What Materials Block Space Radiation

I chose this experiment because I love space and wanted to investigate an aspect of space that's new to me. Space engineering is evolving quickly, sections of our atmosphere, are thinning. satellites, probs, and humans travel into space and we must protect ourselves. Finding the best materials to do so is essential. Without any blockade radiation destroys our cells and can cause cancer and organ failure, if we can block the radiation then we can save lives. There are many types of radiation; electromagnetic radiation (anything on the electromagnetic spectrum), and particle radiation, which is radiation that has mass. In terms of the harm it can do, radiation fits into two categories: ionizing and non-ionizing radiation. Ionizing radiation is the radiation that's strong enough to hurt you. Gamma radiation is the most penetrating type of radiation, and what I used in this experiment. Dense materials are best for blocking radiation. However, due to the bremsstrahlung effect, some materials emit x-rays that could cause more harm. Instead, it is best to use materials that can absorb radiation. I hypothesized that materials with similar components to our atmosphere like water and plastic that are high in hydrogen, will better block the radiation because our atmosphere blocks powerful radiation from harming us on earth. The aluminum foil will block the least because of the bremsstrahlung effect, and the two physical barriers, paper and felt, will block similarly to each other, the denser blocking slightly more.

I researched a lot about radiation and the materials that are used to block it in space now. I used a lot of NASA websites and checked my information with other websites to ensure it was correct. In this experiment, I used about 1/4 cup of water in a small Plastic bag to 152.4 cm of aluminum foil, 152.4 cm of plastic wrap, a Radiation detector, 50 beads of uranium glass, Two sheets of felt, and Four sheets of paper. there are different amounts of each material to ensure they were all the same thickness. My procedure was to put my uranium beads on the table and my radiation detector on top with a selected material between, turn on the detector, watch the dosimeter, and record the total accumulative dose every twenty seconds for five minutes. To ensure there were no anomalies in the data I conducted 5 tests before my experiment and wrote the results of these tests down but didn't use them in my results. After I had the data from my experiment I referenced this data to ensure there were no extreme differences. To create my materials, I used roughly the same length of plastic wrap and aluminum foil and folded them until they were around the same thickness and area with as little air inside as possible. Similarly, I used two sheets of felt and paper, but the paper even when cut and layered wasn't as thick, so I added more sheets until the thicknesses matched. For the water, I put in 1/4 cup in a bag and added or reduced the amount until it matched the thickness of the other materials, others helped me to look at and compare the thicknesses to ensure they matched

When I conducted my experiment, the baseline test with no material blocking the source measured at an average of 0.042438 mSv. The felt, the less dense of the two materials I chose to see the difference the density would make measured at 0.037188 mSv then the paper the denser physical barrier measured at 0.027 mSv. The aluminum foil, though close, blocked more, measuring at 0.0265 mSv. The plastic and water were even closer, the plastic measuring at 0.014938 mSv and the water blocking the most at 0.013188 mSv. Over the five-minute time the radiation was measured, the levels built up differently depending on the material that was blocking. Each of the materials measurements were almost linier except the aluminum foil which had a huge jump around the two-minute mark. This is likely the detector starting to pick up some of the x-rays created from the bremsstrahlung effect. The baseline test (no barrier) jumped up at the end, whereas the others stayed consistent near the end. This seems to be the materials flattening out their radiation levels compared to the tests with no material. My hypothesis was; if materials are placed between a gamma radiation source and detector, the materials with similar components to our atmosphere (water) will better block the radiation because of how well our atmosphere blocks powerful radiation. The plastic will block the second most, as it is high in hydrogen and can be used to block radiation. The aluminum foil will block the least, and the two simple barriers (felt and paper) will block similarly to each other, the denser blocking slightly more. The results show the water blocking most, and plastic the second, this aligns with my hypothesis. However, the aluminum foil blocked the next most; whereas I predicted the x-rays it emitted would place it in last. The paper, as the denser simple barrier blocked around the same amount as the aluminum foil, and significantly more than the felt which blocked the least by quite a bit.

My hypothesis was; if materials are placed between a gamma radiation source and detector, the materials with similar components to our atmosphere (water) will better block the radiation. The plastic will block the second most, The aluminum foil will block the least, and the two simple barriers will block similarly, the denser blocking more. The water blocked the most, and plastic the second, However, the aluminum foil blocked the next most. The paper, as the denser simple barrier blocked around the same amount as the aluminum foil, and significantly more than the felt. I learned a lot about radiation and different materials during my research and experiment, especially about the bremsstrahlung effect. The tin foil placed third, whereas I predicted the x-rays it emitted would compensate for all it blocked and place it in last. I learnt that this was because the x-rays coming from the bremsstrahlung effect weren’t as much as I anticipated, if i would have had access to material with a higher atomic number, like lead, it would have created more x-rays. The kinetic force of the radiation also plays a part in this process. Apart from the aluminum foil, the density of the felt and paper made a bigger difference than I predicted. I thought the felt and paper would be close, because the other materials all had special properties. I underestimated the difference their densities could make.

If I were to redo this experiment, I would test over a longer time to see how it might change the results. I would also try different materials and radiations that I don’t have access to right now, like beta radiation, lead, and the technique of layering materials that NASA uses. This information could be used in the future of space travel or if our atmosphere ever becomes too weak to protect us on earth. The next biggest thing is to find how practical each material would be to use, and find the best way to apply them.

I would like to thank my mom for helping me acquire the materials needed for this project, helping me to print images, keeping me on track, and helping to paint my display board. I would also like to thank my siblings for their assistance in painting the board. I would like to thank my dad as well for helping me measure and confirm the thickness of the materials. Lastly a thanks to all the teachers who gave class time and advice to help me with this project. Thank you.

Government of Canada, (16/10/2026) Types and Sources of Radiation. Retrieved from: https://www.cnsc-ccsn.gc.ca/eng/resources/radiation/types-and-sources-of-radiation/

U.S. Centers for Disease Control and Prevention (19/02/2024) About Health Effects of Radiation. Retrieved from:  https://www.cdc.gov/radiation-health/about/health-effects-of-radiation.html

Let's Talk Science, (25/09//2019) What are the Different Types of Radiation. Retrieved from:  https://letstalkscience.ca/educational-resources/backgrounders/what-are-different-types-radiation#:~:text=There%20are%20several%20types%20of,ray%20equipment%20leave%20the%20room.

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HPS Specialists in Radiation Protection (John P. Hageman) (26/01/2015) Radiation Effects of Electronic Equipment. Retrieved from:  https://hps.org/publicinformation/ate/q11162/

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NASA's Goddard Space Flight Center Conceptual Image Lab (13/07/2020) Solar Energetic Particles. Retrieved from:   https://svs.gsfc.nasa.gov/20320/

Barrier Technologies (Will Muldoon) (16/10/2024) What Stops Gamma Radiation? Shielding Explained. Retrieved from:  https://barriertechnologies.com/what-stops-gamma-

Curious Droid (Paul Shillito) (28/03/2020) How do you Protect Spacecraft from the Radiation of Space? Retrieved from:   https://www.youtube.com/watch?v=9Uc1VXL3Q7g

European Nucellar Society (2026) Bremsstrahlung Retrieved from:  https://www.euronuclear.org/glossary/bremsstrahlung/

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European Nucellar Society (2026) bremsstrahlung (image) https://www.euronuclear.org/glossary/bremsstrahlung/)