Log entry time 08:53:22 on April 14, 2012

Entry number 374333

Followups:

• 374418 04/14/12 12:56 R. Michaels [target] check encoder position

The target polarization is still quite high, above 29%, so it looks like 
an anneal will not be necessary until later today.

The continued high polarization gives us pause, but looking at the decay 
in polarization in time attached below, nothing is too out of the 
ordinary.  This decay is quite similar to the last two decays of 
positively polarized material the 7th and 8th.

If the decay is a bit slower, that's not unexpected. The slow raster is a 
bit bigger than it has been; about 2cm instead of 1.8cm.  We're also 
sticking with 50nA beam current, when previous decays have 60nA, 
occasionally.  What is worrisome is the beam position shift to the right 
by 2mm; since the bottom coil enters from the left of the cup, the coil 
may be travelling through more material unused by the beam in this 
configuration.  That would artificially raise our measured polarization 
by a bit, but I don't think we're seeing much of this.

Of course, that's all assuming I have left and right correct in my head.  
The bottom cup has the coil coming from the same side as the dummy, as 
seen in the picture below, so if someone can bring up the slow raster 
plot which showed the dummy coil, that would be helpful.  I couldn't find 
it on the halog.

At any rate, I mostly believe this good polarization, so we'll delay the 
anneal until later in the day.

Figure 1

Figure 2