HETG is the High-Energy Transmission Grating on the Chandra X-ray satellite. It consists of two sets of gratings, each with different period: The Medium Energy Grating (MEG) and the High Energy Gratings (HEG). Both gratings are mounted on a single support structure and therefore are used together. The HETG is described in detail in a chapter in the Chandra Proposers' Observatory Guide.
The HETG was designed and build at MIT by the group of HETG Principal Investigator Prof. Claude R. Canizares.
Information about the current calibration of the HETG can be found at the main CXC calibration web page.
Before launch, all instruments on Chandra were extensively tested on the ground in the X-ray calibration facility (XRCF). Most of this data is only of historical interest at this point, but occasionally, we might have to look back to the ground calibration data.
Quarterly reports are given twice a year to update all groups in the Chandra X-ray Center on recent progress. Reports about the HETG are listed here.
Early in the mission, progress reports were nominally given monthly, but in some cases, several months are summarized into one report.
The HETG was designed, built, and tested at MIT in Cambridge, MA, USA. The membrane-supported gold gratings that disperse the light were developed and made in the Space Nanotechnology Laboratory (formerly known as the Space Microstructures Laboratory) in Building 37. Gratings where then tested on an X-ray beamline in building NE-80.