Search for Axions and Chameleons with CAST - Axions from Dark Matter and Antiquark Nuggets, Solar Axions and Solar Chameleons

The physics programme described in this addendum covers a period of three years to consolidate the pro-posal CERN-SPSC-2015-021 / SPSC-P-352. The addendum comprises four distinct activities, which can be carried out by the CAST Collaboration in parallel: - Search for streaming Dark Matter axions and axions from anitquark nuggets with tunable cavities, optionally operated with fast axion mass scanning techniques - Develop new tunable microwave filter cavities to reach higher axions masses - Search for solar axions with low noise micropattern detectors and Xenon gas for photon conversion - Continue the ongoing KWISP project towards a highly sensitive interferometric particle detector to discover chameleons coming from the sun. This technique is suggestive for a new method to search for short range forces including axion exchange.