Liverpool Telescope Technical Note 1: Telescope and IO:O Throughput

This project contains "LT Tech. Note 1: Telescope and IO:O Throughput" and plain text data files tabulating both the final results and the input data used for the analysis. This includes filter transmission profiles and a model of the CCD detector quantum efficiency for the Liverpool Telescope and IO:O instrument. Abstract of the main paper: We measure the absolute photon efficiency of the Liverpool Telescope using observations of photometric standard stars and a throughput model of the IO:O instrument. Over a period of 1 year following mirror re-coating the telescope transmission is in the range 73-79% over 4000-10000 Angstroms. Transmission in the u'-band (~3500 Angstroms) is slightly lower at 65%. Immediately following mirror re-coating the throughput is shown to be consistent within 4% to predictions for two reflections from bare-aluminium-coated optics. The telescope throughput (two reflections) degrades at a rate ~0.0002 mag/day. Also presented are the effective wavelengths and widths for the u',g',r',i',z',B,V broad-band filters, taking into account all optical components of the system.