The Cherenkov Telescope Array CTA will be the first open facility for gamma-ray astronomy in the very-high-energy domain, with a performance which is dramatically improved over existing instruments in terms of sensitivity, energy coverage, survey
capability and flexibility. CTA will probe non-thermal phenomena in the Universe – known to have comparable energy content to other forms of energy such as thermal radiation – both in our own Galaxy and at cosmological distances, addressing questions in astrophysics, astroparticle physics, particle physics, plasma physics, cosmology, and fundamental physics.

The CTA preparatory phase – CTA-PP – will address a number of crucial prerequisites for the approval, construction and operation of CTA:

• the legal framework, governance schemes, and financial regulations under which CTA will be constructed and operated
• the preparation of funding agreements between potential funding agencies
• the preparation of contracts with potential host countries for the CTA instrument
• the detailed technical design and costing of the CTA observatory
• the selection of sites where CTA will be deployed, and detailing and cost-estimation of the required site infrastructure
• the schemes for procurement and industry involvement in the technical design and construction of CTA
• the required linking with relevant science communities regarding the detailed definition of the science program, the corresponding final optimisation of the observatory layout, and the definition of user services and data access.

For CTA-PP, support is sought primarily for work on the legal, governance and financial issues, for the installation of a project office coordinating and supporting management of CTA-PP as well as the design of CTA and the planning of the implementation, and for studies regarding the optimisation and production of CTA components by industry. The ultimate delivery of CTA-PP will be a detailed implementation plan for the CTA infrastructure.