نتایج جستجو برای: neutron capture

تعداد نتایج: 162999  

Journal: :Australian Journal of Physics 1977

Journal: :Astronomy and Astrophysics 2021

Context. Carbon-enhanced metal-poor (CEMP) r/s-stars show surface-abundance distributions characteristic of the so-called intermediate neutron capture process (i-process) nucleosynthesis. We previously showed that ingestion protons in convective helium-burning region a low-mass low-metallicity star can explain surface abundance distribution observed CEMP r/s stars relatively well. Such an i-pro...

2000
Yong-Zhong Qian

I discuss the recent progress in our understanding of nucleosynthesis via rapid neutron capture, the r-process, based on meteoritic data for the early solar system and observations of stars at low metallicities. At present, all data require that there be two distinct kinds of r-process events and suggest that supernovae are associated with these events. The diversity of supernova sources for th...

2010
J. E. Escher F. S. Dietrich N. D. Scielzo

2012

Boron Neutron Capture Therapy (BNCT) can be performed at a facility with a nuclear reactor or at hospitals that have developed alternative neutron sources. A beam of epithermal neutrons penetrates the brain tissue, reaching the malignancy. Once there the epithermal neutrons slow down and these low-energy neutrons combine with boron 10 (delivered beforehand to the cancer cells by drugs or antibo...

2000
Katja Langen Arlene J. Lennox Paul M. DeLuca

The Neutron Therapy Facility at Fermilab has treated cancer patients since 1976. Since then more than 2,300 patients have been treated and a wealth of clinical information accumulated. The therapeutic neutron beam at Fermilab is produced by bombarding a beryllium target with 66 MeV protons. The resulting continuous neutron spectrum ranges from thermal to 66 MeV in neutron energy. It is clear th...

2009
E. Litvinova H. P. Loens

We have computed dipole strength distributions for nickel and tin isotopes within the Relativistic Quasiparticle Time Blocking approximation (RQTBA). These calculations provide a good description of data, including the neutron-rich tin isotopes 130,132Sn. The resulting dipole strengths have been implemented in HauserFeshbach calculations of astrophysical neutron capture rates relevant for r-pro...

1999
Jenny Westin Christopher Sneden John J. Cowan

New high resolution, very high signal-to-noise spectra of ultra-metal-poor (UMP) giant stars HD 115444 and HD 122563 have been gathered with the High-Resolution Echelle Spectrometer of the McDonald Observatory 2.7m Telescope. With these spectra, line identification and model atmosphere analyses have been conducted, emphasizing the neutron-capture elements. Twenty elements with Z > 30 have been ...

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