共查询到20条相似文献,搜索用时 31 毫秒
1.
D. B. Gin V. G. Kiptily A. A. Pasternak I. N. Chugunov A. E. Shevelev G. Gorini M. Tardocchi M. Nocente JET-EFDA contributors 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(7):931-936
A parametrization of the partial cross section of the 9Be(α, nγ)12C reaction in the α-particle energy range of 0.3–7.9 MeV is presented, along with the count rates of γ quanta. The need to
consider subbarrier (Eα < 1.9 MeV) α-particles in plasma for temperatures T
α < 0.2 MeV is substantiated. The shapes of the Doppler-broadened 4.44 MeV γ line and the count rates of γ quanta in the plasma
of the JET tokamak are measured for the first time and compared to the calculated values. An estimated T
α ≲ 160 keV is obtained. 相似文献
2.
A. V. Derbin S. B. Bakhlanov A. I. Egorov I. A. Mitropolsky V. N. Muratova D. A. Semenov E. V. Unzhakov 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(4):481-486
We searched for resonant excitation of the first excited state of the 169Tm nucleus by axions formed inside the Sun by the Primakoff effect, A + 169Tm → 169Tm* → 169Tm + γ (8.41keV). Gamma quanta with an energy of 8.41keV were registered by a sectionalized Si(Li) detector installed in a
low-background setup. As a result, we set a new upper limit for the photon to axion coupling constant, g
Aγ
(GeV−1)m
A
(eV) ≤ 1.06 × 10−5, which for a hadronic axion model corresponds to a mass limit of m
A
≤ 169 eV at a 90% confidence level. 相似文献
3.
We propose a new method for γ-direction measurements for the CsI calorimeter of the E391 experiment. This method is based
on using the GRRBF neural network. By using this method, the sensitivity of the E391 experiment could be significantly increased.
Current results could be applied to other experiments in which the same γ detector is used. 相似文献
4.
The principles of construction and the results of testing of a system for measuring P-odd asymmetries in nuclear reactions with polarized cold neutrons by the integrated method of recording events at the neutron
polarization switching frequency above the fundamental frequencies of the reactor power fluctuation spectrum are presented.
It is shown experimentally that if the signal under investigation is characterized by the spectral density of power decreasing
with increasing frequency, switching of the equipment at a higher frequency decreases the measuring error. The dependence
of the error of measurements of P-odd asymmetry in the emission of γ quanta in the 10B(n, α)7Li* ⟹ γ ⟹ 7Li(g.s.) reaction on the neutron polarization switching frequency is derived. The system described here is implemented experimentally
for the first time. 相似文献
5.
Muminov A. T. Muminov T. M. Norboev K. Osmanov B. S. Salikhbaev U. S. Safarov A. N. Skvortsov V. V. Suleymanov R. D. 《Technical Physics》2011,56(9):1345-1352
Scattering of bremsstrahlung electron beam (E
e
= 6.25 MeV) collimated with a vertical divergence δγ ≈ ±60 μrad and incident on the mercury surface at glancing angles α = −37, −83, and −140 μrad is studied on the 118-m-long
path length. The specular reflection effect is detected in the spectral and angular distributions of γ quanta with energies
up to 3 MeV. The reflection coefficients vary from 0 to ∼17% depending on the angles of incidence and the γ quanta energy. 相似文献
6.
A. V. Daniel J. H. Hamilton A. V. Ramayya A. S. Fomichev Yu. Ts. Oganessian G. S. Popeko A. M. Rodin G. M. Ter-Akopian J. K. Hwang D. Fong C. Goodin K. Li J. O. Rasmussen D. Seweryniak M. Carpenter C. J. Lister Sh. Zhu R. V. F. Janssens J. Batchelder J. Kliman L. Krupa W. -C. Ma S. J. Zhu L. Chaturvedi J. D. Cole 《Physics of Atomic Nuclei》2006,69(8):1405-1408
A new experiment devoted to the fission of 252Cf is described. It continued a series of our experiments based on correlation measurements of γ rays emitted by fission fragment pairs. The measurements of γ-γ and γ-γ-γ coincidences were done at Gammasphere with closed 252Cf sources. The open source was used for the first time in the last experiment. Fission fragment detectors were arranged in
the center hole of Gammasphere. Correlations between fission fragment masses, total kinetic energy, and γ rays were observed. The first, preliminary results of data analysis are discussed.
The text was submitted by the authors in English. 相似文献
7.
T. S. Yuldashbaev I. Absalyamova N. Kulakhmedov Kh. Nuritdinov 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):440-442
We evaluate the primary gamma quanta (PGQ) energy spectrum slope at E
γ > 1014 eV. To accomplish this, a new method based on analyzing the data obtained in high-mountain experiments with large-scale X-ray
emulsion chambers (XECs) is used. 相似文献
8.
《The European Physical Journal A - Hadrons and Nuclei》2008,35(3):333-342
The exclusive reactions γp → K
*0Σ+(1189) and γp → K
0π0Σ+(1189) , leading to the p 4π0 final state, have been measured with a tagged photon beam for incident energies from threshold up to 2.5GeV. The experiment
has been performed at the tagged photon facility of the ELSA accelerator (Bonn). The Crystal Barrel and TAPS detectors were
combined to a photon detector system of almost 4π geometrical acceptance. Differential and total cross-sections are reported.
At energies close to the threshold, a flat angular distribution has been observed for the reaction γp → K
0π0Σ+ suggesting dominant s -channel production. Σ*(1385) and higher-lying hyperon states have been observed. An enhancement in the forward direction in the angular distributions
of the reaction γp → K
*0Σ+ indicates a t -channel exchange contribution to the reaction mechanism. The experimental data are in reasonable agreement with recent theoretical
predictions. 相似文献
9.
The contribution of final-state interactions to the muon transverse polarization in the decay K
+ → μ+
v
γ is calculated within chiral perturbation theory to O(p
6) terms. It is shown that the O(p
6) corrections to the transverse polarization are much smaller than the O(p
4) leading contribution.
Original Russian Text ? V.V. Braguta, A.A. Likhoded, A.E. Chalov, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No.
2, pp. 386–391. 相似文献
10.
G. L. Bochek O. S. Deiev N. I. Maslov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(2):356-361
The GEANT 4.9.2 software package is applied for the simulation of primary and Compton scattered bremsstrahlung spectra. The
possibility of restoring primary γ-radiation spectra with the energy 0.02–1200 MeV using Compton scattering on secondary scattering
targets is studied. The advantages of light targets using are demonstrated. An additional bremsstrahlung contribution from
e±-pairs is calculated for high-energy γ quanta; the influence of CXR on the form of scattered X-ray quantum spectra is estimated.
The spectra which have a multipeak structure are restored. For high-energy γ quanta there occurs significant spread of energies
in the Compton scattered radiation spectrum, which imposes stringent conditions on collimation and detector resolution capability.
The possibility of measuring the bremsstrahlung spectra from a primary target during high-angle Compton scattering is estimated. 相似文献
11.
E. Algin A. Schiller A. Voinov U. Agvaanluvsan T. Belgya L. A. Bernstein C. R. Brune R. Chankova P. E. Garrett S. M. Grimes M. Guttormsen M. Hjorth-Jensen M. J. Hornish C. W. Johnson T. Massey G. E. Mitchell J. Rekstad S. Siem W. Younes 《Physics of Atomic Nuclei》2007,70(9):1634-1639
Nuclear level densities and radiative strength functions (RSFs) in 56Fe and 57Fe were measured using the 57Fe(3He, αγ) and 57Fe(3He, 3He′γ) reactions, respectively, at the Oslo Cyclotron Laboratory. A low-energy enhancement in the RSF below 4-MeV energy was observed.
This finding cannot be explained by common theoretical models. In a second experiment, two-step cascade intensities with soft
primary transitions from the 56Fe(n, 2γ) reaction were measured. The agreement between the two experiments confirms the low-energy enhancement in the RSFs. In a
third experiment, the neutron evaporation spectrum from the 55Mn(d, n)56Fe reaction was measured at 7-MeV deuteron energy at the John Edwards Accelerator Laboratory at Ohio University. Comparison
of the level density of 56Fe obtained from the first and third experiments gives an overall good agreement. Furthermore, observed enhancement for soft
γ rays is strengthened by the last experiment.
The text was submitted by the authors in English. 相似文献
12.
V.G. Alpatov Yu.D. Bayukov A.V. Davydov Yu.N. Isaev G.R. Kartashov M.M. Korotkov V.E. Rad'ko A.A. Sadovsky V.M. Samoylov 《Hyperfine Interactions》1997,107(1-4):231-246
The temperature dependence of the 109Ag γ-ray self-absorption was investigated for the horizontal and vertical directions of emission. The source was a single-crystal
silver plate containing atoms of parent radionuclide 109Cd. Gamma-radiation of this γ-source and that of the monitoring γ-source, 57Co, were registered by a pair of Ge(Li)-detectors. As a result of cooling the source from 77 K to ~12 K a relative decrease
was observed of the intensity of the horizontally emitted γ-rays equal to 0.00064±0.00044. For the vertical direction the
corresponding intensity change turned out to be -0.00047±0.00051. Although these data, as one would see, give some evidence
for the possible effect of the gravitation on the resonant γ-ray absorption, future measurements must show if these results
aren’t a consequence of any apparatus effect. The ways for developments in this study are discussed and some hindrances are
considered.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
Yu. G. Kudenko 《Physics of Atomic Nuclei》2002,65(2):244-248
Recent advances in a search for a T-violating transverse muon polarization in the decays K
+ → π
0
μ
+
ν and K
+ → μ
+
νγ in the on-going E246 experiment at KEK are reported. Future prospects in polarization measurements are also discussed.
From Yadernaya Fizika, Vol. 65, No. 2, 2002, pp. 269–273.
Original English Text Copyright ? 2002 by Kudenko.
This article was submitted by the author in English. 相似文献
14.
Shen Shuifa Fang Keming Gu Jiahui Liu Qingcheng Xu Furong 《The European Physical Journal A - Hadrons and Nuclei》2007,32(2):149-158
The decay of 95Ru has been investigated by means of γ-ray spectroscopy. The 95Ru nuclei were produced by the reaction 92Mo( α, n) 95Ru at a beam energy of 17MeV. High-purity Ge detectors have been used singly and in coincidence to study γ-rays in the decay of 95Ru to 95Tc. 132 γ-rays are reported, among them, energies and intensities for 127 transitions have been determined. A decay scheme of 95Ru with 31 levels is proposed which accommodates 127 of these transitions. Spins and parities for three new levels are proposed
from calculated log ft values, measured γ-ray branching ratios, and in-beam experiment results of the daughter nucleus 95Tc. Combining with the high-spin states observed by in-beam γ-ray spectroscopy of previous decay works, the structure of the excited states of 95Tc is discussed in the framework of the projected shell model. 相似文献
15.
A 4π position-sensitive, axisymmetrical assembly of Si-Au charged-particle detectors is proposed, implemented, and tested on a
beam of heavy ions; the dimensions and structure of the device are conducive to the organization of coincidences of charged
reaction products with discrete γ rays emitted by the daughter nucleus and registered by a system of ultrapure Ge detectors. First results are obtained from
an investigation of the reaction 58Ni(16O,α2pγ)68Ge at E
0=74.5 MeV.
Zh. Tekh. Fiz. 68, 139–142 (April 1998) 相似文献
16.
M. N. Achasov S. E. Baru A. V. Berdyugin A. V. Bozhenok A. D. Bukin D. A. Bukin S. V. Burdin T. V. Dimova S. I. Dolinsky V. P. Druzhinin M. S. Dubrovin I. A. Gaponenko V. B. Golubev V. N. Ivanchenko A. A. Korol S. V. Koshuba I. N. Nesterenko E. V. Pakhtusova A. A. Polunin E. E. Pyata A. A. Salnikov S. I. Serednyakov V. V. Shary Yu. M. Shatunov V. A. Sidorov Z. K. Silagadze Yu. S. Velikzhanin 《JETP Letters》1998,68(7):573-575
The φ(1020)→ηγ→3π
0
γ decay is studied in the SND experiment at the VEPP-2M e
+
e
− collider. The measurements give a branching ratio Bφ→ ηγ)=(1.246±0.025±0.057)%.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 7, 549–551 (10 October 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
17.
Y. Ma S. Ajimura K. Aoki M. Dairaku Y. Y. Fu H. Fujioka T. Fukuda K. Futatsukawa K. Hosomi W. Imoto M. Kawai Y. Kakiguchi S. Kinoshita T. Koike N. Maruyama M. Mimori S. Minami Y. Miura K. Miwa Y. Miyagi T. Nagae D. Nakajima H. Noumi K. Shirotori T. Suzuki T. Takahashi T. N. Takahashi H. Tamura K. Tanida N. Terada A. Toyoda K. Tsukada M. Ukai S. H. Zhou 《The European Physical Journal A - Hadrons and Nuclei》2007,33(3):243-246
In this paper, a preliminary result from the latest hypernuclear γ -ray spectroscopy experiment (KEK-E566) is presented together
with a short discussion. The experiment was performed at the KEK-PS K6 beam line in 2005. In this experiment, the 12C(π+, K
+)12
ΛC reaction was employed to populate 12
ΛC/11
ΛB hypernuclei. A germanium detector array, Hyperball2, was constructed to detect γ -rays emitted from the hypernuclei produced.
Three hypernuclear γ -ray peaks were observed and assigned. 相似文献
18.
J. Junkersfeld A. V. Anisovich G. Anton R. Bantes O. Bartholomy R. Beck Yu. Beloglazov R. Bogendörfer R. Castelijns V. Crede A. Ehmanns J. Ernst I. Fabry H. Flemming A. Fösel M. Fuchs Ch. Funke R. Gothe A. Gridnev E. Gutz St. Höffgen I. Horn J. Hößl H. Kalinowsky F. Klein E. Klempt H. Koch M. Konrad B. Kopf B. Krusche J. Langheinrich H. Löhner I. Lopatin J. Lotz H. Matthäy D. Menze J. Messchendorp V. A. Nikonov D. Novinski M. Ostrick H. van Pee A. Radkov A. V. Sarantsev S. Schadmand C. Schmidt H. Schmieden B. Schoch G. Suft V. Sumachev T. Szczepanek U. Thoma D. Walther Ch. Weinheimer 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):365-372
Differential and total cross-sections for photoproduction of γp→pπ
0
ω and γp→Δ
+
ω were determined from measurements of the CB-ELSA experiment, performed at the electron accelerator ELSA in Bonn. The measurements
covered the photon energy range from the production threshold up to 3GeV. 相似文献
19.
D. B. Gin V. G. Kiptily A. A. Pasternak I. N. Chugunov A. E. Shevelev 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(6):750-755
A technique for selecting the parameters required for describing the angular correlation function and finding their energy
dependence has been developed. Joint analysis of a Doppler-broadened 4.44 MeV γ lineshape from the 9Be(α, nγ)12C reaction in the range 1.9–4.5 MeV of E
α energies and with n- and γ-angular distributions was performed. The Doppler-broadened lineshapes were modeled and compared using data measured
in the JET plasma experiment. Relativistic effects were analyzed. 相似文献
20.
We analyse the exclusive channel pˉ↦γπ0, assuming handbag dominance. The soft parts are parametrized in terms of CGLN amplitudes for the qˉ↦γπ0 transition and form factors for the pˉ↦qˉ ones; the latter represent moments of Generalized Distribution Amplitudes. We present a combined fit to Fermilab data from
E760 taking simultaneously into account information from other exclusive reactions, especially from pˉ↦γγ data. Overall a nicely consistent picture emerges, such that one can hope, that our theoretical analysis will be reliable
also for the kinematics of GSI/FAIR, which, hopefully, will provide much more precise and complete data. Consequently, data
from this facility should improve our knowledge both on the proton-antiproton distribution amplitudes and the pion production
mechanism. 相似文献