I apologize for the confusion, but there is no instrument called CHACE-2 associated with the Chandrayaan-2 mission. Chandrayaan-2 was the second lunar exploration mission by the Indian Space Research Organisation (ISRO), which aimed to land a rover on the Moon's surface.
The Chandrayaan-2 mission carried several scientific instruments, including the Orbiter High-Resolution Camera (OHRC), the Terrain Mapping Camera-2 (TMC-2), the Imaging Infrared Spectrometer (IIRS), and the Dual-Frequency Synthetic Aperture Radar (DFSAR), among others. These instruments were primarily designed to study the lunar surface, composition, and the presence of water ice.
While the Chandrayaan-2 mission contributed valuable data about the Moon, there was no specific instrument dedicated to studying the lunar exosphere or any discovery related to it mentioned in the mission's objectives or results.
If you have any other questions or need further clarification, feel free to ask!