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21.
The cross sections of carbon nucleus photodisintegration into protons and neutrons with high multiplicity for photon energies from 700 to 1500 MeV were measured. The experiment was performed at the tagged photon beam of the GRAAL setup using the wide-aperture detector LAGRANγE. It was shown that multifragmentation up to complete disintegration into separate nucleons is initiated by elementary reactions of meson photoproduction with a subsequent intranuclear cascade. 相似文献
22.
V.Vegna V.Bellini J.P.Bouquet L.Casano A.D'Angelo J.P.Didelez R.Di Salvo A.Fantini D.Franco G.Gervino F.Ghio G.Giardina B.Girolami A.Giusa M.Guidal E.Hourany A.S.Ignatov R.Kunnel A.Lapik A.Lleres P.Levi Sandri F.Mammoliti G.Mandaglio M.Manganaro M.Moricciani A.N.Mushkarenkov V.G.Nedorezov C.Randieri D.Rebreyend N.V.Rudnev G.Russo C.Schaerf M.L.Sperduto M.C.Sutera A.Turinge 《中国物理C(英文版)》2009,33(12)
The GRAAL experimental set-up consists of a polarized and tagged photon beam that covers an energy range from a minimum of 600 MeV up to a maximum of 1500 MeV, of a liquid Hydrogen or Deuterium target and of the 4π Lagrange detector optimized for photon detection. It allows the study of pseudo-scalar and vector meson photoproduction on the nucleon in the energy range corresponding to the second and the third resonance regions. In the following, the Σ beam asymmetries in η and π~0 photoproduction on quasi-free nucleon are shown. Also single and double polarization observables in K~+A photoproduction on free proton are shown; they are important to confirm the role of new or poorly known resonances in the 1900 MeV mass region. 相似文献
23.
A. V. Andreev Yu. M. Burmistrov S. V. Zuyev E. S. Konobeevski M. V. Mordovskoy V. G. Nedorezov 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(6):748-751
An activation measuring complex containing a W–Be photoneutron source of neutrons and a lowbackground gamma spectrometer is designed at the Russian Academy of Sciences Institute for Nuclear Research. The photoneutron source is mounted on the beam of a LUE-8 industrial electron linear accelerator with an electron energy of 7–8 MeV and contains a tungsten bremsstrahlung target, a photoneutron beryllium target, and a fast neutron moderator. The measuring component of the complex includes a detector made from high purity germanium, positioned inside a low-background chamber with active-passive protection. Neutron-activation analysis (NAA) is used to determine the content of microimpurities in a substance. A procedure for measuring ultralow contents of elements in aerosol filters is developed. Contents of Au, As, Sb, Mn, Fe, W, and other elements are measured in a variety of samples. The limits of detecting microimpurities in materials are estimated. 相似文献
24.
A.?A.?TuringeEmail author A.?M.?Lapik A.?N.?Mushkarenkov V.?G.?Nedorezov N.?V.?Rudnev GRAAL collaboration 《Physics of Particles and Nuclei》2017,48(1):95-101
New data on the fragmentation of carbon nuclei by photons with energies from 800 to 1500 MeV, obtained in the collaboration GRAAL, are presented. These data include the yields of heavier fragments than nucleons. Comparison of new results with literature data, obtained with real and virtual photons in reactions with electrons and relativistic ions (Coulomb dissociation) is done using a general approach in frame of the Weizsäcker–Williams model. Possible reasons for the observed differences between them are discussed. 相似文献
25.
A. Lleres O. Bartalini V. Bellini J. P. Bocquet P. Calvat M. Capogni L. Casano M. Castoldi A. D'Angelo J. -P. Didelez R. Di Salvo A. Fantini C. Gaulard G. Gervino F. Ghio B. Girolami A. Giusa M. Guidal E. Hourany V. Kouznetsov R. Kunne A. Lapik P. Levi Sandri D. Moricciani A. N. Mushkarenkov V. Nedorezov L. Nicoletti C. Perrin C. Randieri D. Rebreyend F. Renard N. Rudnev T. Russew G. Russo C. Schaerf M. -L. Sperduto M. -C. Sutera A. Turinge 《The European Physical Journal A - Hadrons and Nuclei》2007,31(1):79-93
Beam asymmetries and hyperon recoil polarizations for the reactions γp → K
+Λ and γp → K
+Σ0 have been measured from the threshold production to 1500MeV with the GRAAL facility located at the ESRF in Grenoble. These
results complement the database for the beam asymmetry, covering for the first time the production threshold region. Recent
theoretical analyses are presented for which the beam asymmetry data bring interesting new information and allow to better
determine some resonance parameters. Most importantly, these results strengthen the need of a new D13 state around 1900MeV. 相似文献
26.
Physics of Atomic Nuclei - A structural configuration and parameters of a modernized source of electrons and gamma quanta with energy of 4–10 MeV are presented. The source is designed on the... 相似文献
27.
28.
O. Bartalini V. Bellini J. P. Bocquet M. Capogni L. Casano M. Castoldi P. Calvat A. D'Angelo R. Di Salvo A. Fantini C. Gaulard G. Gervino F. Ghio B. Girolami A. Giusa V. Kouznetsov A. Lapik P. Levi Sandri A. Lleres D. Moricciani A. N. Mushkarenkov V. Nedorezov L. Nicoletti C. Perrin D. Rebreyend F. Renard N. Rudnev T. Russew G. Russo C. Schaerf M. -L. Sperduto M. -C. Sutera A. Turinge 《The European Physical Journal A - Hadrons and Nuclei》2005,26(3):399-419
Neutral pion photoproduction has been measured from 550 to 1500 MeV with the GRAAL facility, located at the ESRF in Grenoble.
Differential cross-section and beam asymmetry have been measured over a wide angular range. These high-precision data improve
significantly the database for the beam asymmetry in the second and third resonance regions covering for the first time the
energy domain 1100-1500 MeV. New partial-wave analyses including these data are presented for which the beam asymmetry brings
crucial constraints. 相似文献
29.
O. Bartalini V. Bellini J. P. Bocquet P. Calvat A. D’Angelo J. -P. Didelez R. Di Salvo A. Fantini F. Ghio B. Girolami M. Guidal A. Giusa E. Hourany A. S. Ignatov R. Kunne A. M. Lapik P. Levi Sandri A. Lleres D. Moricciani A. N. Mushkarenkov V. G. Nedorezov C. Perrin D. Rebreyend F. Renard N. V. Rudnev T. Russew G. Russo C. Schaerf M. -L. Sperduto M. -C. Sutera A. A. Turinge 《Physics of Atomic Nuclei》2008,71(1):75-82
The total photoabsorption cross section on a free proton was measured at the GRAAL facility in the energy range E
γ = 600−1500 MeV. The large-aperture LAGRANγE detector and a liquid hydrogen target were used in the experiment performed with
a back-scattered Compton gamma beam. To improve the accuracy, two alternative methods were employed. First, a subtraction
method of using empty-target measurements allowed the cross section σ
tot to be evaluated directly because of a low level of the electromagnetic background. Second, an algorithm for evaluating σ
tot on the basis of summing the dominating partial cross sections was developed. Experimental results obtained for σ
tot by the two methods are compared with existing data.
The article was translated by the authors.
Published in Russian in Yadernaya Fizika, 2008, Vol. 71, No. 1, pp. 76–83. 相似文献
30.
S. V. Zuyev V. G. Nedorezov E. S. Konobeevski A. A. Turinge 《Physics of Atomic Nuclei》2018,81(4):442-446
A procedure for measuring photonuclear-reaction cross sections by employing the method of quasimonochromatization of the bremsstrahlung photon spectrum is developed. This procedure permits determining reaction cross sections via measuring the reaction yield at three fixed values of the electron energy. The procedure is equivalent to measuring the cross section in question for quasimonochromatic photons. Bremsstrahlung-photon spectra are obtained using state-of-the-art simulation means involving the GEANT4 code as applied to a specific experiment with allowance for its geometry, target thicknesses, electron-beam parameters, etc. The results obtained by simulating quasimonochromatic distributions of bremsstrahlung photons are presented for experiments at the LUE-8-5 linear electron accelerator of Institute for Nuclear Research (Moscow, Russian Academy of Sciences). These results are found to be in good agreement with the experimental energy distribution of the cross section for the reaction 111Cd(γ, γ') in the energy range between 5 and 8 MeV. 相似文献