A multi‐sampleCs‐sputter negative ion source has been evaluated for generating7BeO−beams for measuring the nuclear‐astrophysically important7Be(p,&ggr;)8Breaction at the Holifield Radioactive Ion Beam Facility. The design features and operational parameters of the source are described and measured efficiencies for forming beams ofNi−,C−andMgO−and estimated efficiencies for generating beams ofBeO−for the proposed experiment are presented in this report. © 2003 American Institute of Physics