Learning Radiation Kit

$75.00

With the Learn Radiation Kit, you can see the effects of radiation with your own eyes! Using the thermoset polymer, CR-39, you can expose it to alpha radiation and see exactly where alpha particles hit, its approximate energy, and what direction it was going. When a high energy particle impacts the polymer it breaks bonds and allows for preferential etching during post-exposure processing. These etched tracks can then be observed and characterized under a microscope, or with enough exposure, be seen with the unaided eye.

We will gladly develop, image, and characterize your CR-39 particle track detectors, if you would like us to do so. We charge $159.99 to process all 14 of the CR-39 particle track detectors in the Teaching Radiation kit and to provide you with the digital images of the detectors, provided we process all 14 detectors simultaneously. For other development pricing, please contact BSI.

This kit includes:

• (14) CR-39 pieces with protective film
• (2) 2% Thorium-tungsten rod
• (1) Varied distance 3D printed holder
• (1) Varied time 3D printed holder
• Instructions on its use, safety procedures, teaching aid and worksheet

Alternatively, we will be happy to sell you the necessary apparatus to do this development and analysis on your own. This is what we call the ‘Do It Yourself (DIY) Option, and we recommend it for those who would like to teach the Learning Radiation module to multiple classes for many years to come.  Please see our DIY kit pricing below.  We are also available to assist you in re-applying your existing equipment to DIY.

Assembled kit

These thorium-tungsten rods contain about 2% thorium-232, which is a very low-level radioisotope that emits alpha particles by radioactive decay. Th-232’s half-life is over 14 billion years, which is longer than the likely age of the universe, making it one of many nearly stable radioisotopes that we call primordial nuclides.

These alpha particles that come from the Th-232 decay are not radioactive, since they are just energetic helium ions that lose their charge once they come to rest and become common helium atoms. But when they are emitted, they are very energetic, with an energy of approximately 4.1 million electron volts (MeV) which is over 160 million times more energetic than their random motion once they slow down. At this energy, the helium atom loses both of electrons, so they are ions with a charge of +2e, and traveling at about 0.4% of the speed of light.

Optical microscope image of 7 day exposure at 0.6″ distance.

Option 1: BSI will provide you with a development kit for $599.00 to chemically process your CR-39 particle track detectors. You will need to separately purchase your own sodium hydroxide, and to follow the heating instructions carefully using the hot plate that we provide while following our safety instructions carefully.

Option 2:  BSI will sell you a reconditioned optical microscope with an ocular camera and a computer interface for $1,299.  This includes the cost of a new lap-top, loaded with the imaging and image analysis software that you will need to understand your results. Please see the image of this DIY system, below.  Please note that that the actual reconditioned optical microscope may vary, but it will be fully adequate to support your DIY activities. This system will be able to assist the user by counting the number of tracks in a reference area.  For an additional price, BSI can provide advanced AI-based analysis tools which differentiate between different particle tracks, particle arrival angles, and particle energies, and to provide displays showing the distribution of these traits within the observed particle tracks.  Please contact BSI if you would like us to work with you to develop custom analysis software for your specific research applications.

Click here for more information for best practice for the use of CR-39.

Click here for electron microscope web application image. This image is of our CR-39 exposed to Am-241 alpha particles. Notice the direction of impact and depth of penetration. Here is the same image with AI labeling of features.