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.
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
2 3D printed holders, 2 2% thorium tungsten rods, 14 pieces of CR-39
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.
CR-39 after 7 day contact exposure and subsequent developing etch.
Optical microscope image of 7 day exposure at 0.6″ distance.
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.