[b1_ana] LiD

[O. A. Rondon]

Hi Karl,

- This is what I think about the target physics of LiD.

The main issues with LiD are that the polarization takes a long time to
ramp up, longer than ND3 and therefore it takes "forever" to thermalize.
Not a problem if the ratio method is used.

Also, the maximum Pz ~ 30-35%, is lower, but no anneals are needed.
Basically the maximum Pz is the average Pz.

LiD could be a good material for a 6.5 T solenoid target. At Pz = 71%
has been achieved at 0.25 K. Given its superb radiation resistance, I
would expect it to beat ND3 at 1 K and 100 nA.

The SLAC LiD experience is reported here. The conclusions section says
it all.
http://dx.doi.org/10.1016/S0168-9002(98)01341-2

- This is what I said about the nuclear properties

O. A. Rondon wrote:
> 
> Things are a bit trickier for LiD, since the alpha cluster in Li would
> contribute to the denominator, but not to the numerator, and the
> effective polarization of the D cluster in Li is not the 6Li
> polarization. So an analysis like that of my E155 tech note (posted at
> the URL shown below,) suitably modified to take into account that the
> beam polarization is not involved, is needed
> 
http://twist.phys.virginia.edu/%7Eor/lidnucl.pdf
> 
> Also, we need to keep in mind that LiD has > 4% 7Li and 2% H, both of
> which polarize very high (>~70%) and with the very large proton
> asymmetry could complicate things significantly, so using LiD would need
> detailed study.

Cheers,

Oscar


Karl Slifer wrote:
> I thought that it got absorbed into eg1-dvcs?
> 
> ---
> Karl J. Slifer
> Assistant Professor
> University of New Hampshire
> Telephone : 603-722-0695
> 
> 
> On Thu, May 2, 2013 at 1:57 PM, <narbe at jlab.org> wrote:
> 
>> Hi Karl,
>>
>> If you're referring to the g1d experiment, that unfortunately got killed
>> back in 2009.
>>
>> Narbe
>>
>>
>>> Hi all,
>>>
>>> LiD has better dilution factor and prob better polarization, but we
>>> decided
>>> to not use it for last PAC.  Can someone remind me why we backed away
>> from
>>> using it?  I guess it was the ambiguity of how to treat the Li (=He+D),
>>> but
>>> in the mean time, I think Peter ran an experiment comparing LiD to ND3,
>> so
>>> we'd be on firmer ground now.
>>>
>>> Oscar, I think you looked closely at this. Can we use LiD?
>>>
>>> -Karl
>>> _______________________________________________
>>> b1_ana mailing list
>>> b1_ana at jlab.org
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>>
>>
> 
> 
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