FIRST OPERATING EXPERIENCE WITH THE CERN DECELERATING RFQ FOR ANTIPROTONS

The RFQD decelerates antiprotons from a momentum of 100 MeV/c (kinetic energy 5.31 MeV) down to a kinetic energy variable between ~10 keV and 120 keV. A novel feature is the implementation of a floating internal RF structure, mounted on HV insulators, to allow continuous post-deceleration or acceleration by a DC bias. A description of the system is given, followed by reports on the first operating experience with the ASACUSA experiment, dedicated performance measurements and consolidation progress. 1 DESCRIPTION OF THE SYSTEM The RFQ decelerates the beam ejected from the Antiproton Decelerator ring AD [1] at CERN. The key parameters are given in table 1 below. Table 1: RFQ key parameters Operating frequency 202.5 MHz Shunt impedance 13.8 k: Vane voltage 167 kV Maximum electric field 33 MV/