1. Energy of Neutrons in Our Lower Atmosphere Team: Half-Life

2. Team Members Paul Mayeurpam006@latech.edu 318-257-4675 Matt Vankerkhovempv007@latech.edu 337-280-9357 Richard Cheviousrtc009@latech.edu 318-257-4369 Nak Choinhc004@latech.edu 318-572-4909 Rachael Deichrad012@latech.edu 318-257-2411

3. Project Proposal Our group would like to use novel detectors, called “MicroGeiger Sensors”, developed by Dr. Chester Williams, at the Institute of Micro Manufacturing (IfM) at Louisiana Tech University. We will purchase two photodiodes and then these devices will be coated with scintillation material. One doped with gadolinium material the other undoped. We hope to use the detector developed by Dr. Chester Williams to determine how many beta particles and neutron are in the troposphere.

4. Cosmic Ray Shower

5. What is a Cosmic Ray Shower? The process of a cosmic ray particle colliding with particles in our atmosphere and disintegrating into smaller pions, muons, and the like, is called a cosmic ray shower. When these primary cosmic rays hit Earth's atmosphere at around 30,000m above the surface, the impacts cause nuclear reactions which produce pions. These pions decay into a muon and muon neutrino (also called antineutrino) at about 9000 m altitude, which rain down upon the surface of the earth, traveling at about 0.998c. Many muons decay on the way down into neutrinos and an electron while others reach the surface, but there are still enough to be detected fairly easily. Actually, about 200 rain down on each square meter of Earth every second. Primary cosmic rays are made up of mostly protons.rain down upon the surface of the earth

6. What Are We Measuring and How? Beta particles, which are simply electrons produced during the showing process, can be detected by scintillation counters. Beta particles interact with the scintillator through ionization. The excitation of the atoms of a certain media by ionizing particles results in luminescence (scintillation), which can be recorded by a photo detector that we install on our circuit board. Neutrons, being electrically neutral, cannot ionize a scintillator. In order to detect a neutron, it must captured by a nucleus, and the products of the nuclear of the resulting (unstable) isotope detected. The element gadolinium (which has a high capture cross-section for thermal neutrons) absorbs the neutrons, producing prompt gamma emission and later decaying via beta decay. These beta particles are detected by the gadolinium doped scintillator counter. We now have a scintillator with a count of just beta particles and one with a count of beta particles and neutrons turned into beta particles. The rate for neutrons will then be (Rate neutrons = Rate gadolinium doped scintillator – Rate plain scintillator)

7. Photodiode

8. Box Design

9. Electrical Design

10. Schedule Board design construction:04 January 2005completed Board construction:10 January 2005completed Box construction: Inner box14 January 2005completed Outer box13 January 2005completed Project management meeting:27 January 2005completed Testing: Batteries24 February 2005completed Board14 January 2005completed Sensors06 April 2005 Boxes30 March 2005 5m Impact03 April 2005 Insulation28 March 2005 Meeting with IfM representatives:01 March 2005completed Sensors obtained:26 April 2005 Preliminary design report (PDR):24 March 2005 PDR defense (video conference):30 March 2005 Software Testing/Debugging:10 April 2005 Interfacing Sensors with micro controller:10 April 2005 CDR: TBD FRR: TBD

11. Price Budget ItemPrice Foam$3/ board InsulationProvided Photodiodes$30 Batteries$4 Thermacare Hand Warmers$10 ScintillatorsProvided Hot Glue$3/ pack of 20 Hot Glue GunProvided Total Price$46

12. Weight Budget ItemWeight in grams BalloonSat67 g Heating element22 g Batteries (two)74 g Inner box 64 g Outer box 113 g Total Items Weight340 g

13. Risk Management Risk EventLikelihoodImpactDetection Difficulty When 341Construction Given 1, we are unable to find feasible means to Calibrate Said sensors 251construction 132 242 311 Software failure233Flight Hardware failure233Flight We are unable to find Payload once landed251Post-Flight Internal temperature drops too low during flight241Flight weight budget is exceeded231Any point pre-flight Money budget is exceeded241Any point pre-flight Milestone not met231Any point pre-flight Unable to activate electronics on flight line 151Pre-Flight Unable to recall flight data151Post-Flight Data does not match model111Post-Flight

14. Work Breakdown Schedule

15. References Reference 1: http://www.centrovision.com/tech2.htmhttp://www.centrovision.com/tech2.htm Reference 2: “Commercializing Neutrons” by Dr. Chester Wilson Reference 3: http://www.udt.com/Datasheets/Other/PhotodiodeCharacteristics.pdfhttp://www.udt.com/Datasheets/Other/PhotodiodeCharacteristics.pdf Reference 4: http://www.advancedphotonix.com/pdf/High_Speed_Si_Pin.pdfhttp://www.advancedphotonix.com/pdf/High_Speed_Si_Pin.pdf Reference 5: http://en.wikipedia.orghttp://en.wikipedia.org Reference 6: http://helios.gsfc.nasa.gov/cosmic.htmlhttp://helios.gsfc.nasa.gov/cosmic.html Reference 7: http://www.ngdc.noaa.gov/stp/SOLAR/COSMIC_RAYS/cosmic.htmlhttp://www.ngdc.noaa.gov/stp/SOLAR/COSMIC_RAYS/cosmic.html Reference 8: http://www.research.ibm.com/journal/rd/421/ziegler.htmlhttp://www.research.ibm.com/journal/rd/421/ziegler.html Reference 9: http://spacegrant.montana.edu/borealis/missions/BOR0109A/index.phphttp://spacegrant.montana.edu/borealis/missions/BOR0109A/index.php

16. Questions?