Wouldn't it be easier to just stick a know, calibrated hall proble in
the middle, right outside of the target window. It wouldn't be exact
(since the probe is not in the target) but I imagine we can get an idea
of a diviation from 45 degrees to about 10%. The only trick is placing
a probe there when all fields (target and blast) are on.
Vitaliy
Karen Dow wrote:
>
> 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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