Gamma Required Practical

This is a demonstration of the A level Physics Require Practical (for English examination boards): Investigation of the Variation of Intensity of Gamma Radiation with Distance.

[@graememoran3300]

Thank you for this! Will be using this with my class tomorrow!

[@KarbineKyle]

The inverse square law! I like doing this with different radionuclides! You will get a nice exponential curve! Alpha is the hardest, since it's being attenuated easily by air. Putting an alpha source and an alpha scintillator in a vacuum would make that easier-much like an alpha particle spectrometer. My guess is that source is from _IsoTrak._ I live in the US, but I can often tell where these sources are made. Thanks for sharing this video! 👍

[@Sarkar.editsz]

Great video... Thank u ❤🙏

[@nateclishe622]

Great video!, where can I find a container like that?

[@QuantumBoffin]

Nate Clishe The container came with the source, which was obtained from an education supplier (I think we got it from SciChem in the UK). The contained, to be frank, is not ideal, as it is Aluminium and so it does not provide as effective shielding as a lead container would. Having said that, though, with appropriate handling it is safe enough.

[@mr.microcuries2078]

Great video and demonstration of the inverse square law! Always stay ALARA and distance is the easiest way. What radioisotope did you use in the video? It has a unique shielding configuration that I really like. Where did you get it from?

[@davidroberts6138]

The source is Caesium 136 - a pure gamma emitter. I agree regarding safety. Ideally it should be handled using tongs, but it nigh on impossible to remove it from the holder that way.

[@mr.microcuries2078]

Thanks, And sorry about my first comment. I had to comment on ALARA as this is a perfect example of how distance can sometimes be one of the best and cheapest methods of shielding when possible. I was not questioning your safety at all around such a small source. I strongly agree that it would be much more dangerous trying to handle a round source with tongs rather than with your hands. lol that would be very hard to separate with tongs it might go flying somewhere. I have a number of microCurie Cs-137 disk sources and after doing calculations I would have to hold them for hours for my hand to get the dose equivalent of a dental x ray. Unfortunately my sources did not come with such a fancy shielding and source holder. One of those would be nice to have. Cs-136 is a very short lived isotope with a hl of only 13 days and only decays via beta emission. I don't know of any Cs isotopes that only emit gamma radiation. Most likely your source is a Cs-137 source. If it is Cs-137 than it will decay via beta decay to Ba-137m and then the gamma emission of 660kev will come from the the meta stable isotope of Ba-137m becoming stable Ba-137. Because your isotope emits beta and gamma you could theoretically do a beta deflection experiment with your source if you wanted to show how gamma can not be deflected by magnets while beta particles will be greatly deflected by a magnetic field. Great video and thanks for the reply!

[@davidroberts6138]

No problem - I didn't take offense, but thought I ought to mention it as usually I wouldn't handle any sources by hand. Being a stick source, though, the stick provides some separation.