We propose to enhance the kaon identi cation capabilities of the GlueX detector by constructing an FDIRC (Focusing Detection of Internally Reflected Cherenkov) detector utilizing the decommissioned BaBar DIRC components. The GlueX FDIRC will significantly enhance the GlueX physics program by allowing one to search for and study hybrid mesons decaying into kaon fi nal states. Such systematic studies of kaon final states are essential for inferring the quark flavor content of hybrid and conventional mesons. The GlueX FDIRC will reuse one-third of the synthetic fused silica bars that were utilized in the BaBar DIRC. A new focussing photon camera, read out with MaPMTs, is being developed. We propose operating the enhanced GlueX detector in Hall D for a total of 220 days at an average intensity of 5 x 10^7 photons/s, a program that was approved by PAC42.
