SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Radiation dose from primary cosmic rays compared to dose from gamma rays produced by proton-proton reactions in solar flare - spacecraft shield
Termination of proton-proton chain in stellar interiors, noting influence of deuterium and helium 3 burning reactions
Stellar temperature and density effects on proton- proton chain termination and endoergic electron- capture reaction rate
Relative signs of nuclear magnetic resonance proton-proton coupling constants in styrene sulfide and styrenimine
Detection of neutrino emission by sun from nuclear reactions
Differential cross-section and polarization measurements in proton-proton scattering
Nucleon-nucleon scattering behavior at energies near 200 MeV, and proton-proton reaction
Scattering cross section resulting from proton- proton reaction
Secondary protons from interstellar cosmic-ray collisions, noting solar modulation effects on detection
Production spectrum of high energy electrons from high energy cosmic ray pion decay and proton- proton collisions
High energy measurement of neutron-proton elastic scattering, noting diffraction peak existence, differential cross section and secondary forward peak
Strongly magnetized relativistic degenerate electron gas proton-proton reaction rates and electron capture over various temperatures, densities and magnetic field strengths
Investigation of the premain sequence evolution and the main sequence evolution of stars of 5, 10, 20, 30, 100, and 200 solar masses. Normal stars in this entire mass range normally convert hydrogen into helium by the CN-cycle on the main sequence. The present hydrogen-helium stars of 5 and 10 solar masses must reach higher central temperatures in order to convert hydrogen to helium by the proton-proton chains. Consequently, the mean densities in the stars are greater, and the surface temperatures are higher than in normal stars. In the stars of 20 solar masses and larger, the proton-proton chains do not succeed in supplying the necessary luminosity of the stars by the time the contraction has produced a central temperature near 10 to the 8th K. At that point triple-alpha reactions generate small amounts of C12, which then acts as a catalyst in the CN-cycle, the rate of which is then limited by the beta-decays occurring within the cycle. During the evolution of these more massive stars, the central temperature remains in the vicinity of 10 to the 8th K, and the surface temperature on the main sequence approaches 100,000.
The double differential cross sections for the production of protons and deuterons from targets of Be, C, Al, Fe, Cu, Ge, W, and Pb were obtained at laboratory angles of scatter of 10, 20, 30, 40, 50, and 60 degrees for 558-MeV incident protons. The position of the quasi-elastic peak, discernible in the cross sections up to approximately 40 degrees, corresponded closely to the theoretical predictions for proton-proton elastic scattering at 558 MeV. The mean ratio of deuteron to proton energy-integrated cross sections was 0.056 + or - 0.008. The dependence of energy-integrated cross sections for both protons and deuterons on target mass number A varied from A to the 1/3 power at 10 degrees to A to the 2/3 power above approximately 30 degrees. The ratio of energy-integrated deuteron cross sections for quasielastic processes to that for reactions yielding a deuteron-pi-meson pair was approximately 10 percent.
Total cross section parameterizations for neutral and charged pion production in nucleon-nuelcon collisions are compared to an extensive set of experimental data over the projectile momentum range from threshold to 300 GeV. Both proton-proton and proton-neutron reactions are considered. Good agreement between parameterizations and experiment is found, and therefore the parameterizations will be useful for applications, such as transport codes.