The Effect of Grid Shape on Maximum Neutron Rates

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Conrad Farnsworth
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The Effect of Grid Shape on Maximum Neutron Rates

Post by Conrad Farnsworth » Tue Feb 14, 2012 3:51 am

You may post this work freely as long as you direct credit to the original

Summarized, I took different grid shapes and logged their maximum CPM
on the meter @ -30kv. The Upright cross outperformed both my spherical
grid and flat cross. The flat cross did worse than my spherical grid and
upright cross due to arcing within the chamber.

Also, if you feel that your name should be included in my
Acknowledgments page feel free to let me know and I'll replace the page in
my binder.
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Re: The Effect of Grid Shape on Maximum Neutron Rates

Post by charlie_mccartney » Mon Aug 05, 2013 1:31 am

I believe you meant lethal on the first paragraph.
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Andrew Haynes
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Re: The Effect of Grid Shape on Maximum Neutron Rates

Post by Andrew Haynes » Sun Sep 01, 2013 4:05 am

Nice work, Need more post like this.
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Chris Bradley
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Re: The Effect of Grid Shape on Maximum Neutron Rates

Post by Chris Bradley » Sun Sep 01, 2013 7:05 am

This is a good, practical and step-by-step effort and I'll take nothing away from that ...

... but ..
The results rejected the null hypothesis by assigning it a p value of .1%, more than enough reason to reject it and accept, the proposed hypothesis that “If the inner grid shape is similar to the outer grid then neutron output rates will be higher when compared to a spherical grid.”
An experimental rejection of the null hypothesis does not give you a reason to accept the hypothesis. All it means is that this particular experiment gave no reason to reject it.

It is possible that your null hypothesis can be logically shown to cover all alternatives to the hypothesis, such as where there is a 'negative', e.g. a non-existence, prediction made, and can therefore discount a hypothesis. But you do not construct a hypothesis to accept it by an experiment. The null hypothesis seeks, and can only seek, to disprove a hypothesis.

In this case, I cannot see how you quantify the similarity of shapes and what happens when the shape of a spherical grid is similar to the outer grid, which is an experimental condition that your hypothesis should be covering but that you have not tested for.

I would have to say that I imagine that an experiment with spherical inner and outer grids that are less similar than another experiment between your cross shapes may still lead to relatively more neutrons. But I struggle with quantifying 'less similar'.

For example, if you were to find that an ellipsoid shaped grid in a spherical fusor gave more neutrons than a spherical shaped grid, then this would disprove the hypothesis, but your experiment does not seek to provide data on such a scenario.

This is not at all meant to be negative. I think your particular experiment "supports the principle that higher neutron yields can be gained for a given outer shell, by matching the inner grid to the shell's shape", and as I have said it is a sound piece of work and I will second the view that it would be nice to see more documented write-ups like this. Well done.

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Richard Hull
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Re: The Effect of Grid Shape on Maximum Neutron Rates

Post by Richard Hull » Tue Sep 03, 2013 4:26 pm

My comments on this paper were posted last month in a forum for discussion.


Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Advith G
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Re: The Effect of Grid Shape on Maximum Neutron Rates

Post by Advith G » Tue Sep 10, 2013 10:25 pm

I agree with andy, this was really good. Thank you.

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