Can Geiger Counter Ticks be converted into particle/wave counts?

[kvidtr]

TL;DR Summary: Currently working on a project for lab where we're sending Geiger counters 100k feet into the air. Goal is to determine radiation as a function of altitude. Need some guidance.

Hi everyone,

I'm currently working on a project for lab where we're sending Geiger counters 100k feet up into the stratosphere via weather balloons. The professor has asked us to determine radiation as a function of altitude. We're sending up two counters with the intent on measuring radiation due to gamma rays and beta particles.

The gamma ray Geiger counter will be fully covered to prevent alpha and beta particles from setting it off, with the beta particle counter being lightly covered as to just block alpha particles. Then, we'll subtract the gamma counts from the beta counts to get our beta number.

I initially thought this was going to be as simple as, "Send up the Geiger counters, measure the tick rate as a function of altitude, mission accomplished." But my professor is not interested in ticks related to Sieverts; they want actual counts of how many gamma rays and beta particles are coming through.

My thought was that if I can somehow convert Sieverts into some sort of unit of energy, I can then use Sieverts to eventually get to a gamma ray number, and then I can use the same process as above for figuring out my beta particle number.

The problem is, I don't think I know enough about what I'm looking for in order to produce meaningful google results. If anyone could give me some breadcrumbs to follow, I'd be greatly appreciative.

Also, I apologize if this is the wrong section for this sort of question. The papers I was trying to read through were labeled as "Nuclear particle physics," and while this is 'homework' in some sense, I didn't see an option that really fit this description. Also I'm in first year physics, currently doing E&M.

 

[Tom.G]

Each 'Tick' is an instance of the radiation hitting some atom(s) in the sensor, making that atom an ion. This ionization spreads to nearby atoms and creates a small amount of plasma. The electric field applied to the sensor then has a conductive path for current flow. The current flow is then amplified and heard as a 'TIck.'

The 'Ticks' are then integrated and displayed on a meter.

Of course not all radiation will succesfully ionize a conductive path, so there will be some calibration needed for the meter reading.

Hopefully that is enough theory to get the project started.

Have Fun!
Tom

And please keep us updated on your progress and results, we like to learn too!

 

[kvidtr]

Each 'Tick' is an instance of the radiation hitting some atom(s) in the sensor, making that atom an ion. This ionization spreads to nearby atoms and creates a small amount of plasma. The electric field applied to the sensor then has a conductive path for current flow. The current flow is then amplified and heard as a 'TIck.'

The 'Ticks' are then integrated and displayed on a meter.

Of course not all radiation will succesfully ionize a conductive path, so there will be some calibration needed for the meter reading.

Hopefully that is enough theory to get the project started.

Have Fun!
Tom

And please keep us updated on your progress and results, we like to learn too!

Thank you for your response! I understand (I think) the basic process of ionization leading to ticks, but is there a way to know the minimum amount of energy required to cause that ionization?

I'm pretty sure the glass chamber in our Geiger counter is filled with air, which means it can sustain an E-field of a magnitude ## 3 \cdot 10^6 \frac V M##. Is that something that will help me figure out the energy contained in the ionization and allow me to reverse engineer my way back to finding the minimum energy required? Or is that even going to be useful information?

Also I'll gladly post the progress/results after if you and anyone else are interested! Can't post the whole report online probably, but some graphs and potential videos from 100k feet in the air, provided I keep our GoPro well insulated, is definitely on the table :)

 

[Tom.G]

As I recall, the fill gas is an inert gas such as Argon and at low pressure.

Try these links for more info:
https://www.google.com/search?hl=en&q=operation+of+geiger+muller+tube
https://en.wikipedia.org/wiki/Geiger–Müller_tube

Cheers,
Tom