The pressure at X END has been bouncing around due to the programmed voltage steps of the main ion pump controller. In order to stabilize this we have set the voltage to 7 KV. This is also the same setting as the Y END pump.
The immediate response has been an increase in pressure to ~2e-8 torr. We expect the pressure to fall back to the low e-9 range as the pump sputters and exposes fresh surfaces.