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Hello-
My son is conducting the Physics experiment regarding observing background radiation using the homemade cloud chamber and has questions regarding in the interpretation of his data:
1. For clarity, can you explain what each directional track is representing?
Horizontal-what are you assuming are the sources
Angular-what are you assuming are the sources
Vertical-background radiation coming from either the sky or the ground?
2. Regarding measuring the time at which tracks appear and whether they are random or have a pattern:
Does the increase or decrease in frequency of a certain type of pattern imply there is more of that source present?
3. What does spiral mean? A combination of 2 or more patterns?
Appreciate if you could elaborate more on this so that he understands what he's measuring and looking for based upon his hypothesis. He is adjusting his project by taking measurements in different parts of our home.
Kindest regards,
Joy Dozier
interpretation of data cloud chamber
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deleted-184203
- Posts: 5
- Joined: Mon Dec 30, 2013 12:11 am
- Occupation: former flight surgeon, homeschooler
- Project Question: Does the shape of an aircraft affect its radar detectability? This is the project question.
The question my son has is in reference to the project design. I will post that in the forum. - Project Due Date: 4 weeks
- Project Status: I am just starting
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bradleyshanrock-solberg
- Former Expert
- Posts: 260
- Joined: Thu Aug 25, 2005 7:44 am
- Occupation: Software Engineer/QA Lead - Quality, Risk Assessment, Statistics, Problem Solving
- Project Question: BS Caltech Engineering & Applied Science (Mechanical Engineering, Materials Science)
Research in Traffic and Ceramic Composites
25 years doing IT, various roles, for multinational manufacturing company - Project Due Date: n/a
- Project Status: Not applicable
Re: interpretation of data cloud chamber
Hello, welcome to the forum.
A link to the exact project your son is attempting would be very helpful in trying to answer your questions. However I think I get the general idea, so lets see if this is helpful.
1. This question is asking the experimenter to explain the trails seen in the cloud chamber. What could be a source of the radiation observed? Obvious sources might be something like sunlight, maybe wifi or a microwave oven that was on, but also most inanimate objects emit small amounts of radiation too. Most experiments of this type I'm familiar with have a radioactive source of some kind that generates more obvious traces than you generally get outside or in a room, but the kinds of radiation sources I worked with in college would be far too dangerous for a middle-school experiment. If you have a radiation source, distinguishing between radiation type by wavelength is usually part of the experiment (alpha vs beta vs gamma rays). For this kind of measurement, you need to have a way of calculating angles and length of traces in the cloud chamber.
2. The first question is asking about the traces by "geometry". This question is asking about behavior when time passes. Do the traces appear at a regular rate, or do they come in "bursts". Are there patterns that might tell you something about the radiation sources in the area? For this kind of measurement you have to note what time each trace appeared, in addition to the angle/trace length/location measurements you take to answer the first question.
3. Spirals - well I had to do a bit of research online, and take my 10 minutes of poking around and these explanations with a grain of salt. Alpha radiation makes short,fat traces, Beta long thin traces. (alpha particles are big and easily slowed by the cloud..dangerous if the source is ingested but in real life usually stopped by even a layer of clothing, beta are smaller with better penetration and you can see that with the long traces. Gamma radiation is just light (photons) at a very tight wavelength (ditto X-Rays). Unlike the relatively massive alpha and beta particles, they're unlikely to hit (interact with) a gas molecule and cause anything to happen. What they do in a cloud chamber is interact with the walls on occasion, causing streaks to appear similar to beta (long, thin). The interesting part about the spirals is if the trace is weak (a weak beta particle or a not especially energetic electron kicked off from the wall by a gamma ray) the earth's magnetic field will cause it to spin. If you actually put a strong magnetic field in the cloud chamber, this is much more pronounced. Gamma rays will often produce weak traces that spin, near as I can tell, where a beta particle's more likely to have a straight trace, then maybe a hook near the end if it loses energy but still has enough interaction with the gas to be visible.
I recommend that your son does some study on sources of radiation in the everyday world (there are a lot of potential sources), and the differences in the kinds of radiation you can detect in a cloud chamber (alpha vs beta particles, vs electrons knocked out of the side of the wall by x-rays or gamma rays)
A link to the exact project your son is attempting would be very helpful in trying to answer your questions. However I think I get the general idea, so lets see if this is helpful.
1. This question is asking the experimenter to explain the trails seen in the cloud chamber. What could be a source of the radiation observed? Obvious sources might be something like sunlight, maybe wifi or a microwave oven that was on, but also most inanimate objects emit small amounts of radiation too. Most experiments of this type I'm familiar with have a radioactive source of some kind that generates more obvious traces than you generally get outside or in a room, but the kinds of radiation sources I worked with in college would be far too dangerous for a middle-school experiment. If you have a radiation source, distinguishing between radiation type by wavelength is usually part of the experiment (alpha vs beta vs gamma rays). For this kind of measurement, you need to have a way of calculating angles and length of traces in the cloud chamber.
2. The first question is asking about the traces by "geometry". This question is asking about behavior when time passes. Do the traces appear at a regular rate, or do they come in "bursts". Are there patterns that might tell you something about the radiation sources in the area? For this kind of measurement you have to note what time each trace appeared, in addition to the angle/trace length/location measurements you take to answer the first question.
3. Spirals - well I had to do a bit of research online, and take my 10 minutes of poking around and these explanations with a grain of salt. Alpha radiation makes short,fat traces, Beta long thin traces. (alpha particles are big and easily slowed by the cloud..dangerous if the source is ingested but in real life usually stopped by even a layer of clothing, beta are smaller with better penetration and you can see that with the long traces. Gamma radiation is just light (photons) at a very tight wavelength (ditto X-Rays). Unlike the relatively massive alpha and beta particles, they're unlikely to hit (interact with) a gas molecule and cause anything to happen. What they do in a cloud chamber is interact with the walls on occasion, causing streaks to appear similar to beta (long, thin). The interesting part about the spirals is if the trace is weak (a weak beta particle or a not especially energetic electron kicked off from the wall by a gamma ray) the earth's magnetic field will cause it to spin. If you actually put a strong magnetic field in the cloud chamber, this is much more pronounced. Gamma rays will often produce weak traces that spin, near as I can tell, where a beta particle's more likely to have a straight trace, then maybe a hook near the end if it loses energy but still has enough interaction with the gas to be visible.
I recommend that your son does some study on sources of radiation in the everyday world (there are a lot of potential sources), and the differences in the kinds of radiation you can detect in a cloud chamber (alpha vs beta particles, vs electrons knocked out of the side of the wall by x-rays or gamma rays)
-
deleted-184203
- Posts: 5
- Joined: Mon Dec 30, 2013 12:11 am
- Occupation: former flight surgeon, homeschooler
- Project Question: Does the shape of an aircraft affect its radar detectability? This is the project question.
The question my son has is in reference to the project design. I will post that in the forum. - Project Due Date: 4 weeks
- Project Status: I am just starting
Re: interpretation of data cloud chamber
Hello and thank you for your responses. Here's the link to the project:
https://www.sciencebuddies.org/science- ... p087.shtml
My son read over your reponses and found them very helpful. I believe he has a better understanding of what he's testing for and why. He has done quite a bit of backround research on the subject. I am glad he's not using a radioactive source though:)
All the best,
Joy Dozier
https://www.sciencebuddies.org/science- ... p087.shtml
My son read over your reponses and found them very helpful. I believe he has a better understanding of what he's testing for and why. He has done quite a bit of backround research on the subject. I am glad he's not using a radioactive source though:)
All the best,
Joy Dozier