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- Newsgroups: sci.physics.fusion
- Path: sparky!uunet!think.com!ames!pacbell.com!tandem!zorch!fusion
- From: blue@nscl01.nscl.msu.edu
- Subject: Re: Blue's questions about BYU experiment
- Message-ID: <009663FD.A8B04B40.10540@dancer.nscl.msu.edu>
- Sender: scott@zorch.SF-Bay.ORG (Scott Hazen Mueller)
- Reply-To: blue@nscl01.nscl.msu.edu
- Organization: Sci.physics.fusion/Mail Gateway
- Date: Thu, 7 Jan 1993 17:41:35 GMT
- Lines: 34
-
- In reply to BartB, perhaps it would help if I gave a bit more complete
- description of the data which is under discussion. This is not a
- case in which there is a well defined peak at the appropriate energy
- and that is all. As is common for measurements of this sort, there
- are in fact two measurements required: one for effect and one in which
- the effect is somehow turned off without altering significantly the
- interferring background signal. The background determined with the
- effect turned off must then be subtracted from the measurement for
- effect to see any net signal that remains. It sounds more straight
- forward than it may actually be. For starters both the measurement
- for effect and for background are subject to statistical fluctuations.
- Furthermore in the experiment under discussion the background may
- have an unknown time dependence that limits the acuracy with which
- one can due a subtraction of two data sets recorded at different
- times. The background measurement may not be "proper" for other
- reasons, such as a removal of a background source such as the
- palladium sample itself. Finally, one question I am raising
- about this experiment has to do with the nature of the signal
- the detector would record even in the absence of background. In
- the Czir-Jensen paper that describes the detector, the calibration
- spectrum shown is not in accord with the signal claimed in Jones
- paper. This is not just a question of extrapolation beyond the data.
- The data is more or less a continuum from zero energy to well beyond
- anything associated with 2.45 MeV neutrons. It is a very tough
- experimental problem, and when it has only been done once and several
- other attempts give different results or nothing at all.... well
- I don't think it is one of those "facts" that Jed Rothwell says
- we just have to accept.
-
- As an aside, Thanks to Jon Webb for his well stated reply to Jed's
- latest. Saves me the trouble.
-
- Dick Blue
- NSCL@MSU
-