[b1_ana] draft V3

[Oscar Rondon-Aramayo]

Quick reply: I don't think we can beat the ND3 time constant of 60-90 
minutes for polarization build up, especially if we need to go to Pz > 45%. 
But driving it down with microwaves to Pz just above zero (we don't want to 
overshoot, because we need Pzz = 0) should help with the depolarization.

Cheers,

Oscar



On Sat, 4 May 2013 19:36:13 -0400
  Karl Slifer <karl.slifer at unh.edu> wrote:
> 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
>>