The Cassegrain Atmospheric Dispersion Compensator ("Cass ADC")
module for the Keck I telescope allows LRIS to operate with
reduced differential refraction from zenith to an airmass of 2.
The module was designed and built at UCO/Lick observatory, was
delivered in January 2007, and saw first light later in that
month. The Cass ADC has undergone commissioning during semester
2007A and was released for shared risk observing in June 2007.
Pending successful completion of its Operational Readiness Review
in July 2007, the Cass ADC will be released for routine observing
with LRIS in semester 2007B starting with the August LRIS run.