ABSOLUTE DIFFERENTIAL CROSS SECTIONS FOR SMALL-ANGLE NEUTRAL-NEUTRAL AND ION-NEUTRAL ELASTIC SCATTERING AT KEV ENERGIES

This thesis reports measurements of absolute cross sections, differential in angle, for elastic scattering of keV-energy atomic H and He projectiles from He, Ne, Ar, Kr, Xe, H$\sb 2$, and N$\sb 2$ at laboratory scattering angles between 0.02$\sp\circ$ and 0.5$\sp\circ$. It also reports measurements of absolute cross sections, differential in angle, for elastic scattering of keV-energy H$\sp +$ and He$\sp {+}$ projectiles from He, Ne, Ar, Kr, and Xe and H$\sb 2$ at laboratory scattering angles between 0.04$\sp\circ$ and 1.0$\sp\circ$. Comparisons are made between measured differential cross sections and those calculated from various model potentials, revealing the range of validity of potentials appearing in the literature. Experimental cross sections are also integrated over the angular range to obtain partial total cross sections, which are compared with those appearing in the literature