Extracting americium from a smoke detector is pretty straight-forward and really easy to do. Americium 241 is contained within a small button in the smoke detector. Americium has a really long half life (432.2 years), which makes it ideal for smoke detectors. It mainly emits alpha radiation, which is not terribly dangerous unless ingested because your skin is thick enough to block the majority of alpha particles (essentially helium atoms).
The way smoke detectors work is really cool. They work oppositely to the way I thought they did. I assumed that they literally detected the presence of smoke. In actuality, smoke detectors detect the absence of radiation. Americium gives off radiation, which is detected by the detector contained within the device. When smoke gets into the device, it blocks the alpha particles from getting to the detector, which sets off the alarm. That's why it's so easy to set it off.
Now, to get Americium, I took a broken smoke detector (I think there was something wrong with the wire connections), and tore it apart until I found the americium button. Then I cut it out with a really strong pair of scissors. As long as the little glass container containing the americium remains intact, keeping it in a paper container will block all radiation.
Why do you want to extract americium? So you can look at the alpha radiation of course! This can be done by building a spinthariscope (which involves stripping the silver activated zinc sulfide phosphor from the cathode ray tube in a CRT TV or computer monitor) OR by holding the americium button up to the camera of a smartphone or iPod (especially the front facing camera). I am pretty confused by this actually. If you align the button just right with the camera, you can observe small flashes of light that look kind of like sparks. And (up to a certain point) it seems that the cheaper the camera is (less MP), the easier it is too see these specks of light. So maybe you are actually observing gamma particles (photons hitting the camera?)? If you have an explanation (and even if you don't), please feel free to leave a comment.
(I have an RSS feed now, too! It's the orange button on the top right)
The way smoke detectors work is really cool. They work oppositely to the way I thought they did. I assumed that they literally detected the presence of smoke. In actuality, smoke detectors detect the absence of radiation. Americium gives off radiation, which is detected by the detector contained within the device. When smoke gets into the device, it blocks the alpha particles from getting to the detector, which sets off the alarm. That's why it's so easy to set it off.
Now, to get Americium, I took a broken smoke detector (I think there was something wrong with the wire connections), and tore it apart until I found the americium button. Then I cut it out with a really strong pair of scissors. As long as the little glass container containing the americium remains intact, keeping it in a paper container will block all radiation.
Why do you want to extract americium? So you can look at the alpha radiation of course! This can be done by building a spinthariscope (which involves stripping the silver activated zinc sulfide phosphor from the cathode ray tube in a CRT TV or computer monitor) OR by holding the americium button up to the camera of a smartphone or iPod (especially the front facing camera). I am pretty confused by this actually. If you align the button just right with the camera, you can observe small flashes of light that look kind of like sparks. And (up to a certain point) it seems that the cheaper the camera is (less MP), the easier it is too see these specks of light. So maybe you are actually observing gamma particles (photons hitting the camera?)? If you have an explanation (and even if you don't), please feel free to leave a comment.
(I have an RSS feed now, too! It's the orange button on the top right)