The Effect of Granite - Part 1

Note: Diagram not to scale.

Setup

A large granite slab was placed above the detector on stands.

The detector was run in coincidence mode with and without the granite slab in place and in upper single mode with and without the slab in place.

The detector was oriented with a heading of N56W. All tests were run in direct sunlight. Each condition was run for a total of 10 minutes.

Granite is a material that can contain radioactive elements. Based on the conclusion drawn from the thorium experiment, it is expected that granite, which is also radioactive, will cause an increase in count rate.

Granite Slab Dimensions - Length and Width

Note: Diagram not to scale.

Granite Slab Dimensions - Thickness

Note: Diagram not to scale.

The slab is bordered with an extruded lip that increases the overall thickness of the slab.

Results - Coincidence Mode

With each data point's margin of error, it is impossible to determine if there is any effect.

Statistically, there is no significant difference between these data points, as they are within a one sigma error range of each other.

Thus, granite does not affect the detector's coincidence mode count rate.

Note: The error bars of both data points are covered by their data points' dots.

Results - Upper Single Mode

When run in the upper single mode, the opposite result from the result expected was obtained!

But how could this be possible? Something must be missing...

It turns out that a variable was unaccounted for. By placing the granite slab over the detector, the sunlight that previously shone on the scintillator paddles was blocked. Thus, this experiment may possess a systemic error where light pollution causes extraneous measurements.

However, it must first be shown that light pollution affects count rate before the data collected in the experiment may be classified as the results of systemic error.

Next Experiment!

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Experiment Setup - Photo

Note: The photo is a reconstruction of the original experiment designed to give viewers a better understanding of the experiment setup. As it is a reconstruction, all and any values displayed in the photo (heading, light level, height and orientation of granite slab, surroundings, etc.) are not to be considered as true to the original experiment.

Note: The original experiment was conducted in the daytime. However, it is important to recognize that the granite affected the level of the light reaching the scintillator paddles. While the light level displayed in the photo cannot be considered to be an accurate representation of the light conditions of the original experiment, it does show how the granite slab affected the amount of light pollution in each trial.

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