The Infrared Imaging Spectrograph (IRIS) for TMT: the atmospheric dispersion corrector

摘要

We present a conceptual design for the atmospheric dispersion corrector (ADC)for TMT's Infrared Imaging Spectrograph (IRIS). The severe requirements of thisADC are reviewed, as are limitations to observing caused by uncorrectableatmospheric effects. The requirement of residual dispersion less than 1milliarcsecond can be met with certain glass combinations. The design decisionsare discussed and the performance of the design ADC is described. Alternativeoptions and their performance tradeoffs are also presented.