I analyzed run 9585 from this morning and extrated rough gains for the upstream and downstream BCMs.
It was rough because of its limited range (from 0.5 to 4 uA), because Hall B was on (but we checked that it was a small contribution at 4uA -see previous entry) and because we did not get data for the faraday cup. We calibrated the BCMs against OLO2.
Here are the results from this calibration:
U1 coeff=0.277+/-0.000 const=-0.166+/-0.003 U3 coeff=0.090+/-0.000 const=-0.033+/-0.003 U10 coeff=0.059+/-0.000 const= 0.007+/-0.003 D1 coeff=0.246+/-0.000 const=-0.062+/-0.003 D3 coeff=0.079+/-0.000 const= 0.005+/-0.003 D10 coeff=0.025+/-0.000 const= 0.020+/-0.003 ======== U1 tcl process constant= 3702 offset= 614 U3 tcl process constant= 11399 offset= 381 U10 tcl process constant= 17360 offset= -130 D1 tcl process constant= 4160 offset= 258 D3 tcl process constant= 12892 offset= -70 D10 tcl process constant= 40665 offset= -804
These results are to be compared to the one from the November 24 calibration here.
Using the tcl process calibration constants, one can see clearly that the culprit is indeed the downstream calibration before the amplifiers.
|new calibration | old calibration | new/old
U1 |3702 | 3764 | 0.98
U3 |11399 | 11480 | 0.99
U10 |17360 | 17423 | 1.00
D1 |4160 | 4430 | 0.94
D3 |12892 | 13625 | 0.95
D10 |40665 | 42870 | 0.95