The two GIF files, emi.GIF and coll.GIF , give data that bear on the emission characteristics of PSI in the keeper-only mode. In emis.gif, the source was operated in a metal vacuum chamber (1.2 m in diam, approx 3 m long, source on axis on one end, pressure about 100 microPascals) in keeper-only mode, with keeper current of 400 mA and keeper voltage of 21 V. The current emitted from the source was recorded on the y axis as a function of anode bias voltage relative to chamber ground, on the x axis, positive indicating ion flow away from the source. In coll.gif, the source was operated in the same mode, and a metal plate 0.33 square meter in area and 0.48 m downstream of the PSI exit orifice was biased to the voltage given on the x axis, and it collected a current indicated on the y axis.