The Central Tracker proposed by the Bari and Lecce INFN groups(*) for the detector IDEA at FCC-ee and CEPC is an ultra-light drift chamber, with all stereo cells, operating with an helium-based gas mixture and equipped with cluster counting/timing readout techniques. Main peculiarities of this design are the high transparency (which allows to lower the multiple scattering contribution to the charged particles momentum resolution) and the very promising particle identification capabilities.
The proposal is inspired by the original design of the KLOE drift Chamber, successfully operated at the Daphne e+e- collider of the Frascati INFN Laboratories during 20 years (from 1999 until 2019). This design evolved to the one of the drift chamber of the MEG2 experiment, presently taking data at PSI Laboratory in Zurich.
A full length drift chamber prototype is planned to be built and tested by the groups from INFN Lecce and Bari in the coming years. It will test: the wires’ electrostatic stability at full length and at nominal stereo angles, different wire materials, anchoring procedures, and tension recovery scheme, front-end, digitization and acquisition chain, etc.
The R&D program developed over the last few years has regarded five different topics:
- engineering design of the drift chamber with thin wires and the separation of the gas envelope and the wire supporting structure (“feed-through-less” ), in order to increase chamber granularity but reducing material, multiple scattering and total tension on end plates. a novel recovery scheme of the mechanical wire tension is designed;
- development of a new type of field wires based on carbon monofilaments coated with a thin metal film to allow for ease of soldering;
- development of a fast digitizer coupled to a FPGA for fast filtering and pre-analysis of the signal spectra, aiming at strongly reducing the amount of data transfer;
- beam test on different configurations of drift tubes to establish the optimal operating parameters for an efficient application of the cluster counting technique;
- simulation and reconstruction of tracks in the IDEA drift chamber exploiting the cluster counting technique for particle identification and the cluster timing technique for improving the impact parameter resolution.
(*) M. Abbrescia, M. Anwar, A. Corvaglia, B. D’anzi, N. De Filippis, F. De Santis, D. Diacono, W. Elmetenawee, E. Gorini, F. Grancagnolo, S. Grancagnolo, F.G. Gravili, F. Loddo, M. Louka, S. Maggiore, A. Miccoli, M. Panareo, G. Pappalettera, M. Primavera, F.M. Procacci, A. Ventura, C. Veri



![dch3 Relative dE/dx (left) and dN/dx (right) resolutions for tracks of different lengths. The same tracks, made of the same hits, have been analyzed with 20% truncated mean in the case of dE/dx and with peak finding and clusterization algorithms in case of dN/dx. The red curve at left describes the L-0.37 trend of the empirical dependence as in [I. Lehraus et al., “Particle identification by dE/dx sampling in high pressure drift detectors”, Nucl. Instr. And Methods Pys. Res. 196 (1982) 361]. At right, the red curve indicates the N-0.5 behavior.](https://web.infn.it/RD_FCC/wp-content/uploads/2025/01/dch3.png)

