Status of the RFQ Beam Cooler for SPES project at LNL

Abstract

The SPES project is the new Radioactive Ion Beam facility under construction at the Laboratori Nazionali of Legnaro, Italy. In this framework, the realization of a new RFQ Beam Cooler (RFQBC) is in progress. This device allows to improve 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 the very low energy (eV) ions (Q=1+) which 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 done. 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 (500W) 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 REGATA experiment of the 5th scientific committee of INFN and it is carrying on within the COOLBEAM experiment.