Re: telconf and run

[Bernhard Lauss <lauss@berkeley.edu>]

Dear friends,


Let me add to Peter's email a short reasoning for my suggestion:


On my page for tomorrow's teleconference I show that
if we do not have any unforseen other problems, the Run10
analysis error will be dominated by the error in the high Z impurity
correction.
View it at:
http://weak0.physics.berkeley.edu/weakint/research/muons/private/bernhard/highz-analysis-run8-10may06.html
(note that my efficiency knowledge is +-28%. which is better than Peter's
usual +-50% error assumption)


Therefore, I believe it is important to gain any possible better knowledge
on our high Z impurities in this run 10.

Doing the trick with the measurement at 2 hydrogen flow rates and
seeing the corresponding increase in CHUPS and impurity events
is interesting, however,
if we do not see anything different than in the last run,
we don't know anything more.
One could always argue that the Run9 measurement was wrong,
because the system was not equilibrated. Correct,
However, the high flow rate measurement was reliable because
similar values were observed during a long run period.
The low flowrate measurement might not have equilibrated.
bear in mind that one needs more than twice the humidity
reading observed to explain our yield.
Looking at figures 11 and 13 of my Run9 impurity note
shows, I believe, that this increase is rather unlikely.
(e.g. going to 60 ppm yield in Fig 13.)

Therefore I presently do not see that if we redo this
change in flux measurement , we will see  much difference to
last run, and especially there is hardly room to see the
>factor 2 difference we need to explain our observation
with Literature rates (though one should not fully exclude anything).

As the pura dew point transmitter has at this low moisture
concentrations 50% error in absolute,
(Peter thinks it's better because we are actually measuring
at a factor 10 larger pressure)
one should consider to obtain the moisture concentration via
a more accurate though expensive method.
2 available ones: - chilled mirror hygroskop
		  - cavity ring down spectroscopy

If we are able to find such a device and either borrow or
rent it within the next 3 weeks, we could build it into
a by pass of the system and control monitor the Pura readings online.



	  best regards

		Bernhard



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Bernhard Lauss                 E-Mail: lauss@socrates.berkeley.edu
Physics Department
366 LeConte Hall
University of California @ Berkeley
Berkeley, CA 94720                             Tel: (510)-642 4057
United States                                  Fax: (510)-642 9811
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