Re: Revisions to the high-Z impurity correction table

[Claude Petitjean <claude.petitjean@psi.ch>]

Dear Tom,

I studied today your memo on improved impurity corrections.  - I think you
made indeed a comprehensive and quite perfect job!

Here are 2 considerations I made:

1) What would be the additional correction if the muon capture rate on the
    proton would also be incuded in your formalism?

 - basically, the free muon life time l_o needs to be replaced in your
    parameter x by the real disapearance rate (l_o+L_s),
   where L_s is our singlet capture rate, about 0.0015 of  l_o.
 - since x appears more or less linearly in the formula for Y, your 
yield gets
   just reduced this relative amount of 0.0015.
 - this is indeed a negligible contribution.

2) You assume that in our run8 clean fill conditions we had mainly impurity
    captures on Nitrogen. This was however a controversial issue, since
    the Chemists analysed about 10 ppb Nitrogen - while the capture yield
    suggested rather some 100 ppb.

    In runs 9 and 10, using a humidity sensor,  we concluded so far that at
    least half, but very likelly 90% of the observed impurities come from
    humidity (Oxygen).

    I do not see a difference to run 8, since in all these runs the Nitrogen
    was efficiently cleaned by the CHUPS system.

   Therefore, would it not be more appropriate to take from table 3 for 
delta_r/Y
   the Oxygen value (0.800) rather than Nitrogen (0.823), or at least a mix?

   Fortunately, the difference between these values is rather small.

Thats all comments that I have. I'm looking foreward to see in due time some
writeup of your work!

With best regards

Claude


Tom Banks wrote:

>Dear MuCappers,
>
>I have just posted a memo on my homepage which describes my revisions to
>Peter's longstanding table of numbers pertaining to the high-Z impurity
>correction:
>
>  http://weak0.physics.berkeley.edu/weakint/research/muons/private/tbanks_dir/Documents/high-Z-table-revised.pdf
>
>I still have to finalize some literature references, but the body of the
>document is essentially complete and ready for inspection.
>
>As you will see, the changes to the values of the important quantity
>(delta r)/Y are not large, but they are large enough to affect the size of
>our high-Z correction for Run8 by roughly 1.5 Hz.  I would greatly
>appreciate it if you could find the time to peruse the document and see if
>it all make sense.  I think it is especially important that Steve and
>Peter K. inspect the calculations so that we can establish a consensus on
>the table's values.
>
>Regards,
>Tom
>  
>