During production running, NH3 with nominal running conditions, we can double check the bleed-through as measured by MCC using the HRS, we can do the following HRS bleed-through measurement.
0) Note the HHR rate during a trip (i.e. cosmic rate) variable = Rate_Cosmic
1) Note the HRS rate with the nominal Hall A current. variable = Rate_A+C+Cosmic
2) Note the HRS rate with the Hall A current zero; but Hall C still on (no change in Hall A slit) variable = Rate_C+Cosmic
[call MCC and tell them you are doing a quick bleed-through check and you need the A laser off but the slit to remain unchanged]
% Bleed-through = (Rate_C+Cosmic - Rate_Cosmic ) ------------------------------ (Rate_A+C+Cosmic - Rate_Cosmic )
These numbers need to be reported in the Hall A log with snap shots the scaler screen for the three conditions above.
There should be no changing of the slits during this measurement since the entire point is to determine the bleed-through in the current setup.
Notes: The Hall A slit and attenuator should be setup similar to Hall B's. That is the first sign that everything is correct and shift leader should check at least once a shift (i.e. a shift checklist item). This can be seen on the MCC tools screen.