The effect of annealing on the RHESSI gamma-ray detectors
  The performance of nine RHESSI germanium detectors has been gradually
deteriorating since its launch in 2002 because of radiation damage caused by
passing through the Earth's radiation belts. To restore its former sensitivity,
the spectrometer underwent an annealing procedure in November 2007. It,
however, changed the RHESSI response and affected gamma-ray burst measurements,
e.g., the hardness ratios and the spectral capabilities bellow approximately
100 keV.
