1.5m Atmospheric Dispersion Corrector (ADC)

Created: 01/06/11 by EF
Updated: 04/27/16 by EF

Gabor Furesz (GF) proposed to build an ADC for the 1.5m in 2007. The main goal was to correct for atmospheric dispersion to achieve significant improvements in the sensitivity and wavelength coverage of TRES. However, the ADC will also help with FAST, obviating the need to rotate to the parallactic angle to minizize dispersion. To align a slit to, e.g., the PA of a feature, you still need to use the rotator.

GF obtained funding in 2008 and completed the design in early 2009.

The design (pdf) shows a significant improvement from an ADC.

Mark Ordway led the CE effort to build the unit, which was delivered to FLWO in late November 2009. We then began integrating and testing the hardware to the telescope (TG, WAP and GF) and integrating and testing software to drive the unit (TG and GF).

GF tested the ADC on the telescope on 15 and 16 November 2010.

His report (pdf) showed the unit behaved as expected. The unit generally operates correctly, as has been shown in production starting in 2011 with TRES and FAST.

However, as this report (pdf) shows, we have had instances of malfunctions.

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