Status of the RFQ beam cooler for SPES project at LNL

The SPES project is the new Radioactive Ion Beam facility under construction at the Legnaro National Laboratory, Italy. In this framework, the realization of a new RFQ Beam Cooler (RFQBC) is in progress. This device allows the improvement of the quality of the low energy ion beams produced by the ISOL technique, granting a reduction of transverse emittance and energy spread. The RFQBC is an electromagnetic apparatus operating with oscillating electric fields needed to confine very low energy (eV) ions (Q=1+) that lose both the longitudinal and transversal momentum by making collisions with lighter atoms of the so-called buffer gas (He). This process provides the reduction of the transversal emittance up to 10 times of the initial value and it keeps the energy dispersion within 2-3 eV. The electromagnetic design of the RFQ section and the electrostatic layout of the injection and extraction regions have been made. The beam dynamics study is going on by means of dedicated codes which allow to take into account the interaction of the ions with the buffer gas needed to cool the beams. The RF group of LNS Catania is involved in the design of the RF system (500 W) providing the oscillating high voltage (up to 3 kV) at frequency which varies in the range of 1-30 MHz. The preliminary design of the device started in 2011 in the framework of the REGATA experiment of the 5. scientific committee of INFN and is carrying on within the COOLBEAM experiment. (authors)