SUMMARY

Based on these and many other simulations (too numerous to display) we have made the following conclusions regarding the capabilities of HESSI for imaging/spectroscopy:

• Half-rotation (2-s) maps made of flares with at least 1000 incident photons per collimator per energy bin will show ~50:1 dynamic range on spatial scales from 2.3 to 189 arcsec.

• Spectroscopy of large (X) flares will provide spectral details at the 1 keV level over at least the 5-100 keV range.

• Gamma-ray (1-10 MeV) flares can be imaged with spatial resolution of about an arc minute if they are spatially complex, and of order 10 arcsec if they are comprised of isolated point sources.

• Albedo sources and other extended features can be imaged in the presence of point-like sources if the ratios of their respective integrated flux exceed ~ 1/3.

• Time resolutions as good as 50 ms can be achieved using partial-rotation synthesis if the source consists of 1-3 point sources.

• High-flux flares can be mapped with 0.8 arcsec resolution using the 3rd harmonic of the modulation profiles. The third harmonic also can be used to improve images on coarser scales.

• Flares as weak as ~ 100 photons per collimator per energy bin can be mapped reliably if the background is low or steady.