Log entry time 18:31:25 on June 18, 2010

Entry number 327381

This entry is a followup to: 327377

The goal of using T5 for spot++ is to measure the target density 
profile, as everyone knows.  I think there is a problem with the 
result in halog 327377, and it's probably what happened to me last
night on owl.  There seems to be a background on the L-HRS of order
15 kHz which might be residual activity in the shield hut (??) and
in any case does not go away when you ask the MCC to close the slit.
So I think you need slit = 15 (a bit wide) such that T5 = 150 kHz
and definitely goes on/off with beam on/off.  Then you are measuring
something from the target.

Notice that the X distribution is not sloped ?  No Pb FF ?  That's 
an indication that you are uniformly sampling, not biased by the target.