[b1_ana] draft V3

[Karl Slifer]

PPS : please note that in the overhead I assumed we would switch
polarization states twice per day and I assumed 2 hours each time.  I think
this would imply about 10 "buckets" of polarized counts and 10 "buckets" of
unpolarized counts for each of our 3 x-points.   It is our dominant
overhead at 5 days total.

I think we may have a little room to move here.  Please see the attached
plot from g2p data, where we depolarized the (proton) target by pumping
with microwaves in less than 4 minutes.  The pump up is also very fast with
the new fridge and blasting the wattage of the new microwave cavity the
pump up is about 30 mins to the negative state.  I think polarizing in the
positive state is usually a little faster.

So, perhaps we can be a little more aggressive in our overhead estimate :5
or 10 mins for depolarizing and 30 mins to polarize.  That would give us
the flexibility to increase the number of "buckets" to say 10 or 12 total
per day.  It will be a large overhead (about 12 days just for this), but oh
well.  Would this be sufficient to control the known drifts?

A little more radical would be to explore the idea of flipping from
positive to negative tensor polarization rapidly with an AFP type flip,
which I believe is near instantaneous.  This is essentially what happens
with hole burning anyway I think.

-Karl



---
Karl J. Slifer
Assistant Professor
University of New Hampshire
Telephone : 603-722-0695


On Sat, May 4, 2013 at 6:47 PM, Karl Slifer <karl.slifer at unh.edu> wrote:

>
> Hi All,
>
> I've posted the updated draft at
>
> https://dl.dropboxusercontent.com/u/59933793/tensor_b1_v03.pdf
>
> There is some lagtime for implementation, but I think this reflects pretty
> well where our discussion was about 24 hours ago.  However, we still need:
>
> -updated rates/kin plots from Ellie or Patricia and values for the table
>
> -some consensus on how to address Steve's comments.
>
> It seems we have three options with time running short.
>
> 1) List all possible factors that drift with time and atleast sketch a
> plan to deal with them.
>
> 2) go back to difference of counts.
>
> 3) Cancel submission and work on this for next PAC.
>
> I lean to the first, Oscar leans to the second.  I'd very much like to
> find some consensus on this.  Am I the only one still nerding it up in
> front of my computer on this beautiful spring day?
>
> -Karl
>
> PS : If anyone makes suggestions for changes I would very much appreciate
> that they be in a form that I can put into the document quickly.
>
> ---
> Karl J. Slifer
> Assistant Professor
> University of New Hampshire
> Telephone : 603-722-0695
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailman.jlab.org/pipermail/b1_ana/attachments/20130504/c276a0cd/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: spin_flip.png
Type: image/png
Size: 45700 bytes
Desc: not available
Url : https://mailman.jlab.org/pipermail/b1_ana/attachments/20130504/c276a0cd/attachment-0001.png