[Show abstract][Hide abstract] ABSTRACT: In a track nuclear photoemulsion exposed to a beamof $^7$Li nuclei
accelerated to a momentum of 3 GeV/$c$ per nucleon at the synchrophasotron of
the Joint Institute for Nuclear Research (JINR, Dubna), 13 events in which
$^7$Li nuclei interacting with protons break up into $^3$H and $^4$He fragments
were detected among 3730 inelastic-interaction events. For this fragmentation
channel, the cross section was found to be $8\pm2$ mb. The average value of the
fragment total transverse momentum was $214\pm5$ MeV/$c$. This value
exceedsmarkedly the average value of the transverse-momentumtransfer in the
coherent dissociation of $^7$Li nuclei on track-emulsion nuclei ($166\pm5$
MeV/$c$). The recoil-proton transverse momentum was on average 98% of the total
proton momentum. The longitudinal-momentum distribution of protons was
characterized by a variance of 16 MeV/$c$ and a mean value of $37\pm2$ MeV/$c$.
Physics of Atomic Nuclei 10/2011; 73(11). · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The differential cross section in the transverse momentum Q and a total cross section of (31 ± 4) mb for the coherent dissociation of a 3-A-Ge V/c
7Li nucleus through the 3H + 4He channel have been measured on emulsion nuclei. The observed Q dependence of the cross section is explained by the predominant supposition of the nuclear diffraction patterns on light
(C, N, O) and heavy (Br, Ag) emulsion nuclei. The contributions to the cross section from nuclear diffraction (Q ≤ 400 Me V/c) and Coulomb (Q ≤ 50 Me V/c) dissociations are calculated to be 40.7 and 4 mb, respectively.
[Show abstract][Hide abstract] ABSTRACT: At the JINR Nuclotron, 7Li nuclei are accelerated. The charge-exchange reaction involving these nuclei at an external target provides a secondary
1.23-A-GeV 7Be beam. This beam is used to irradiate emulsion chambers. The mean free path λinel(7Be) = 14.0 ± 0.8 cm for inelastic 7Be interactions in an emulsion coincides within the errors with those for 6Li and 7Li nuclei. More than 10% of the 7Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal
to the charge of the 7Be nucleus and in which charged mesons are not produced. An unusual ratio of the helium isotopes is revealed in the composition
of the doubly charged fragments of the 7Be nuclei: the number of the 3He fragments is twice as large as that of the 4He fragments. Each of 50% of peripheral interaction events includes two doubly charged fragments. The channels of the 7Be fragmentation into charged fragments are presented. In 50% of events, the 7Be fragmentation occurs only into charged fragments without the emission of neutrons. The 4He + 3He channel dominates, whereas each of the 4He + d + p and 6Li + p channels constitutes 10%. Two events without neutron emission are observed in the 3He + t + p and 3He + d + d three-body channels. The mean free path for the coherent dissociation of relativistic 7Be nuclei into 4He + 3He is equal to 7 ± 1 m. The main features of the fragmentation of relativistic 7Be nuclei in such peripheral interactions are explained by the 3He + 4He two-cluster structure of the 7Be nucleus.
Physics of Atomic Nuclei 06/2007; 70(7):1226-1229. · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Experimental observations of the multifragmentation of relativistic light nuclei by means of emulsions are surveyed. Events
that belong to the type of “white stars” and in which the dissociation of relativistic nuclei is not accompanied by the production
of mesons and target-nucleus fragments are considered. An almost complete suppression of the binary splitting of nuclei to
fragments of charge in excess of two, Z > 2, is a feature peculiar to charge topology in the dissociation of Ne, Mg, Si, and S nuclei. An increase in the degree
of nuclear fragmentation manifests itself in the growth of the multiplicity of singly and doubly charged fragments (Z = 1, 2) as the charge of the unexcited fragmenting-nucleus part (which is the main part) decreases. Features of the production
of systems formed by extremely light nuclei α, d, and t are studied in the dissociation of the stable isotopes of Li, Be, B, C, N, and O to charged fragments. Manifestations of
3He clustering can be observed in “white stars” in the dissociation of neutron-deficient isotopes of Be, B, C, and N.
Physics of Atomic Nuclei 02/2005; 68(3):455-465. · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The dissociation of relativistic 7Li nuclei was studied with the photoemulsion technique. The nuclear photoemulsions have been exposed in the beam of 7Li at the momentum of 3 A GeV/c at the JINR synchrophasotron in Dubna. Along the scanned length 239.76 m of 7Li tracks, 1675 inelastic interactions have been found. For the first time the coherent dissociation of the relativistic 7Li nuclei into the (α + t) channel in the nuclear photoemulsion has been detected. The mean free path of this channel in emulsion is equal to 5.4 m and corresponds to the cross section which is equal to 23 ± 5 mb. Previously in the dissociation of the relativistic 6Li nuclei it was found that the main di-cluster configuration of the ground state of 6Li manifests itself as the main channel of coherent dissociation into α-particle and deuteron. The close values of relative yields and kinematic features of these two-particle dissociation channels of 7Li and 6Li suggest that a similar di-cluster configuration consisting of α-particle core and bound together outer nucleons predominates in the dissociating nuclei at relativistic energies also. The data presented prove the validity of the relativistic nuclei dissociation as an effective complementary method for the study of nuclear structure.
Journal of Physics G Nuclear and Particle Physics 09/2004; 30(10):1479. · 2.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: New results concerning the topology of the fragmentation of relativistic nuclei 7Li and 10B are presented. A program is proposed for studying the cluster structure of stable and radioactive nuclei. The use of emulsions
in the investigation of nuclear clustering in the fragmentation of light nuclei at energies are in excess of 1 GeV per nucleon
Physics of Atomic Nuclei 01/2004; 67(3):514-517. · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Using a Li-6 nucleus beam extracted from the JINR Synchrophasotron at momentum 2.67A GeV/c a secondary beam was produced with a composition of 1% of He-6 and 99% of H-3 nuclei. Preliminary results on the features of nucleus-nucleus interactions of He-6 nuclei and charge exchange (CE) of H-3 nucleus are presented. Interactions of He-6 nucleus external neutrons with emulsion nuclei as well as a coherent stripping of He-6 nucleus external neutrons are observed. A mean range of H-3 nuclei to inelastic interactions in the BR-2 type emulsion is equal to 23.$\pm$3.0 cm. A mean range in emulsion for a nuclear CE process H-3 to He-3 is equal to 40$\pm$16 m. The CE cross-sections with a charged meson production or without it are approximately equal. The CE cross-section with excitation of a target nucleus exceeds the one without excitation. The mean transverse momentum of He-3 nuclei is equal to 0.16$\pm$0.03 GeV/c.