Chandra High Energy Transmission Grating (HETG)

Providing the best spectral resolution in X-rays ever

X shaped visualization of HETG dispersed photons in Chandra

About the HETG

Chandra and HETG in
		  front of Supernova

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.

Calibration

Current Calibration

Information about the current calibration of the HETG can be found at the main CXC calibration web page.

XRCF

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.

Reports

History

The HETG was designed, built, and tested at MIT in Cambridge, MA, USA. The grating membranes that disperse the light were developed and made in the Space Microstructures Laboratory in building 37 (today: Space Nanotechnology Laboratory). Gratings where then tested on an X-ray beamline in building NE-80.

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Holography table where grating patterns are written using interference at Space Microstructures Laboratory
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Stress Gauge at Space Microstructures Laboratory
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XRF at Space Microstructures Laboratory
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Alignment at Space Microstructures Laboratory
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Inspection at Space Microstructures Laboratory
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Plating hood at Space Microstructures Laboratory
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RIE at Space Microstructures Laboratory
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Rotoetch at Space Microstructures Laboratory
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MEG facet in its holder
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Engineering model HESS after machining, 6/95
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Mass model HETG before delivery to Kodak, 7/95
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Mass model HETG with covers and alignment reference mirror, 7/95
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Engineering model HETG with grating surrogates installed, 12/95
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Engineering model HETG at vibration testing, 12/95
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Completed Flight Model HETG, 10/96
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Fabrication Group photo, 10/96
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HETG facet inspection, 12/96
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HETG on lift mechanism, 12/96
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HETG near work platform and HRMA, 12/96
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HETG installation, 12/96
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View of aft structure (LETG in foreground), 12/96

Instrument Publications

Publications about the HETG are collected in this ADS library, use the Chandra Bibliography Search to search for publications using data from the HETG.

An annual report of the HETG status and science highlights is given in the Chandra newsletter.