My target update brief for July 26, 2006

I started the week by checking over the numbers from my temperature measurement.  There is a change that should be noted.  \Delta T = 21.48 and not the 5.32 that I noted before.  I also compared the expected ratio from the two chambers (from this calculation) to the actual ratio and I get a 7% difference.  Part of that may be due to corrections that still need to be taken into account.  A large part of this may be due to the polarization diffusion in the cell.

Then, I met with Gordon and Todd who proposed a new strategy for the target analysis.  I will focus on getting polarization numbers for the last kinematic and will work to reduce the uncertainty by tackling the largest uncertainty first.

We identified the two largest uncertainties to be 1) the ``lag'' effect of the target box, and 2) the diffusion uncertainty.

I started to get the polarization numbers for Edna.  I fit the NMR signals using some improved fitting programs.  More work still needs to be done -- for example the effect of using a non-linear background in the fit should be studied.  However, a fit to all good NMR signals has been done.

In a cursory investigation into the lag effect, I looked at the B-field distribution as seen in the NMR measurements.  There I say that the measurements were very consistent and centered around a peak in the wrong location.  This is a guidepost for where the detailed analysis will take me.

The data for the detailed analysis will come from another of Todd's grad students.  Working with me, Joe Katich will collect data that I can use to correct for this lag.

Another look at the lower/upper signal denisty confirms, to me at least, that meaningful density/temperature numbers can be taken from these measurements.

Timeline:
Next week, I will be at the Gordon conference.
When I return, I will begin work on the polarization distribution measurements.  We have data that will help to determine this.  I don't know if it is enough.
I estimate that this will take between 1 and 3 weeks.
This diffusion will give us a sort of dilution factor for the target polarizion.  Then I can re-analyze the EPR measurements and assign a %/(mV*n) number and apply it to all the NMR measurements.  This is another couple of weeks.

This should give very good target numbers for Edna in the next 6 weeks.  This can be accelerated if needed, at the cost of certainty in the numbers.

amk
07/24/2006