  The Cherenkov Telescope Array (CTA) is the next generation observatory for
very high energy gamma rays. The capability of the array to detect gamma-rays
above 10 TeV is going to be achieved with a large number of Small Size
Telescopes (SSTs) which will cover a large area. The subarray composed of SSTs
has to compromise the number of telescopes (cost) and the large effective area.
The separation between the telescopes has to be adjusted to achieve highest
sensitivity with the smallest number of telescopes. On the other hand larger
separation can worsen the energy threshold as well as the energy and angular
resolutions. In our study we have investigated the optimal spacing between the
telescopes of the SST array using an analytical approach and the concept of
telescope cell consisting of four telescopes as well as Monte Carlo simulations
of the sets of cells.
