How Does Beta Radiation Penetration Vary with Aluminium Sheet Thickness?

[robertholmes123]

I have got to design an experiment to measure the thickness of an aluminium sheet with Beta radiation. Basically, it's Beta Thickness gauging and I can use I = I0e^-x to find the thickness if i measure the incident intensity of the radiation and then the intensity of the attenuated ray as it leaves the aluminimum sheet. I also of course have to know the linear attenuation coefficient of aluminium to do this.

I do however have a few questions. I know Beta radiation is stopped by a thin sheet of aluminium which I learned last year, so do i have to a use a source which gives the highest energy beta particles? What type of source would this be and why would you use it??

Also, I have to calibrate the apparatus. I have no idea what this means. Am I calibrating the geiger counter here? Do i just measure the background radiation before i start and subtract that off experimental results to give the actual count. How else would you calibrate, anything referring to the formula above?? It's also asked for a calibration graph. Does anybody know what one of these is?

One last thing... anybody know the linear attenuation cooefficient value for aluminium, can't find it on the net anywer!

Be appreciated if any1 cud help.

Thanks!

 

[Mindscrape]

I'm not so sure about the source, but for calibrating the apparatus you are correct. You will want a counter, and find the counts/dt (where dt is a time interval) for the background and then total with the source. Then you can subtract to find the actual count. By calibration graph I assume it means something about how adding radiation stopping materials, such as lead or aluminum, with the same/purposeful thicknesses will decrease the counts seen by the detector (though I am not entirely sure).

 

[m2003]

First of all, it is important to have a clear and specific research question for your experiment. In this case, the research question would be: "How does the thickness of an aluminium sheet affect the intensity of Beta radiation passing through it?" This will help guide your experiment design and ensure that you are measuring the specific variable you are interested in.

To answer your first question, yes, it is important to use a source that emits high energy beta particles. This will ensure that the radiation is able to penetrate the aluminium sheet and provide accurate measurements. A common source for beta radiation is Strontium-90, which emits high energy beta particles.

Next, to calibrate the apparatus, you will need to determine the relationship between the incident intensity of the radiation and the thickness of the aluminium sheet. This can be done by using aluminium sheets of known thicknesses and measuring the incident and attenuated intensities for each sheet. This will allow you to create a calibration curve or graph, which will help you determine the thickness of unknown aluminium sheets in your experiment.

The linear attenuation coefficient for aluminium can be found in various sources, such as scientific journals or textbooks. It may also be helpful to consult with a physics professor or expert in this field for more accurate and up-to-date information.

In terms of the experiment design, it is important to ensure that all other variables are controlled or kept constant. This includes the distance between the source and the aluminium sheet, the type of detector used, and any external factors that could affect the measurements.

Lastly, it is important to follow all safety protocols when working with beta radiation. This includes wearing appropriate protective gear and handling the source with caution.

Overall, planning and designing an experiment can be a complex process, but with a clear research question, proper calibration and safety measures, and attention to controlling variables, you can ensure accurate and meaningful results.