11 Study of light nuclei cluster structure with nuclear track emulsion Denis Artemenkov VBLHEP, JINR EFB22-Krakow-2013

22 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.

3 Ongoing emulsion experiments ExperimentsCountryAreaGel weight (dry) ProducerFilm/ Gel StatusSpecial requirements OPERA experimentInternatio nal 100,000 m 2 ~30,000kgFujiFilmProducedRefreshing function. Double Hyper nucleiJapana few 1000 kg Not decidedGelDoing R&DFor thick type emulsion Balloon cosmic-rayJapan10 m 2 3 kgFujiFilmProduced Dark MatterJapan, Italy 1 kg (1-2 year) Nagoya / to be done GelDoing R&Dcrystal size ~ 10nm Muon radiography single experiment. ~10 experiments Bern, Italy, Japan a few m 2 /exp. ~ 50m 2 /total a few kg/exp 15 kg/total Fuji or Nagoya FilmProduced or to be produced. Medical applications hadron therapy basic study beam study Proton radiography Dosimetry R&D Japan Bern 10 m 2 1 m 2 5 m 2 3 kg 0.3kg 1.5 kg Fuji / done Fuji / Film Produced

4 12 C→3α

5 12 C  3 , 3.65 A GeV (PAVICOM image)

6 3α (~3-5 ) μm 12 C(n,n’)3α, E n = 14.1 MeV DVIN - explosives detector on the basis of fast tagged neutron method for complex program for population safety in transport 8 Be, Be, 2 + -?

7 9 Be→2α (1.2 A GeV)

8

9 Θ, mrad, mrad, mrad σ Θ, mrad Fraction (Events) Θ n ( ) 4.4 ± ± ± 0.04 (164) Θ w (15.0 – 45.0) 27.0 ± ± ± 0.04 (130) ). Fractions of events Θ n and Θ w demonstrate compliance with weights 0 + and 2 + states of a 8 Be core, adopted in the two-body model, ω 0+ = and ω 2+ = [1,2]. They indicate the presence of these states as components of the ground state of the 9 Be nucleus. 1. Y. L. Parfenova and Ch. Leclercq-Willain, «Hyperfine anomaly in Be isotopes and neutron spatial distribution: A three-cluster model for 9 Be», Phys. Rev. C 72, (2005). 2. Y. L. Parfenova and Ch. Leclercq-Willain, «Hyperfine anomaly in Be isotopes in the cluster model and the neutron spatial distribution», Phys. Rev. C 72, (2005) 9 Be  2  Θ 9 Be   Opening angle distribution of two α-particles

10 10 C→2α+2p (1.2 A GeV)

11 ∑Z fr 2He + 2H He+4H6H N ws N tf C 10C 10C 10C

12 10 С → 9 В+р → 8 Ве+2р (25-30%)

13 Modeling of 10 C fragmentation with Geant4 Model (CHIPS) Experiment

14 7 Be→α+ 3 He (2 3 He) 7 Be→ 6 Be→α+2p (1.2 A GeV)

15 7 Be  2He 7 Li  7 Be ( 1.2 A GeV, 2004) 7 Be He 12 C  7 Be ( 12 N+ 10 C+ 7 Be at 1.2 A GeV, 2006 ) Channel2НеTotal event number n b =0n b >0 4 Не+ 3 Не Не+ 3 Не 14923

16 12 C  7 Be ( 12 N+ 10 C+ 7 Be at 1.2 A GeV) Li  7 Be (1.2 A GeV) 2004 The coherent dissociation of 7 Be nuclei is mainly attributable to two-cluster structure 3 He + 4 He. 3 He clusters contribution is twice of the 4 He one, indicating the strong manifestation of 3 He clustering in relativistic processes. This type of clustering is most pronounced in channel 4 He + 3 He in coherent dissociation of 7 Be nuclei, not accompanied by the emission of neutrons

17 7 Be He H H 7 Be  He+2H 7 Be  6 Be+n  4 He+2 1 H+n ? 7 Be 6 Be n 4 He p p n

18 6 Ве

19 Summary The presented observations serve as an illustration of prospects of the Nuclotron and NTE for nuclear physics researches. Due to a record space resolution the emulsion technique provides unique entirety in studying of light nuclei, especially, neutron-deficient ones. Providing the 3D observation of narrow dissociation vertices this classical technique gives novel possibilities of moving toward more and more complicated nuclear systems. The results of an exclusive study of the interactions of relativistic 7,9 Be, 10,12 C nuclei lead to the conclusion that the known features of their structure are clearly manifested in very peripheral dissociations.

20 Thursday, 12 th September, Poster session.