Arcetri Solar Physics Group

The Interferometric BIdimensional Spectrometer
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The Interferometric BIdimensional Spectrometer (IBIS) is a next generation bidimensional spectrometer based on a dual Fabry-Perot interferometric system. It combines high-spectral resolution with short exposure times and a large field of view, as well as the ability to work in polarized light. This makes IBIS a powerful instrument addressing a variety of important observational programs in solar physics.

IBIS uses two air-spaced etalons mounted in series to isolate a narrow portion of the solar spectrum (approximately 25-40 mÅ, or 1/100,000th of the visible spectrum) in the 5800 to 8600 Å range. By varying the spacing of etalons, the transmitted wavelength can be controlled, allowing the instrument to tune through the atomic lines in the solar spectrum. In this way a three-dimensional ( x, y, λ )map can be built up, allowing the determination of physical parameters throughout the observed field. The high instrumental transmission (~15-20%) and nearly instantaneous interferometer tuning (few tens of milliseconds) allow a full spectral line to be scanned in just a few seconds.

IBIS is installed at the Dunn Solar Telescope (DST) at the National Solar Observatory in Sunspot, NM, USA, where it is fed by a 76-element high-order adaptive optics system. This allows it to achieve diffraction limited imaging in a broad range of atmospheric conditions. IBIS is available to the community as a facility instrument at the DST.

line center intensity in Fe I 7090 Å line center velocity in Fe I 7090 Å
(scaled to +/- 1.25 km/sec)
line center intensity in Ca II 8542 Å

Images obtained by IBIS during its installation in June, 2003.
The full field of view is 80 arcseconds in diameter and the box shows an enlargement of a 5 x 8 arcsecond2 region near the center of the field.

Further Information
     IBIS Description
     IBIS Gallery
     Publications and Presentations
     Technical Notes
     IBIS First Light

Last Updated: 04 May, 2004