HIFI Instrument

The HIFI instrument (Heterodyne Instrument for Far-Infrared) was developed at the Netherlands Institute for Space Research (SRON) in Groningen, by a consortium led by SRON’s Th. de Graauw. The instrument performs very high-resolution spectroscopy and comprises:

  • 7 heterodyne receivers with a angular resolution of 11 to 45°:
    • 5 bipolar SAS mixers operating on a 480-1250 GHz frequency band
    • 2 unipolar HED mixers operating on a 1410-1910 GHz band
  • An Acousto-Optical Spectrometer (AOS)

Modèle de Vol du FPU de HIFI - Crédits SRON   Schéma de HIFI - Crédits SRON

Signal path through HIFI
HIFI signal path

3 French laboratories contributed to the HIFI instrument: LERMA/IRAM, IRAP (former CESR), and the Bordeaux Observatory.

LERMA/IRAM took part in developing the HIFI instrument by delivering the band 1  MSA (Mixer Sub-Assembly).

The CESR (now IRAP) contributed by developing the High Resolution Spectrometer (HRS). Here are its primary functions for high-resolution spectral analysis:

  • conditioning the signal’s frequency and strength (using the IF Module),
  • digitising the signal and calculating its auto-correlation function (using the ACS module),
  • and transmitting the data to the SL (using the DC/DC converter).

The Bordeaux Observatory delivered the HRS’s IF Module.