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Title: Astrophysical S{sub 17}(0) factor from a measurement of the {sup 2}H({sup 7}Be,{sup 8}B)n reaction at E{sub c.m.}=4.5 MeV

Abstract

Angular distribution measurements of {sup 2}H({sup 7}Be,{sup 7}Be){sup 2}H and {sup 2}H({sup 7}Be,{sup 8}B)n reactions at E{sub c.m.}{approx}4.5 MeV were performed to extract the astrophysical S{sub 17}(0) factor using the asymptotic normalization coefficient (ANC) method. For this purpose a pure, low emittance {sup 7}Be beam was separated from the primary {sup 7}Li beam by a recoil mass spectrometer operated in a novel mode. A beam stopper at 0 deg. allowed for the use of a higher {sup 7}Be beam intensity. Measurement of the elastic scattering in the entrance channel using kinematic coincidence, facilitated the determination of the optical model parameters needed for the analysis of the transfer data. The present measurement significantly reduces errors in the extracted {sup 7}Be(p,{gamma}) cross section using the ANC method. We get S{sub 17} (0) = 20.7 {+-} 2.4 eV b.

Authors:
; ; ; ; ;  [1]; ;  [2]; ;  [3];  [4];  [5];  [6];  [7];  [8];  [9];  [10]
  1. Nuclear Science Centre, P.O. Box 10502, Aruna Asaf Ali Marg, New Delhi 110067 (India)
  2. Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)
  3. Department of Nuclear Physics, Andhra University, Visakhapatnam 530003 (India)
  4. Department of Physics, Himachal Pradesh University, Shimla 171005 (India)
  5. Department of Physics, Gauhati University, Jalukbari-Guwahati 787014 (India)
  6. IUC-DAEF Kolkata Centre, Bidhan Nagar, Kolkata 700092 (India)
  7. Department of Physics and Astrophysics, Delhi University, New Delhi 110007 (India)
  8. Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India)
  9. Department of Physics, Saurashtra University, Rajkot 360005 (India)
  10. Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064 (India)
Publication Date:
OSTI Identifier:
20771237
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 73; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevC.73.015808; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ANGULAR DISTRIBUTION; BERYLLIUM 7; BERYLLIUM 7 REACTIONS; BORON 8; CAPTURE; COSMIC NEUTRINOS; CROSS SECTIONS; DEUTERIUM TARGET; ELASTIC SCATTERING; EV RANGE; MEV RANGE; NUCLEOSYNTHESIS; OPTICAL MODELS; PROTON REACTIONS; RECOILS

Citation Formats

Das, J.J., Sugathan, P., Madhavan, N., Jhingan, A., Nath, S., Varughese, T., Datar, V.M., Navin, A., Rao, P.V. Madhusudhana, Sastry, D.L., Dhiman, S.K., Barua, S., Sinha, A.K., Singh, R., Ray, A., Kulkarni, R.G., and Shyam, R. Astrophysical S{sub 17}(0) factor from a measurement of the {sup 2}H({sup 7}Be,{sup 8}B)n reaction at E{sub c.m.}=4.5 MeV. United States: N. p., 2006. Web. doi:10.1103/PhysRevC.73.015808.
Das, J.J., Sugathan, P., Madhavan, N., Jhingan, A., Nath, S., Varughese, T., Datar, V.M., Navin, A., Rao, P.V. Madhusudhana, Sastry, D.L., Dhiman, S.K., Barua, S., Sinha, A.K., Singh, R., Ray, A., Kulkarni, R.G., & Shyam, R. Astrophysical S{sub 17}(0) factor from a measurement of the {sup 2}H({sup 7}Be,{sup 8}B)n reaction at E{sub c.m.}=4.5 MeV. United States. doi:10.1103/PhysRevC.73.015808.
Das, J.J., Sugathan, P., Madhavan, N., Jhingan, A., Nath, S., Varughese, T., Datar, V.M., Navin, A., Rao, P.V. Madhusudhana, Sastry, D.L., Dhiman, S.K., Barua, S., Sinha, A.K., Singh, R., Ray, A., Kulkarni, R.G., and Shyam, R. Sun . "Astrophysical S{sub 17}(0) factor from a measurement of the {sup 2}H({sup 7}Be,{sup 8}B)n reaction at E{sub c.m.}=4.5 MeV". United States. doi:10.1103/PhysRevC.73.015808.
@article{osti_20771237,
title = {Astrophysical S{sub 17}(0) factor from a measurement of the {sup 2}H({sup 7}Be,{sup 8}B)n reaction at E{sub c.m.}=4.5 MeV},
author = {Das, J.J. and Sugathan, P. and Madhavan, N. and Jhingan, A. and Nath, S. and Varughese, T. and Datar, V.M. and Navin, A. and Rao, P.V. Madhusudhana and Sastry, D.L. and Dhiman, S.K. and Barua, S. and Sinha, A.K. and Singh, R. and Ray, A. and Kulkarni, R.G. and Shyam, R.},
abstractNote = {Angular distribution measurements of {sup 2}H({sup 7}Be,{sup 7}Be){sup 2}H and {sup 2}H({sup 7}Be,{sup 8}B)n reactions at E{sub c.m.}{approx}4.5 MeV were performed to extract the astrophysical S{sub 17}(0) factor using the asymptotic normalization coefficient (ANC) method. For this purpose a pure, low emittance {sup 7}Be beam was separated from the primary {sup 7}Li beam by a recoil mass spectrometer operated in a novel mode. A beam stopper at 0 deg. allowed for the use of a higher {sup 7}Be beam intensity. Measurement of the elastic scattering in the entrance channel using kinematic coincidence, facilitated the determination of the optical model parameters needed for the analysis of the transfer data. The present measurement significantly reduces errors in the extracted {sup 7}Be(p,{gamma}) cross section using the ANC method. We get S{sub 17} (0) = 20.7 {+-} 2.4 eV b.},
doi = {10.1103/PhysRevC.73.015808},
journal = {Physical Review. C, Nuclear Physics},
number = 1,
volume = 73,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}
  • The differential cross section for the {sup 7}Be({ital d},{ital n}){sup 8}B reaction at {ital E}{sub c.m.}=5.8MeV has been measured using the {sup 7}Be beam generated by the radioactive nuclear beam facility at China Institute of Atomic Energy. The {sup 8}Be ions were detected in full geometry with a two-dimensional position sensitive {Delta}{ital E}-{ital E} counter telescope. The reaction cross section was determined to be 58{plus_minus}8mb. The angular distribution data were analyzed with the distorted-wave Born approximation calculation. The astrophysical {ital S}{sub 17}(0) factor for the {sup 7}Be({ital p},{gamma}){sup 8}B reaction was derived to be 27.4{plus_minus}4.4eVb through the asymptotic normalization constantmore » extracted from the experimental data. {copyright} {ital 1996 The American Physical Society.}« less
  • A Comment on the Letter by Weiping Liu, {ital et al.}, Phys.Rev.Lett.{bold 77}, 611 (1996). {copyright} {ital 1998} {ital The American Physical Society}
  • The partial cross sections from the neutron capture state to the ground and first excited states in {sup 8}Li have been separately determined for the first time at stellar neutron energy. The direct and weak cascade {gamma} rays from the capture and first excited states to the ground state were measured by means of anti-Compton NaI(Tl) and anti-Compton HPGe spectrometers, respectively. The {gamma}-ray branching ratio and the cross sections thus determined agree with that for thermal neutrons assuming a 1/v neutron velocity dependence. By comparing the cross sections with calculations based on the nonresonant direct capture mechanism it is shownmore » that the cross sections are sensitive to the interaction potential of the incident neutron with the {sup 7}Li target nucleus. This analysis confirms the possibility of deriving the parameters necessary for the calculation of the astrophysical S factor S{sub 17}(E) for the {sup 7}Be(p,{gamma}){sup 8}B reaction in the upper energy range above 500 keV.« less
  • We have performed continuum-discretized coupled channels (CDCC) calculations of the breakup of {sup 8}B on {sup 58}Ni and direct proton transfer for the {sup 8}B+{sup 58}Ni system at laboratory energies of 20-28.4 MeV. The influence of the {sup 7}Be core-target optical potential (OP) on the breakup cross section was investigated. Elastic scattering angular distributions for the {sup 7}Be+{sup 58}Ni and {sup 8}B+{sup 58}Ni systems at five different energies around the Coulomb barrier were studied, and a reasonable energy-independent OP for each system was obtained. Using these OPs and two different {sup 7}Be-p relative motion wave functions, and summing breakup andmore » direct proton transfer contributions, we were able to fit the experimental cross section at a {sup 8}B laboratory energy of 25.75 MeV. We calculated the excitation function for the {sup 7}Be emission in the {sup 8}B+{sup 58}Ni reaction, where {sup 7}Be products were measured at the forward angle {theta}{sub lab}=45 deg. in the energy interval E{sub lab}=20-28.4 MeV. In view of the peripheral character of the {sup 8}B breakup reaction at near-barrier energies, we could extract the asymptotic normalization coefficient for the {sup 7}Be-p system, which was found to be C{sub Be-p,p{sub 3}/{sub 2}}{sup 2}=0.543{+-}0.027 fm{sup -1}. Finally, the astrophysical S{sub 17}(0) factor was found to be S{sub 17}(0)=20.8{+-}1.1 eV b.« less
  • At very low energies of astrophysical interest, the {sup 7}Be({ital p},{gamma}){sup 8}B reaction is almost totally peripheral. Consequently, the overall normalization of the cross section for this reaction is defined by the asymptotic normalization coefficient of the bound-state wave function of {sup 8}B in the two-body channel {sup 7}Be+{ital p}. The reaction {sup 7}Be({sup 3}He,{ital d}){sup 8}B is suggested as a tool to measure this asymptotic normalization coefficient thereby allowing one to define the absolute value of the astrophysical factor, {ital S}{sub 17}(0), for the {sup 7}Be({ital p},{gamma}){sup 8}B reaction.