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Re: [Phys-L] Coincidence Statistics



I'm doing some pulse shape discrimination with pulses from an x-ray
source.  There isn't really any interesting physics to find here.  But it
is selecting double peaks very well.

Here's a animation of the "bad" pulses:
https://www.youtube.com/watch?v=eqcRmTUZb64

Paul

On Mon, Nov 20, 2023 at 12:55 PM Paul Nord <Paul.Nord@valpo.edu> wrote:

> John,
>
> I'm not quite following that.  Your equation doesn't include the time bin.
>
> In my example, I had two sources at 0.1 Hz.  A coincidence rate Rc was
> calculated at 0.01 Hz.
> Your equation calculates a coincidence probability of 0.91%.  The
> agreement is good and the difference is most interesting.
>
> Are we assuming that the units are those of time bins?
>
> For the probability of one or more coincident events would we need to put
> that time resolution number into the equation (t)?
>
> Pc = (1 - e^(-R1*t))(1 - e(-R2*t))
>
> That gives us the same result when time resolution is 1 unit.  But when
> you change it to 2 units, the probability of coincidence goes to 3.28%.
> And not the 2% calculated by the method given in the Canberra lab writeup.
>
> Paul
>
> On Sat, Nov 18, 2023 at 2:59 PM John Denker via Phys-l <
> phys-l@mail.phys-l.org> wrote:
>
>> Alas on 11/18/23 1:52 PM, I wrote:
>> >     Pc = (1 - exp R1)(1 - exp R2)                  [1]
>>
>>
>> That's missing some minus signs. Should be:
>>
>>     Pc = (1 - exp(-R1))(1 - exp(-R2))                  [1b]
>>
>> The conclusions remain unchanged.
>>
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>