Line: 1 to 1 | ||||||||
---|---|---|---|---|---|---|---|---|
Lab Assignment: Statistics of Random events | ||||||||
Line: 23 to 23 | ||||||||
| ||||||||
Added: | ||||||||
> > |
When writing up the lab you should include a breif description of the important parts of this experiment:
Write Up | |||||||
AnalysisAs with the MonteCarloLab you will need to histogram your data and then perform a fit to determine the mean rate and standard deviation. The histogram should include
| ||||||||
Changed: | ||||||||
< < | Once you have your histograms, one for each of sets of data, you will need to fit it to a Gaussian and a Poisson distribution seperately. You will extract the mean and standard deviations from the fit parameters determining which distribution fits best via a "goodness of fit" estimator. One such estimator is the normalized chi-squared "χ2/ν" where ν is the number of bin minus the number of parameters in the fit. The Gaussian fits can be done in MN_FIT as before, but you will have to do more work with the Poisson fits since MN_FIT doesn't have a Poisson function internally defined. You can do one of two things:
| |||||||
> > | Once you have your histograms, one for each of sets of data, you will need to fit it to a Gaussian and a Poisson distribution seperately. The fits determine the mean and width or standard deviations of the functional forms. You then compare the two fits and use a "goodness of fit" estimator to establish which function is the best fit. One such estimator is the normalized chi-squared "χ2/ν" where ν is the number of bin minus the number of parameters in the fit. The Gaussian fits can be done in MN_FIT as before, but you will have to do more work with the Poisson fits since MN_FIT doesn't have a Poisson function internally defined. You can do one of two things:
| |||||||
GradingRubric |
Line: 1 to 1 | ||||||||
---|---|---|---|---|---|---|---|---|
Added: | ||||||||
> > |
Lab Assignment: Statistics of Random eventsIn this lab the goal is to explore the statistics of random events. The events will this time be generated by a physical process that is random in nature, namely the radioactive decay of a sample of 90Sr. Strontium 90 is a rare isotope of Strontium, is a beta emitter (e-) and has a half life of 28.9 years. The relatively long lifetime will insure a "steady-state decay rate" that remains constant over the time scale of the lab and thus provide you with random sample of events to count.Assignment: Is the Rate a Poisson or Gaussian Statistic?In this experiment you will do three sets of 100 measurements for the beta decay rate of 90Sr. You will then determine the mean rate by fitting your data to the appropriate distribution, either a Poisson and Gaussian. The experiment should be setup to record events at three different rates over a given time interval. To do this set up the counter/timer to record counts in 1 second interval with rates determined by the height of the source.
Equipment:To count the number of decays of the radioactive source you will need to setup equipment that can detect the emission of electrons in this energy range. You will use the cosmic ray telescope in the lab for the dection of the electrons. Basically the telescope consists of a piece of plastic scintillator made out of material that when exposed to charged particles reacts by emitting light. The light travels through the plastic material, designed to be transparent to the emitted light, reflecting from surfaces, colliding with other electrons etc, some of the photons end up at the front of the photomultiplier tube (PMT). The PMT is an electronic device based on the photoelectric effect that first converts a small number photons, into an amplified electrical signal sufficiently large to be easily recored by standard laboratory equipment. You should provide in your writeup an a short description of how the emitted electrons are detected by the equipment you use in this experiment. The list of necessary equipment is:
AnalysisAs with the MonteCarloLab you will need to histogram your data and then perform a fit to determine the mean rate and standard deviation. The histogram should include
|