Search for High-Frequency Structures in Electron Emission from H$_{2}$ by 2 MeV/u C$^{6+}$ Impact

Electron emission from H$_{2}$ by fast ion impact has been shown to produce interference effects in the spectra of ejected electrons.$^{1}$ This interference is analogous to Young's double-slit experiment. However, unlike Young's experiment, intramolecular scattering can give rise to secondary interferences with 2-3 times higher frequencies.$^{1}$ Recently, still higher-frequency structures were observed for p+H$_{2}$ collisions, and it was suggested that this might occur when the impinging particle is identical with the H$_{2}$ target nuclei.$^{2}$ To test this hypothesis, electron emission was measured for several observation angles using C$^{6+}$ projectiles instead of H$^{+}$. This work was done using the WMU tandem Van de Graaff. If no high-frequency structure occurs for C$^{6+}$, then the identical particle explanation emerges as a stronger possibility; if the structure persists, then another explanation must be sought. Preliminary examination of the data suggests high-frequency structures, but further detailed analysis is needed. $^{1}$N. Stolterfoht \textit{et al}., Phys. Rev. Lett. \textbf{87}, 023201 (2001); and \textbf{69}, 012701 (2004). $^{2}$S. Hossain \textit{et al}., Phys. Rev. A\textbf{72}, 010701 (2005).