Design considerations for future DAΦNE upgrades D. Alesini, G. Benedetti, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, A. Clozza, G. Delle Monache, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, E. Levichev, C. Ligi, F. Marcellini, G. Mazzitelli, C. Milardi, L. Pellegrino, M.A. Preger, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, P. Piminov, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, M. Zobov Presented by A. Gallo ABSTRACT The Frascati Φ-Factory DAΦNE has been delivering luminosity to the KLOE, DEAR and FINUDA experiments since year 2000. Since April 2004 the KLOE run has been resumed and recently peak luminosity of 1.0⋅10 32 cm -2 s -1 and integrated luminosity of 6.2 pb -1 /day have been achieved. The scientific program of the three high-energy experiments sharing DAΦNE operation will be completed approximately by the end of year 2006. A scientific program for DAΦNE beyond that date has not been defined yet and it is matter of discussion in the high- energy physics and accelerator physics communities. In this paper we present some future scenarios for DAΦNE, discussing the expected ultimate performances of the machine as it is now and addressing the design for an energy and/or luminosity upgrade. The options presented in the following are not exhaustive and they are intended to give a glance of what is doable using the existing infrastructures. 1. Expected ultimate performances of DAΦNE with the present hardware The histories of the achieved peak and daily integrated luminosities at DAΦ NE since, respectively, years 2000 and 2002 are shown in Fig. 1. Even though the progress over the years has been continuous and substantial, we believe that a significant further improvement in terms of peak and integrated luminosities is still possible. Fig. 1: History of peak and daily integrated luminosities at DAΦNE The improvement expectations mainly rely on: − Implementing of a lattice providing negative momentum compaction factor α c to shorten the bunch and decrease the vertical beta-function β y * at the Interaction Point (IP); − Moving the betatron tunes ν x,y towards the integer to reduce the beam-beam induced blow-up of the bunches; − Increasing the beam currents by improving the beam dynamics and the performances of the active feedback systems.