1. Project RNG: Radiation-Based Random Number Generator
Team Oregon Chub
Colton Hamm (Team Leader)
Alex Brotherston
Ashley Donahoo
Matt Johnson
Advisor:
Dr. Hoffbeck, Dr. VanDeGrift,
Dr. Osterberg
Industry Representative:
Mr. John Haner
Bonneville Power Administration
University of Portland School of Engineering

2. Introduction Our project generates random numbers from radioactivity
Building a radiation sensor, designing a MOSIS chip and using 7-segment displays
University of Portland School of Engineering

3. Scorecard Completed Final Report v0.9 Interfaced Geiger tube with CPLD
University of Portland School of Engineering

4. Additional Accomplishments
Gathered over 3700 bits of data to be analyzed for statistical tests.
Replaced function generator with batteries to power device.
3 batteries
University of Portland School of Engineering

5. Plans Conduct statistical tests Complete Final Report v.95
Add reset and hold buttons to device
Work on Founder’s Day presentation
University of Portland School of Engineering

6. Milestones Status Description Original Target Previous Present
Completed
Construct and test the prototype voltage multiplier.
14 Feb 11
11 Feb 11
Construct final voltage multiplier
21 Feb 11
20 Feb 11
 Interface pulse generator, transformer, voltage multiplier, and Geiger tube
14 Mar 11
22 Feb 11
Missed
Final Report v0.9
13 Mar 11
25 Mar 11
Interface Geiger tube and CPLD
30 Mar 11
21 Mar 11
Interface all aspects of device
29 Mar 11
On Track
Final Report v0.95
1 Apr 11
Final Report v1.0
8 Apr 11
Founder’s Day Presentation Complete
12 Apr 11
Toward the end of this file are two slides titled “Understanding Milestone Dates” and “Color Coding Milestones” respectively. Review these carefully before completing this slide.
University of Portland School of Engineering

7. Concerns/Issues
Concerns regarding battery power, especially with the large display for Founder’s Day.
Concerned about statistical tests proving that our numbers are truly random.
Concerns that case may not be done by Founder’s Day and shielding issues.
University of Portland School of Engineering

8. Conclusions
The Geiger tube, CPLD, and display have all been interfaced and are working.
Statistical tests will show if numbers are truly random.
University of Portland School of Engineering

9. Questions?
University of Portland School of Engineering

10. Secret Geiger Tube Slides
Model: Geiger Tube as a Switch
Switch=open, V=500v
Switch Closes, V=
500v*10M/(1M+10M)=455v
The capacitor blocks DC, so the signal starts at 0 volts, and falls by 45 volts when the switch closes V
University of Portland School of Engineering

11. A Geiger–Müller tube consists of a tube filled with a low-pressure inert gas, such as neon, and an organic vapor or a halogen gas. The tube contains electrodes, between which there is a potential difference of several hundred volts, but no current flowing. The walls of the tube are either entirely metal or have their inside surface coated with a conductor to form the cathode while the anode is a wire passing up the center of the tube.
When ionizing radiation passes through the tube, some of the gas molecules are ionized, creating positively charged ions, and electrons. The strong electric field created by the tube's electrodes accelerates the ions towards the cathode and the electrons towards the anode. The ion pairs gain sufficient energy to ionize further gas molecules through collisions on the way, creating an avalanche of charged particles.
This results in a short, intense pulse of current which passes (or cascades) from the negative electrode to the positive electrode and is measured or counted.
-Wikipedia 0v
-40v
University of Portland School of Engineering