Light nucleus clustering in fragmentation above 1 A GeV N. P. Andreeva a, D. A. Artemenkov b,V....
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Transcript of Light nucleus clustering in fragmentation above 1 A GeV N. P. Andreeva a, D. A. Artemenkov b,V....
Light nucleus clustering in fragmentation above 1 A GeV
N. P. Andreevaa, D. A. Artemenkovb,V. Bradnovab, M. M. Chernyavskyc, A. Sh. Gaitinova, S. P. Kharlamovc, A. D. Kovalenkob, М. Haiducd, S. G. Gerasimovc, L. A. Goncharovac, N. Kachalovab
V. G. Larionovac, F. G. Lepekhine, A. I. Malakhovb, A. A. Moiseenkof, G. I. Orlovac, N. G. Peresadkoc, N. G. Polukhinac, P. A. Rukoyatkinb, V. V. Rusakovab, V. R. Sarkisyanf, T. V. Schedrinab, B. B. Simonove, E.
Stane, R. Stanoevag, I. Tsakovg, S. Vokalh, P. I. Zarubinb, I.G Zarubinab
aInsitutute of Physics and Technology, Almaty, KazakhstanbJoint Institute for Nuclear Research, Dubna, Russia
cP. N. Lebedev Physical Institute, RAS, Moscow, RussiadInstitute of Space Sciences, Bucharest-Magurele, Romania
ePetersburg Institute of Nuclear Physics, RAS, Gatchina, RussiafErevan Physical Institute, Erevan, Armenia
gInsttitute for Nuclear Research and Nuclear Energy, BAS, Sofia, BulgariahP. J. Safarik University, Kosice, Slovakia
4.5 A GeV/c 4.5 A GeV/c 1616O O
4.5A GeV/c 4.5A GeV/c 1616OO
2.9A GeV/c 2.9A GeV/c 1414NN
1414N Dissociation with N Dissociation with 88Be like Be like fragmentationfragmentation
3 after
proton
Mg-SiMg-Si Dissociation into Dissociation into charge state charge state
2+2+2+2+2+12+2+2+2+2+1
5 +proton
4.5A GeV/c 4.5A GeV/c 2020Ne Peripheral Dissociation into charge stateNe Peripheral Dissociation into charge state
2+2+2+2+2 with 2+2+2+2+2 with 88Be like fragmentsBe like fragments
4.5A GeV/c 4.5A GeV/c 2424Mg Peripheral Dissociation into charge stateMg Peripheral Dissociation into charge state
2+2+2+2+2+2 with 2+2+2+2+2+2 with 88Be and Be and 1212CC** like fragments like fragments
dN/dTn
Tn=(M*n - n M )/(4 n ), MeV
0
0.8 1.6 2.4
4.5A GeV/c12C:<T3>=0.4 MeV
22Ne5 24Mg5 +3He
Boltzmann constant, k /approx 10-4 eV K-1
Typical Temperature Range, Ŧ /approx 5∙108-9 K per α
pα=√(2mα ∙Tα) pα /approx 20-120 MeV
Planck constant, ħ /approx 200 MeV fm
λ=ħ/p de Broglie wave lengths /approx 1-10 fm
λcohα /approx Rα λcoh
He /approx RHe
Tα/THe= Ŧα/ Ŧ He= (RHe/Rα)2 /approx 1010
Macroscopic quantum coherence phenomena in atomic physics /approx 1 K
Macroscopic quantum coherence phenomena in atomic physics /approx 1010 K
The common topological feature for fragmentation of the Ne, Mg, and Si nuclei consists in a
suppression of binary splitting to fragments with charges larger than 2.
The growth of the fragmentation degree is revealed in an increase of the multiplicity of singly and doubly charged fragments up to complete dissociation with
increasing of excitation. This circumstance shows in an obvious way on a
domination of the multiple cluster states having high density over the binary states having lower energy
thresholds.
158 A GeV/c Pb158 A GeV/c Pb
158 A GeV/c Pb158 A GeV/c Pb
CClluusstteerriinngg iinn LLiigghhtt NNuucclleeiitt
33HHee
66LLii
77LLii
66HHee
77BBee
88BB
1122CC
1100BB
1122NN
1111BB
1111CC
99BBee
1100CC
Secondary beams of light radioactive nuclei will be produced mostly via charge exchange reactions. 8B and 9Be beams has been formed via fragmentation of 10B.
Clustering building blocks: more than one nucleon bound, stable & no exited states below particle decay thresholds – deuteron, triton, 4He, and 3He nuclei
pp process
dd fusion
A=4
+ or e - capture
Hep Process
A=5
A=6=0.092 MeV
++4.5A GeV/c 4.5A GeV/c 66Li Coherent Li Coherent Dissociation (PAVICOM image)Dissociation (PAVICOM image)
66LLii
Triton Clustering
7Li
7Li. About 7% of all inelastic interactions of 7Li nuclei are “white” stars (80 events).
Decay of 7Li nucleus to -particle and triton - 40 events.
=1.5 MeV
=0.092 MeV
=0.23 MeV
=1.4 MeV
=1.58 MeV
5Li
6Be
7B
8C
11N
Toward stability frontier
Splitting to HeHe with two target fragments,
HeHe, HeHH, 6Lip, and 4H.
2 A GeV/c 7Be.
Relativistic 7Be fragmentation: 2+2
The 7Вe*3He decay is occured in 22 “white stars” with 2+2 topology. In the latter, 5 “white” stars are identified as the 7Вe*(n) 3He3He decay. Thus, a 3He clustering is clearly
demonstrated in dissociation of the 7Be nucleus.
“Ternary H&He Process”
+
8B 0.769 s
The 10B nuclei with a momentum of 2A GeV/c and an intensity of about 108 nuclei per cycle were accelerated at
the JINR nuclotron. A beam of secondary nuclei of a magnetic rigidity corresponding to Z/A = 5/8 (10В8B
fragmentation) was provided for emulsions. We plan to determine the probabilities
8B7Bер (9), 3,4He3Hep (8), 6Lipp (1), HeHHp (7) , and HHHpp (1).
A=8=0.23 MeV
8He (118 ms) , 8Li (838 ms)
(770 ms)
=0.0000068 MeV
A=9
=0.00054 MeV
1.3A GeV 9Be dissociation in 2+2. 10B9Be, Nuclotron, 2004.
“white” star
with recoil proton
with heavy fragment of target nucleus
“Ternary 3He Process”
+
9C 0.1265 s9B 540 eV
6Be & 3He
2 A GeV/c carbon beam of a magnetic rigidity Z/A = 6/9 (12C9C) was provided for emulsions to determine the probabilities
9C 8Bp (1) , 7Bерp (2) , HeHepp (7), 6Lipp (0) , HeHHpp (5) , HeHeHe (3).
1.9 A GeV 1.9 A GeV 1010BB
10B is disintegrated to 2 doubly charged and 1singly
charged particles in 70% of “white” stars. A singly charged particle is the deuteron in 40% like in
case of 6Li. 8Be contribution is 20%.
10В9Bep – 3%
=1.58 MeV
A=11
“3He Process: mixed isotope fusion”
+
11C 20.38 m
13O 8.58 ms
6Be & 4He
12N 11.0 ms +
14O 70.6 s
15O 122 s
+ 11B 80.2 %
CNO cycle
12C 98.89 %
7Be 53.3 d
10C 19.2 s
10B 19.8%
14O 70.6 s
11N 1.58 MeV
12O 0.4 MeV
15F 1 MeV
13N 10 min
20Na 448 ms
20Mg 95 ms
Walking along proton stability line
12N 11 ms
16Ne 0.122 MeV
14N 99.6%
13O 8.58 ms 14O 70.6 s
15O 122 s 16O 99.8%
19F 100%
20Ne 90.48%
16F 0.04 MeV17F 64.5 s 18F 110 min
17Ne 109 s 18Ne 1.67 s 19Ne 17.2 s
12O 0.4 MeV
9C, 126.5 ms
6Be, 0.092 MeV
+12 MeV
+16 MeV
+38 MeV
Multifragmentation in H&He
10C 19.2 s
13O 8.58 ms
16Ne 0.122 MeV
Multifragmentation in H&He
11C 20.38 m
14O 70.6 s
17Ne 109 s
20Mg 95 ms
Multifragmentation in H&He
Fragmentation of relativistic nuclei provides an excellent quantum “laboratory” to explore the transition of nuclei from the ground state to a gas-like phase composed of nucleons and few-nucleon clusters having no excited states, i. e. d, t, 3He, and .
The research challenge is to find indications for the formation of quasi-stable systems significantly exceeding the sizes of the fragments. Search for such states is of interest since they can play a role of intermediate states for a stellar nuclear fusion due to dramatically reduced Coulomb repulsion.
The fragmentation features might assist one to disclose the scenarios of few-body fusions as processes inverse to fragmentation.
2 A GeV/c 2 A GeV/c 1010B B 88BB