1. The Work Being Done at the Ion Beam Laboratory at Texas A&M University Van D. Willey Columbia High School Under the Direction of Lin Shao Assistant Professor Department of Nuclear Engineering Texas A&M University

2. Pressure Vessel Pressuerizer Steam Generator Pump Containment

3. Radiation Damage Creation Schematic of a nuclear pressure vessel and a displacement cascade generated by a neutron.

4. Ion Beam Deposition (~10 eV) Ion Implantation (~100 keV) Ion Beam Analysis (~1 MeV) Interaction of ion beams with a crystalline solid

5. Show and Tell Low power Ion beams can be used to deposit one material on the surface of another….gold or aluminum onto silicon. This can be used to make useful things like radiation detectors and solar cells. STAAR/TEKS 2(e), 8(b), 8(d)

6. Use as Radiation Detector Radiation causes multiple electron- hole pairs to be formed Electron hole pairs are accelerated across the potential barrier

7. Student Activity The student will make a solar car from a selection of K’Nex building pieces, a solar collector and a motor. She will then optimize the positioning of the collector (with respect to the sun) for maximum speed. If the activity is done indoors, hopefully the same effect can be experienced with the overhead lights or maybe a selection of flashlights. STAAR/TEKS 2(e), 8(b), 8(d)

8. Student Activity The student will determine the optimum type of light source to maximize the speed of a commercially available solar- powered toy car. He will use incandescent and LED flashlights held at a specified height over the car to power the car a pre-measured distance. He will then be able to show how the distance from the light to the car affects the speed of the car STAAR/TEKS 2(e), 8(b), 8(d)

9. F/A 18C D 200 keV 10 keV 1.7 MeV1 MeV 140 keV Five Accelerators (ion energy from 10 keV to 1.7 MeV): One of the largest university ion irradiation facilities in US)

10. Student Activity Operation of the Ion Accelerator requires precise control, some of which is supplied through the use of a temperature control device called a thermocouple.

11. Student Activity She will use a multi- meter to see the induced voltage across a shop-built thermocouple She will find the corresponding temperature from an online chart for that type or thermocouple. STAAR/TEKS 2(e), 5(d)

12. Source Protons are most popular ion for PIXE Sputter source is used –Metal Hydride Source is first given a negative charge Ions are pulled off of the sample by a relatively weak electric field

13. The Accelerator looks more like this

14. Mass purification Magnet –A large electromagnet is used here to purify the mass Calculating radius of curvature –Speed and charge of particle are known –Magnet field strength is controlled by supplied current –The radius can be controlled to purify the beam

15. Mass Purification As charges move perpendicular to a magnetic field a force is applied to them This charge will accelerate the ions around the curve –F=constant=ma Too massive not enough acceleration Too small too much acceleration

16. Student Activity Simulate the effect of the turning magnet with small bar magnets, a ball bearing and a section of Hot Wheels track She will then be asked to write a short summary of why she chose the design she used. STAAR/TEKS 2(e), 8(b), 8(d)

17. RBS - Rutherford Backscattering for depth profiles of complex thin films (up to a few microns thick and down to a few nm depth resolution). EBS - Elastic (i.e. non-Rutherford) backscattering (for better C, N, O analysis). ERD - Elastic Recoil Detection (used for H analysis). PIXE- Particle (usually proton) Induced X-ray Emission NRA - Nuclear Reaction Analysis (isotope specific). IBIC - Ion Beam Induced Charge. STIM - Scanning transmission ion microscopy. Ion Beam Analysis RBS, PIXE NRA STIM Ion beam view port Electronics Port 3-D stage

18. EDS Spectrum of human hair

21. PIXE (Particle Induced X-Ray Emission) Setup

22. X-ray Production Steps –Charge particle is accelerated –Enters surface of material –Interacts using electromagnetic force with tightly bound electron Ejection of electron No ejection if very low energy –Electron leaves inner shell –Electrons drop to fill lower shell Production of X-ray Production of auger electrons

23. Van Willey Columbia High School van.willey@cbisd.com Lin Shao Department of Nuclear Engineering Texas A&M University lshao@ne.tamu.edu Lloyd Price Texas A&M University USRG 2011 lloydmprice@gmail.com Thank you!