Fragmentation channels of relativistic {sup 7}Be nuclei in peripheral interactions

Journal Article · Sun Jul 15 04:00:00 EDT 2007 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778807070137· OSTI ID:21075836

Peresadko, N G; Aleksandrov, Yu A ^[1]; Bradnova, V; Vokal, S ^[2]; Gerasimov, S G; Dronov, V A ^[1]; Zarubin, P I; Zarubina, I G; Kovalenko, A D ^[2]; Larionova, V G ^[1]; Malakhov, A I; Rukoyatkin, P A; Rusakova, V V ^[2]; Kharlamov, S P; Fetisov, V N ^[1]

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1. Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)
2. Joint Institute for Nuclear Research (Russian Federation)

At the JINR Nuclotron, {sup 7}Li nuclei are accelerated. The charge-exchange reaction involving these nuclei at an external target provides a secondary 1.23-A-GeV {sup 7}Be beam. This beam is used to irradiate emulsion chambers. The mean free path {lambda}{sub inel}({sup 7}Be) = 14.0 {+-} 0.8 cm for inelastic {sup 7}Be interactions in an emulsion coincides within the errors with those for {sup 6}Li and {sup 7}Li nuclei. More than 10% of the {sup 7}Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal to the charge of the {sup 7}Be 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 {sup 7}Be nuclei: the number of the {sup 3}He fragments is twice as large as that of the {sup 4}He fragments. Each of 50% of peripheral interaction events includes two doubly charged fragments. The channels of the {sup 7}Be fragmentation into charged fragments are presented. In 50% of events, the {sup 7}Be fragmentation occurs only into charged fragments without the emission of neutrons. The {sup 4}He + {sup 3}He channel dominates, whereas each of the {sup 4}He + d + p and {sup 6}Li + p channels constitutes 10%. Two events without neutron emission are observed in the {sup 3}He + t + p and {sup 3}He + d + d three-body channels. The mean free path for the coherent dissociation of relativistic {sup 7}Be nuclei into {sup 4}He + {sup 3}He is equal to 7 {+-} 1 m. The main features of the fragmentation of relativistic {sup 7}Be nuclei in such peripheral interactions are explained by the {sup 3}He + {sup 4}He two-cluster structure of the {sup 7}Be nucleus.

• OSTI ID: 21075836
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 7 Vol. 70; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BEAMS
BERYLLIUM 7
CHARGE-EXCHANGE REACTIONS
DISSOCIATION
EMULSIONS
FRAGMENTATION
GEV RANGE
HELIUM 3
HELIUM 4
INTERACTIONS
JINR
LITHIUM 6
LITHIUM 7
MEAN FREE PATH
MESONS
NEUTRON EMISSION
NEUTRONS
NUCLEAR REACTIONS
PERIPHERAL COLLISIONS
RELATIVISTIC RANGE