# Introduction

Our atmosphere protects us from much of the damaging radiation from space. The higher in altitude, the less atmosphere is there to protect us. It is our intention to measure radiation levels as our balloon gains altitude.

# Question

• How do radiation levels change with altitude?

# Hypothesis

If the altitude of the balloon increases, the radiation levels will increase at at exponential rate.

# Variables

Independent Variable: Altitude

Dependent Variable: Radiation Levels

Controlled Variable: The Sampling Rate

LabQuest 2

# Procedure

1. Become familiar with how the Lab Quest radiation detector works.

2. Measure radiation levels in the classroom and various locations around campus.

3. Build a Styrofoam box to protect the equipment from extreme temperatures.

4. On launch day, set-up the Lab Quest start the experiment, place it in it's box, and place it in the payload container.

5. Launch the balloon.

6. Retrieve the balloon and analyze the data.

# Data

## Radiation Before the Flight

Data was collected in Mr. Brode's classroom (D-Building), the center of the courtyard, the Media Center (A-Building), and in the Art room (B-Building). The measurements were made at different times on different days. Below is a sample of the data that was recorded during a run.

Settings: Rate = 0.1 samples/s (1 sample every 10 seconds)

Interval=10 s/sample

Duration=600 s

Data:Min = 0 (During a 10 second period, no radiation was detected.)

Max= 6 (During a 10 second period, six radioactive particles were detected.)

Mean=2 (The mean average of the radioactive particles detected during 10 second intervals was two.)

Std. dev:=1.5089 (Standard Deviation)

Samples= 600

In total, three-thousand samples were made at 10 second intervals.

## Radiation During Flight

When the Lab Quest was recovered, the data file contained the following information.

Min= 0

Max= 1

Mean=0

Std. dev.=0.51493

Samples- 12

The settings were as follows:

Rate =3200 samples/h (1 sample every 1.125 seconds)

Interval=0.0003125 h/sample

Duration=3.0 h

# Analysis

The mean average was 2 for 2,995 samples. Five samples had a mean average of three. Since 99.8% of the samples had a mean of 2, this value will be used when comparing the radiation levels during flight with the radiation levels measured on the ground. It should also be noted that the greatest number of particles detected during any sample taken before the launch was nine.

The data for the radiation levels during flight was not useful since it stopped collecting data after 13.5 s. The Lab Quest was still on the ground at that point. We were expecting 9600 samples during the 3 h flight. The cause for the missing data is unknown at this point. The student that placed the Lab Quest in it's Styrofoam box remembers accidentally pressing the power button which might have turned the unit off. They pulled it out of the box and made sure that it was working and then it was put back in the box. When the Lab Quest was recovered, the battery was dead. This is an indication that it was turned on before the flight and remained on until the battery died. The time between launch and recovery was about 29 h. During one of the tests we ran before the launch, the Lab Quest collected data for 18 hours and the battery did not fail. The battery was very low after 18 hours. One possible reason for the device only collecting data for 13.5 s is that the battery may not have been fully charged. It was plugged into the charger for 12 h before the flight. Another possibility is that the student forgot to start the experiment when they placed it in the box the second time. The process of starting the Lab Quest and placing it in the box was recorded on video. Analysis of the video indicates that the student did accidentally hit the power button while placing the Lab Quest in the box. The experiment was started 19 seconds into the video. At 33 seconds into the video, the power button was accidentally pressed. This is a 14 second interval. The Lab Quest only recorded data for 13.5 s. When the power button is pressed during a run, it stops the experiment and the message "You have unsaved data. Do you wish to save or discard the data?" The choices are "Discard, Cancel, or Save". When the students pulled the Lab Quest out of the box to check it, they touch the screen and probably selects "Cancel". Then, they did not appear to touch the screen again before the Lab Quest was placed back in the box. In order to restart the experiment, it is necessary to hit the "Play" button and then select "Discard". It was very sunny and it was difficult to see the screen. This may have been a factor in restarting the experiment.

Experiment Started (19 s)

Power Button Accidentally Pressed Stopping Experiment after 14 s

Cancel Button Selected

Final Check Before Returning to Box