OCCASO, homogeneous sample of open clusters with precise chemical abundance determination

The OCCASO survey (Open Clusters Chemical Abundances from Spanish Observatories) targets old OCs, observing in median 6 red clump stars in each of them. We use higher resolution spectroscopy (R > 65,000), high signal-to-noise (SNR~70), and wider wavelength coverage (400-900 nm) than massive spectroscopic surveys such as APOGEE, GES, and the forthcoming WEAVE and 4MOST. Spectra for 312 stars in 33 clusters have been acquired and fully analysed. Among the clusters of our sample NGC6705, NGC6791, Berkeley 17, and four of the recently discovered UBC clusters highlight. We have determined abundances using the methods of equivalent width and spectral synthesis of 21 chemical elements produced by different nucleosynthesis processes such as iron-peak, alpha, odd-z and neutron capture elements. Our precision in abundance determination is between 0.03 and 0.13 dex depending on the studied element. Our accurate radial velocities (10m / s) and abundances combined with the Gaia kinematic data allow us to determine the orbits of the OCs and study the chemical gradients in the Galactic disc. Specifically, in this work we present the results of Galactocentric radial gradients.