Study of  7 Be relativistic fragmentation in nuclear track emulsion

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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

7Li7Be (charge exchange, at 1.2 A GeV)

2004

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

12C7Be (in mixed beam of 12N+10C+7Be at 1.2 A GeV)

2006

Table 1. Charge composition of the fragments in events with Q=4

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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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G4EMDissociationG4EMDissociationCrossSection

Started: 3000 of 7Be nuclei at 1.2 A GeVProduced: 7 events of 7Be6Be+n;

Data modeling of 7Be EM dissociation at 1.2 A GeV

6BeAtomic Mass: 6.0197258 0.0000059 amuExcess Mass: 18374.465 5.468 keVBinding Energy: 26924.058 5.468 keVSpin: 0+Half life: 92 keV (5.010-6 fs)Mode of decay: 2 Proton to He-4Decay energy: 1.372 MeV

http://atom.kaeri.re.kr

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7Be

He

H

H

7BeHe+2H

7Be6Be+n4He+21H+n

?7Be

6Be

n

4He

p

p

n

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pHepHepHemmMQ 2444 22

pHepHepHe

mmMQ 444

ppHepLiBeBe 4567

6Ве 5Li

12C7Be (in mixed beam of 12N+10C+7Be at 1.2 A GeV), 2006

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7Be2He

7Li7Be (charge exchange, at 1.2 A GeV) 2004

7BeHe

10

MeVmmMQHeHeHeHeHeHe

59,1343434

12C7Be (in mixed beam of 12N+10C+7Be at 1.2 A GeV)

2006

7Li7Be (charge exchange, at 1.2 A GeV)

2004

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2

3

1

3

120 17.1

itti AARW

λexp=14,2 ± 0,2 cm(our experiment)

Mean free path λinel

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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/http://becquerel.jinr.ru/