Help | Contact Us
NukeWorker.com
NukeWorker Menu "Directed" Geiger counter for gamma radiation

Author Topic: "Directed" Geiger counter for gamma radiation  (Read 5274 times)

0 Members and 1 Guest are viewing this topic.

Offline MareTranquil

"Directed" Geiger counter for gamma radiation
« on: Apr 29, 2011, 11:41 »
Hello.

For a personal project, I'd like to know if its possible to modify a tiny geiger mueller tube like this one in a way so that it only detects gamma radiation from a small arc of only a few degrees, while ignoring other gamma radiation sources. The obvious Idea would be to attach something like a long lead tube around the instrument which simply blocks all unwanted sources. My question is: would it be possible to do this and end up with something thats still somewhat small (not larger than a cigar would be perfect), or would this be rather impossible because of the massive required shielding?

Cycoticpenguin

  • Guest
Re: "Directed" Geiger counter for gamma radiation
« Reply #1 on: Apr 29, 2011, 04:01 »
gamma shielding... difficult.

The only way Id see this being possible is by using 2 detectors.

have one with an certain amount of lead around it, and have the other free. Calculate the difference and extrapolate the shielded difference to get what you want. Tenth thickness of lead is 2 inches, so Unless you want a 300 pound detector....


Offline MareTranquil

Re: "Directed" Geiger counter for gamma radiation
« Reply #2 on: Apr 29, 2011, 05:05 »
Thanks, thats a nice idea.

One more short question: Would it help to use a low energy gamma source, like I-123 with its ~30keV?

Offline RDTroja

  • Site Heretic
  • Gold Member
  • *
  • Posts: 3948
  • Total likes: 168
  • Karma: 4553
  • Gender: Male
  • I knew I got into IT for a reason!
Re: "Directed" Geiger counter for gamma radiation
« Reply #3 on: Apr 29, 2011, 06:03 »
Thanks, thats a nice idea.

One more short question: Would it help to use a low energy gamma source, like I-123 with its ~30keV?

If that is the isotope you are looking for, then yes. It would be less useful (or even useless) for other isotopes of higher energies.

Many years ago (1976, to be exact) I saw a directional gamma meter -- not discriminating to a single direction, but indicating direction to the source. It was pocket sized and had an array of very small detectors around the periphery of the case. The gentleman that owned it had brought it with him from Eastern Europe -- I never saw another one. Very cool, but probably not what you are looking for.
"I won't eat anything that has intelligent life, but I'd gladly eat a network executive or a politician."

                                  -Marty Feldman

"Politics is supposed to be the second-oldest profession. I have come to understand that it bears a very close resemblance to the first."
                                  -Ronald Reagan

I have never made but one prayer to God, a very short one: 'O Lord, make my enemies ridiculous.' And God granted it.

                                  - Voltaire

Offline OldHP

  • Very Heavy User
  • *****
  • Posts: 502
  • Total likes: 0
  • Karma: 276
  • Gender: Male
  • Tell Recruiters to use NukeWorker.com
Re: "Directed" Geiger counter for gamma radiation
« Reply #4 on: Apr 29, 2011, 09:56 »
(not larger than a cigar would be perfect

Most of the instrument manufacturers have available a good shielded GM or NaI detector; however, cigar sized (and I assume you also mean weight) - unless your looking for a very specific very low energy gamma with no other isotopes or other potential sources present, the answer is a very simple NO!

I saw the same instrument RDT described along about the same time, but here again, what you are asking for it is not a fit.
Humor is a wonderful way to prevent hardening of the attitudes! unknown
The government is like a baby's alimentary canal, with a happy appetite at one end and no responsibility at the other. Regan

Offline namlive

Re: "Directed" Geiger counter for gamma radiation
« Reply #5 on: Apr 30, 2011, 06:11 »
Instead of an arc, I would use a sphere with shielding at the center. That way I could get an area profile. Instead of using GM tube, use  TLD type material. Take your read out. Divide by the period of time it was placed in the area to get a dose profile.
No one gets out alive.

 


NukeWorker ™ is a registered trademark of NukeWorker.com ™, LLC © 1996-2021 All rights reserved.
All material on this Web Site, including text, photographs, graphics, code and/or software, are protected by international copyright/trademark laws and treaties. Unauthorized use is not permitted. You may not modify, copy, reproduce, republish, upload, post, transmit or distribute, in any manner, the material on this web site or any portion of it. Doing so will result in severe civil and criminal penalties, and will be prosecuted to the maximum extent possible under the law.
Privacy Statement | Terms of Use | Code of Conduct | Spam Policy | Advertising Info | Contact Us | Forum Rules | Password Problem?