[ml] Statistics / software question

Christoph Maier cm.hardware.software.elsewhere at gmail.com
Fri May 11 22:37:22 PDT 2012


The NaI(Tl) or better yet, CsI(Tl) is the stuff hard to get by.
We need to find a Jeriellsworthesque way to cook that in our own kitchen,
or at tastebridge.

Looks like it's time for my (nowadays) semi-annual dose of noisebridge
reality distortion soon.

Data: CSV, if you please.

On Fri, May 11, 2012 at 10:30 PM, Jake <jake at spaz.org> wrote:

> well i've stashed graphical plots of the bins, but I do not have stored
> raw data at this time because my java program what makes these graphics
> doesn't save the serial data to a file.  oops.
>
> But i will correct that asap and start providing data.  in the meantime
> you can look at these plots:
> http://spaz.org/~jake/r/mccad/**rad/thorium-zoomed.png<http://spaz.org/%7Ejake/r/mccad/rad/thorium-zoomed.png>
> http://spaz.org/~jake/r/mccad/**rad/thorium-unzoomed.png<http://spaz.org/%7Ejake/r/mccad/rad/thorium-unzoomed.png>
> http://spaz.org/~jake/r/mccad/**rad/carnotite-zoomed.png<http://spaz.org/%7Ejake/r/mccad/rad/carnotite-zoomed.png>
> http://spaz.org/~jake/r/mccad/**rad/carnotite-unzoomed.png<http://spaz.org/%7Ejake/r/mccad/rad/carnotite-unzoomed.png>
>
> and you will notice that there's absolutely no data there, it's all noise.
> I have determined that this is because my scintillating crystal of NaI(Tl)
> is "fried" meaning the person who sold it to me was an asshole, and the
> amount of blue light coming out of the crystal has nothing to do with the
> energy of the original gamma.  Random data.
>
> fortunately I have other crystals (including a BGO crystal) and I will
> capture more data soon, which will hopefully look more like this:
>
> http://spaz.org/~jake/r/mccad/**rad/MCA2.Cs137.jpeg<http://spaz.org/%7Ejake/r/mccad/rad/MCA2.Cs137.jpeg>
>
> there is other data, from an older version of this detector with a
> different crystal (a nasty ruined crystal but maybe not quite fried)
> which you can look at here:
>
> http://spaz.org/~jake/r/mccad/**rad/data/<http://spaz.org/%7Ejake/r/mccad/rad/data/>
>
> -jake
>
>
> On Fri, 11 May 2012, Christoph Maier wrote:
>
>  Link to the raw data, please.
>>
>> On Fri, May 11, 2012 at 8:55 PM, Wladyslaw Zbikowski
>> <embeddedlinuxguy at gmail.com> wrote:
>>      Hi, my friend Jake has a little project for which we might be
>>      able to
>>      use some statistics expertise.
>>
>>      We are taking analog readings from a device (a voltage pulse).
>>      The
>>      voltage pulse represents the energy of a single X-ray particle
>>      (in
>>      MeV). We know what the energy signature is supposed to look like
>>      for
>>      this particular radioactive material; i.e. there are peaks where
>>      certain energies are highly represented, and valleys where other
>>      energy levels are rare. So we would like to correlate our
>>      measurement
>>      with the expected signature.
>>
>>      The problems are:
>>
>>      1. A lot of noise. We have a signal:noise ratio around 1:1 or as
>>      good
>>      as 4:1, because of background radiation and attempts at
>>      shielding.
>>
>>      2. We don't know exactly how the voltage we read maps to MeV.
>>      I.e.
>>      Voltage is a function of Energy, presumably linear, but we don't
>>      know
>>      exactly the scale (how many MeV per volt).
>>
>>      SO in short, we have a graph of our data, and we want to
>>      force-fit it
>>      to the graph we expect. My idea is to apply noise removal and
>>      scaling,
>>      getting the closest possible match. Any thoughts on this? R?
>>      Python?
>>      Possible topic for a meetup? We can post the graphs and the
>>      software
>>      if anyone is interested to see.
>>
>>      Thanks in advance!
>>      ______________________________**_________________
>>      ml mailing list
>>      ml at lists.noisebridge.net
>>      https://www.noisebridge.net/**mailman/listinfo/ml<https://www.noisebridge.net/mailman/listinfo/ml>
>>
>>
>>
>>
>>
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