Interesting thread going on in SED newsgroup...
http://groups.google.com/group/sci.electronics.design/browse_thread/thread/d99b2b7ad28787ba#
Newsgroups: sci.electronics.design, sci.physics
From: Jan Panteltje <pantel...@yahoo.com>
Date: Tue, 20 Mar 2012 12:38:32 GMT
Local: Tues, Mar 20 2012 5:38 am
Subject: How about it? Experiments of the third kind , take 999999.
This is an idea for an experiment I may or may not do.
The background:
There have been reported seasonal variations in radioactive decay in
the past.
Now If I took a simple tritium light, and a good quality photo-diode,
put both in a light proof box, and logged that with a 10 bit PIC ADC
with a decent Vref for say a year to FLASH, say 1 sample / hour, run the
whole thing of some battery. 10 bits per hour makes 87660 bits per year,
or 10950 bytes per year. Have the PIC wake up once every hour to save
power.
Would the light intensity from a tritium light be [linear] proportional
to the decay of the tritium? And then next year analyze the result (if
any)?
note, see:
http://panteltje.com/pub/da_test_setup_IMG_3382.JPG
http://panteltje.com/pub/tritium_light_movie_mvi_3243.avi
http://panteltje.com/panteltje/pic/
On a sunny day (Fri, 23 Mar 2012 20:43:37 -0700) it happened Jamie M
<jmor...@shaw.ca> wrote in <jkjftf$dd...@speranza.aioe.org>:
> I remember you saying you have some PMT's, if the tritium could
> replace the phosphor in a PMT, then it would just be an electron
> multiplier tube getting electrons from the tritium and would be more
> sensitive than having to measure the light off a phosphor, should be
> able to detect each electron emitted from the tritium atoms?
The big problem with PMTs is that they are so sensitive to magnetic
fields. Even the earth magnetic field, and especially at low anode
voltages, as then the electrons have low speed and are easily deflected.
I think magnetic influences can explain the seasonal changes in the
Russian experiment with Plutonium, more current the electric wiring in
the winter (light on longer) than in the summer, it could even be
somebody walking in with a steel watch that is slightly magnetic, I have
tried walking about with a magnet with the tritium light taped to the
front of the PMT, and measuring the voltage drop over the PMT anode
resistor, 10% changes at 1 meter are normal. So that rules out, for an
experiment that has to run so long, PMTs. I was very happy and actually
surprised that the tritium light does not seem to react to a powerful
magnet right next to it., One systematic error less to worry about.
(see long thread, 150 msgs)
(((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
William J. Beaty http://staff.washington.edu/wbeaty/
beaty, chem washington edu Research Engineer
billb, amasci com UW Chem Dept, Bagley Hall RM74
206-543-6195 Box 351700, Seattle, WA 98195-1700
