I Radioactivity measurements -- finding a fit for lab measurements

1. Jun 2, 2016

YanivW

As a part of an experiment in radioactivity, we placed an alpha particles emitting source (Am) and a sensor in a vacuum chamber, and measured the power (number of particles per time unit) for various angles of the sensor.
Our goal is to fit a theoretical function to our measurements (power vs. angle) so we can integrate it and get the total power of the source.
At first we've been told to fit a gaussian, but then we saw that it's peak is "cut". We found in some book that a fit to f(x)=e^-(x^4) will give better results, and that the reason to this have something to do with the fact that the source isn't a perfect source point, i.e. it has finite dimensions.
I will be glad if someone could think of a reasonable explanation to this.
Thanks a lot!

2. Jun 4, 2016

Staff: Mentor

Do you have a sketch of the setup? A perfect spherical source will emit uniformly in all directions, some angular dependence has to come from source or detector.