skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Three-Body Correlations In 6He Revealed In The Quasi-Free Knockout Reaction 4He(6He,2{alpha})2n

Abstract

The 4He(6He,2{alpha})2n reaction was studied in experiments designed for the observation of a quasi-free scattering (QFS) occurring between the {alpha} core of the Borromean 6He nuclei and the 4He target nuclei. The helium gas target cooled down to 14 K was bombarded by a 25A MeV secondary beam of 6He nuclei produced at the fragment separator ACCULINNA (Dubna). The data were analyzed with the use of the Plane Wave Impulse Approximation (PWIA) and the three-body wave function of 6He and taking into account the n - n final state interaction. Correlation obtained in the reaction exit channel between the momentum values characteristic to the {alpha}-2n and n-n subsystems were found to be consistent with the PWIA predictions. This suggests that QFS could be suitable for the study of other Borromean nuclei.

Authors:
; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3]; ;  [4]
  1. Flerov Laboratory of Nuclear Reactions, JINR, 141980 Dubna (Russian Federation)
  2. Kurchatov Institute, Kurchatov sq. 1, 123182 Moscow (Russian Federation)
  3. RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan)
  4. GANIL, BP 5027, F-14076 Caen Cedex 5 (France)
Publication Date:
OSTI Identifier:
21061830
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 912; Journal Issue: 1; Conference: International symposium on exotic nuclei, Khanty-Mansiysk (Russian Federation), 17-22 Jul 2006; Other Information: DOI: 10.1063/1.2746579; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALPHA REACTIONS; CORRELATIONS; FINAL-STATE INTERACTIONS; HELIUM 4; HELIUM 6; IMPULSE APPROXIMATION; KNOCK-OUT REACTIONS; MEV RANGE; NUCLEAR STRUCTURE; QUASI-FREE REACTIONS; SCATTERING; SECONDARY BEAMS; THREE-BODY PROBLEM; WAVE FUNCTIONS; WAVE PROPAGATION

Citation Formats

Sidorchuk, S. I., Fomichev, A. S., Golovkov, M. S., Gorshkov, V. A., Gorshkov, A. V., Krupko, S. A., Oganessian, Yu. Ts., Rodin, A. M., Slepnev, R. S., Stepantsov, S. V., Ter-Akopian, G. M., Wolski, R., Korsheninnikov, A. A., Nikolskii, E. Yu., Roussel-Chomaz, P., and Mittig, W.. Three-Body Correlations In 6He Revealed In The Quasi-Free Knockout Reaction 4He(6He,2{alpha})2n. United States: N. p., 2007. Web. doi:10.1063/1.2746579.
Sidorchuk, S. I., Fomichev, A. S., Golovkov, M. S., Gorshkov, V. A., Gorshkov, A. V., Krupko, S. A., Oganessian, Yu. Ts., Rodin, A. M., Slepnev, R. S., Stepantsov, S. V., Ter-Akopian, G. M., Wolski, R., Korsheninnikov, A. A., Nikolskii, E. Yu., Roussel-Chomaz, P., & Mittig, W.. Three-Body Correlations In 6He Revealed In The Quasi-Free Knockout Reaction 4He(6He,2{alpha})2n. United States. doi:10.1063/1.2746579.
Sidorchuk, S. I., Fomichev, A. S., Golovkov, M. S., Gorshkov, V. A., Gorshkov, A. V., Krupko, S. A., Oganessian, Yu. Ts., Rodin, A. M., Slepnev, R. S., Stepantsov, S. V., Ter-Akopian, G. M., Wolski, R., Korsheninnikov, A. A., Nikolskii, E. Yu., Roussel-Chomaz, P., and Mittig, W.. Tue . "Three-Body Correlations In 6He Revealed In The Quasi-Free Knockout Reaction 4He(6He,2{alpha})2n". United States. doi:10.1063/1.2746579.
@article{osti_21061830,
title = {Three-Body Correlations In 6He Revealed In The Quasi-Free Knockout Reaction 4He(6He,2{alpha})2n},
author = {Sidorchuk, S. I. and Fomichev, A. S. and Golovkov, M. S. and Gorshkov, V. A. and Gorshkov, A. V. and Krupko, S. A. and Oganessian, Yu. Ts. and Rodin, A. M. and Slepnev, R. S. and Stepantsov, S. V. and Ter-Akopian, G. M. and Wolski, R. and Korsheninnikov, A. A. and Nikolskii, E. Yu. and Roussel-Chomaz, P. and Mittig, W.},
abstractNote = {The 4He(6He,2{alpha})2n reaction was studied in experiments designed for the observation of a quasi-free scattering (QFS) occurring between the {alpha} core of the Borromean 6He nuclei and the 4He target nuclei. The helium gas target cooled down to 14 K was bombarded by a 25A MeV secondary beam of 6He nuclei produced at the fragment separator ACCULINNA (Dubna). The data were analyzed with the use of the Plane Wave Impulse Approximation (PWIA) and the three-body wave function of 6He and taking into account the n - n final state interaction. Correlation obtained in the reaction exit channel between the momentum values characteristic to the {alpha}-2n and n-n subsystems were found to be consistent with the PWIA predictions. This suggests that QFS could be suitable for the study of other Borromean nuclei.},
doi = {10.1063/1.2746579},
journal = {AIP Conference Proceedings},
number = 1,
volume = 912,
place = {United States},
year = {Tue May 22 00:00:00 EDT 2007},
month = {Tue May 22 00:00:00 EDT 2007}
}
  • Low lying states of the unbound 9He system were investigated by means of the (d,p) reaction. A cryogenic deuterium target was bombarded by a secondary 8He beam. Complete kinematics measurements were accomplished. The observed 9He states are broad and overlapping. Their spins and parities have been unambiguously determined. Data from a 6He({alpha},2{alpha})2n experiment have been analyzed in terms of a quasi-free scattering approach. A large effect of the 2n final state interaction on the internal 6He momentum distribution has been demonstrated.
  • Measurements of the (..cap alpha..,2..cap alpha..) reaction on /sup 9/Be, /sup 12/C, /sup 16/O, and /sup 20/Ne targets at E/sub ..cap alpha../=140 MeV were made at 20 angle pairs. The quasi-free knockout mechanism appears to dominate the reaction. The experimental data were analyzed with distorted-wave impulse approximation calculations. The factorization approximation employed in the calculations was tested explicitly and found to be valid. The shapes of the calculated energy sharing spectra are in satisfactory agreement with the data. The predicted absolute cross sections were found to be very sensitive to the cluster-core bound state radius parameter, and a bound statemore » radius R=2.52A/sub c//sup ts1/3/ fm is necessary to obtain absolute spectroscopic factors consistent with existing theoretical values. Several possible explanations for this excessive value are suggested. Comparisons are made with other alpha knockout and transfer reactions.« less
  • The total cross section of the 3He(d,p)4He reaction at the super low-energy region is calculated by the three-body Faddeev equations in the 3He-p-n model. The result is compared with the ''double polarized'' total cross section in which both of the incident deuteron and the target 3He are set in a spin parallel way. The PEST potential for the p-n interaction, the REST potential for the p-3He and n-3He interactions are adopted, respectively. The off-shell importance of the p-3He and n-3He potentials is emphasized to reproduce the 5Li (3/2+) resonance. The cross section enhancement of 3He(d,p)4He reaction by the spin polarizationsmore » is confirmed.« less
  • The /sup 2/H( alpha ,p alpha )n reaction was studied in a kinematically complete experiment at several angles and energies suitable for observing photon- alpha quasi-free scattering (QFS) and proton-neutron finalstate interactions (FSI). The data were analyzed in terms of various quasi-two-body models, with the strong contributions from p- alpha and n- alpha interactions in the ground states of /sup 5/Li and /sup 5/He, which are present in most of the spectra, taken into account. A modified impulse approximation was found to describe reasonably well the spectra dominated by p- alpha OFS and FSI. A characteristic increase of yield wasmore » observed in the region of low relative p-n energy; this can only be explained by the admission of at least 1% of isospin-forbidden proton- neutron FSI in the spinsinglet state. (auth)« less