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Title: Active target studies of the αp-process at CRIB

The αp-process is a sequence of (α, p)(p, γ) reactions important to the nuclear trajectory to higher masses in type I X-ray bursts. Specifically, the αp-process is schematically pure helium-burning, and thus unlike pure hydrogen-burning processes, does not require slow β{sup +} decays. Explosive helium burning is responsible for the observed short rise-times of X-ray bursts but ultimately gives way to the rp-process as the Coulomb barrier increases. Because the stellar reaction rates of these (α, p) reactions are poorly known over the relevant astrophysical energies, we performed systematic studies of the {sup 18}Ne(α,p), {sup 22}Mg(α,p) and {sup 30}S(α,p) reactions at the Center for Nuclear Study (CNS) low-energy radioactive ion beam separator, called CRIB. We produce the radioactive beams in-flight and scan the center-of-mass energy down into the Gamow Window using a thick target in inverse kinematics. The helium target gas also serves as part of the detector system, an active target, which was newly designed for these measurements. The active target, which uses gas electron multiplier (GEM) foils, allows for higher beam injection rates than previous multi-sampling and tracking proportional counters (MSTPC). We present a summary of our recent results from these active target experiments at CRIB.
Authors:
; ; ; ; ;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ; ;  [11] ;  [12] ; more »;  [13] ;  [14] ; « less
  1. Center for Nuclear Study, Graduate School of Science, The University of Tokyo (Japan)
  2. Center for Nuclear Study, Graduate School of Science, The University of Tokyo, Japan and Research Center for Nuclear Physics (RCNP), Osaka University (Japan)
  3. Institute of Physics (Viet Nam)
  4. Center for Nuclear Study, Graduate School of Science,Tthe University of Tokyo (Japan)
  5. (The Institute of Physical and Chemical Research) (Japan)
  6. (China)
  7. Center for Nuclear Study, Graduate School of Science, The University of Tokyo, Japan and Institute of Physics (Viet Nam)
  8. Department of Physics and Astronomy, McMaster University (Canada)
  9. Department of Physics, University of Catania and INFN (Italy)
  10. Center for Nuclear Study, Graduate School of Science, The University of Tokyo, Japan and Department of Physics, University of Catania and INFN (Italy)
  11. Institute of Modern Physics, Chinese Academy of Sciences (China)
  12. Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK) (Japan)
  13. Department of Physics, Tohoku University (Japan)
  14. Institute for Basic Science (Korea, Republic of)
Publication Date:
OSTI Identifier:
22280453
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1594; Journal Issue: 1; Conference: OMEG12: 12. international symposium on origin of matter and evolution of galaxies, Tsukuba (Japan), 18-21 Nov 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALPHA REACTIONS; ASTROPHYSICS; BEAM INJECTION; COSMIC X-RAY BURSTS; COULOMB FIELD; ELECTRON MULTIPLIERS; HELIUM; HELIUM BURNING; HYDROGEN BURNING; MAGNESIUM 22; NEON 18; NUCLEAR DECAY; NUCLEAR REACTION KINETICS; PROPORTIONAL COUNTERS; PROTON REACTIONS; RADIOACTIVE ION BEAMS; SULFUR 30; X RADIATION