P-matrix and J-matrix approaches. Coulomb asymptotics in the harmonic oscillator representation of scattering theory

The relation between the R- and P-matrix approaches and the harmonic oscillator representation of the quantum scattering theory (J-matrix method) is discussed. We construct a discrete analogue of the P-matrix that is shown to be equivalent to the usual P-matrix in the quasiclassical limit. A definition of the natural channel radius is introduced. As a result, it is shown to be possible to use well-developed technique of R- and P-matrix theory for calculation of resonant states characteristics, scattering phase shifts, etc., in the approaches based on harmonic oscillator expansions, e.g., in nuclear shell-model calculations. P-matrix is used also for formulation of the method of treating Coulomb asymptotics in the scattering theory in oscillator representation.Comment: Revtex, 57 pages including 15 figures; to be published in Annals of Physic

Novel NN interaction and the spectroscopy of light nuclei

Nucleon-nucleon (NN) phase shifts and the spectroscopy of $A \le 6$ nuclei are successfully described by an inverse scattering potential that is separable with oscillator form factors.Comment: 4 pages, 1 figure, 13 table

Deposition of nanocrystalline silicon films into low frequency induction RF discharge

Results of experiments on obtaining nanocrystalline silicon films with the method of stimulated plasma-enhanced chemical vapor deposition (PECVD) into low frequency induction RF discharge (880 kHz) allowed in silicon tetrachloride diluted with hydrogen are presented. High rate value, as 2.41 nm/s, of silicon film deposition was achieved. X-ray diffraction phase-shift analysis was pursued, the value of unit spacing of crystalline lattice was determined and nanocrystalline silicon film structure was studied.Представлены результаты исследований по получению пленок нанокристаллического кремния методом стимулированного плазмохимического осаждения (СПХО) в низкочастотном индукционном ВЧ-разряде (880 кГц), возбуждаемом в тетрахлориде кремния (SiCl4), разбавленным водородом. Получена высокая скорость осаждения пленки кремния – 2,41 нм/с. Проведен рентгеноструктурный фазовый анализ, определена величина периода кристаллической решетки, исследована структура нанокристаллической пленки кремния.Представлено результати досліджень по одержанню плівок нанокристалічного кремнію методом стимульованого плазмохімічного осадження (СПХО) в низькочастотному індукційному ВЧ-розряді (880 кГц), збудженим у тетрахлоріді кремнію (SіCl4), розведеним воднем. Одержано високу швидкість осадження плівки кремнію – 2,41 нм/с. Проведено рентгеноструктурний фазовий аналіз, визначено величину періоду кристалічної ґратки, досліджено структуру нанокристалічної плівки кремнію

Gauges and Cosmological Backreaction

We present a formalism for spatial averaging in cosmology applicable to general spacetimes and coordinates, and allowing the easy incorporation of a wide variety of matter sources. We apply this formalism to a Friedmann-LeMaitre-Robertson-Walker universe perturbed to second-order and present the corrections to the background in an unfixed gauge. We then present the corrections that arise in uniform curvature and conformal Newtonian gauges.Comment: 13 pages. Updated: reference added, typos corrected, exposition clarified. Version 3: Replaced with version published by JCA

Hamiltonian Light-Front Field Theory: Recent Progress and Tantalizing Prospects

Fundamental theories, such as Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD) promise great predictive power addressing phenomena over vast scales from the microscopic to cosmic scales. However, new non-perturbative tools are required for physics to span from one scale to the next. I outline recent theoretical and computational progress to build these bridges and provide illustrative results for Hamiltonian Light Front Field Theory. One key area is our development of basis function approaches that cast the theory as a Hamiltonian matrix problem while preserving a maximal set of symmetries. Regulating the theory with an external field that can be removed to obtain the continuum limit offers additional possibilities as seen in an application to the anomalous magnetic moment of the electron. Recent progress capitalizes on algorithm and computer developments for setting up and solving very large sparse matrix eigenvalue problems. Matrices with dimensions of 20 billion basis states are now solved on leadership-class computers for their low-lying eigenstates and eigenfunctions.Comment: 8 pages with 2 figure

Ab-initio calculation of the 6Li{}^6Li binding energy with the Hybrid Multideterminant scheme

We perform an ab-initio calculation for the binding energy of ${}^6Li$ using the CD-Bonn 2000 NN potential renormalized with the Lee-Suzuki method. The many-body approach to the problem is the Hybrid Multideterminant method. The results indicate a binding energy of about $31 MeV$, within a few hundreds KeV uncertainty. The center of mass diagnostics are also discussed.Comment: 18 pages with 3 figures. More calculations added, to be published in EPJ

Long- and short-term earthquake prediction in Kamchatka

This paper presents the results of long- and short-term earthquake prediction obtained during 1971–1974. They can be summarized as follows: The map of long-term prediction for the Kurile—Kamchatka zone compiled in 1965 and supplemented in 1972 by S.A. Fedotov is in good agreement (in four of four possible cases) with recorded seismicity. The results obtained allow us to suppose that the areas for which the log (Ep/Es) of small earthquakes is low may be the areas of future large earthquakes. Prediction of active periods for the Kamchatka earthquakes with M > 7 has been made on the basis of studying the correlation of seismicity with the lunar tide with a 18.6-year period. A possibility has been found for using the phenomenon of “induced foreshocks” for earthquake prediction, i.e., when a large remote earthquake induces small preceding events in the zone of preparation of a large earthquake. The following three methods were used for operative short-term prediction of the time and place of future earthquakes with M > 5.5. 1.(1) Use of specific electrotelluric field anomalies, from 5 to 20 days in duration, which are recorded by a specially designed network of stations. 2.(2) Method of Vp/Vs anomalies. The anomalously high and low Vp/Vs values for a seismic station point to the possibility of large earthquakes near the latter. 3.(3) The earthquake statistics method described by Fedotov et al. in 1972. Short-term seismic prediction is being made twice a week in two versions: Forecast I (for the whole of Kamchatka) and Forecast II (for each of six overlapping segments of the Kamchatka seismic zone). This paper discusses the results of successful testing of short-term earthquake prediction during two years. During the “alarm” periods the probability of large earthquakes is double the average. Paper presented at the Symposium on Earthquake Forerunners Searching, Tashkent, May 26–June 1, 1974

Manifestation of three-body forces in three-body Bethe-Salpeter and light-front equations

Bethe-Salpeter and light-front bound state equations for three scalar particles interacting by scalar exchange-bosons are solved in ladder truncation. In contrast to two-body systems, the three-body binding energies obtained in these two approaches differ significantly from each other: the ladder kernel in light-front dynamics underbinds by approximately a factor of two compared to the ladder Bethe-Salpeter equation. By taking into account three-body forces in the light-front approach, generated by two exchange-bosons in flight, we find that most of this difference disappears; for small exchange masses, the obtained binding energies coincide with each other.Comment: 24 pages, 8 figures, submitted in Few-Body System

Electron irradiation test facility for irradiation of structural materials in conditions of molten salt reactor

A new device, Electron Irradiation Test Facility (EITF), has been created at electron linear accelerator Linac-10 at Accelerator R&D Complex affiliated with NSC KIPT. This facility allows to carry on studies on corrosion resistance of differently shaped samples of the Hastelloy type alloys in the melt of zirconium and sodium fluoride salts at high temperature. A container assembly (CA) that held samples was irradiated for 700 hours in the radiation field of electron beam with the energy ∼10 MeV and average current ∼500 microAmps (power∼5 kW ). The CA consisting of 16 containers (made of a carbon-carbon composite) that were loaded with research samples of Hastelloy alloys in the melt of the salts ZrF₄ и NaF was placed in air-tight protective shell made of stainless steel. During the irradiation, the CA was placed in argon atmosphere. The CA temperature was monitored with three thermocouples. Over the entire length of the irradiation process the stationary temperature regime was provided: 650°С ± 15°С.На лінійному прискорювачі електронів ЛП−10 НДК «Прискорювач» ННЦ ХФТІ створено установку “Стенд для радіаційних випробувань”, яка дозволяє проводити дослідження корозійної стійкості зразків різних модифікацій сплавів типу “хастелой ”в разплаві фторидних солей цирконію та натрію при високій температурі. У радіаційному полі пучка електронів з енергією ∼10 МеВ та среднім струмом ∼500 мкА (потужністю ∼5 кВт ) впродовж 700 годин проведено опромінення збірки контейнерів з досліджуваними зразками. Збірку з 16 контейнерів (з вуглець-вугецевого композиту), заповнених зразками “хастелою”в расплаві солей ZrF₄ та NaF, розміщено в герметичній захистній оболонці з нержавіючої сталі. Збірка при опроміненні знаходилась в атмосфері аргону. Температура збірки контролювалась трьома термопарами.. Впродовж процесу опромінення підтримувався стаціонарний температурний режим: (650 ± 15°С).На линейном ускорителе электронов ЛУ-10 НИК «Ускоритель» ННЦ ХФТИ создана установка “Стенд для радиационных испытаний”, позволяющая проводить исследования коррозионной стойкости образцов различных модификаций сплавов типа “хастеллой ”в расплаве фторидных солей циркония и натрия при высокой температуре.В радиационном поле пучка электронов с энергией ∼10 МэВ и средним током ∼500 мкА (мощностью ∼5 кВт ) в течение 700 ч проведено облучение сборки контейнеров с образцами. Сборка из 16 контейнеров (из углерод-углеродного композита), заполненных исследуемыми образцами “хастелоя”в расплаве солей ZrF₄ и NaF, помещалась в герметичную защитную оболочку из нержавеющей стали. Сборка при облучении находилась в атмосфере аргона. Температура ее контролировалась тремя термопарами. На протяжении всего процесса облучения обеспечивался стационарный температурный режим (650 ± 15)°С

Tandem proton accelerator as injector for TRAPP

To inject protons to the TRAPP (synchrotron for therapy of cancer) a tandem accelerator has been constructed. Its parameters are: protons energy is 1.4 MeV, current is 3 mA, pulse duration is 2 μs, frequency is up to 1 Hz. Negative hydrogen ions are extracted through the slit from a magnetron discharge on the heated surface of the LaB6 cathode. The beam of negative ions with an initial energy of 25 kV accelerates up to the half energy in the first accelerating tube, than recharges into protons in gas nitrogen target in a tube at a potential of 700 kV. After that, the proton beam doubles its energy in the second accelerating tube. Operating and control of the tandem are by means of computer