ABSTRACT
In this paper, X-ray and gamma-ray propagation in crystals having a constant strain gradient and flat or cylindrical surfaces is investigated. When a displacement field is present, the Takagi-Taupin equations are solved either by the Riemann-Green method or by a numerical method. The results are applied to study the operation of a double-crystal Laue-Laue diffractometer having a flat collimating crystal followed by a bent analyzer crystal. In particular, the effect of the analyzer strain on the location of the diffraction peaks in the dispersive and non-dispersive set-up is examined, thus confirming the previously reported peak location as being set only by the diffracting-plane spacing on the analyzer entrance surface.
Subject(s)
Crystallization , Gamma Rays , X-Rays , Models, Theoretical , Surface PropertiesABSTRACT
We report the stopping power of molecular hydrogen for antiprotons of kinetic energy above the maximum (approximately 100 keV) with the purpose of comparing with the proton one. Our result is consistent with a positive difference in antiproton-proton stopping powers above approximately 250 keV and with a maximum difference between the stopping powers of 21%+/-3% at around 600 keV.
ABSTRACT
Total and differential cross sections for the exclusive reaction pp-->pp rho observed via the pi(+)pi(-) decay channel have been measured at p(beam)=3.67 GeV/c. The observed total meson production cross section is determined to be (23.4+/-0.8+/-8) mu b and is significantly lower than typical cross sections used in model calculations for heavy-ion collisions. The differential cross sections measured indicate a strong anisotropy (approximately cos(theta(CM)(rho)) in the rho(0) meson production.
