The early data with reversed ABS transverse holding field indicates that
the low polarization sector has swapped to the other side. This suggests
that the problem is not with the detector or reconstruction, but perhaps
with our knowledge of the target spin angle. The tensor elastic asymmetry
is sensitive to this; the vector asymmetry is not as sensitive. Another
possibility is that the target density is different for the two tensor
states by 5% or so.
We will run until tomorrow morning as we are. Then we will put the
transverse field back to the normal (left) direction, and reduce the
longitudinal field to change the spin angle and try to understand where the
problem is. Changing the longitudinal field should not create a beam
tuning problem.
ABS turbopump power supply was replaced this morning, so the target
density should be back to normal.
Aaron attempted to recover the missing wire in left sector, inner chamber,
outer superlayer first cell, middle wire. Now two wires in the cell appear
to be missing. When Aaron finishes class this afternoon, he will need an
access to the South Hall to correct the problem.
Karen
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