The "cloud chamber" that does not require dry ice. |
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| PURPOSE: Cloud chambers are used for teaching about [Radiation] This cloud chamber does not need dry ice for cooling. It uses "ice gel" for cooling device, and this cloud chamber can be used many times when re-freezed in a freezer. |
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| TARGET: Junior High School (9th grade) High School |
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| CATEGORY: Physics Chemistry |
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| HOW TO MAKE: [Materials] for cloud chamber plastic cups ... 2 aluminum tape felt for cooling device ("cold plate") heatsink ...1 "ice gel"(Frozen Sheet – 18OC, Ruck Stone Co. Ltd. ) aluminum tape |
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| - Remove the bottom of one plastic cup*. - Cover the hole with the aluminum tape. - Cut some felts as the same size as the hole. - Stack three felts and secure with a stapler. - Stick felts inside the cup*. - Fix two cups together and secure with aluminum tape. |
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| - Wrap aluminum tape around the heatsink. - Pour "ice gel" inside the heatsink. - Seal the heatsink with aluminum tape. The cross-view is shown in Fig1. |
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| HOW TO USE: - Put the "cold plate" in the freezer for more than 24 hours. - Place the radiation source on the "cold plate". - Warm ethanol to about 60oC. - Pour 6mL ethanol to cloud chamber's felts. - Put the cloud chamber on the "cold plate". - Pour 100mL warm water into the upper cup of the cloud chamber. - You will be able to see the particle tracks in about 1 minute. Particle tracks will be seen as in figure 2. |
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| REFERENCES Masahiro Kamata and Miki Kubota, "Simple cloud chambers using gel ice packs", Phys. Educ. 47 429-433, (2012) |
