CUSP source was off for the night, following Keerthi's development. He had increased the current on FC6 and the arc current substantially. More later.

Meanwhile, restart source and let it condition for a bit.

Later ~14:00 we have 200enA on FC6. Source gas is shut off presently. Time for some mass scans. Strategy: Identical mass scans without and with source gas, to check background ratios.

Later ~15:00: Mass scans with source gas closed complete. Note: IOS pressure is 5.25e-7 Torr, slightly higher than earlier. It was ~3e-7 this morning. Possible leak in gas manifold fitting?

Later ~16:30: Try out different combinations of gas and source parameters. We cannot get the gas flow low enough so far. Optimal source:

Fil = 130A (3.1V)

Arc = 67V (0.9A)

FC6 = 7.5eµA 4He2+ & H2

Note: Increasing any of these parameters much above these numbers causes the bias to current-limit at 1mA.

Later ~18:00: Check beam current at H+ and H3+:

FC3 = 140µA

FC6 = 1.42A at A/q = 1 i.e. H+

FC6 = 149enA at A/q = 3 i.e. H3+

FC6 = ~80µA at A/q = 4 i.e. 4He1+

FC6 = 1.78eµA at A/q = 16 i.e. O+

FC6 = 2.29A at A/q = 18 i.e. H2O

Plot 1: FC6 current for last evening.

Plot 2: Scan 0 to 5 and back.

Plot 3: Scan 0 to 40 (same parameters as yesterday).

Plot 4: Scan 0 to 40 and back.

Plot 5: Combo development session stripchart.