The BTC (Big Throughput Camera), formerly known as LACCD, is a Mosaic Imager built by Tony Tyson (Bell Labs) and Gary Bernstein (U. Michigan). The BTC contains four thinned SITe 2048 CCDs, plus all readout electronics and control computer. A Sparc Ultra 2 computer with fast disk and tape storage is available for data inspection and reduction. The BTC was successfully used at the CTIO 4-m prime focus during visitor runs in May and December 1996, and then became available to all users for semesters I and II of 1997 and 1998. At the end of semester I 1999 the BTC will be replaced with the "NOAO MOSAIC II Imager."
In May 1998 CCDs #1 and #2 were replaced with superior devices. Visit the WWW site
The BTC will be scheduled in two or three block runs per semester, at the 4-m prime focus only. We will only schedule the CTIO prime focus imager, which contains a single SITe 2K CCD, for programs which require filters unavailable in the large size needed for the BTC. Programs satisfied with a 6 x 6 arcmin field and for which better image sampling or U band photometry is important should consider using the 4-m RC focus. Pixel size is 0.16 arcsec with a SITe 2K CCD, and the U band throughput is double that of the prime focus. The information on these WWW pages should help you decide whether or not the BTC will be advantageous for your 4-m imaging program. Please contact me (awalker@noao.edu) if you have further questions regarding the use of the BTC at CTIO.
Note: Anyone interested in obtaining their own filters is recommended to have them made in the 5.75 x 5.75 inch size rather than 6 x 6 inches, with maximum thickness 12 mm. The smaller size will allow the filters to be useable both with the "NOAO Mosaic Imager" and with the BTC.