Re: analysis reports of Tom Banks and Steve Clayton

["Evgeny Maev" <maev@pnpi.spb.ru>]

 Dear Peter,

   Thank you for sending me Tom's and Steve's
   analysis reports. We disscussed these reports with Oleg also.

> Tom and Steve have posted their analysis reports. Please use the link
> http://www.npl.uiuc.edu/exp/mucapture/coll/unblind/unblind.html
> Very soon Fred's report on the mu+ analysis will follow, and Brendan
> is working on the impurity data from run10.
> Please have a careful look at their impressive reports and send us
> questions, suggestions and critical comments,
>
>
    About comments and suggestions:
    After first looking of the analysis reports,
    we can propose for discussion following topics:

   1. The high Z-impurity correction for the effective muon disappeareance
      rate (lamda) using experimental impurity yield (Yexp).

     If we correct understand Tom's and Steve's reports, they
     used for the lamda correction following values:
       Yexp=12.89ppm(Tom) and Yexp=10.67(Steve).
     Taking into account the efficiency of the capture events
     registration (Eff=0.55 for oxygen) the real yields(Y=Yexp/Eff) are
      Y=23.4ppm(Tom) and Y=19.4ppm(Steve).
     During Run8 the impurity yield (Yexp) was inconstant:
     a) first ~60 hours production after start of cleaning with CHUPS the
     Yexp was changed from ~300ppm up to 20 ppm , after that CHUPS was
     disconnected on 20 hours and Yexp increased up to ~40 ppm.
     b) after that, CHUPS was connected again and reached the
       equilibrium state with Yeff about 10ppm. Hydrogen
        flow was Q= 1.6 l/hour (data taking time T~200 hours).
     c) Q was increased up to 2.6 l/hour and Yeff was decreased up to 7ppm
        (T~300 hours).
     d) Q was increased up to 3 l/min and Yeff was decreased up to ~6 ppm
      ( T~ 80 hours).
       We propose to skip first ~ 100 hours, when the conditions was very
       unstable and Yeff changed more then 10 times. During next of ~ 600
       hours data taking Yeff was less than 10 ppm and
               AVERAGE Yeff is~ 8 ppm.

       We think that for correction better use this value
       or to make corrections separately for different levels of impurity.

     2. To determinate the value of the effective muon disappearance
        rate (lamda) was used one exponential fit with constant background.

       In the real situation we have 4 exponential time distribution
       with background, that ,in principle, is not ideal constant.

      May be, it is possible to make some estimations,
      how changing the value of the lamda and all corrections (impurity,
      molecular ppmu formation and molecular orto-para transition)
      for real 4 exp time distribution and time dependent background.


      We hope that our few remarks will be useful for discussion
      and wish you the great and successful meeting.

      Congratulations to Steve and Tom for their excellent work.

     With best regards,
                     Evgeny and Oleg