The CHARA-Michigan Phasetracker (CHAMP) successfully tracks fringes in 4-telescope and 6-telescope modes when observing high-visibility targets. We have found that our primary targets (Young Stellar Objects) have unexpectedly low visibility fringes (<20%) for most baselines at CHARA, generally below our tracking thresholds. We have undertaken an upgrade cycle in 2011-2012 to re-optimize CHAMP to allow group-delay tracking on the faintest fringes possible. We describe our multi-pronged strategy using special dicroics, new piezo scanners, and our first attempts to explore CHARA J-band made possible by using special metrology-blocking laser filters. CHAMP can now be used with all the combiners at CHARA. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
|Title of host publication||Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series|
|Subtitle of host publication||Amsterdam, Netherlands | July 01, 2012|
|Number of pages||1|
|Publication status||Published - 12 Sep 2012|
|Name||Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series|