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James Webb Space Telescope
TFI: Tunable Filter Imager

TFI is now a Heritage Instrument

In July 2011 the Canadian Space Agency (CSA) reluctantly discontinued work on the Tunable Filter Imager (TFI) when it became clear that issues associated with the cryogenic operation of its Fabry-Perot etalon were unlikely to be resolved in time to meet the instrument's delivery schedule. Instead, CSA will provide a reconfigured instrument - the Near InfraRed Imager and Slitless Spectrograph (NIRISS) - that enhances the capabilities of the JWST Observatory while being simpler to fabricate and operate.


A science instrument known as the Tunable Filter Imager (TFI), is packaged with the guide camera (FGS), but is functionally independent. The TFI will be used solely for science observations and will have a selectable band of resolution R~100 across its 2.2' x 2.2' field between 1.5 - 5 µm.

The Canadian Space Agency will provide the TFI to the JWST Project. The prime contractor is Com Dev. The Principal Investigator for the TFI is René Doyon from the Université de Montréal.

Latest News

April 6, 2011

The FGS and TFI underwent an alignment and risk mitigation campaign in a cryogenic environment at the David Florida Laboratory (DFL) in Kanata, Ontario (Canada) in Dec 2010 and Jan 2011. Preparations are currently underway for the final test activities in the summer and fall of 2011.