RHESSI has observed the 7Be and 7Li -ray lines from fusion of accelerated alpha particles with ambient helium produced during the 2002 July 23 solar are that erupted at a heliocentric angle of 73 deg. This is the first observation of the lines with a germanium spectrometer. We have fit the measured lines with calculated shapes for different energy and angular distributions for the interacting alpha particles. A particle distribution from saturated pitch-angle scattering in the corona provides the best fit, but isotropic, downward-isotropic, or fan-beam distributions also provide acceptable fits. We can rule out a downward-beamed distribution with 99.99% confidence. RHESSI measurements of other Doppler-shifted nuclear de--excitation lines are consistent with a forward isotropic distribution of interacting particles in a magnetic loop tilted by approximately 40 deg from the normal to the solar surface toward Earth. Such a distribution is also consistent with the alpha-4He line shape with approximately 15% confidence.
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