresponds to entanglement with the largest quantum number that has been demonstrated in an experiment. The results may also open novel ways to couple single photons to massive objects, enhance angular resolution, and highlight OAM as a promising way to increase the information capacity of a single photon.
Viaggiu, Stefano
2016-07-01
In this paper we present a statistical description of the cosmological constant in terms of massless bosons (gravitons). To this purpose, we use our recent results implying a non vanishing temperature {T_{Λ }} for the cosmological constant. In particular, we found that a non vanishing T_{Λ } allows us to depict the cosmological constant Λ as composed of elementary oscillations of massless bosons of energy hbar ω by means of the Bose-Einstein distribution. In this context, as happens for photons in a medium, the effective phase velocity v_g of these massless excitations is not given by the speed of light c but it is suppressed by a factor depending on the number of quanta present in the universe at the apparent horizon. We found interesting formulas relating the cosmological constant, the number of quanta N and the mean value overline{λ } of the wavelength of the gravitons. In this context, we study the possibility to look to the gravitons system so obtained as being very near to be a Bose-Einstein condensate. Finally, an attempt is done to write down the Friedmann flat equations in terms of N and overline{λ }.
Water Dynamics at the Root of Metamorphosis in Living Organisms
Directory of Open Access Journals (Sweden)
Paola Rosa Spinetti
2010-09-01
Full Text Available Liquid water has been recognized long ago to be the matrix of many processes, including life and also rock dynamics. Interactions among biomolecules occur very differently in a non-aqueous system and are unable to produce life. This ability to make living processes possible implies a very peculiar structure of liquid water. According to modern Quantum Field Theory (QFT, a complementary principle (in the sense of Niels Bohr holds between the number N of field quanta (including the matter field whose quanta are just the atoms/molecules and the phase Ф. This means that when we focus on the atomic structure of matter it loses its coherence properties and, vice versa, when we examine the phase dynamics of the system its atomic structure becomes undefined. Superfluid liquid Helium is the first example of this peculiar quantum dynamics. In the present paper we show how consideration of the phase dynamics of liquid water makes the understanding of its peculiar role in the onset of self-organization in living organisms and in ecosystems possible.
Directory of Open Access Journals (Sweden)
Jennifer Pasquier
2015-06-01
Full Text Available The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp. The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading, we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.
Kamińska, D; Gajos, A; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Curceanu, C; Dulski, K; Głowacz, B; Gupta-Sharma, N; Gorgol, M; Hiesmayr, B C; Jasińska, B; Korcyl, G; Kowalski, P; Krzemień, W; Krawczyk, N; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Silarski, M; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P
We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the [Formula: see text] decays with angular and energy resolution equal to [Formula: see text] and [Formula: see text], respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.
Investigation of X-ray lasers on the SOKOL-P facility at RFNC-VNIITF
Gavrilov, D. S.; Andriyash, A. V.; Vikhlyaev, D. A.; Gorokhov, S. A.; Dmitrov, D. A.; Zapysov, A. L.; Kakshin, A. G.; Kapustin, I. A.; Loboda, E. A.; Lykov, V. A.; Politov, V. Yu.; Potapov, A. V.; Pronin, V. A.; Rykovanov, G. N.; Sukhanov, V. N.; Tischenko, A. S.; Ugodenko, A. A.; Chefonov, O. V.
2007-11-01
The experiments [1] have demonstrated generation of the laser X-radiation (LXR) λ=326A on 3p-3s transitions of Ne-like Ti ions at sequential irradiation of the targets by two laser pulses, focused into a narrow line. The small signal gain equaled 30cm-1. The intensity was 0.5.10^12 W/cm^2 in the prepulse of 0.4ns and 10^14 W/cm^2 in the master pulse of 4ps (delay 1.5 ns). The dependence of LXR yield on the laser energy is demonstrated to have an exponential form. The traveling pumping wave mode was realized using the reflective echelon and the LXR yield is as great as 5-fold. The latest experiments have demonstrated the LXR generation on 4d-4p of Ni-like molybdenum λ=189A. The development of LXR generation model, and numerical codes which allow for the quanta delay effects, quanta refraction in plasma with heavy density gradient, and also the saturation effect have made it possible to describe the experimental dependence of the output LXR yield on the active medium length. Good quantitative agreement is also evident when estimating the output LXR yield on Ne-like Ti ions. [1]Andriyash Quantum Electronics 36 511
Effect of finite phosphor thickness on detective quantum efficiency
Energy Technology Data Exchange (ETDEWEB)
Nishikawa, R.M.; Yaffe, M.J.; Holmes, R.B. (Univ. of Toronto (Canada))
1989-09-01
In this paper we describe theoretically the relationship between the finite thickness of a phosphor screen and its spatial-frequency-dependent detective quantum efficiency DQE(f-). The finite thickness of the screen causes a variation in both the total number of light quanta emitted from the screen in a burst from a given x-ray interaction and in the spatial distribution of the quanta within the light burst (i.e., shape or point spread function (PSF) of the light burst). The variation in magnitude of the burst gives rise to a spatial-frequency-independent reduction in DQE, characterized by the scintillation efficiency As. The variation in PSF causes a roll off in DQE with increasing spatial frequency which we have characterized by the function Rc(f). Both As and Rc(f) can be determined from the moments of the distribution of the spatial Fourier spectrum of light bursts emitted from the phosphor and thus they are related: As is a scaling factor for Rc(f). Our theory predicts that it is necessary for all light bursts which appear at the output to have the same magnitude to maximize As and the same shape to maximize Rc(f). These requirements can lead to the result that the fluorescent screen with the highest modulation transfer function will not necessarily have the highest DQE(f) even at high spatial frequencies.
The detective quantum efficiency of photon-counting x-ray detectors using cascaded-systems analyses
Energy Technology Data Exchange (ETDEWEB)
Tanguay, Jesse [Robarts Research Institute and Department of Medical Biophysics, Western University, London, Ontario N6A 5C1 (Canada); Yun, Seungman [Biomedical Engineering Program, Western University, London, Ontario N6A 5C1 (Canada); School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, Ho Kyung [School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Cunningham, Ian A. [Robarts Research Institute, Department of Medical Biophysics, and Biomedical Engineering Program, Western University, London, Ontario N6A 5C1 (Canada)
2013-04-15
Purpose: Single-photon counting (SPC) x-ray imaging has the potential to improve image quality and enable new advanced energy-dependent methods. The purpose of this study is to extend cascaded-systems analyses (CSA) to the description of image quality and the detective quantum efficiency (DQE) of SPC systems. Methods: Point-process theory is used to develop a method of propagating the mean signal and Wiener noise-power spectrum through a thresholding stage (required to identify x-ray interaction events). The new transfer relationships are used to describe the zero-frequency DQE of a hypothetical SPC detector including the effects of stochastic conversion of incident photons to secondary quanta, secondary quantum sinks, additive noise, and threshold level. Theoretical results are compared with Monte Carlo calculations assuming the same detector model. Results: Under certain conditions, the CSA approach can be applied to SPC systems with the additional requirement of propagating the probability density function describing the total number of image-forming quanta through each stage of a cascaded model. Theoretical results including DQE show excellent agreement with Monte Carlo calculations under all conditions considered. Conclusions: Application of the CSA method shows that false counts due to additive electronic noise results in both a nonlinear image signal and increased image noise. There is a window of allowable threshold values to achieve a high DQE that depends on conversion gain, secondary quantum sinks, and additive noise.
The detective quantum efficiency of photon-counting x-ray detectors using cascaded-systems analyses.
Tanguay, Jesse; Yun, Seungman; Kim, Ho Kyung; Cunningham, Ian A
2013-04-01
Single-photon counting (SPC) x-ray imaging has the potential to improve image quality and enable new advanced energy-dependent methods. The purpose of this study is to extend cascaded-systems analyses (CSA) to the description of image quality and the detective quantum efficiency (DQE) of SPC systems. Point-process theory is used to develop a method of propagating the mean signal and Wiener noise-power spectrum through a thresholding stage (required to identify x-ray interaction events). The new transfer relationships are used to describe the zero-frequency DQE of a hypothetical SPC detector including the effects of stochastic conversion of incident photons to secondary quanta, secondary quantum sinks, additive noise, and threshold level. Theoretical results are compared with Monte Carlo calculations assuming the same detector model. Under certain conditions, the CSA approach can be applied to SPC systems with the additional requirement of propagating the probability density function describing the total number of image-forming quanta through each stage of a cascaded model. Theoretical results including DQE show excellent agreement with Monte Carlo calculations under all conditions considered. Application of the CSA method shows that false counts due to additive electronic noise results in both a nonlinear image signal and increased image noise. There is a window of allowable threshold values to achieve a high DQE that depends on conversion gain, secondary quantum sinks, and additive noise.
Blue tensor spectrum from particle production during inflation
Energy Technology Data Exchange (ETDEWEB)
Mukohyama, Shinji; Namba, Ryo [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Peloso, Marco [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Shiu, Gary, E-mail: shinji.mukohyama@ipmu.jp, E-mail: ryo.namba@ipmu.jp, E-mail: peloso@physics.umn.edu, E-mail: shiu@physics.wisc.edu [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)
2014-08-01
We discuss a mechanism of particle production during inflation that can result in a blue gravitational wave (GW) spectrum, compatible with the BICEP2 result and with the r < 0.11 limit on the tensor-to-scalar ratio at the Planck pivot scale. The mechanism is based on the production of vector quanta from a rolling pseudo-scalar field. Both the vector and the pseudo-scalar are only gravitationally coupled to the inflaton, to keep the production of inflaton quanta at an unobservable level (the overproduction of non-gaussian scalar perturbations is a generic difficulty for mechanisms that aim to generate a visible GW signal from particle production during inflation). This mechanism can produce a detectable amount of GWs for any inflationary energy scale. The produced GWs are chiral and non-gaussian; both these aspects can be tested with large-scale polarization data (starting from Planck). We study how to reconstruct the pseudo-scalar potential from the GW spectrum.
Blue Tensor Spectrum from Particle Production during Inflation
Mukohyama, Shinji; Peloso, Marco; Shiu, Gary
2014-01-01
We discuss a mechanism of particle production during inflation that can result in a blue gravitational wave (GW) spectrum, compatible with the BICEP2 result and with the r < 0.11 limit on the tensor-to-scalar ratio at the Planck pivot scale. The mechanism is based on the production of vector quanta from a rolling pseudo-scalar field. Both the vector and the pseudo-scalar are only gravitationally coupled to the inflaton, to keep the production of inflaton quanta at an unobservable level (the overproduction of non-gaussian scalar perturbations is a generic difficulty for mechanisms that aim to generate a visible GW signal from particle production during inflation). This mechanism can produce a detectable amount of GWs for any inflationary energy scale. The produced GWs are chiral and non-gaussian; both these aspects can be tested with large-scale polarization data (starting from Planck). We study how to reconstruct the pseudo-scalar potential from the GW spectrum.
Energy Technology Data Exchange (ETDEWEB)
Chomaz, Philippe [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)
1998-12-31
In the world of infinitely small, the world of atoms, nuclei and particles, the quantum mechanics enforces its laws. The discovery of Quanta, this unbelievable castration of the Possible in grains of matter and radiation, in discrete energy levels compels us of thinking the Single to comprehend the Universal. Quantum Numbers, magic Numbers and Numbers sign the wave. The matter is vibration. To describe the music of the world one needs keys, measures, notes, rules and partition: one needs quantum mechanics. The particles reduce themselves not in material points as the scholars of the past centuries thought, but they must be conceived throughout the space, in the accomplishment of shapes of volumes. When Einstein asked himself whether God plays dice, there was no doubt among its contemporaries that if He exists He is a geometer. In a Nature reduced to Geometry, the symmetries assume their role in servicing the Harmony. The symmetries allow ordering the energy levels to make them understandable. They impose there geometrical rules to the matter waves, giving them properties which sometimes astonish us. Hidden symmetries, internal symmetries and newly conceived symmetries have to be adopted subsequently to the observation of some order in this world of Quanta. In turn, the symmetries provide new observables which open new spaces of observation 17 refs., 16 figs.
Mathur, Samir D
2012-01-01
The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome `remnants'. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in the bound state. The interior of the black hole gets completely altered to a `fuzzball' structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates ...
Quantum graviton creation in a model universe
Berger, B. K.
1974-01-01
Consideration of the mechanism of production of gravitons in the empty, anisotropic, spatially inhomogeneous Gowdy three-torus cosmology. The Gowdy cosmology is an exact solution of the vacuum Einstein equations and is obtained as a generalization of the homogeneous empty Bianchi Type I (Kasner) cosmology by permitting the metric components to depend on one of the space variables in addition to time. The Hamiltonian methods of Arnowitt, Deser, and Misner are employed to identify the dynamical variables which are to be quantized. The WKB regime solution is identical to that found by Doroshkevich, Zel'dovich, and Novikov (DZN) for a universe containing collisionless anisotropic radiation. Using a procedure similar to that of Parker (1971) or Zel'dovich and Starobinskii (1971) for defining quantum number, it is found that the DZN large-time radiation consists of quanta (gravitons) created from an initial vacuum. The quantum behavior is much like the semiclassical enhancement of quantum number with the added feature of creation of quanta from vacuum fluctuations.
Goldman, Emily A; Smith, Erik M; Richardson, Tammi L
2013-03-15
The utility of a multiple-fixed-wavelength spectral fluorometer, the Algae Online Analyser (AOA), as a means of quantifying chromophoric dissolved organic matter (CDOM) and phytoplankton photosynthetic activity was tested using algal cultures and natural communities from North Inlet estuary, South Carolina. Comparisons of AOA measurements of CDOM to those by spectrophotometry showed a significant linear relationship, but increasing amounts of background CDOM resulted in progressively higher over-estimates of chromophyte contributions to a simulated mixed algal community. Estimates of photosynthetic activity by the AOA at low irradiance (≈ 80 μmol quanta m(-2) s(-1)) agreed well with analogous values from the literature for the chlorophyte, Dunaliella tertiolecta, but were substantially lower than previous measurements of the maximum quantum efficiency of photosystem II (F(v)/F(m)) in Thalassiosira weissflogii (a diatom) and Rhodomonas salina (a cryptophyte). When cells were exposed to high irradiance (1500 μmol quanta m(-2) s(-1)), declines in photosynthetic activity with time measured by the AOA mirrored estimates of cellular fluorescence capacity using the herbicide 3'-(3, 4-dichlorophenyl)-1',1'-dimethyl urea (DCMU). The AOA shows promise as a tool for the continuous monitoring of phytoplankton community composition, CDOM, and the group-specific photosynthetic activity of aquatic ecosystems.
Hawking radiation a particle physics perspective
Visser, M
1993-01-01
It has recently become fashionable to regard black holes as elementary particles. By taking this suggestion seriously it is possible to cobble together an elementary particle physics based estimate for the decay rate $(\\hbox{black hole})_i \\to (\\hbox{black hole})_f + (\\hbox{massless quantum})$. This estimate of the spontaneous emission rate contains two free parameters which may be fixed by demanding that the high energy end of the spectrum of emitted quanta match a blackbody spectrum at the Hawking temperature. The calculation, though technically trivial, has important conceptual implications: (1) The existence of Hawking radiation from black holes is ultimately dependent only on the fact that massless quanta (and all other forms of matter) couple to gravity. (2) The thermal nature of the Hawking spectrum depends only on the fact that the number of internal states of a large mass black hole is enormous. (3) Remarkably, the resulting formula for the decay rate gives meaningful answers even when extrapolated t...
Andreev, G N; Schrader, B; Boese, R; Rademacher, P; von Cranach, L
2001-12-01
Using an improved sampling arrangement we observed the FT Raman spectra of the different phases of a 'jumping crystal', an inositol derivative. The phase transition produced--as consequences of large changes of the unit cell constants--changes in frequency and intensity mainly of CH deformation vibrations. Photochemical reactions, usually produced with light quanta in the visible range, are not activated with the quanta from the Nd:YAG laser at 1064 nm. The Raman spectra of the 'dark' form of a dinitrobenzyl pyridine and afterwards the 'light' form, the product of its illumination in the visible range, were recorded. We could not observe changes of most bands, especially not of the NO2-vibrations; however, a new strong band appeared at 1253 cm(-1), which may be due to the expected NH-photo-isomer. Genuine gemstones and fakes can be unambiguously identified by FT Raman spectroscopy. This is especially useful for the stones whose physical properties are quite similar to those of diamonds--moissanite and zirconia. The quality of diamonds can be estimated from relative band intensities; however, this is not in complete agreement with the internationally accepted visual qualification. Synthetic diamonds produced by CVD (chemical vapor deposition) show remarkable differences from natural ones in their FT-Raman spectra.
Kamińska, D; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Curceanu, C; Dulski, K; Głowacz, B; Gupta-Sharma, N; Gorgol, M; Hiesmayr, B C; Jasińska, B; Korcyl, G; Kowalski, P; Krzemień, W; Krawczyk, N; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Silarski, M; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P
2016-01-01
We present a study of the application of the Jagiellonian Positron Emission Tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps$\\to3\\gamma$ decays with angular and energy resolution equal to $\\sigma(\\theta) \\approx 0.4^{\\circ}$ and $\\sigma(E) \\approx 4.1$ keV, respect...
Moskal, P; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Giergiel, K; Gorgol, M; Jasińska, B; Kamińska, D; Kapłon, Ł; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Sharma, N G; Słomski, A; Silarski, M; Strzelecki, A; Wieczorek, A; Wiślicki, W; Witkowski, P; Zieliński, M; Zoń, N
2016-01-01
Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the 2 x...
Hod, Shahar
2015-01-01
The holographic principle has taught us that, as far as their entropy content is concerned, black holes in $(3+1)$-dimensional curved spacetimes behave as ordinary thermodynamic systems in flat $(2+1)$-dimensional spacetimes. In this essay we point out that the opposite behavior can also be observed in black-hole physics. To show this we study the quantum Hawking evaporation of near-extremal Reissner-Nordstr\\"om black holes. We first point out that the black-hole radiation spectrum departs from the familiar radiation spectrum of genuine $(3+1)$-dimensional perfect black-body emitters. In particular, the would be black-body thermal spectrum is distorted by the curvature potential which surrounds the black hole and effectively blocks the emission of low-energy quanta. Taking into account the energy-dependent gray-body factors which quantify the imprint of passage of the emitted radiation quanta through the black-hole curvature potential, we reveal that the $(3+1)$-dimensional black holes effectively behave as p...
Directory of Open Access Journals (Sweden)
Krause, Décio
2011-02-01
Full Text Available Nobel laureate Hans Dehmelt trapped a positron for three months, which was named “Priscilla”. Dehmelt said that we could not doubt the identity of Priscilla. This poses us a philosophical problem, for we have learnt from quantum physics (in most of its interpretations that quantum objects shouldn’t have individuality. In this paper, we address on the questions of naming quanta and the issue of individuation. We conclude by saying that, although Dehmelt has named something, this something is not an individual.
El Premio Nobel Hans Dehmelt aprisionó un positron, que fue llamado “Priscilla”. Dehmelt dijo que no podemos dudar de la identidad de Priscilla. Eso nos coloca un problema filosófico, puesto que aprendimos con la mecánica cuántica (en sus principales interpretaciones que los objetos cuánticos no deberían tener individualidad. En este artículo, discutimos las cuestiones de nombrar los quanta y las cuestiones de la individuación. Conclúyenos que, a pesar de que Dehmelt nombró algo, ese algo no es un individuo.
Energy Technology Data Exchange (ETDEWEB)
Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others
1995-12-31
A possibility to construct high-intensity tunable monochromatic{gamma}-source at high energy storage rings is discussed. It is proposed to produce {gamma}-quanta by means of Compton backscattering of laser photons on electrons circulating in the storage. The laser light wavelength is chosen in such a way that after the scattering, the electron does not leave the separatrix. So as the probability of the scattering is rather small, energy oscillations are damped prior the next scattering. As a result, the proposed source can operate in {open_quotes}parasitic{close_quote} mode not interfering with the main mode of the storage ring operation. Analysis of parameters of existent storage rings (PETRA, ESRF, Spring-8, etc) shows that the laser light wavelength should be in infrared, {lambda}{approximately} 10 - 400 {mu}m, wavelength band. Installation at storage rings of tunable free-electron lasers with the peak and average output power {approximately} 10 MW and {approximately} 1 kW, respectively, will result in the intensity of the {gamma}-source up to {approximately} 10{sup 14}s{sup -1} with tunable {gamma}-quanta energy from several MeV up to several hundreds MeV. Such a {gamma}-source will reveal unique possibilities for precision investigations in nuclear physics.
Results of experimental investigations of cobalt beta decay rate variation
Baurov, Yu A; Nikitin, V A; Dunin, V B; Tihomirov, V V; Sergeev, S V; Demchuk, N A
2013-01-01
Results of long-term investigations of variation of cobalt beta decay rate from 28.12.2010 till 08.02.2012 are presented. The scintillation spectrometer with two LaBr3 detectors is used to register of gamma-quanta with energy 1.173 and 1.332 MeV accompanying cobalt beta decay. Counting rate of each detector and their gamma-quanta coincidence are collected in successive time intervals 10 s. The statistical Kolmogorov-Smirnov method for data analysis is used. Temperature influence on experimental results is also analyzed. Deviations of beta decay counting rate from constant distribution during the days were detected in those decades: from 11.03 to 21.03 with significance level a = 0.1; from 22.04 to 02.05 with a=0.0125; from 24.06 to 04.07 with a=0.05; from 04.08 to 14.08 with a=0.05.
Solar cosmic ray bursts and solar neutrino fluxes
Basilevakaya, G. A.; Nikolsky, S. I.; Stozhkov, Y. I.; Charakhchyan, T. N.
1985-01-01
The neutrino flux detected in the C1-Ar experiment seems to respond to the powerful solar cosmic ray bursts. The ground-based detectors, the balloons and the satellites detect about 50% of the bursts of soalr cosmic ray generated on the Sun's visible side. As a rule, such bursts originate from the Western side of the visible solar disk. Since the solar cosmic ray bursts are in opposite phase withthe 11-year galactic cosmic ray cycle which also seems to be reflected by neutrino experiment. The neutrino generation in the bursts will flatten the possible 11-year behavior of the AR-37 production rate, Q, in the Cl-Ar experiment. The detection of solar-flare-generated gamma-quanta with energies above tens of Mev is indicative of the generation of high-energy particles which in turn may produce neutrinos. Thus, the increased Q during the runs, when the flare-generated high energy gamma-quanta have been registered, may be regarded as additional evidence for neutrino geneation in the solar flare processes.
Black hole evaporation without an event horizon
Bardeen, James M
2014-01-01
A reformulation of the calculation of the semi-classical energy-momentum tensor on a Schwarzschild background, the Bousso covariant entropy bound, and the ER=EPR conjecture of Maldacena and Susskind taken together suggest a scenario for the evaporation of a large spherically symmetric black hole formed in gravitational collapse in which 1) the classical r = 0 singularity is replaced by an initially small non-singular core inside an inner apparent horizon, 2) the radius of the core grows with time due to the increasing entanglement between Hawking radiation quanta outside the black hole and the Hawking partner quanta in the core contributing to the quantum back-reaction, and 3) by the Page time the trapped surfaces disappear and all quantum information stored in the interior is free to escape. The scenario preserves unitarity without any need for a "firewall" in the vicinity of the outer apparent horizon. Qbits in the Hawking radiation are never mutually entangled, and their number never exceeds the Bekenstein...
Stepšys, A.; Mickevicius, S.; Germanas, D.; Kalinauskas, R. K.
2014-11-01
effective way, which allows us to calculate matrix of the brackets up to a few hundred times more rapidly and more accurate than in a previous version. Solution method: Using external parallelization libraries and mutable precision we created a pack of numerical codes based on the methods of compact expressions of the three and four-particle harmonics oscillator brackets 3HOB, 4HOB, presented in [3]. Restrictions: For double precision version calculations can be done up to harmonic oscillator (HO) energy quanta e=28. For quadruple precision mantissa is equal to approximately 34 decimal digits, therefore calculations can be done up to HO energy quanta to e=52. Running time: The running time depends on the harmonic oscillator energy quanta, cluster size and the precision of intermediate calculations. More information on Table 1 for 3HOB and Table 2 for 4HOB. Reasons for a new version: The new program version expands the limits of harmonic oscillator energy quanta and gives shorter calculation time. Extend the limits of calculation of HOB First version was able to produce harmonic oscillator transformation brackets for three and four particles if E≤HO energy quanta. With this version of our program, if quadruple or arbitrary precision functions are being used, it is possible to calculate three and four particle harmonic oscillator transformation brackets for greater values of energy and momenta, while sustaining tolerable margin of error. Calculation time As the code of previous version of program was redone using parallelism paradigma, it is now possible to reduce the calculation time of transformation matrices significantly, depending on the size of computing cluster, as the dimensions of matrices are growing very rapidly according to the energy and momenta values. subroutinematrix_4HOB_dimensionCalculates the dimension of 4HOB matrix. subroutinematrix_3HOB_dimensionCalculates the dimension of 3HOB matrix, subroutinematrix_3HOBCalculates the global state array which is
Local Monte Carlo Implementation of the Non-Abelian Landau-Pomeranchuk-Migdal Effect
Zapp, Korinna; Wiedemann, Urs Achim
2009-01-01
The non-abelian Landau-Pomeranschuk-Migdal (LPM) effect arises from the quantum interference between spatially separated, inelastic radiation processes in matter. A consistent probabilistic implementation of this LPM effect is a prerequisite for extending the use of Monte Carlo (MC) event generators to the simulation of jet-like multi-particle final states in nuclear collisions. Here, we propose a local MC algorithm, which is based solely on relating the LPM effect to the probabilistic concept of formation time for virtual quanta. We demonstrate that this implementation of formation time physics alone accounts probabilistically for all analytically known features of the non-abelian LPM-effect, including the characteristic L^2-dependence of average parton energy loss and the characteristic $\\sqrt{\\omega}$-modification of the gluon energy distribution. Additional kinematic constraints are found to modify these L^2- and $\\omega$-dependencies characteristically in accordance with analytical estimates.
Kirilyuk, A P
2001-01-01
Following Max Planck's hypothesis of quanta (quant-ph/0012069) and the matter wave idea of Louis de Broglie (quant-ph/9911107), Erwin Schroedinger proposed, at the beginning of 1926, the concept of the wavefunction and the wave equation for it. Though endowed with a realistic undular interpretation by its farther, the wavefunction could not be considered as a real 'matter wave' and has been provided with the abstract, formally probabilistic interpretation. In this paper we show how the resulting 'mysteries' of the standard theory are resolved within the unreduced, dynamically multivalued description of the underlying, essentially nonlinear interaction process (quant-ph/9902015, quant-ph/9902016), without artificial modification of the Schroedinger equation. The causal, totally realistic wavefunction emerges as the dynamically probabilistic intermediate state of a simple system with interaction performing dynamically discrete transitions between its localised, incompatible 'realisations' ('corpuscular' states)...
Micromegas for imaging hadronic calorimetry
Adloff, C; Cap, S; Chefdeville, M; Dalmaz, A; Drancourt, C; Espargiliere, A; Gaglione, R; Gallet, R; Geffroy, N; Jacquemier, J; Karyotakis, Y; Peltier, F; Prast, J; Vouters, G
2011-01-01
The recent progress in R&D of the Micromegas detectors for hadronic calorimetry including new engineering-technical solutions, electronics development, and accompanying simulation studies with emphasis on the comparison of the physics performance of the analog and digital readout is described. The developed prototypes are with 2 bit digital readout to exploit the Micromegas proportional mode and thus improve the calorimeter linearity. In addition, measurements of detection efficiency, hit multiplicity, and energy shower profiles obtained during the exposure of small size prototypes to radioactive source quanta, cosmic particles and accelerator beams are reported. Eventually, the status of a large scale chamber (1{\\times}1 m2) are also presented with prospective towards the construction of a 1 m3 digital calorimeter consisting of 40 such chambers.
A Non-Perturbative Gauge-Invariant QCD: Ideal vs. Realistic QCD
Fried, H M; Sheu, Y -M
2011-01-01
A basic distinction, long overlooked, between the conventional, "idealistic" formulation of QCD, and a more "realistic" formulation is brought into focus by a rigorous, non-perturbative, gauge-invariant evaluation of the Schwinger solution for the QCD generating functional in terms of exact Fradkin representations for the Green's functional $\\mathbf{G}_{c}(x,y|A)$ and the vacuum functional $\\mathbf{L}[A]$. The quanta of all (Abelian) quantized fields may be expected to obey standard quantum-mechanical measurement properties, perfect position dependence at the cost of unknown momenta, and vice-versa, but this is impossible for quarks since they always appear asymptotically in bound states, and their transverse position or momenta can never, in principle, be exactly measured. Violation of this principle produces an absurdity in the exact evaluation of each and every QCD amplitude. We here suggest a phenomenological change in the basic QCD Lagrangian, such that a limitation of transverse precision is automatical...
Quantum-coherent coupling of a mechanical oscillator to an optical cavity mode
Verhagen, E; Weis, S; Schliesser, A; Kippenberg, T J
2011-01-01
Quantum control of engineered mechanical oscillators can be achieved by coupling the oscillator to an auxiliary degree of freedom, provided that the coherent rate of energy exchange exceeds the decoherence rate of each of the two sub-systems. We achieve such quantum-coherent coupling between the mechanical and optical modes of a micro-optomechanical system. Simultaneously, the mechanical oscillator is cooled to an average occupancy of n = 1.7 \\pm 0.1 motional quanta. Pulsed optical excitation reveals the exchange of energy between the optical light field and the micromechanical oscillator in the time domain at the level of less than one quantum on average. These results provide a route towards the realization of efficient quantum interfaces between mechanical oscillators and optical fields.
Directory of Open Access Journals (Sweden)
Devendra Kumar
2014-06-01
Full Text Available In this paper, we present a reliable algorithm based on the homotopy analysis transform method (HATM to solve the linear and nonlinear Klein–Gordon equations. The Klein–Gordon equation is the equation of motion of a quantum scalar or pseudoscalar field, a field whose quanta are spinless particles. It describes the quantum amplitude for finding a point particle in various places, the relativistic wave function, but the particle propagates both forwards and backwards in time. The HATM is a combined form of the Laplace transform method and homotopy analysis method. The method provides the solution in the form of a rapidly convergent series. Some numerical examples are used to illustrate the preciseness and effectiveness of the proposed method. The results show that the HATM is very efficient, simple and can be applied to other nonlinear problems.
Energy Technology Data Exchange (ETDEWEB)
Gerasimenko, B.F. [V.G. Khlopin Radium Inst., Saint Peterburg (Russian Federation)
1997-03-01
The calculations of integral spectra of prompt neutrons of spontaneous fission of {sup 244}Cm and {sup 246}Cm were carried out. The calculations were done by the Statistical Computer Code Complex SCOFIN applying the Hauser-Feschbach method as applied to the description of the de-excitation of excited fission fragments by means of neutron emission. The emission of dipole gamma-quanta from these fragments was considered as a competing process. The average excitation energy of a fragment was calculated by two-spheroidal model of tangent fragments. The density of levels in an excited fragment was calculated by the Fermi-gas model. The quite satisfactory agreement was reached between theoretical and experimental results obtained in frames of Project measurements. The calculated values of average multiplicities of neutron number were 2,746 for {sup 244}Cm and 2,927 for {sup 246}Cm that was in a good accordance with published experimental figures. (author)
Propensities toward C{sub 2}H({ital {tilde A}} {sup 2}{Pi}) in acetylene photodissociation
Energy Technology Data Exchange (ETDEWEB)
Zhang, J.; Riehn, C.W.; Dulligan, M.; Wittig, C. [Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482 (United States)
1995-10-15
When expansion-cooled acetylene is excited to the {nu}{sup {double_prime}}{sub 1}+3{nu}{sup {double_prime}}{sub 3} vibrational level (4 quanta of CH-stretch) and then photodissociated at 248.3 nm, the dominant product channel is C{sub 2}H({ital {tilde A}} {sup 2}{Pi}). This differs markedly from one-photon 193.3 nm photodissociation, which provides 1200 cm{sup {minus}1} less energy and yields C{sub 2}H({ital {tilde X}} {sup 2}{Sigma}{sup +}) as the primary product. Photodissociation at 121.6 nm yields C{sub 2}H({ital {tilde A}} {sup 2}{Pi}) exclusively. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
A chip-integrated coherent photonic-phononic memory
Merklein, Moritz; Vu, Khu; Madden, Stephen J; Eggleton, Benjamin J
2016-01-01
Controlling and manipulating quanta of coherent acoustic vibrations - phonons - in integrated circuits has recently drawn a lot of attention, as phonons can function as unique links between radiofrequency and optical signals and access quantum regimes. It has been shown that radiofrequency signals can be controlled and stored via piezo-electrically actuated coherent phonons. Coherent phonons, however, can also be directly excited by optical photons through strong acousto-optic coupling in integrated circuits that guide photons as well as phonons. These hypersound phonons have similar wavelength as the exciting optical field but travel at a 5-orders of magnitude lower velocity. This allows the realization of a coherent optical buffer, a long time desired yet elusive device for on-chip optical signal processing. In this letter we demonstrate a coherent on-chip memory storing the entire coherent information carried by light, phase and amplitude, as acoustic phonons. The photonic-phononic memory provides GHz-band...
An Analog Model for Light Propagation in Semiclassical Gravity
Bessa, C H G; Ford, L H
2014-01-01
We treat a model based upon nonlinear optics for the semiclassical gravitational effects of quantum fields upon light propagation. Our model uses a nonlinear material with a nonzero third order polarizability. Here a probe light pulse satisfies a wave equation containing the expectation value of the squared electric field. This expectation value depends upon the presence of lower frequency quanta, the background field, and modifies the effective index of refraction, and hence the speed of the probe pulse. If the mean squared electric field is positive, then the pulse is slowed, which is analogous to the gravitational effects of ordinary matter. Such matter satisfies the null energy condition and produce gravitational lensing and time delay. If the mean squared field is negative, then the pulse has a higher speed than in the absence of the background field. This is analogous to the gravitational effects of exotic matter, such as stress tensor expectation values with locally negative energy densities, which lea...
Park, G Barratt; Jiang, Jun; Saladrigas, Catherine A; Field, Robert W
2016-04-14
The C̃ (1)B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X̃ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C̃ state below 1600 cm(-1) of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C̃ electronic state.
Measurable Maximal Energy and Minimal Time Interval
Dahab, Eiman Abou El
2014-01-01
The possibility of finding the measurable maximal energy and the minimal time interval is discussed in different quantum aspects. It is found that the linear generalized uncertainty principle (GUP) approach gives a non-physical result. Based on large scale Schwarzshild solution, the quadratic GUP approach is utilized. The calculations are performed at the shortest distance, at which the general relativity is assumed to be a good approximation for the quantum gravity and at larger distances, as well. It is found that both maximal energy and minimal time have the order of the Planck time. Then, the uncertainties in both quantities are accordingly bounded. Some physical insights are addressed. Also, the implications on the physics of early Universe and on quantized mass are outlined. The results are related to the existence of finite cosmological constant and minimum mass (mass quanta).
Controlled electromigration and oxidation of free-standing copper wires
Hauser, J. S.; Schwichtenberg, J.; Marz, M.; Sürgers, C.; Seiler, A.; Gerhards, U.; Messerschmidt, F.; Hensel, A.; Dittmeyer, R.; Löhneysen, H. v.; Hoffmann-Vogel, R.
2016-12-01
We have studied controlled electromigration (EM) in free-standing copper wires. Besides electrical characterization by voltage-current measurements, structural analyses have been performed by means of scanning electron microscopy and cross-sectional microprobe measurements. We have found that oxidation during the EM in air stabilizes the free-standing wire against uncontrolled blowing, making it possible to thin the conductive part of the wire down to a conductance of a few conductance quanta G_0=2e^2{/}h. The decisive influence of oxidation by air on the EM process was confirmed by control experiments performed under ultra-high vacuum conditions. In line with these findings, free-standing Au wires were difficult to thin down reproducibly to a conductance of a few G_0. Estimates of the local temperature in the free-standing wire are obtained from finite element method calculations.
Dikii, N. P.; Dovbnya, A. N.; Lyashko, Yu. V.; Medvedev, D. V.; Medvedeva, E. P.; Uvarov, V. L.; Achkasov, K. V.
2011-07-01
Nuclear physics methods are used to determine the diffusion coefficients of Na, Ca, Mn, K, and 222Rn in clinoptilolite (Sokirnitsa occurrence, Ukraine) and in natural tuff (Yucca Mountain, Nevada, United States) and in tuff irradiated by γ-quanta ( E max = 23 MeV) to a dose of 107 Gy at a leaching temperature of 37°C. The diffusion coefficients of sodium and potassium in clinoptilolite are found to differ considerably: 4 × 10-17 and 2 × 10-20 m2/s, respectively. This indicates the influence of aquacomplexes on the cation transfer. The diffusion coefficient of radon in these materials is determined: in clinoptilolite it equals 2.5 × 10-12 m2/s.
Bogdanov, Yu. I.; Katamadze, K. G.; Avosopyants, G. V.; Belinsky, L. V.; Bogdanova, N. A.; Kulik, S. P.; Lukichev, V. F.
2016-12-01
The estimation of high order correlation function values is an important problem in the field of quantum computation. We show that the problem can be reduced to preparation and measurement of optical quantum states resulting after annihilation of a set number of quanta from the original beam. We apply this approach to explore various photon bunching regimes in optical states with gamma-compounded Poisson photon number statistics. We prepare and perform measurement of the thermal quantum state as well as states produced by subtracting one to ten photons from it. Maximum likelihood estimation is employed for parameter estimation. The goal of this research is the development of highly accurate procedures for generation and quality control of optical quantum states.
Single-Site Tetracoordinated Aluminum Hydride Supported on Mesoporous Silica. From Dream to Reality!
Werghi, Baraa
2016-09-26
The reaction of mesoporous silica (SBA15) dehydroxylated at 700 °C with diisobutylaluminum hydride, i-Bu2AlH, gives after thermal treatment a single-site tetrahedral aluminum hydride with high selectivity. The starting aluminum isobutyl and the final aluminum hydride have been fully characterized by FT-IR, advanced SS NMR spectroscopy (1H, 13C, multiple quanta (MQ) 2D 1H-1H, and 27Al), and elemental analysis, while DFT calculations provide a rationalization of the occurring reactivity. Trimeric i-Bu2AlH reacts selectively with surface silanols without affecting the siloxane bridges. Its analogous hydride catalyzes ethylene polymerization. Indeed, catalytic tests show that this single aluminum hydride site is active in the production of a high-density polyethylene (HDPE). © 2016 American Chemical Society.
Gamma-beam propagation in the anisotropic medium
Maisheev, V A
2000-01-01
Propagation of gamma-beam in the anisotropic medium is considered. The simpliest example of such a medium of the general type is a combination of the two linearly polarized monochromatic laser waves with different frequencies (dichromatic wave). The optical properties of this combination are described with the use of the permittivity tensor. The refractive indices and polarization characteristics of normal electromagnetic waves propagating in the anisotropic medium are found. The relations, describing variations of gamma-beam intensity and Stokes parameters as functions of propagation length are obtained. The influence of laser wave intensity on the propagation process are calculated. The gamma-beam intensity losses in the dichromatic wave depend on the initial circular polarization of gamma-quanta. This effect is also applied to the single crystals, which are oriented in some regions of coherent pair production. In principle, the single crystal sensitivity to a circular polarization can be used for determina...
A quantum parametric oscillator with trapped ions
Ding, Shiqian; Hablutzel, Roland; Loh, Huanqian; Matsukevich, Dzmitry
2015-01-01
A system of harmonic oscillators coupled via nonlinear interaction is a fundamental model in many branches of physics, from biophysics to electronics and condensed matter physics. In quantum optics, weak nonlinear interaction between light modes has enabled, for example, the preparation of squeezed states of light and generation of entangled photon pairs. While strong nonlinear interaction between the modes has been realized in circuit QED systems, achieving significant interaction strength on the level of single quanta in other physical systems remains a challenge. Here we experimentally demonstrate such interaction that is equivalent to photon up- and down-conversion using normal modes of motion in a system of two Yb ions. The nonlinearity is induced by the intrinsic anharmonicity of the Coulomb interaction between the ions and can be used to simulate fully quantum operation of a degenerate optical parametric oscillator. We exploit this interaction to directly measure the parity and Wigner functions of ion ...
Smolyaninov, Igor I
2013-01-01
We demonstrate that high Tc superconductors exhibit hyperbolic metamaterial behavior in the far infrared and THz frequency ranges. In the THz range the hyperbolic behavior occurs only in the normal state, while no propagating modes exist in the superconducting state. Wave equation, which describes propagation of extraordinary light inside a hyperbolic metamaterial exhibits 2+1 dimensional Lorentz symmetry. The role of time in the corresponding effective 3D Minkowski spacetime is played by the spatial coordinate aligned perpendicular to the copper oxide layers. Such superconductor-based hyperbolic metamaterials exhibit a quantum phase transition at T=0, in which the effective Minkowski spacetime arise in the mixed state of the superconductor at some critical value of external magnetic field. Nucleation of Minkowski spacetime occurs via formation of quantized Abrikosov vortices, so that these vortices play the role of Minkowski spacetime quanta. Thus, the described system may be used as an experimental model of...
Quantum Exclusion of Positive Cosmological Constant?
Dvali, Gia
2014-01-01
We show that a positive cosmological constant is incompatible with the quantum-corpuscular resolution of de Sitter metric in form of a coherent state. The reason is very general and is due to the quantum self-destruction of the coherent state because of the scattering of constituent graviton quanta. This process creates an irreversible quantum clock, which precludes eternal de Sitter. It also eliminates the possibility of Boltzmann brains and Poincare recurrences. This effect is expected to be part of any microscopic theory that takes into account the quantum corpuscular structure of the cosmological background. This observation puts the cosmological constant problem in a very different light, promoting it, from a naturalness problem, into a question of quantum consistency. We are learning that quantum gravity cannot tolerate exceedingly-classical sources.
Robust Concurrent Remote Entanglement Between Two Superconducting Qubits
Directory of Open Access Journals (Sweden)
A. Narla
2016-09-01
Full Text Available Entangling two remote quantum systems that never interact directly is an essential primitive in quantum information science and forms the basis for the modular architecture of quantum computing. When protocols to generate these remote entangled pairs rely on using traveling single-photon states as carriers of quantum information, they can be made robust to photon losses, unlike schemes that rely on continuous variable states. However, efficiently detecting single photons is challenging in the domain of superconducting quantum circuits because of the low energy of microwave quanta. Here, we report the realization of a robust form of concurrent remote entanglement based on a novel microwave photon detector implemented in the superconducting circuit quantum electrodynamics platform of quantum information. Remote entangled pairs with a fidelity of 0.57±0.01 are generated at 200 Hz. Our experiment opens the way for the implementation of the modular architecture of quantum computation with superconducting qubits.
Reductive Dechlorination of p-Chlorophenol by Nanoscale Iron
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
To investigate reductive dechlorination of 4-chlorophenol (4-CP) by nanoscale Fe0 under different conditions.Methods Nanoscale Fe0 was synthesized by using reductive method. 4-CP and its intermediate products were analyzed by HPLC. Chlorine ion was quantified with DX-100 ion chromatograph. Nano-iron particles were observed under a FEI Quanta 200 FEG environmental scanning electron microscope (ESEM).Results The size of the particles was in the range of 10-100 nm. The nano-iron particles could reduce 4-CP effectively. The initial concentration of 4-CP increased with the decrease of the relative degradation rate,whereas the reduced amount of 4-CP increased. Temperature could influence both the dechlorination rate and the reaction pathway. Moreover,the stability and durability of nanoscale Fe0 was evaluated through batch studies over extended periods of time.Conclusion The nanoscale Fe0 can be used for sustainable treatment of contaminants in groundwater.
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
Kamińska, D; Białas, P; Czerwiński, E; Gajos, A; Gorgol, M; Jasińska, B; Kapłon, Ł; Korcyl, G; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Rundel, O; Sharma, N G; Silarski, M; Słomski, A; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zieliński, M; Zgardzińska, B; Moskal, P
2015-01-01
In this paper we present prospects for using the J-PET detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons would imply the existence of physics phenomena beyond the Standard Model. Previous measurements resulted in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of about 10-3. The J-PET detector allows to determine those values with better precision thanks to a unique time and angular esolution combined with a high geometrical acceptance. Achieving the aforementioned is possible due to application of polymer scintillators instead of crystals as detectors of annihilation quanta.
Towards a Realistic Parsing of the Feynman Path Integral
Directory of Open Access Journals (Sweden)
Ken Wharton
2016-01-01
Full Text Available The Feynman path integral does not allow a one real path interpretation, because the quantum amplitudes contribute to probabilities in a non-separable manner. The opposite extreme, all paths happen, is not a useful or informative account. In this paper it is shown that an intermediate parsing of the path integral, into realistic non-interfering possibilities, is always available. Each realistic possibility formally corresponds to numerous particle paths, but is arguably best interpreted as a spacetime-valued field. Notably, one actual field history can always be said to occur, although it will generally not have an extremized action. The most obvious concerns with this approach are addressed, indicating necessary follow-up research. But without obvious showstoppers, it seems plausible that the path integral might be reinterpreted to explain quantum phenomena in terms of Lorentz covariant field histories.Quanta 2016; 5: 1–11.
Morlet Wavelets in Quantum Mechanics
Directory of Open Access Journals (Sweden)
John Ashmead
2012-11-01
Full Text Available Wavelets offer significant advantages for the analysis of problems in quantum mechanics. Because wavelets are localized in both time and frequency they avoid certain subtle but potentially fatal conceptual errors that can result from the use of plane wave or δ function decomposition. Morlet wavelets in particular are well-suited for this work: as Gaussians, they have a simple analytic form and they work well with Feynman path integrals. But to take full advantage of Morlet wavelets we need to supply an explicit form for the inverse Morlet transform and a manifestly covariant form for the four-dimensional Morlet wavelet. We construct both here.Quanta 2012; 1: 58–70.
Therapy imaging: a signal-to-noise analysis of metal plate/film detectors.
Munro, P; Rawlinson, J A; Fenster, A
1987-01-01
We have measured the modulation transfer functions [MTF (f)'s] and the noise power spectra [NPS (f)] of therapy x-ray detectors irradiated by 60Co, 6- and 18-MV radiotherapy beams. Using these quantities, we have calculated the noise-equivalent quanta [NEQ (f)] and the detective quantum efficiency [DQE (f)] to quantitate the limitations of therapy detectors. The detectors consisted of film or fluorescent screen-film combinations in contact with copper, lead, or tungsten metal plates. The resolution of the detectors was found to be comparable to fluorescent screen-film combinations used in diagnostic radiology, however, the signal-to-noise ratio [SNR (f)] of the detectors was limited due to film granularity. We conclude that improved images can be obtained by using alternative detector systems which have less noise or film granularity.
Stierstorfer, K; Spahn, M
1999-07-01
The detective quantum efficiency (DQE) is widely accepted as the most relevant parameter to characterize the image quality of medical x-ray systems. In this article we describe a solid method to measure the DQE. The strength of the method lies in the fact that it is self-normalizing so measurements at very low spatial frequencies are not needed. Furthermore, it works on any system with a response function which is linear in the small-signal approximation. We decompose the DQE into several easily accessible quantities and discuss in detail how they can be measured. At the end we lead the interested reader through an example. Noise equivalent quanta and normalized contrast values are tabulated for standard radiation qualities.
Magnetic flux disorder and superconductor-insulator transition in nanohole thin films
Granato, Enzo
2016-08-01
We study the superconductor-insulator transition in nanohole ultrathin films in a transverse magnetic field by numerical simulation of a Josephson-junction array model. Geometrical disorder due to the random location of nanoholes in the film corresponds to random flux in the array model. Monte Carlo simulation in the path-integral representation is used to determine the critical behavior and the universal resistivity at the transition as a function of disorder and average number of flux quanta per cell, fo. The resistivity increases with disorder for noninteger fo while it decreases for integer fo, and reaches a common constant value in a vortex-glass regime above a critical value of the flux disorder Dfc. The estimate of Dfc and the resistivity increase for noninteger fo are consistent with recent experiments on ultrathin superconducting films with positional disordered nanoholes.
On Emergent Physics, "Unparticles" and Exotic "Unmatter" States
Directory of Open Access Journals (Sweden)
Smarandache F.
2008-10-01
Full Text Available Emergent physics refers to the formation and evolution of collective patterns in systems that are nonlinear and out-of-equilibrium. This type of large-scale behavior often develops as a result of simple interactions at the component level and involves a dynamic interplay between order and randomness. On account of its universality, there are credible hints that emergence may play a leading role in the Tera-ElectronVolt (TeV sector of particle physics. Following this path, we examine the possibility of hypothetical high-energy states that have fractional number of quanta per state and consist of arbitrary mixtures of particles and antiparticles. These states are similar to "un-particles", massless fields of non-integral scaling dimensions that were recently conjectured to emerge in the TeV sector of particle physics. They are also linked to "unmatter", exotic clusters of matter and antimatter introduced few years ago in the context of Neutrosophy.
Vortices and nanostructured superconductors
2017-01-01
This book provides expert coverage of modern and novel aspects of the study of vortex matter, dynamics, and pinning in nanostructured and multi-component superconductors. Vortex matter in superconducting materials is a field of enormous beauty and intellectual challenge, which began with the theoretical prediction of vortices by A. Abrikosov (Nobel Laureate). Vortices, vortex dynamics, and pinning are key features in many of today’s human endeavors: from the huge superconducting accelerating magnets and detectors at the Large Hadron Collider at CERN, which opened new windows of knowledge on the universe, to the tiny superconducting transceivers using Rapid Single Flux Quanta, which have opened a revolutionary means of communication. In recent years, two new features have added to the intrinsic beauty and complexity of the subject: nanostructured/nanoengineered superconductors, and the discovery of a range of new materials showing multi-component (multi-gap) superconductivity. In this book, leading researche...
Analysis of light regime in continuous light distributions in photobioreactors.
Brindley, Celeste; Fernández, F G Acién; Fernández-Sevilla, J M
2011-02-01
Maximum photobioreactor (PBR) efficiency is a must in applications such as the obtention of microalgae-derived fuels. Improving PBR performance requires a better understanding of the "light regime", the varying irradiance that microalgal cells moving in a dense culture are exposed to. We propose a definition of light regime that can be used consistently to describe the continuously varying light patterns in PBRs as well as in light/dark cycles. Equivalent continuous and light/dark regimes have been experimentally compared and the results show that continuous variations are not well represented by light/dark cycles, as had been widely accepted. It has been shown that a correct light regime allows obtaining photosynthetic rates higher than the corresponding to continuous light, the so-called "flashing light effect" and that this is possible in commercial PBRs. A correct PBR operation could result in photosynthetic efficiency close to the optimum eight quanta per O(2).
Determination of ketone bodies in blood by headspace gas chromatography-mass spectrometry
DEFF Research Database (Denmark)
Holm, Karen Marie Dollerup; Linnet, Kristian; Rasmussen, Brian Schou
2010-01-01
A gas chromatography-mass spectrometry (GC-MS) method for determination of ketone bodies (ß-hydroxybutyrate, acetone, and acetoacetate) in blood is presented. The method is based on enzymatic oxidation of D-ß-hydroxybutyrate to acetoacetate, followed by decarboxylation to acetone, which was quant......A gas chromatography-mass spectrometry (GC-MS) method for determination of ketone bodies (ß-hydroxybutyrate, acetone, and acetoacetate) in blood is presented. The method is based on enzymatic oxidation of D-ß-hydroxybutyrate to acetoacetate, followed by decarboxylation to acetone, which...... from 98 to 107%, demonstrating the suitability of the method for measuring ketone bodies over a wide concentration range. The method has been applied to cases in which ketoacidosis was suspected as the cause of death in diabetics or chronic alcoholics, as well as to cases in which another cause...
Realization of the Haldane-Kane-Mele Model in a System of Localized Spins
Kim, Se Kwon; Ochoa, Héctor; Zarzuela, Ricardo; Tserkovnyak, Yaroslav
2016-11-01
We study a spin Hamiltonian for spin-orbit-coupled ferromagnets on the honeycomb lattice. At sufficiently low temperatures supporting the ordered phase, the effective Hamiltonian for magnons, the quanta of spin-wave excitations, is shown to be equivalent to the Haldane model for electrons, which indicates the nontrivial topology of the band and the existence of the associated edge state. At high temperatures comparable to the ferromagnetic-exchange strength, we take the Schwinger-boson representation of spins, in which the mean-field spinon band forms a bosonic counterpart of the Kane-Mele model. The nontrivial geometry of the spinon band can be inferred by detecting the spin Nernst effect. A feasible experimental realization of the spin Hamiltonian is proposed.
Killoran, N; Huelga, S F; Plenio, M B
2015-10-21
Recent evidence suggests that quantum effects may have functional importance in biological light-harvesting systems. Along with delocalized electronic excitations, it is now suspected that quantum coherent interactions with certain near-resonant vibrations may contribute to light-harvesting performance. However, the actual quantum advantage offered by such coherent vibrational interactions has not yet been established. We investigate a quantum design principle, whereby coherent exchange of single energy quanta between electronic and vibrational degrees of freedom can enhance a light-harvesting system's power above what is possible by thermal mechanisms alone. We present a prototype quantum heat engine which cleanly illustrates this quantum design principle and quantifies its quantum advantage using thermodynamic measures of performance. We also demonstrate the principle's relevance in parameter regimes connected to natural light-harvesting structures.
Energy Technology Data Exchange (ETDEWEB)
Killoran, N.; Huelga, S. F.; Plenio, M. B. [Institut für Theoretische Physik, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm (Germany)
2015-10-21
Recent evidence suggests that quantum effects may have functional importance in biological light-harvesting systems. Along with delocalized electronic excitations, it is now suspected that quantum coherent interactions with certain near-resonant vibrations may contribute to light-harvesting performance. However, the actual quantum advantage offered by such coherent vibrational interactions has not yet been established. We investigate a quantum design principle, whereby coherent exchange of single energy quanta between electronic and vibrational degrees of freedom can enhance a light-harvesting system’s power above what is possible by thermal mechanisms alone. We present a prototype quantum heat engine which cleanly illustrates this quantum design principle and quantifies its quantum advantage using thermodynamic measures of performance. We also demonstrate the principle’s relevance in parameter regimes connected to natural light-harvesting structures.
High-Penetration PV Integration Handbook for Distribution Engineers
Energy Technology Data Exchange (ETDEWEB)
Seguin, Rich [Electrical Distribution Design, Blacksburg, VA (United States); Woyak, Jeremy [Electrical Distribution Design, Blacksburg, VA (United States); Costyk, David [Electrical Distribution Design, Blacksburg, VA (United States); Hambrick, Josh [Electrical Distribution Design, Blacksburg, VA (United States); Mather, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)
2016-01-01
This handbook has been developed as part of a five-year research project which began in 2010. The National Renewable Energy Laboratory (NREL), Southern California Edison (SCE), Quanta Technology, Satcon Technology Corporation, Electrical Distribution Design (EDD), and Clean Power Research (CPR) teamed together to analyze the impacts of high-penetration levels of photovoltaic (PV) systems interconnected onto the SCE distribution system. This project was designed specifically to leverage the experience that SCE and the project team would gain during the significant installation of 500 MW of commercial scale PV systems (1-5 MW typically) starting in 2010 and completing in 2015 within SCE’s service territory through a program approved by the California Public Utility Commission (CPUC).
New Photonis XP20D0 photomultiplier for fast timing in nuclear medicine
Energy Technology Data Exchange (ETDEWEB)
Moszynski, M. [Soltan Institute for Nuclear Studies, PL 05-400 Swierk-Otwock (Poland)]. E-mail: marek@ipj.gov.pl; Gierlik, M. [Soltan Institute for Nuclear Studies, PL 05-400 Swierk-Otwock (Poland); Kapusta, M. [Soltan Institute for Nuclear Studies, PL 05-400 Swierk-Otwock (Poland); Nassalski, A. [Soltan Institute for Nuclear Studies, PL 05-400 Swierk-Otwock (Poland); Szczesniak, T. [Soltan Institute for Nuclear Studies, PL 05-400 Swierk-Otwock (Poland); Fontaine, Ch. [Photonis. Av. Roger Roncier, B.P. 520, F 19106 Brive La Gaillarde Cedex (France); Lavoute, P. [Photonis. Av. Roger Roncier, B.P. 520, F 19106 Brive La Gaillarde Cedex (France)
2006-11-01
Growing interest in the time-of-flight positron emission tomography (TOF PET) prompts the study of a new Photonis XP20D0 photomultiplier, equipped with a screening grid at the anode, in application to a fast timing with LSO and LaBr{sub 3} crystals. The high time resolution of 200{+-}4 and 210{+-}4 ps was obtained for 511 keV annihilation quanta using LaBr{sub 3} and LSO crystals in the coincidence experiment with a small BaF{sub 2} crystal, respectively. It reflects an importance of the grid and high quantum efficiency of the XP20D0. A high-time resolution observed in the present experiments makes good prospects for a development of TOF PET.
Directory of Open Access Journals (Sweden)
Ovidiu Cristinel Stoica
2016-01-01
Full Text Available Wavefunction collapse is usually seen as a discontinuous violation of the unitary evolution of a quantum system, caused by the observation. Moreover, the collapse appears to be nonlocal in a sense which seems at odds with general relativity. In this article the possibility that the wavefunction evolves continuously and hopefully unitarily during the measurement process is analyzed. It is argued that such a solution has to be formulated using a time symmetric replacement of the initial value problem in quantum mechanics. Major difficulties in apparent conflict with unitary evolution are identified, but eventually its possibility is not completely ruled out. This interpretation is in a weakened sense both local and realistic, without contradicting Bell's theorem. Moreover, if it is true, it makes general relativity consistent with quantum mechanics in the semiclassical framework.Quanta 2016; 5: 19–33.
Exact results for spin dynamics and fractionalization in the Kitaev Model.
Baskaran, G; Mandal, Saptarshi; Shankar, R
2007-06-15
We present certain exact analytical results for dynamical spin correlation functions in the Kitaev Model. It is the first result of its kind in nontrivial quantum spin models. The result is also novel: in spite of the presence of gapless propagating Majorana fermion excitations, dynamical two spin correlation functions are identically zero beyond nearest neighbor separation. This shows existence of a gapless but short range spin liquid. An unusual, all energy scale fractionalization of a spin-flip quanta, into two infinitely massive pi fluxes and a dynamical Majorana fermion, is shown to occur. As the Kitaev Model exemplifies topological quantum computation, our result presents new insights into qubit dynamics and generation of topological excitations.
Einstein, 1905-2005 : Poincaré seminar
Darrigol, Olivier; Duplantier, B; Rivasseau, Vincent; Einstein 1905-2005 : séminaire Poincaré
2006-01-01
The Poincaré Seminar is held twice a year at the Institute Henri Poincaré in Paris. The goal of this seminar is to provide up-to-date information about general topics of great interest in physics. Both the theoretical and experimental results are covered, with some historical background. Particular care is devoted to the pedagogical nature of the presentation. This volume is devoted to Einstein's 1905 papers and their legacy. After a presentation of Einstein's epistemological approach to physics, and the genesis of special relativity, a centenary perspective is offered. The geometry of relativistic spacetime is explained in detail. Single photon experiments are presented, as a spectacular realization of Einstein's light quanta hypothesis. A previously unpublished lecture by Einstein, which presents an illuminating point of view on statistical physics in 1910, at the dawn of quantum mechanics, is reproduced. The volume ends with an essay on the historical, physical and mathematical aspects of Brownian motion...
A microfabricated surface-electrode ion trap for scalable quantum information processing
Seidelin, S; Bollinger, J J; Britton, J; Chiaverini, J; Epstein, R J; Hume, D B; Jost, J D; Langer, C; Leibfried, D; Ozeri, R; Reichle, R; Shiga, N; Wesenberg, J H; Wineland, D J
2006-01-01
We demonstrate confinement of individual atomic ions in a radio-frequency Paul trap with a novel geometry where the electrodes are located in a single plane and the ions confined above this plane. This device is realized with a relatively simple fabrication procedure and has important implications for quantum state manipulation and quantum information processing using large numbers of ions. We confine laser-cooled Mg-24 ions approximately 40 micrometer above planar gold electrodes. We measure the ions' motional frequencies and compare them to simulations. From measurements of the escape time of ions from the trap, we also determine a heating rate of approximately five motional quanta per millisecond for a trap frequency of 5.3 MHz.
Unified relativistic physics from a standing wave particle model
Vera, R A
1995-01-01
An extremely simple and unified base for physics comes out by starting all over from a single postulate on the common nature of matter and stationary forms of radiation quanta. Basic relativistic, gravitational (G) and quantum mechanical properties of a standing wave particle model have been derived. This has been done from just dual properties of radiation's and strictly homogeneous relationships for nonlocal cases in G fields. This way reduces the number of independent variables and puts into relief (and avoid) important inhomogeneity errors of some G theories. It unifies and accounts for basic principles and postulates physics. The results for gravity depend on linear radiation properties but not on arbitrary field relations. They agree with the conventional tests. However they have some fundamental differences with current G theories. The particle model, at a difference of the conventional theories, also fixes well-defined cosmological and astrophysical models that are different from the rather convention...
Afanasev, S.; Vishnevskiy, A.; Vishnevskiy, D.; Rogachev, A.; Tyutyunnikov, S.
2017-05-01
As part of the Energy & Transmutation project, we are developing a detector for neutrons with energies in the 10-100 MeV range emitted from the target irradiated by a charged-particle beam. The neutron is detected by measuring the time-of-flight and total kinetic energy of the forward-going recoil proton [1] knocked out at a small angle from a thin layer of plastic scintillator, which has to be selected against an intense background created by γ quanta, scattered neutrons, and charged particles. On the other hand, neutron energy has to be measured over the full range with no extra tuning of the detector operation regime. Initial measurements with a source of 14.1-MeV neutrons are reported.
Large non-gaussianity in axion inflation.
Barnaby, Neil; Peloso, Marco
2011-05-06
The inflationary paradigm has enjoyed phenomenological success; however, a compelling particle physics realization is still lacking. Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry. We reconsider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields cΦFF, which is generically present in these models. This coupling leads to production of gauge quanta, which provide a new source of inflaton fluctuations, δΦ. For c≥10(2)M(p)(-1), these dominate over the vacuum fluctuations, and non-Gaussianity exceeds the current observational bound. This regime is typical for concrete realizations that admit a UV completion; hence, large non-Gaussianity is easily obtained in minimal and natural realizations of inflation.
Adiabatic pumping of Chern-Simons axion coupling.
Taherinejad, Maryam; Vanderbilt, David
2015-03-06
We study the adiabatic pumping of the Chern-Simons axion (CSA) coupling along a parametric loop characterized by a nonzero second Chern number C^{(2)} from the viewpoint of the hybrid Wannier representation, in which the Wannier charge centers are visualized as sheets defined over a projected 2D Brillouin zone. We derive a new formula for the CSA coupling, expressing it as an integral involving Berry curvatures and potentials defined on the Wannier charge center sheets. We show that a loop characterized by a nonzero C^{(2)} requires a series of sheet-touching events at which 2π quanta of Berry curvature are passed from sheet to sheet, in such a way that e^{2}/h units of CSA coupling are pumped by a lattice vector by the end of the cycle. We illustrate these behaviors via explicit calculations on a model tight-binding Hamiltonian and discuss their implications.
Villari, Leone Di Mauro; Biancalana, Fabio; Conti, Claudio
2016-01-01
We have very little experience of the quantum dynamics of the ubiquitous nonlinear waves. Observed phenomena in high energy physics are perturbations to linear waves, and classical nonlinear waves, like solitons, are barely affected by quantum effects. We know that solitons, immutable in classical physics, exhibit collapse and revivals according to quantum mechanics. However this effect is very weak and has never been observed experimentally. By predicting black hole evaporation Hawking first introduced a distinctly quantum effect in nonlinear gravitational physics.Here we show the existence of a general and universal quantum process whereby a soliton emits quantum radiation with a specific frequency content, and a temperature given by the number of quanta, the soliton Schwarzschild radius, and the amount of nonlinearity, in a precise and surprisingly simple way. This result may ultimately lead to the first experimental evidence of genuine quantum black hole evaporation. In addition, our results show that bla...
Tensile strength and the mining of black holes.
Brown, Adam R
2013-11-22
There are a number of important thought experiments that involve raising and lowering boxes full of radiation in the vicinity of black hole horizons. This Letter looks at the limitations placed on these thought experiments by the null energy condition, which imposes a fundamental bound on the tensile-strength-to-weight ratio of the materials involved, makes it impossible to build a box near the horizon that is wider than a single wavelength of the Hawking quanta, and puts a severe constraint on the operation of "space elevators" near black holes. In particular, it is shown that proposals for mining black holes by lowering boxes near the horizon, collecting some Hawking radiation, and dragging it out to infinity cannot proceed nearly as rapidly as has previously been claimed. As a consequence of this limitation, the boxes and all the moving parts are superfluous and black holes can be destroyed equally rapidly by threading the horizon with strings.
Bennett, A. J.; Lee, J. P.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.
2016-10-01
Obtaining substantial nonlinear effects at the single-photon level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the photons. We report effective interactions between photons, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.
Kurian, P; Lindesay, J
2014-01-01
Several living systems have been examined for their apparent optimization of structure and function for quantum behavior at biological length scales. Orthodox type II endonucleases, the largest class of restriction enzymes, recognize four-to-eight base pair sequences of palindromic DNA, cut both strands symmetrically, and act without an external metabolite such as ATP. While it is known that these enzymes induce strand breaks by attacking phosphodiester bonds, what remains unclear is the mechanism by which cutting occurs in concert at the catalytic centers. Previous studies indicate the primacy of intimate DNA contacts made by the specifically bound enzyme in coordinating the two synchronized cuts. We propose that collective electronic behavior in the DNA helix generates coherent oscillations, quantized through boundary conditions imposed by the endonuclease, that provide the energy required to break two phosphodiester bonds. Such quanta may be preserved in the presence of thermal noise and electromagnetic in...
Multigap RPC for PET: development and optimisation of the detector design
Georgiev, Georgi; Kozhuharov, Venelin; Lessigiarska, Iglika; Litov, Leandar; Pavlov, Borislav; Petkov, Peicho
2012-01-01
Transforming the resistive plate chambers from charged-particle into gamma-quanta detectors opens the way towards their application as a basic element of a hybrid imaging system, which combines positron emission tomography (PET) with magnetic resonance imaging (MRI) in a single device and provides non- and minimally- invasive quantitative methods for diagnostics. To this end, we performed detailed investigations encompassing the whole chain from the annihilation of the positron in the body, through the conversion of the created photons into electrons and to the optimization of the electron yield in the gas. GEANT4 based simulations of the efficiency of the RPC photon detectors with different converter materials and geometry were conducted for optimization of the detector design. The results justify the selection of a sandwich-type gas-insulator-converter design, with Bi or Pb as converter materials.
On the first Solvay Congress in 1911
Straumann, Norbert
2011-01-01
Late in October 1911, eighteen leading scientists from all over Europe met to the first of a famous sequence of Solvay conferences in Brussels. This historical meeting was mainly devoted to "The Theory of Radiation and the Quanta", at a time when the foundations of physics were totally shaken. Although "nothing positive came out" (Einstein), it is interesting to see the diverging attitudes of Europe's most famous scientists in the middle of the quantum revolution. After a few general remarks about the conference, I shall focus on some of the most interesting contributions and discussions. Einstein, at 32 the youngest, was clearly most aware of the profound nature of the crises. He gave the final talk entitled "The Present State of the Problem of Specific Heats", but he put his theme into the larger context of the quantum problem, and caused a barrage of challenges, in particular from Lorentz, Planck, Poincar\\'{e}, and others.
Killoran, Nathan; Plenio, Martin B
2014-01-01
Recent evidence suggests that quantum effects may have functional importance in biological light-harvesting systems. Along with delocalized electronic excitations, it is now suspected that quantum coherent interactions with certain near-resonant vibrations contribute to light-harvesting performance. However, the actual quantum advantage offered by such coherent vibrational interactions has not yet been established. We investigate a quantum design principle, whereby coherent exchange of single energy quanta between electronic and vibrational degrees of freedom can enhance a light-harvesting system's power above what is possible by thermal mechanisms alone. We present a prototype quantum heat engine which cleanly illustrates this quantum design principle, and quantify its quantum advantage using thermodynamic measures of performance. We also demonstrate the principle's applicability for realistic biological structures.
Energy Technology Data Exchange (ETDEWEB)
Patil, Vidya, E-mail: vidya.patil@ruparel.edu; Patki, Mugdha, E-mail: mugdha.patki@ruparel.edu [D. G. Ruparel College, Senapati Bapat Marg, Mahim, Mumbai – 400 016 (India)
2016-05-06
Many nonlinear optical (NLO) crystals have been identified as potential candidates in optical and electro-optical devices. Use of NLO organic crystals is expected in photonic applications. Hence organic nonlinear optical materials have been intensely investigated due to their potentially high nonlinearities, and rapid response in electro-optic effect compared to inorganic NLO materials. There are many methods to grow organic crystals such as vapor growth method, melt growth method and solution growth method. Out of these methods, solution growth method is useful in providing constraint free crystal. Single crystals of Dopamine have been grown by evaporating the solvents from aqueous solution. Crystals obtained were of the size of orders of mm. The crystal structure of dopamine was determined using XRD technique. Images of crystals were obtained using FEG SEM Quanta Series under high vacuum and low KV.
Method of Obtaining a Composite Material Based on Small-Dispersed Particles
Directory of Open Access Journals (Sweden)
D.G. Batryshev
2016-10-01
Full Text Available In this work a method of obtaining a composite material based on small-dispersed particles is considered. Proposed method consists of two steps of separation, mechanical – rough separation and plasma – soft separation, and also of step of deposition a catalytic nanolayer by wet impregnation of separated particles in an aqueous solution of nickel nitrate. During such procedure a composite powder of small-dispersed zeolite particles with average diameter of 5 m and catalytic nickel layer was obtained. All obtained samples were studied on a Quanta 3D 200i scanning electron microscope. Microscopic analysis and obtained experimental results show, that increasing of dispersion of separated powder allows for increasing a mass of catalyst in the composite, and the used separation method in plasma for obtaining of particles with high dispersion do not erode a catalytic layer.
Quantum and thermal phase escape in extended Josephson systems
Energy Technology Data Exchange (ETDEWEB)
Kemp, A.
2006-07-12
In this work I examine phase escape in long annular Josephson tunnel junctions. The sine-Gordon equation governs the dynamics of the phase variable along the junction. This equation supports topological soliton solutions, which correspond to quanta of magnetic flux trapped in the junction barrier. For such Josephson vortices an effective potential is formed by an external magnetic field, while a bias current acts as a driving force. Both together form a metastable potential well, which the vortex is trapped in. When the driving force exceeds the pinning force of the potential, the vortex escapes and the junction switches to the voltage state. At a finite temperature the driving force fluctuates. If the junction's energy scale is small, the phase variable can undergo a macroscopic quantum tunneling (MQT) process at temperatures below the crossover temperature. Without a vortex trapped, the metastable state is not a potential minimum in space, but a potential minimum at zero phase difference. (orig.)
Patil, Vidya; Patki, Mugdha
2016-05-01
Many nonlinear optical (NLO) crystals have been identified as potential candidates in optical and electro-optical devices. Use of NLO organic crystals is expected in photonic applications. Hence organic nonlinear optical materials have been intensely investigated due to their potentially high nonlinearities, and rapid response in electro-optic effect compared to inorganic NLO materials. There are many methods to grow organic crystals such as vapor growth method, melt growth method and solution growth method. Out of these methods, solution growth method is useful in providing constraint free crystal. Single crystals of Dopamine have been grown by evaporating the solvents from aqueous solution. Crystals obtained were of the size of orders of mm. The crystal structure of dopamine was determined using XRD technique. Images of crystals were obtained using FEG SEM Quanta Series under high vacuum and low KV.
Observation of a kilogram-scale oscillator near its quantum ground state
Abbott, B.; Abbott, R.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Amin, R.; Anderson, S. B.; Anderson, W. G.; Arain, M. A.; Araya, M.; Armandula, H.; Armor, P.; Aso, Y.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Ballmer, S.; Bantilan, H.; Barish, B. C.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barton, M. A.; Bastarrika, M.; Bayer, K.; Betzwieser, J.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, K.; Blackburn, L.; Blair, D.; Bland, B.; Bodiya, T. P.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Brinkmann, M.; Brooks, A.; Brown, D. A.; Brunet, G.; Bullington, A.; Buonanno, A.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Camp, J. B.; Cannizzo, J.; Cannon, K.; Cao, J.; Cardenas, L.; Casebolt, T.; Castaldi, G.; Cepeda, C.; Chalkley, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Christensen, N.; Clark, D.; Clark, J.; Cokelaer, T.; Conte, R.; Cook, D.; Corbitt, T.; Coyne, D.; Creighton, J. D. E.; Cumming, A.; Cunningham, L.; Cutler, R. M.; Dalrymple, J.; Danilishin, S.; Danzmann, K.; Davies, G.; DeBra, D.; Degallaix, J.; Degree, M.; Dergachev, V.; Desai, S.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Drever, R. W. P.; Duke, I.; Dumas, J.-C.; Dupuis, R. J.; Dwyer, J. G.; Echols, C.; Effler, A.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, T.; Fairhurst, S.; Fan, Y.; Fazi, D.; Fehrmann, H.; Fejer, M. M.; Finn, L. S.; Flasch, K.; Fotopoulos, N.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Garofoli, J.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L.; González, G.; Gossler, S.; Gouaty, R.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grimaldi, F.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G.; Harstad, E.; Hayama, K.; Hayler, T.; Heefner, J.; Heng, I. S.; Hennessy, M.; Heptonstall, A.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hosken, D.; Hough, J.; Huttner, S. H.; Ingram, D.; Ito, M.; Ivanov, A.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamat, S.; Kanner, J.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalili, F. Ya; Khan, R.; Khazanov, E.; Kim, C.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R. K.; Kozak, D.; Kozhevatov, I.; Krishnan, B.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M. M.; Lantz, B.; Lazzarini, A.; Lei, M.; Leindecker, N.; Leonhardt, V.; Leonor, I.; Libbrecht, K.; Lin, H.; Lindquist, P.; Lockerbie, N. A.; Lodhia, D.; Lormand, M.; Lu, P.; Lubinski, M.; Lucianetti, A.; Lück, H.; Machenschalk, B.; MacInnis, M.; Mageswaran, M.; Mailand, K.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A.; Markowitz, J.; Maros, E.; Martin, I.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McIntyre, G.; McIvor, G.; McKechan, D.; McKenzie, K.; Meier, T.; Melissinos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C. J.; Meyers, D.; Miao, H.; Miller, J.; Minelli, J.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Mohanty, S.; Moreno, G.; Mossavi, K.; Mow-Lowry, C.; Mueller, G.; Mukherjee, S.; Mukhopadhyay, H.; Müller-Ebhardt, H.; Munch, J.; Murray, P.; Myers, E.; Myers, J.; Nash, T.; Nelson, J.; Newton, G.; Nishizawa, A.; Numata, K.; O'Dell, J.; Ogin, G.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pan, Y.; Pankow, C.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Perreca, A.; Petrie, T.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Postiglione, F.; Principe, M.; Prix, R.; Quetschke, V.; Raab, F.; Rabeling, D. S.; Radkins, H.; Rainer, N.; Rakhmanov, M.; Ramsunder, M.; Rehbein, H.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Rivera, B.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, A.; Rogan, A. M.; Rollins, J.; Romano, J. D.; Romie, J.; Route, R.; Rowan, S.; Rüdiger, A.; Ruet, L.; Russell, P.; Ryan, K.; Sakata, S.; Samidi, M.; Sancho de la Jordana, L.; Sandberg, V.; Sannibale, V.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R.; Savov, P.; Schediwy, S. W.; Schilling, R.; Schnabel, R.; Schofield, R.; Schutz, B. F.; Schwinberg, P.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Sinha, S.
2009-07-01
We introduce a novel cooling technique capable of approaching the quantum ground state of a kilogram-scale system—an interferometric gravitational wave detector. The detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) operate within a factor of 10 of the standard quantum limit (SQL), providing a displacement sensitivity of 10-18 m in a 100 Hz band centered on 150 Hz. With a new feedback strategy, we dynamically shift the resonant frequency of a 2.7 kg pendulum mode to lie within this optimal band, where its effective temperature falls as low as 1.4 μK, and its occupation number reaches about 200 quanta. This work shows how the exquisite sensitivity necessary to detect gravitational waves can be made available to probe the validity of quantum mechanics on an enormous mass scale.
Energy Technology Data Exchange (ETDEWEB)
Arbuzov, V.I.; Kangro, A.R.; Rogulis, U.T.; Tolstoi, M.N.; Vitol, I.K.
1986-11-01
This paper attempts to establish the effect of temperature on the tunnel luminescence (TL) in a region of temperature (less than 90 K) at which effective absorption and emission of vibrational quanta are possible but the suprabarrier processes are ruled out. It is shown that the intensity of TL of pure and Tb/sup 3 +/-activated Na20.3SiO/sub 2/ glass excited at 120 K increases over the 40 to 90 K range. This temperature dependence of TL is produced by the thermoactivated tunnel transport of electrons with less than the threshold mobility along the trapping centers which precedes the radiative tunnel recombination. The energy of the thermal activation of such a transport is only 2-3 times greater than that of the thermal vibrations.
Flux Exclusion Superconducting Quantum Metamaterial: Towards Quantum-level Switching
Savinov, V.; Tsiatmas, A.; Buckingham, A. R.; Fedotov, V. A.; de Groot, P. A. J.; Zheludev, N. I.
2012-01-01
Nonlinear and switchable metamaterials achieved by artificial structuring on the subwavelength scale have become a central topic in photonics research. Switching with only a few quanta of excitation per metamolecule, metamaterial's elementary building block, is the ultimate goal, achieving which will open new opportunities for energy efficient signal handling and quantum information processing. Recently, arrays of Josephson junction devices have been proposed as a possible solution. However, they require extremely high levels of nanofabrication. Here we introduce a new quantum superconducting metamaterial which exploits the magnetic flux quantization for switching. It does not contain Josephson junctions, making it simple to fabricate and scale into large arrays. The metamaterial was manufactured from a high-temperature superconductor and characterized in the low intensity regime, providing the first observation of the quantum phenomenon of flux exclusion affecting the far-field electromagnetic properties of the metamaterial. PMID:22690319
The light-cone Fock state expansion and hadron physics phenomenology
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.J.
1997-06-01
The light-cone Fock expansion is defined in the following way: one first constructs the light-cone time evolution operator and the invariant mass operator in light-cone gauge from the QCD Lagrangian. The total longitudinal momentum and transverse momenta are conserved, i.e. are independent of the interactions. The matrix elements of the invariant mass operator on the complete orthonormal basis of the free theory can then be constructed. The matrix elements connect Fock states differing by 0, 1, or 2 quark or gluon quanta, and they include the instantaneous quark and gluon contributions imposed by eliminating dependent degrees of freedom in light-cone gauge. Applications of light-cone methods to QCD phenomenology are briefly described.
Brächer, T.; Heussner, F.; Pirro, P.; Meyer, T.; Fischer, T.; Geilen, M.; Heinz, B.; Lägel, B.; Serga, A. A.; Hillebrands, B.
2016-12-01
Magnonic spin currents in the form of spin waves and their quanta, magnons, are a promising candidate for a new generation of wave-based logic devices beyond CMOS, where information is encoded in the phase of travelling spin-wave packets. The direct readout of this phase on a chip is of vital importance to couple magnonic circuits to conventional CMOS electronics. Here, we present the conversion of the spin-wave phase into a spin-wave intensity by local non-adiabatic parallel pumping in a microstructure. This conversion takes place within the spin-wave system itself and the resulting spin-wave intensity can be conveniently transformed into a DC voltage. We also demonstrate how the phase-to-intensity conversion can be used to extract the majority information from an all-magnonic majority gate. This conversion method promises a convenient readout of the magnon phase in future magnon-based devices.
Volfson, Boris
2013-09-01
The hypothesis of transition from a chaotic Dirac Sea, via highly unstable positronium, into a Simhony Model of stable face-centered cubic lattice structure of electrons and positrons securely bound in vacuum space, is considered. 13.75 Billion years ago, the new lattice, which, unlike a Dirac Sea, is permeable by photons and phonons, made the Universe detectable. Many electrons and positrons ended up annihilating each other producing energy quanta and neutrino-antineutrino pairs. The weak force of the electron-positron crystal lattice, bombarded by the chirality-changing neutrinos, may have started capturing these neutrinos thus transforming from cubic crystals into a quasicrystal lattice. Unlike cubic crystal lattice, clusters of quasicrystals are "slippery" allowing the formation of centers of local torsion, where gravity condenses matter into galaxies, stars and planets. In the presence of quanta, in a quasicrystal lattice, the Majorana neutrinos' rotation flips to the opposite direction causing natural transformations in a category comprised of three components; two others being positron and electron. In other words, each particle-antiparticle pair "e-" and "e+", in an individual crystal unit, could become either a quasi- component "e- ve e+", or a quasi- component "e+ - ve e-". Five-to-six six billion years ago, a continuous stimulation of the quasicrystal aetherial lattice by the same, similar, or different, astronomical events, could have triggered Hebbian and anti-Hebbian learning processes. The Universe may have started writing script into its own aether in a code most appropriate for the quasicrystal aether "hardware": Eight three-dimensional "alphabet" characters, each corresponding to the individual quasi-crystal unit shape. They could be expressed as quantum Turing machine qubits, or, alternatively, in a binary code. The code numerals could contain terminal and nonterminal symbols of the Chomsky's hierarchy, wherein, the showers of quanta, forming the
Study for luminescence performance of three methyl xanthine derivatives
Wei, Yan-Li; Dong, Chuan; Shuang, Shao-Min; Liu, Dian-Sheng
2005-09-01
In this paper, the low-temperature phosphorescence (LTP), the low-temperature fluorescence (LTF), the paper substrate room-temperature phosphorescence (PS-RTP) and the room fluorescence (RTF) properties of caffeine (CF), theophylline (TP), and theobromine (TB) are investigated and compared, and some rules are found out: their maximal excitation wavelength and emission wavelength are in the range of 270-300 nm and 395-445 nm, respectively. And the PS-RTP characters of lifetime, polarization and quanta yield are also investigated and compared. It is found that their lifetimes of PS-RTP are all in the level of 0.1 s. They belong to long-life phosphorescence and their PS-RTP spectra are incompletely polarized.
Holographic Theory of Gravity and Cosmology
Ng, Y Jack
2016-01-01
According to the holographic principle, the maximum amount of information stored in a region of space scales as the area of its two-dimensional surface, like a hologram. We show that the holographic principle can be understood heuristically as originated from quantum fluctuations of spacetime. Applied to cosmology, this consideration leads to a dynamical cosmological constant $\\Lambda$ of the observed magnitude, in agreement with the result obtained for the present and recent cosmic eras, by using unimodular gravity and causal-set theory. By generalizing the concept of entropic gravity, we find a critical acceleration parameter related to $\\Lambda$ in galactic dynamics, and we construct a phenomenological model of dark matter which we call "modified dark matter" (MDM). We provide successful observational tests of MDM at both the galactic and cluster scales. We also discuss the possibility that the quanta of both dark energy and dark matter obey the quantum Boltzmann statistics or infinite statistics as descri...
Direct Measurement of Photon Recoil from a Levitated Nanoparticle
Jain, Vijay; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas
2016-01-01
The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency $\\Omega_0$, this measurement back-action adds quanta $\\hbar\\Omega_0$ to the oscillator's energy at a rate $\\Gamma_{\\rm recoil}$, a process called photon recoil heating, and sets bounds to quantum coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure $\\Gamma_{\\rm recoil}$. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to micro-Kelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for th...
Statistics of black hole radiance and the horizon area spectrum
Bekenstein, Jacob D
2015-01-01
The statistical response of a Kerr black hole to incoming quantum radiation has heretofore been studied by the methods of maximum entropy or quantum field theory in curved spacetime. Neither approach pretends to take into account the quantum structure of the black hole itself. To address this last issue we calculate here the conditional probability distribution associated with the hole's response by assuming that the horizon area has a discrete quantum spectrum, and that its quantum evolution corresponds to jumps between adjacent area eigenvalues, possibly occurring in series, with consequent emission or absorption of quanta, possibly in the same mode. This "atomic" model of the black hole is implemented in two different ways and recovers the previously calculated radiation statistics in both cases. The corresponding conditional probably distribution is here expressed in closed form in terms of an hypergeometric function.
Features of multiphoton-stimulated bremsstrahlung in a quantized field
Burenkov, Ivan A.; Tikhonova, Olga V.
2010-12-01
The process of absorption and emission of external field quanta by a free electron during the scattering on a potential centre is investigated in the case of interaction with a quantized electromagnetic field. The analytical expression for differential cross-sections and probabilities of different multiphoton channels are obtained. We demonstrate that in the case of a non-classical 'squeezed vacuum' initial field state the probability for the electron to absorb a large number of photons appears to be larger by several orders of magnitude in comparison to the classical field and leads to the formation of the high-energy plateau in the electron energy spectrum. The generalization of the Marcuse effect to the case of the quantized field is worked out. The total probability of energy absorption by electron from the non-classical light is analysed.
Features of multiphoton-stimulated bremsstrahlung in a quantized field
Energy Technology Data Exchange (ETDEWEB)
Burenkov, Ivan A; Tikhonova, Olga V, E-mail: ovtikhonova@mail.r [Institute of Nuclear Physics, Moscow State University, Leninskie Gory 1, Moscow, 119991 (Russian Federation)
2010-12-14
The process of absorption and emission of external field quanta by a free electron during the scattering on a potential centre is investigated in the case of interaction with a quantized electromagnetic field. The analytical expression for differential cross-sections and probabilities of different multiphoton channels are obtained. We demonstrate that in the case of a non-classical 'squeezed vacuum' initial field state the probability for the electron to absorb a large number of photons appears to be larger by several orders of magnitude in comparison to the classical field and leads to the formation of the high-energy plateau in the electron energy spectrum. The generalization of the Marcuse effect to the case of the quantized field is worked out. The total probability of energy absorption by electron from the non-classical light is analysed.
A unified approach to equilibrium statistics in closed systems with random dynamics
Biró, Tamás S
2016-01-01
In a balanced version of decay and growth processes a simple master equation arrives at a final state including the Poisson, Bernoulli, negative binomial and P\\'olya distribution. Such decay and growth rates incorporate a symmetry between the observed subsystem and the rest of a total system with fixed total number of states, K, and occupation numbers N. We give both a complex network and a particle production dynamics interpretation. For networks we follow the evolution of the degree distribution, P(n), in a directed network where a node can activate k fixed connections from K possible partnerships among all nodes while n is a random variable counting the links per node, and N is the total number of connections, which is also fixed. For particle physics problems P(n) is the probability of having n particles (or other quanta) distributed among k states (phase space cells) while altogether a fixed number of N particles reside on K states.
Regular vibrational state progressions at the dissociation limit of SCCl2.
Chowdary, Praveen D; Gruebele, Martin
2009-01-14
We observe sharp features in the vibrational spectrum of SCCl(2) at and above its two lowest-lying dissociation limits. Highly regular vibrational progressions persist at dissociation, as in some smaller molecules studied previously by others. Nearly all of the SCCl(2) transitions studied by stimulated emission pumping can be assigned and fitted by a simple effective Hamiltonian without resonance terms, up to a total vibrational excitation of 36 quanta. The character of the highly excited vibrational wave functions is not normal mode-like, but it nonetheless arises gradually from the normal modes as the energy increases. The number of sharp vibrational features observed matches a scaling model that predicts localization of nearly all vibrational states near dissociation as the size of a polyatomic molecule increases.
Improved high-fidelity transport of trapped-ion qubits through a multi-dimensional array
Blakestad, R B; VanDevender, A P; Wesenberg, J H; Biercuk, M J; Leibfried, D; Wineland, D J
2011-01-01
We have demonstrated transport of Be+ ions through a 2D Paul-trap array that incorporates an X-junction, while maintaining the ions near the motional ground-state of the confining potential well. We expand on the first report of the experiment [1], including a detailed discussion of how the transport potentials were calculated. Two main mechanisms that caused motional excitation during transport are explained, along with the methods used to mitigate such excitation. We reduced the motional excitation below the results in Ref. [1] by a factor of approximately 50. The effect of a mu-metal shield on qubit coherence is also reported. Finally, we examined a method for exchanging energy between multiple motional modes on the few-quanta level, which could be useful for cooling motional modes without directly accessing the modes with lasers. These results establish how trapped ions can be transported in a large-scale quantum processor with high fidelity.
Towards a Quantum Theory of Solitons
Dvali, Gia; Gruending, Lukas; Rug, Tehseen
2015-01-01
We formulate a quantum coherent state picture for topological and non-topological solitons. We recognize that the topological charge arises from the infinite occupation number of zero momentum quanta flowing in one direction. Thus, the Noether charge of microscopic constituents gives rise to a topological charge in the macroscopic description. This fact explains the conservation of topological charge from the basic properties of coherent states. It also shows that no such conservation exists for non-topological solitons, which have finite mean occupation number. Consequently, they can have an exponentially-small but non-zero overlap with the vacuum, leading to vacuum instability. This amplitude can be interpreted as a coherent state description of false vacuum decay. Next we show that we can represent topological solitons as a convolution of two sectors that carry information about topology and energy separately, which makes their difference very transparent. Finally, we show how interaction among the soliton...
Ultralow thermal conductivity in Electrolessly Etched (EE) Silicon Nanowires
Hippalgaonkar, Kedar; Chen, Renkun; Budaev, Bair; Tang, Jinyao; Andrews, Sean; Murphy, Padraig; Mukerjee, Subroto; Moore, Joel; Yang, Peidong; Majumdar, Arun
2009-03-01
EE process produces single-crystalline Silicon nanowires with rough walls. We use suspended structures to directly compute the heat transfer through single nanowires. Nanowires with diameters less than the mean free path of phonons impede transport by boundary scattering. The roughness acts as a secondary scattering mechanism to further reduce phonon transport. By controlling the amount of roughness it is possible to push limits to the extent that nanowire conductance close to quanta of thermal conductance,πkB^2 T / πkB^2 T 6 . - 6 is observed. Traditionally, the lower limit of conductivity is amorphous Silicon at 1 W/mK at room temperature. The measured conductivity of our nanostructures challenges even this amorphous limit pointing towards previously unstudied mechanisms of thermal resistance. We measure thermal conductivity of ˜150nm diameter EE wires to be ˜1 W/mK.
Physics at TeV e{sup +}e{sup {minus}} linear colliders
Energy Technology Data Exchange (ETDEWEB)
Chanowitz, M.S.
1992-01-01
A survey is presented of the physics opportunities at TeV e{sup +}e{sup {minus}} linear colliders. Examples are given of physics that might emerge in e{sup +}e{sup {minus}} collisions and in {gamma}{gamma} collisions using the back-scattered laser technique, including {gamma}{gamma} {yields} ZZ scattering as a probe of ultraheavy quanta. The second portion of the talk focuses on physics that must emerge at or below the TeV scale--the mechanism of electroweak symmetry breaking. In particular a very rough estimate is presented of the most challenging possible signal of symmetry breaking, strong WW scattering, as a function of collider energy. A subtheme, made explicit in the concluding section, is the continuing complementarity of e{sup +}e{sup {minus}} and pp colliders in the domain of TeV physics.
Physics at TeV e sup + e sup minus linear colliders
Energy Technology Data Exchange (ETDEWEB)
Chanowitz, M.S.
1992-01-01
A survey is presented of the physics opportunities at TeV e{sup +}e{sup {minus}} linear colliders. Examples are given of physics that might emerge in e{sup +}e{sup {minus}} collisions and in {gamma}{gamma} collisions using the back-scattered laser technique, including {gamma}{gamma} {yields} ZZ scattering as a probe of ultraheavy quanta. The second portion of the talk focuses on physics that must emerge at or below the TeV scale--the mechanism of electroweak symmetry breaking. In particular a very rough estimate is presented of the most challenging possible signal of symmetry breaking, strong WW scattering, as a function of collider energy. A subtheme, made explicit in the concluding section, is the continuing complementarity of e{sup +}e{sup {minus}} and pp colliders in the domain of TeV physics.
Abdel-Latif, Mahmoud K
2011-01-01
The excitation of the degenerate $E_1$ carbonyl stretching vibrations in dimanganese decacarbonyl is shown to trigger wave packet circulation in the subspace of these two modes. On the time scale of about 5 picoseconds intramolecular anharmonic couplings do not cause appreciable disturbance, even under conditions where the two $E_1$ modes are excited by up to about two vibrational quanta each. The compactness of the circulating wave packet is shown to depend strongly on the excitation conditions such as pulse duration and field strength. Numerical results for the solution of the seven-dimensional vibrational Schr\\"odinger equation are obtained for a density functional theory based potential energy surface and using the multi-configuration time-dependent Hartree method.
Einstein's quantum theory of the monatomic ideal gas: non-statistical arguments for a new statistics
Pérez, Enric
2010-01-01
In this article, we analyze the third of three papers, in which Einstein presented his quantum theory of the ideal gas of 1924-1925. Although it failed to attract the attention of Einstein's contemporaries and although also today very few commentators refer to it, we argue for its significance in the context of Einstein's quantum researches. It contains an attempt to extend and exhaust the characterization of the monatomic ideal gas without appealing to combinatorics. Its ambiguities illustrate Einstein's confusion with his initial success in extending Bose's results and in realizing the consequences of what later became to be called Bose-Einstein statistics. We discuss Einstein's motivation for writing a non-combinatorial paper, partly in response to criticism by his friend Ehrenfest, and we paraphrase its content. Its arguments are based on Einstein's belief in the complete analogy between the thermodynamics of light quanta and of material particles and invoke considerations of adiabatic transformations as ...
'Nature and the Greeks' and 'Science and Humanism'
Schrödinger, Erwin
2014-11-01
Foreword; Part I. Nature and the Greeks: 1. The motives for returning to ancient thought; 2. The competition, reason v. senses; 3. The Pythagoreans; 4. The Ionian enlightenment; 5. The religion of Xenophanes, Heraclitus of Ephesus; 6. The atomists; 7. What are the special features?; Part II. Science and Humanism: 1. The spiritual bearing of science on life; 2. The practical achievements of science tending to obliterate its true import; 3. A radical change in our ideas of matter; 4. Form, not substance, the fundamental concept; 5. The nature of our 'models'; 6. Continuous descriptions and causality; 7. The intricacy of the continuum; 8. The makeshift of wave mechanics; 9. The alleged breakdown of the barrier between subject and object; 10. Atoms or quanta - the counter-spell of old standing, to escape the intricacy of the continuum; 11. Would physical indeterminacy give free will a chance?; 12. The bar to prediction, according to Niels Bohr; Literature.
Quantum Entanglement of Very High Angular Momenta
Fickler, Robert; Plick, William N; Krenn, Mario; Schaeff, Christoph; Ramelow, Sven; Zeilinger, Anton
2012-01-01
Single photons with helical phase structure may carry a quantized amount of orbital angular momentum (OAM) and are of great interest in quantum information science and fundamental tests of quantum theory. Since there is no theoretical upper limit on how many quanta of OAM a single photon can carry, those systems offer the possibility to create superpositions for one particle and entanglement between two particles with an arbitrary high difference in the quantum number. By transferring polarization entanglement to the OAM degree-of-freedom with an interferometric scheme, we created and observed entanglement up to $600\\bar{h}$ difference in the orbital angular momentum. To our knowledge, we have thus demonstrated entanglement of the highest quantum number in any experiment so far. The only restrictive factor towards even higher numbers arises due to current technical limitations. Furthermore, we show experimentally that the entanglement of very high OAM can be used to improve applications, like the sensitivity ...
A unified theory of quantum Hall effect and high temperature superconductivity
Fujita, Shigeji; Suzuki, Akira
2014-03-01
The quantum Hall effect (QHE) and high temperature superconductivity (HTSC) have remarkable common features. They occur only in two-dimensional (2D) solids. The critical temperature Tc of some HTSC exceeds 160K while the room temperature QHE is observed in graphene. The cause of both QHE and HTSC is the phonon exchange attraction. We develop a theoretical model for the QHE in terms of the composite bosons (fermions), each containing an electron and an odd (even) number of fluxons (magnetic flux quanta). The composite particles (boson, fermion) are bound by the phonon exchange attraction. If the Bose-Einstein condensation (BEC) of the composite (c)- bosons occurs, then the system exhibits zero resistivity and the associated Hall conductivity plateau. The Hall conductivity is calculated rigorously without averaging. The mystery of the fractional charge carried by the c-bosons is resolved in our model.
Readily releasable pool of synaptic vesicles measured at single synaptic contacts.
Trigo, Federico F; Sakaba, Takeshi; Ogden, David; Marty, Alain
2012-10-30
To distinguish between different models of vesicular release in brain synapses, it is necessary to know the number of vesicles of transmitter that can be released immediately at individual synapses by a high-calcium stimulus, the readily releasable pool (RRP). We used direct stimulation by calcium uncaging at identified, single-site inhibitory synapses to investigate the statistics of vesicular release and the size of the RRP. Vesicular release, detected as quantal responses in the postsynaptic neuron, showed an unexpected stochastic variation in the number of quanta from stimulus to stimulus at high intracellular calcium, with a mean of 1.9 per stimulus and a maximum of three or four. The results provide direct measurement of the RRP at single synaptic sites. They are consistent with models in which release proceeds from a small number of vesicle docking sites with an average occupancy around 0.7.
Nonclassical correlations between single photons and phonons from a mechanical oscillator
Riedinger, Ralf; Norte, Richard A; Slater, Joshua A; Shang, Juying; Krause, Alexander G; Anant, Vikas; Aspelmeyer, Markus; Gröblacher, S
2015-01-01
Interfacing a single photon with another quantum system is a key capability in modern quantum information science. It allows quantum states of matter, such as spin states of atoms, atomic ensembles or solids, to be prepared and manipulated by photon counting and, in particular, to be distributed over long distances. Such light-matter interfaces have become crucial for fundamental tests of quantum physics as well as for realizations of quantum networks. Here we report nonclassical correlations between single photons and phonons -- the quanta of mechanical motion -- from a nanomechanical resonator. We implement a full quantum protocol involving initialization of the resonator in its quantum ground state of motion and subsequent generation and readout of correlated photon-phonon pairs. The observed violation of a Cauchy-Schwarz inequality is clear evidence for the nonclassical nature of the generated mechanical state. Our results show the availability of on-chip solid-state mechanical resonators as light-matter ...
State refinements and coarse graining in a full theory embedding of loop quantum cosmology
Bodendorfer, Norbert
2016-01-01
Bridging between descriptions involving few large and many small quantum numbers is the main open problem in loop quantum gravity. In other words, one would like to be able to represent the same physical system in terms of a few "coarse" quantum numbers, while the effective dynamics at the coarse level should agree with the one induced by a description involving many small quantum numbers. Efforts to understand this relationship face the problem of the enormous computational complexity involved in evolving a generic state containing many quanta. In a cosmological context however, certain symmetry assumptions on the quantum states allow to simplify the problem. In this paper, we will show how quantum states describing a spatially flat homogeneous and isotropic universe can be refined while the dynamics of the coarse observables is unchanged. The involved states are solutions to the Hamiltonian constraint when terms coming from spatial derivatives are neglected, i.e. one works in the approximation of non-intera...
Asynchronous discrete event schemes for PDEs
Stone, D.; Geiger, S.; Lord, G. J.
2017-08-01
A new class of asynchronous discrete-event simulation schemes for advection-diffusion-reaction equations is introduced, based on the principle of allowing quanta of mass to pass through faces of a (regular, structured) Cartesian finite volume grid. The timescales of these events are linked to the flux on the face. The resulting schemes are self-adaptive, and local in both time and space. Experiments are performed on realistic physical systems related to porous media flow applications, including a large 3D advection diffusion equation and advection diffusion reaction systems. The results are compared to highly accurate reference solutions where the temporal evolution is computed with exponential integrator schemes using the same finite volume discretisation. This allows a reliable estimation of the solution error. Our results indicate a first order convergence of the error as a control parameter is decreased, and we outline a framework for analysis.
Ramsey Interference with Single Photons
Clemmen, Stéphane; Farsi, Alessandro; Ramelow, Sven; Gaeta, Alexander L.
2016-11-01
Interferometry using discrete energy levels of nuclear, atomic, or molecular systems is the foundation for a wide range of physical phenomena and enables powerful techniques such as nuclear magnetic resonance, electron spin resonance, Ramsey-based spectroscopy, and laser or maser technology. It also plays a unique role in quantum information processing as qubits may be implemented as energy superposition states of simple quantum systems. Here, we demonstrate quantum interference involving energy states of single quanta of light. In full analogy to the energy levels of atoms or nuclear spins, we implement a Ramsey interferometer with single photons. We experimentally generate energy superposition states of a single photon and manipulate them with unitary transformations to realize arbitrary projective measurements. Our approach opens the path for frequency-encoded photonic qubits in quantum information processing and quantum communication.
Transfer of optical orbital angular momentum to a bound electron
Schmiegelow, Christian T.; Schulz, Jonas; Kaufmann, Henning; Ruster, Thomas; Poschinger, Ulrich G.; Schmidt-Kaler, Ferdinand
2016-10-01
Photons can carry angular momentum, not only due to their spin, but also due to their spatial structure. This extra twist has been used, for example, to drive circular motion of microscopic particles in optical tweezers as well as to create vortices in quantum gases. Here we excite an atomic transition with a vortex laser beam and demonstrate the transfer of optical orbital angular momentum to the valence electron of a single trapped ion. We observe strongly modified selection rules showing that an atom can absorb two quanta of angular momentum from a single photon: one from the spin and another from the spatial structure of the beam. Furthermore, we show that parasitic ac-Stark shifts from off-resonant transitions are suppressed in the dark centre of vortex beams. These results show how light's spatial structure can determine the characteristics of light-matter interaction and pave the way for its application and observation in other systems.
Chirality as an inherent general property of matter.
Davankov, Vadim
2006-08-01
A statement has been formulated that chirality is an indispensable inherent property of all material objects, at one level of organization of matter or another. The translation of chirality from one level of material objects to another deserves our attention. The parity violation of weak interactions can be discussed in terms of the homochirality of the pool of fundamental particles, as it translates into optical activity of metal vapors. Individual photons and energy quanta are considered to be chiral entities, too, since they can be separated into beams of circularly polarized radiation. The chiral structure of the universe has been proposed and a method of determining the orientation of the axis of rotation of the universe suggested.
Wilczek, Frank
2004-01-01
Powerful symmetry principles have guided physicists in their quest for nature's fundamental laws. The successful gauge theory of electroweak interactions postulates a more extensive symmetry for its equations than are manifest in the world (8 pages) Powerful symmetry principles have guided physicists in their quest for nature's fundamental laws. The successful gauge theory of electroweak interactions postulates a more extensive symmetry for its equations than are manifest in the world. The discrepancy is ascribed to a pervasive symmetry-breaking field, which fills all space uniformly, rendering the Universe a sort of exotic superconductor. So far, the evidence for these bold ideas is indirect. But soon the theory will undergo a critical test depending on whether the quanta of this symmetry-breaking field, the so-called Higgs particles, are produced at the Large Hadron Collider (due to begin operation in 2007).
Amplified Fermion Production from Overpopulated Bose Fields
Berges, J; Sexty, D
2014-01-01
We study the real-time dynamics of fermions coupled to scalar fields in a linear sigma model, which is often employed in the context of preheating after inflation or as a low-energy effective model for quantum chromodynamics. We find a dramatic amplification of fermion production in the presence of highly occupied bosonic quanta for weak as well as strong couplings. For this we consider the range of validity of different methods: lattice simulations with male/female fermions, the mode functions approach and the quantum 2PI effective action with its associated kinetic theory. For strongly coupled fermions we find a rapid approach to a Fermi-Dirac distribution with time-dependent temperature and chemical potential parameters, while the bosons are still far from equilibrium.
Institute of Scientific and Technical Information of China (English)
王朝; 刘建伟; 陈秀波; 毕亚港; 尚涛
2015-01-01
This study proposes two novel fault tolerant deterministic secure quantum communication (DSQC) schemes resistant to collective noise using logical Bell states. Either DSQC scheme is constructed based on a new coding function, which is designed by exploiting the property of the corresponding logical Bell states immune to collective-dephasing noise and collective-rotation noise, respectively. The secret message can be encoded by two simple unitary operations and decoded by merely performing Bell measurements, which can make the proposed scheme more convenient in practical applications. Moreover, the strategy of one-step quanta transmission, together with the technique of decoy logical qubits checking not only reduces the influence of other noise existing in a quantum channel, but also guarantees the security of the communi-cation between two legitimate users. The final analysis shows that the proposed schemes are feasible and robust against various well-known attacks over the collective noise channel.
Modification of Textile Materials' Surface Properties Using Chemical Softener
Directory of Open Access Journals (Sweden)
Jurgita KOŽENIAUSKIENĖ
2011-03-01
Full Text Available In the present study the effect of technological treatment involving the processes of washing or washing and softening with chemical cationic softener "Surcase" produced in Great Britain on the surface properties of cellulosic textile materials manufactured from cotton, bamboo and viscose spun yarns was investigated. The changes in textile materials surface properties were evaluated using KTU-Griff-Tester device and FEI Quanta 200 FEG scanning electron microscope (SEM. It was observed that the worst hand properties and the higher surface roughness are observed of cotton materials if compared with those of bamboo and viscose materials. Also, it was shown that depending on the material structure the handle parameters of knitted materials are the better than the ones of woven fabrics.http://dx.doi.org/10.5755/j01.ms.17.1.249
Nonlinear nanomechanical resonators for quantum optoelectromechanics
Rips, S; Hartmann, M J
2012-01-01
We present a scheme for enhancing the anharmonicity of nanomechanical resonators by subjecting them to inhomogenous electrostatic fields. We show that this approach enables access to a novel regime of optomechanics, where the nonlinearity per quanta of the mechanical motion becomes comparable to the linewidth of the optical cavities employed. In this "resolved nonlinearity regime" transitions between phonon Fock states of the mechanical resonator can be selectively addressed. As one application we show that our approach would allow to prepare stationary phonon Fock states in experimentally realistic devices. Such states are manifestly non-classical as they show pronounced negative Wigner functions. We calculate the mechanical steady state by tracing out the cavity modes in the weak optomechanical coupling limit and corroborate our results by a numerical analysis of the full dynamics including the cavity modes. Finally, we show how the negativity of the stationary states' Wigner function can be read off the ou...
Femtosecond Transient Absorption Spectra and Relaxation Dynamics of SWNT in SDS Micellar Solutions
Nadtochenko, V. A.; Lobach, A. S.; Gostev, F. E.; Tcherbinin, D. O.; Sobennikov, A.; Sarkisov, O. M.
2005-09-01
Transient absorption spectra and relaxation dynamics of excited SWNT were studied by femtosecond absorption spectroscopy as a function of: the energy of excitation quanta (ℏω = 2 eV, 2.5 eV, 4 eV); the density of the excitation energy; polarizations of the pump and probe pulses. The transient absorption spectra were monitored by white supercontinuum light pulse in the spectral region of ˜ 1.2 ÷ 3.6 eV. The induced transient absorption spectra of SWNT are considered as filling of the size-quantized energy bands with nonequilibrium carriers; renormalization of the one-dimensional energy bands at high density of the induced plasma; quantum confined Stark effect and screening of excitons. The anisotropic relaxation rate is observed.
Gorelova, Olga; Baulina, Olga; Solovchenko, Alexei; Selyakh, Irina; Chivkunova, Olga; Semenova, Larisa; Scherbakov, Pavel; Burakova, Olga; Lobakova, Elena
2015-03-01
A quantitative micromorphometric study of the cell compartment rearrangements was performed in a symbiotic chlorophyte Desmodesmus sp. 3Dp86E-1 grown on nitrogen (N) replete or N-free medium under 480 μmol PAR quanta m(-2) s(-1). The changes in the chloroplast, intraplastidial, and cytoplasmic inclusions induced by high light (HL) and N starvation were similar to those characteristic of free-living chlorophytes. The N-sufficient culture responded to HL by a transient swelling of the thylakoid lumen and a decline in photosynthetic efficiency followed by its recovery. In the N-starving cells, a more rapid expansion and thylakoid swelling occurred along with the irreversible decline in the photosynthetic efficiency. Differential induction of starch grains, oil bodies, and cell wall polysaccharides depending on the stress exposure and type was recorded. Tight relationships between the changes in the assimilatory and storage compartments in the stressed Desmodesmus sp. cells were revealed.
Leite, Anderson Cleiton Fernandes; Simon,Samuel
2013-01-01
O objetivo deste artigo é analisar os usos que Werner Heisenberg fez da filosofia grega em sua obra. Pretende-se relacionar tais usos não apenas com a argumentação interna presente nos textos do físico alemão, mas também com o contexto histórico, conflitos e debates entre as diversas interpretações da teoria dos quanta durante a primeira metade do século XX. Faremos, inicialmente, uma apresentação geral da teoria quântica e da presença da filosofia na obra de Heisenberg e, em seguida, um estu...
Bottleneck Accumulation of Hybrid Magnetoelastic Bosons
Bozhko, Dmytro A.; Clausen, Peter; Melkov, Gennadii A.; L'vov, Victor S.; Pomyalov, Anna; Vasyuchka, Vitaliy I.; Chumak, Andrii V.; Hillebrands, Burkard; Serga, Alexander A.
2017-06-01
An ensemble of magnons, quanta of spin waves, can be prepared as a Bose gas of weakly interacting quasiparticles. Furthermore, the thermalization of the overpopulated magnon gas through magnon-magnon scattering processes, which conserve the number of particles, can lead to the formation of a Bose-Einstein condensate at the bottom of a spin-wave spectrum. However, magnon-phonon scattering can significantly modify this scenario and new quasiparticles are formed—magnetoelastic bosons. Our observations of a parametrically populated magnon gas in a single-crystal film of yttrium iron garnet by means of wave-vector-resolved Brillouin light scattering spectroscopy evidence a novel condensation phenomenon: A spontaneous accumulation of hybrid magnetoelastic bosonic quasiparticles at the intersection of the lowest magnon mode and a transversal acoustic wave.
Pulse-shape discrimination with PbWO$_4$ crystal scintillators
Bardelli, L; Bizzeti, P G; Danevich, F A; Fazzini, T F; Kobychev, V V; Krutyak, N; Maurenzig, P R; Mokina, V M; Nagorny, S S; Pashkovskii, M; Poda, D V; Tretyak, V I; Yurchenko, S S
2007-01-01
The light output, $\\alpha/\\beta$ ratio, and pulse shape have been investigated at $-25^\\circ$ C with PbWO$_4$ crystal scintillators undoped, and doped by F, Eu, Mo, Gd and S. The fast $0.01-0.06 \\mu$s and middle $0.1-0.5 \\mu$s components of scintillation decay were observed for all the samples. Slow components of scintillation signal with the decay times $1-3 \\mu$s and $13-28 \\mu$s with the total intensity up to $\\approx50%$ have been recognized for several samples doped by Molybdenum. We found some indications of a pulse-shape discrimination between $\\alpha$ particles and $\\gamma$ quanta with PbWO$_4$ (Mo doped) crystal scintillators.
Tretyak, V I; Bernabei, R; Brudanin, V B; Cappella, F; Caracciolo, V; Cerulli, R; Chernyak, D M; Danevich, F A; d'Angelo, S; Incicchitti, A; Laubenstein, M; Mokina, V M; Poda, D V; Polischuk, O G; Podviyanuk, R B; Tupitsyna, I A
2013-01-01
An experiment to search for double beta processes in 106Cd by using cadmium tungstate crystal scintillator enriched in 106Cd (106CdWO4) in coincidence with the four crystals HPGe detector GeMulti is in progress at the STELLA facility of the Gran Sasso underground laboratory of INFN (Italy). The 106CdWO4 scintillator is viewed by a low-background photomultiplier tube through a lead tungstate crystal light-guide produced from deeply purified archaeological lead to suppress gamma quanta from the photomultiplier tube. Here we report the first results of the experiment after 3233 hours of the data taking. A few new improved limits on double beta processes in 106Cd are obtained, in particular T1/2(2nuECb+) > 8.4e20 yr at 90% C.L.
Pulse-shape discrimination with PbWO{sub 4} crystal scintillators
Energy Technology Data Exchange (ETDEWEB)
Bardelli, L.; Bini, M.; Bizzeti, P.G. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Danevich, F.A. [Institute for Nuclear Research, Prospect Nauki 47, MSP 03680 Kyiv (Ukraine)], E-mail: danevich@kinr.kiev.ua; Fazzini, T.F. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Krutyak, N. [Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Vorob' evy Gory, 119992 Moscow (Russian Federation); Kobychev, V.V. [Institute for Nuclear Research, Prospect Nauki 47, MSP 03680 Kyiv (Ukraine); Maurenzig, P.R. [Dipartimento di Fisica, Universita di Firenze and INFN, 50019 Florence (Italy); Mokina, V.M.; Nagorny, S.S. [Institute for Nuclear Research, Prospect Nauki 47, MSP 03680 Kyiv (Ukraine); Pashkovskii, M. [Department of Semiconductors Physics, Ivan Franko National University, UA-79005 Lviv (Ukraine); Poda, D.V.; Tretyak, V.I.; Yurchenko, S.S. [Institute for Nuclear Research, Prospect Nauki 47, MSP 03680 Kyiv (Ukraine)
2008-01-01
Light output, {alpha}/{beta} ratio, and pulse shape have been investigated at -25 deg. C with PbWO{sub 4} crystal scintillators undoped, and doped by F, Eu, Mo, Gd and S. The fast 0.01-0.06{mu}s and middle 0.1-0.5{mu}s components of scintillation decay were observed for all the samples. Slow components of scintillation signal with decay times 1-3 and 13-28{mu}s with total intensity up to {approx}50% have been recognized for several samples doped by Molybdenum. We found some indications of a pulse-shape discrimination between {alpha} particles and {gamma} quanta with PbWO{sub 4} (Mo doped) crystal scintillators.
Quantum cosmology from group field theory condensates: a review
Gielen, Steffen
2016-01-01
We give, in some detail, a critical overview over recent work towards deriving a cosmological phenomenology from the fundamental quantum dynamics of group field theory (GFT), based on the picture of a macroscopic universe as a "condensate" of a large number of quanta of geometry which are given by excitations of the GFT field over a "no-space" vacuum. We emphasise conceptual foundations, relations to other research programmes in GFT and the wider context of loop quantum gravity (LQG), and connections to the quantum physics of real Bose-Einstein condensates. We show how to extract an effective dynamics for GFT condensates from the microscopic GFT physics, and how to compare it with predictions of more conventional quantum cosmology models, in particular loop quantum cosmology (LQC). No detailed familiarity with the GFT formalism is assumed.
Bennett, A J; Ellis, D J P; Farrer, I; Ritchie, D A; Shields, A J
2016-01-01
Photons do not interact directly with each other, but conditional control of one beam by another can be achieved with non-linear optical media at high field intensities. It is exceedingly difficult to reach such intensities at the single photon level but proposals have been made to obtain effective interactions by scattering photons from single transitions. We report here effective interactions between photons created using a quantum dot weakly coupled to a cavity. We show that a passive single-photon non-linearity can modify the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and sort polarisation correlated photons from an uncorrelated stream using a single spin. These results pave the way for optical switches operated by single quanta of light.
Kar, Supriya
2016-01-01
We show that the massless form fields, in $(4+1)$-dimensional non-perturbation theory of emergent gravity, become massive in a perturbative phase without Higgs mechanism. In particular an axionic scalar sourced by a non-perturbative dynamical correction is absorbed by the form fields to describe a massive NS field theory on an emergent gravitational pair of $(3{\\bar 3})$-brane. Arguably the novel idea of Higgs mechanism is naturally invoked in an emergent gravity underlying a ${\\rm CFT}_6$. Analysis reveals "gravito-weak" and "electro-weak" phases respectively on a vacuum pair in $(4+1)$ and $(3+1)$-dimensions. It is argued that the massive NS field quanta may govern an emergent graviton on a gravitational $3$-brane.
Physics of Gravitational Interaction: Geometry of Space or Quantum Field in Space?
Baryshev, Y
2006-01-01
Gravity theory is the basis of modern cosmological models. Thirring-Feynman's tensor field approach to gravitation is an alternative to General Relativity (GR). Though Field Gravity (FG) approach is still developing subject, it opens new understanding of gravitational interaction, stimulates novel experiments on the nature of gravity and gives possibility to construct new cosmological models in Minkowski space. According to FG, the universal gravity force is caused by exchange of gravitons - the quanta of gravity field. Energy of this field is well-defined and excludes the singularity. All classical relativistic effects are the same as in GR, though there are new effects, such as free fall of rotating bodies, scalar gravitational radiation, surface of relativistic compact bodies, which may be tested experimentally. The intrinsic scalar (spin 0) part of gravity field corresponds to "antigravity" and only together with the pure tensor (spin 2) part gives the usual Newtonian force. Laboratory and astrophysical e...
Heat transport through atomic contacts.
Mosso, Nico; Drechsler, Ute; Menges, Fabian; Nirmalraj, Peter; Karg, Siegfried; Riel, Heike; Gotsmann, Bernd
2017-02-06
Heat transport and dissipation at the nanoscale severely limit the scaling of high-performance electronic devices and circuits. Metallic atomic junctions serve as model systems to probe electrical and thermal transport down to the atomic level as well as quantum effects that occur in one-dimensional (1D) systems. Whereas charge transport in atomic junctions has been studied intensively in the past two decades, heat transport remains poorly characterized because it requires the combination of a high sensitivity to small heat fluxes and the formation of stable atomic contacts. Here we report heat-transfer measurements through atomic junctions and analyse the thermal conductance of single-atom gold contacts at room temperature. Simultaneous measurements of charge and heat transport reveal the proportionality of electrical and thermal conductance, quantized with the respective conductance quanta. This constitutes a verification of the Wiedemann-Franz law at the atomic scale.
Controlling fast transport of cold trapped ions
Walther, Andreas; Ruster, Thomas; Dawkins, Sam T; Ott, Konstantin; Hettrich, Max; Singer, Kilian; Schmidt-Kaler, Ferdinand; Poschinger, Ulrich
2012-01-01
We realize fast transport of ions in a segmented micro-structured Paul trap. The ion is shuttled over a distance of more than 10^4 times its groundstate wavefunction size during only 5 motional cycles of the trap (280 micro meter in 3.6 micro seconds). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10 $\\pm$ 0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing.
DEFF Research Database (Denmark)
Hancke, Kasper; Hancke, Torunn; Olsen, Lasse M.
2008-01-01
photosynthetic rate (PCmax) was strongly stimulated by temperature, reached an optimum for Pro. minimum only (20oC–25oC), and showed a similar relative temperature response for the three applied methods, with Q10 ranging from 1.7 to 3.5. The maximum light utilization coefficient (alfaC) was insensitive......Short-term temperature effects on photosynthesis were investigated by measuring O2 production, PSII-fluorescence kinetics, and 14C-incorporation rates in monocultures of the marine phytoplankton species Prorocentrum minimum (Pavill.) J. Schiller (Dinophyceae), Prymnesium parvum f. patelliferum ( J...... or decreased slightly with increasing temperature. Absolute rates of O2 production were calculated from pulse-amplitude-modulated (PAM) fluorometry measurements in combination with biooptical determination of absorbed quanta in PSII. The relationship between PAM-based O2 production and measured O2 production...
On the first Solvay Congress in 1911
Straumann, Norbert
2011-11-01
Late in October 1911, eighteen leading scientists from all over Europe met to the first of a famous sequence of Solvay conferences in Brussels. This historical meeting was mainly devoted to "The Theory of Radiation and the Quanta", at a time when the foundations of physics were totally shaken. Although "nothing positive came out" (Einstein), it is interesting to see the diverging attitudes of Europe's most famous scientists in the middle of the quantum revolution. After a few general remarks about the conference, I shall focus on some of the most interesting contributions and discussions. Einstein, at 32 the youngest, was clearly most aware of the profound nature of the crises. He gave the final talk entitled "The Present State of the Problem of Specific Heats", but he put his theme into the larger context of the quantum problem, and caused a barrage of challenges, in particular from Lorentz, Planck, Poincaré, and others.
Sakalli, I; Pasaoglu, H
2012-01-01
In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek's tunneling formalism amalgamated with quantum corrections to all orders in \\hbar is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to "no information loss".
Single Microwave Photon Detection with a Trapped Electron
Directory of Open Access Journals (Sweden)
April Cridland
2016-11-01
Full Text Available We investigate theoretically the use of an electron in a Penning trap as a detector of single microwave photons. At the University of Sussex we are developing a chip Penning trap technology, designed to be integrated within quantum circuits. Microwave photons are guided into the trap and interact with the electron’s quantum cyclotron motion. This is an electric dipole transition, where the near field of the microwave radiation induces quantum jumps of the cyclotron harmonic oscillator. The quantum jumps can be monitored using the continuous Stern-Gerlach effect, providing the quantum non demolition signal of the microwave quanta. We calculate the quantum efficiency of photon detection and discuss the main features and technical challenges for the trapped electron as a quantum microwave sensor.
Capobianco, Amedeo; Borrelli, Raffaele; Landi, Alessandro; Velardo, Amalia; Peluso, Andrea
2016-07-21
The absorption band shapes of a solvent tunable donor-acceptor dye have been theoretically investigated by using Kubo's generating function approach, with minimum energy geometries and normal coordinates computed at the DFT level of theory. The adopted computational procedure allows us to include in the computation of Franck-Condon factors the whole set of normal modes, without any limitation on excitation quanta, allowing for an almost quantitative reproduction of the absorption band shape when the equilibrium geometries of the ground and the excited states are well predicted by electronic computations. Noteworthy, the functionals that yield more accurate band shapes also provide good prediction of the moment variations upon excitation; because the latter quantities are rarely available, theoretical simulation of band shapes could be a powerful tool for choosing the most appropriate computational method for predictive purposes.
Analytic continuation of the rotating black hole state counting
Achour, Jibril Ben; Perez, Alejandro
2016-01-01
In loop quantum gravity, a spherical black hole can be described in terms of a Chern-Simons theory on a punctured 2-sphere. The sphere represents the horizon. The punctures are the edges of spin-networks in the bulk which cross the horizon and carry quanta of area. One can generalize this construction and model a rotating black hole by adding an extra puncture colored with the angular momentum J in the 2-sphere. We compute the entropy of rotating black holes in this model and study its semi-classical limit. After performing an analytic continuation which sends the Barbero-Immirzi parameter to +/- i, we show that the leading order term in the semi-classical expansion of the entropy reproduces the Bekenstein-Hawking law independently of the value of J.
Jeskovsky, M; Kovacik, A; Povinec, P P; Puppe, P; Stanicek, J; Sykora, I; Simkovic, F; Thies, J H
2015-01-01
Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture in 74Se. This process is unique, because there is probability for transition to the 2+ excited state in 74Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with anticosmic shielded HPGe spectrometer and the coincidence HPGe-NaI(Tl) spectrometer did not show any evidence for the double-electron capture in 74Se. The best limit for the half-life of the double electron capture in 74Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5x10E19 years.
Radiation-optical effects in glassy Ge-As(Sb)-S systems
Energy Technology Data Exchange (ETDEWEB)
Shpotyuk, O.I. E-mail: karat@ipm.lviv.ua; Golovchak, R.Ya.; Kavetsky, T.S.; Kovalskiy, A.P.; Vakiv, M.M
2000-05-02
The influence of {gamma}-irradiation on the optical properties of chalcogenide bulk glasses from both As{sub 2}S{sub 3}-Ge{sub 2}S{sub 3} and Sb{sub 2}S{sub 3}-Ge{sub 2}S{sub 3} sections of the corresponding glass forming regions has been studied. The '{gamma}-darkening' effect has been observed after radiation treatment by {sup 60}Co {gamma}-quanta with 4.4x10{sup 6} Gy dose. The changes in the optical transmission coefficient have been analyzed according to network arrangement and degree of disorder in the different compositions of chalcogenide glasses.
Hieu Nguyen, Van; Nguyen, Bich Ha
2015-01-01
The present work is a topical review of the theoretical research on the quantum theory of plasmons and plasmon-photon interaction. The plasmons are defined as the quanta of the quantized plasmonic field. The corresponding classical plasmonic field was constructed on the basis of the study of collective oscillations of the electron gas in the solid. The electron-electron Coulomb interaction is taken into account. The explicit forms of the plasmon-photon interaction Lagrangian in canonical quantum mechanics and the plasmon-photon interaction action functional in the functional integral approach are derived. They all show that the interaction processes are nonlocal ones. The physical origin of the nonlocality is the complex structure of plasmons as composite quasiparticles: they cannot be considered as point particles, as was assumed in all phenomenological theories.
Coexisting normal and triaxial superdeformed structures in {sup 165}Lu
Energy Technology Data Exchange (ETDEWEB)
Schoenwasser, G.; Nenoff, N.; Huebel, H. E-mail: hubel@iskp.uni-bonn.de; Hagemann, G.B.; Bednarczyk, P.; Benzoni, G.; Bracco, A.; Bringel, P.; Chapman, R.; Curien, D.; Domscheit, J.; Herskind, B.; Jensen, D.R.; Leoni, S.; Lo Bianco, G.; Ma, W.C.; Maj, A.; Neusser, A.; Oedegaard, S.W.; Petrache, C.M.; Rossbach, D.; Ryde, H.; Singh, A.K.; Spohr, K.H
2004-05-03
High-spin states in {sup 165}Lu were populated in the {sup 139}La({sup 30}Si,4n) reaction at a beam energy of 152 MeV and {gamma}-ray coincidences were measured with the EUROBALL spectrometer array. Nine new rotational bands were discovered, known band structures were considerably extended and many inter-band transitions were found. Structures with normal deformation coexist with bands associated with the strongly deformed triaxial energy minima found in calculations. Three of these triaxial bands form a family of wobbling excitations with phonon quanta n{sub w}=0, 1 and 2. The wobbling mode is a unique signature of nuclear triaxiality. Configuration assignments are discussed for the observed band structures. An exchange of configuration between two of the new bands due to mixing is observed, resulting in different signature partnerships at low and high spins.
Electronic torsional sound in linear atomic chains: chemical energy transport at 1000 km/s
Kurnosov, Arkady A; Maksymov, Andrii A; Burin, Alexander L
2016-01-01
We investigate entirely electronic torsional vibrational modes in linear cumulene chains. The carbon nuclei of a cumulene are positioned along the primary axis so they can participate only in transverse and longitudinal motions. However, the interatomic electronic clouds behave as a torsion spring with remarkable torsional stiffness. The collective dynamics of these clouds can be described in terms of electronic vibrational quanta, which we name torsitons. It is shown that the group velocity of the wavepacket of torsitons is much higher than the typical speed of sound, because of the small mass of participating electrons compared to the atomic mass. For the same reason the maximum energy of the torsitons in cumulenes is as high as a few electronvolts, while the minimum possible energy is evaluated as a few hundred wavenumbers and this minimum is associated with asymmetry of zero point atomic vibrations. Molecular systems for experimental evaluation of the predictions are proposed.
Difference between acoustoelectric and thermoelectric phenomena in superconductors
Energy Technology Data Exchange (ETDEWEB)
Gal' perin, Y.M.; Gurevich, V.L.; Kozub, V.I.
1978-11-01
The acoustoelectric effect in superconductors is discussed. It is compared with the acoustoelectric effect in normal conductors, as well as with the thermoelectric effect in superconductors. We come to the conclusion that, in contrast to the thermoelectric effect, the acoustoelectric effect can be observed in a monometallic superconducting loop. The necessary condition is an asymmetric distribution of the acoustical flux, which is schematically depicted. Different ways of enhancing the acoustoelectric effect are also discussed. It is pointed out that the enhancement of the effect may be achieved if an acoustical wave propagates in a part of a loop where a large number of magnetic flux quanta are trapped. Some possible masking effects (such as discussed by Pegrum and Guenault) which may prevent observation of acoustoelectric and thermoelectric effects are discussed. We discuss also the ways to diminish these masking effects and to extract the effects in question from the experimental data.