Study of 7Be relativistic fragmentation in
nuclear track emulsion
Denis Artemenkov,
VBLHE, JINR (for the BECQUEREL collaboration)
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BECQUEREL at the JINR Nuclotron is devoted systematic exploration of
clustering features of light stable and radioactive nuclei.
The fragmentation of a large variety of light nuclei was investigated using the
emulsions exposed to few A GeV nuclear beams at JINR Nuclotron. A nuclear
track emulsion is used to explore the fragmentation of the relativistic nuclei.
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Study of relativistic 7Be fragmentation in nuclear track emulsion in JINR
12C7Be
7Li7Be
(in mixed beam of 12N+10C+7Be at 1.2 A GeV) (charge exchange, at 1.2 A GeV)
2006
2004
Table 1. Charge composition of the fragments
in events with Q=4
Relativistic
fragments
Target
fragments
Event number
2He
nb=0
nb>0
95
79
He+2H
nb=0
nb>0
52
78
4H
nb=0
nb>0
14
16
Li+H
nb=0
nb>0
3
38
Total
nb=0
nb>0
164
211
3
4
Ion Physics
Electromagnetic Dissociation
• Electromagnetic dissociation is liberation of nucleons or
nuclear fragments as a result of electromagnetic field by
exchange of virtual photons, rather than the strong nuclear
force
• It is important for relativistic nuclear-nuclear interaction,
especially where the proton number of the nucleus is large
• G4EMDissociation model and cross section are an
implementation of the NUCFRG2 (NASA TP 3533)
physics and treats this electromagnetic dissociation (ED).
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Data modeling of 7Be EM dissociation at 1.2 A GeV
G4EMDissociation
G4EMDissociationCrossSection
Started: 3000 of 7Be nuclei at 1.2 A GeV
Produced: 7 events of 7Be6Be+n;
6Be
Atomic Mass: 6.0197258  0.0000059 amu
Excess Mass: 18374.465  5.468 keV
Binding Energy: 26924.058  5.468 keV
Spin: 0+
Half life: 92 keV (5.010-6 fs)
Mode of decay: 2 Proton to He-4
Decay energy: 1.372 MeV
http://atom.kaeri.re.kr
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7BeHe+2H
H
7Be
He
H
7Be6Be+n4He+21H+n
6Be
p
4He
7Be
?
p
n
n
7
Q 4 He  2 p  M
4
He  2 p
 m 4 He  2 m p
Q 4 He  p  M
6Ве
7
4
He  p
 m 4 He  m p
5Li
Be  Be  Li  p  He  p  p
12C7Be
6
5
4
(in mixed beam of 12N+10C+7Be at 1.2 A GeV), 2006
8
7Be2He
He
7Be
7Li7Be
(charge exchange, at 1.2 A GeV) 2004
9
7Li7Be
12C7Be
(in mixed beam of 12N+10C+7Be at 1.2 A GeV)
2006
Q 4 He  3He  M
4
3
He  He
(charge exchange, at 1.2 A GeV)
2004
 m 4 He  m 3 He  1,59 MeV
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Mean free path λinel

W ti    R   At3  Ai3  1 . 17


1
2
0
1




2
λexp=14,2 ± 0,2 cm
(our experiment)
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Summary
• The possibilities of nuclear track emulsion for study of fragmentation
of relativistic light nuclei is shown.
• The production of unstable 6Be in electromagnetic interactions of 7Be
with emulsions nuclei is discussed.
• The most probable channels for 7Be fragmentation are overviewed.
Thank you for your attention!
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http://becquerel.jinr.ru/
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