What do I need to create an ionizing radiation detector with an Arduino?

I have a Science Fair project which is due in a month, and I have decided to create an ionizing radiation detector for my project. I want to create a detector that either sends a value of the amount of radiation to a LCD screen or causes a LED to light up and a Piezo speaker to beep when detecting radiation. I'd like the project to detect the radiation from Americium in a smoke detector, assuming it is safe to do so.

I have an Arduino, a breadboard, and some other parts.

I know that for this project I'll need a Geiger Counter. I was thinking of getting a SI3BG geiger counter on Ebay, but they are all shipped from Ukraine so it would take a week or two to get here. Does anyone have an idea of how I could safely build/buy a Geiger Counter for $20-30 or less? I live in Canada so I'd prefer to buy everything from a North American store.

If it would work, I saw this article on building a Geiger counter using parts which would be easier for me to obtain. It involves 8 PIN photodiodes and uses an app on a phone for calculations. Would it be feasible to replace the app with a program on an Arduino? Is this an easier way to create a sensor?

Also, would the SI3BG detect Americium from a smoke detector, and would it be safe to do so? Would I need to take apart the smoke detector? What would I need to connect the Geiger counter to my Arduino? Is it as simple as connecting jumper cables via a breadboard? And would sending a value to a LCD/LED screen work, or would I need to use a Piezo speaker? Thanks in advance to anyone who can help.

I don't think you will be able to build a geiger tube for $30. The article you linked didn't seem to have much meat, but the pin diode concept is interesting. If I had a science fair approaching, and nothing done, and was committed to detecting ionizing radiation, I'd opt for an electroscope.

You want to be careful with the americium planchet in a smoke detector. It's easily broken, and if accidentally ingested, will cause internal damage. I'd say if you don't know exactly what you are doing, don't. Look for an old glow-in-the-dark watch made in the 1960s or before. The luminous paint contains radium, which will easily discharge an electroscope, or make a geiger counter buzz. And it's relatively safe to handle the watch.

A traditional Geiger counter uses a special gas tube (like your proposed S13BG), which requires high voltage (500 to 1000 volts) to operate. So that is not something that is easy for a beginner to build.

However an Arduino can be used with a Geiger counter to count the pulses, which gives a very accurate indication of radiation due to alpha (smoke detector) and beta particles.

An air-filled ion chamber is much easier, cheaper and simpler to build, but not as sensitive. It will detect a smoke detector alpha source a few cm away.

Normally you would use a DVM to read it out, but it may be possible to do that with the Arduino analog input instead. See this blog article for ion chamber ideas and construction details.

BotJohn: I have a Science Fair project which is due in a month, and I have decided to create an ionizing radiation detector for my project. I want to create a detector that either sends a value of the amount of radiation to a LCD screen or causes a LED to light up and a Piezo speaker to beep when detecting radiation. I'd like the project to detect the radiation from Americium in a smoke detector, assuming it is safe to do so.

I have an Arduino, a breadboard, and some other parts.

I know that for this project I'll need a Geiger Counter. I was thinking of getting a SI3BG geiger counter on Ebay, but they are all shipped from Ukraine so it would take a week or two to get here. Does anyone have an idea of how I could safely build/buy a Geiger Counter for $20-30 or less? I live in Canada so I'd prefer to buy everything from a North American store.

If it would work, I saw this article on building a Geiger counter using parts which would be easier for me to obtain. It involves 8 PIN photodiodes and uses an app on a phone for calculations. Would it be feasible to replace the app with a program on an Arduino? Is this an easier way to create a sensor?

Also, would the SI3BG detect Americium from a smoke detector, and would it be safe to do so? Would I need to take apart the smoke detector? What would I need to connect the Geiger counter to my Arduino? Is it as simple as connecting jumper cables via a breadboard? And would sending a value to a LCD/LED screen work, or would I need to use a Piezo speaker? Thanks in advance to anyone who can help.

I do not believe you can succeed with this project, on time and on budget.

That article makes claims without any backup. It also says one important piece of info.

Their photodiodes detect Beta and Gamma radiation (HIGH ENERGY). Americium decays with low energy Alpha particles.

Do some research on detection of Alpha particles.

EDIT:

I have changed my mind, Just Gut a smoke detector, use their detection circuit. Just interface to their circuit.

Chuck.

If an electroscope is too pedestrian, how about a cloud chamber, made with a glass jar. a block of dry ice, some black construction paper, methyl (wood) alcohol and a high intensity flashlight.

Put a circle of the construction paper on the bottom of the jar, and saturate it with the alcohol.Set the jar on a slab of dry ice, and put your radiation source inside. Shine the light through the jar sideways, and look closely. Faint vapor trails trace out the alpha particles as the traverse the alcohol vapor, and cause it to condense.

jremington: An air-filled ion chamber is much easier, cheaper and simpler to build, but not as sensitive. It will detect a smoke detector alpha source a few cm away.

Normally you would use a DVM to read it out, but it may be possible to do that with the Arduino analog input instead. See this blog article for ion chamber ideas and construction details.

Yeah, powering the Geiger counter will definitely be hard so anything I can power with a 9V or a bunch of AAs is much easier to do The air-filled ion chamber seems like it will work better than a photo diode while not being much harder to build. Do you think that this ion chamber from the same site will work better or worse than the "Improved Transistor Circuit" from the article you linked? It seems much easier to build as I'm not very good at soldering though I do have access to a soldering iron at school.

Build the simpler one first -- it will definitely work (if you are careful to follow the directions) and you will learn to solder.

jremington: Build the simpler one first -- it will definitely work (if you are careful to follow the directions) and you will learn to solder.

In order to make sure I follow the directions properly, is this everything I need to build the detector and connect it to an Arduino other than a soldering iron + solder and glue?

  • 9V battery/batteries + connector(s) for the detector
  • 9-12V of AA batteries + a 8 AA connector for the Arduino + LCD
  • Metal cylindrical can + Metal circular tin
  • 2 alligator clips and 2 5-way binding posts
  • Tape, tinfoil, and possibly Mylar
  • An Arduino + breadboard + jumper cables
  • 1-2 feet of copper wire
  • 4 Darlington Transistors
  • 2 x 10k resistors + 2 x 2.2k resistors
  • A LCD + speaker to output to when radiation is detected

Also, do you know what the 100 uA or 1 VDC item connecting the two sides is in this diagram from the building guide?

The diagram is for the more advanced project, which is not recommended for your first build. The 100 uA or 1 VDC item is a meter.

A DVM will work, and you will need one if you are going to continue with electronics.

You need only 1 Darlington transistor for the simpler detector. The Arduino/LCD etc. won't be useful for the project at this stage.

jremington: The diagram is for the more advanced project, which is not recommended for your first build. The 100 uA or 1 VDC item is a meter.

A DVM will work, and you will need one if you are going to continue with electronics.

You need only 1 Darlington transistor for the simpler detector. The Arduino/LCD etc. won't be useful for the project at this stage.

If I did the more advanced one after the simpler version, would that be everything I would need though?

Yes.

jremington: Yes.

Sorry to bother you, but would I be able to make the circuit using a breadboard instead of gluing resistors and transistors into the circular tin on top of the cylindrical one? And would I still need the circular tin for anything?

would I be able to make the circuit using a breadboard

No. The circuit is extremely susceptible to electronic and electrostatic interference.

Follow the directions closely or it won't work.

jremington: No. The circuit is extremely susceptible to electronic and electrostatic interference.

Follow the directions closely or it won't work.

I've run into some trouble when building the Experimenter's Ionization Chamber. When testing a granite sample (Which may or may not contain traces of radioactive material), I see no difference in voltage. If you have the time, could you look at a diagram I made using a picture of the circuit I made and see if everything is wired correctly? Here is the thread I made with more detail. Thanks again for your help so far.

Please do not split threads like this.