On Both the Time Histories of the 0.511 MeV Line and 2.223 MeV Line from the X4.8 Flare of 23 July 2002 Observed with Rhessi

High-spectral-resolution measurements of the 2.223 MeV neutron capture line and the 0.511 MeV positron-electron annihilation line have been made with the Reuven Ramaty High-Energy Solar Spectroscopic Imager during the X4.8 flare of 23 July 2002. We have tried to explain both the time histories of the 2.223 MeV line and the 0.511 MeV line, adopting a power-law spectrum of accelerated ions. The results show that with a power-law spectral index of 3.52, the calculational time histories can roughly reproduce the observations. An improved fit between the calculated 2.223 MeV line and the observed 2.223 MeV line can be achieved if we allow the spectrum of accelerated ions to vary with time.