From RHESSI Wiki
RHESSI observes X-rays down to 3 keV which includes a number of emission lines. They consist mostly of highly ionized Fe lines. There are no lines above about 10 keV.
Lines in RHESSI Spectra
 Figure 1: A synthetic thermal spectra created with Chianti showing the thermal continuum along with line emission. The red curve shows what RHESSI should observe. |  Figure 2: Figure 1 from Phillips 2008 which shows the Iron and Iron-Nickel complex identifying each line |
 Figure 3: A close up of the Iron complex. |  Figure 4: A close up of the Iron-Nickel complex along with some higher energy Iron lines. Due to small flux in the higher energy lines, RHESSI is only likely to observe the Iron-Nickel complex as can be seen from the (red) RHESSI overlay. |
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