The SPIRAL2 linear accelerator si equipped with a radio frequency quadrupole (RFQ) accepting ion beams with a mass over charge ratio of 3 (M/Q=3). The production of such high charge states is physically possible up to the mass 50 approximately. Above this mass, the ionization processes of such high charge states are very unefficient in the source plasma and the ion beam intensities produced are insufficient. The starter source of the SPIRAL2 injector is PHOENIX V2 (see Figure 1), delivered by the LPSC. This source is a modified version of the PHOENIX CERN (or V1) designed and built in 2004. 

 

 Figure 1: PHOENIX V2 and its rear high voltage trolley

This source can operate up to 60 kV (voltage required by the RFQ) while the whole power equipements are set to ground potential (room temperature coils, microwave generator). This feature is unique in the field of ion sources. PHOENIX V2 features a much higher magnetic confinement. This allows a cost reduction and a simplification of the integration and the use of the source. This compact ion source is equipped with a permanent magnet hexapole delivering 1.35T at the plasma chamber wall (Ø63 mm, L 200 mm). The peak axial magnetic confinement is optimized to reach 2.1T on the atom injection side.  The plasma heating is done with a 1.8 kW 18 GHz klystron. The typical heavy ion beam M/Q=3 intensities produced by PHOENIX V2 for SPIRAL2 are displayed in the table below.

Ion

4He2+

18O6+

19F6+

36Ar12+

36S12+

48Ca16+

58Ni19+

54Cr18+

Intensities (pµA)

1200

216

28.6

17.5

4.6

1.25

1.1

1

The ion beam intensities obtained with PHOENIX V2 are very respectable considering its small plasma chamber volume (600 ml). Extensive ion beam production runs were performed at LPSC from 2010 to 2012 in collaboration with the GANIL and the IPNL. Metallic elements Ca, Ni, Cr were produced with the "LCO" GANIL oven. The metallic beam intensities obtained, of the order of the particle µA, are in fact limited by the oven characteristic itself. The metallic  intensities are expected to be enhanced with a new oven currently under development at GANIL. PHOENIX V2 has been installed on the SPIRAL2 injector in June 2014. The first beam is expected in January 2105. The source will be used to commission the accelerator and for early physics experiments.

Figure 2: sectional viex of PHOENIX V2