1. Duncan Weathers Department of Physics University of North Texas

2. Outline Introduction Typical utilization of the program Sampling of available experiments Using an MeV ion accelerator Using radioactive sources Past participants

3. Introduction What is the Visiting Students and Faculty Program? Brings students and their instructors to UNT to do advanced laboratory exercises in nuclear and atomic physics Utilizes the advanced facilities and capabilities available in the Ion Beam Modification and Analysis Laboratory (IBMAL) Directed principally at programs with limited advanced laboratory opportunities Has garnered NSF support for equipment Visiting schools provide travel support Has been operating for more than two decades

4. IBMAL Ion Beam Modification and Analysis Laboratory Five faculty members 1-2 post-docs 10 graduate students Active research program in accelerator-based physics, principally in materials characterization and modification Equipped with 3 MV tandem, 2.5 MV Van de Graaff, 200 kV Cockcroft-Walton ion accelerators, and an array of detectors, radioactive sources, and nuclear electronics

5. IBMAL

6. A Typical Visit Instructor selects labs and prepares students in advance Instructor and a group of 6 or 7 students travel to UNT on Thursday Students conduct measurements all day Friday, Saturday, and possibly Sunday May complete as many as 6 different exercises UNT graduate students and faculty operate accelerator and oversee experimental set-up Two experiments may run at once, with group divided between them Students are rotated through tasks so that everyone participates Group returns home to finish laboratory reports

7. Experiments Using an MeV Ion Accelerator Rutherford backscattering analysis Particle-induced x-ray emission analysis Nuclear reaction analysis

8. Experiments Using Radioactive Sources Gamma-ray spectroscopy using NaI(Tl) Gamma-ray spectroscopy using HpGe X-ray fluorescence Energy loss of alpha particles in matter Annihilation radiation coincidence studies with 22 Na Neutron activation analysis

9. Rutherford Backscattering Analysis Objectives Determine thicknesses of thin samples Investigate energy dependence of cross section and kinematic factor Investigate angular dependence of cross section and kinematic factor

10. The 2.5 MV Van de Graaff Accelerator

11. Rutherford Backscattering Analysis Setup

12. Rutherford Backscattering Analysis Results He on Cu

13. Rutherford Backscattering Analysis Results He on Cu

14. Rutherford Backscattering Analysis Results

17. Particle-Induced X-Ray Emission Analysis Objectives Calibrate detector Identify unknown target materials Determine thicknesses of thin samples

18. PIXE Detector

19. PIXE Results 1.25 MeV He on In

20. PIXE Results 1.25 MeV He on In

21. Nuclear Reaction Analysis Objectives Measure thicknesses of samples Investigate energy dependence of cross section

22. Nuclear Reaction Analysis Results 11 B(p,  ) 8 Be

23. Gamma Ray Spectroscopy Using NaI(Tl) Objectives Calibrate detector Identify unknown sources Identify typical spectral features Measure detector resolution Measure source activity Measure mass absorption coefficient for lead

24. Gamma Ray Spectroscopy Using NaI(Tl) Set-up NaI(Tl) Photo- multiplier PreampAmplifier MCA/ Computer Bias Power Supply Source

25. Gamma Ray Spectroscopy Using NaI(Tl) Detector

26. Gamma Ray Spectroscopy Using NaI(Tl) Results Photopeak 1 Photopeak 2 Sum Peak Backscatter Lead x-ray Compton Edge

27. Gamma Ray Spectroscopy Using NaI(Tl) Results Photopeak 1 Photopeak 2 Sum Peak Backscatter Lead x-ray Compton Edge 60 Co

28. Gamma Ray Spectroscopy Using NaI(Tl) Results Photopeak 1 Photopeak 2 Sum Peak Backscatter Lead x-ray Compton Edge

29. Past Participants Average of approximately five groups per year Participating schools include: Abilene Christian U.Texas Christian U. Austin CollegeTexas Southern U. Centenary College of LousianaTexas Woman’s U. Rice U. U. of Central Arkansas Sam Houston State U.U. of Louisiana at LaFayette Southeastern Oklahoma State U.U. of the South Southern Methodist U. U. of Texas at El Paso Tarleton State U.Western Kentucky U. Incidental benefit of program: six students have come to graduate school at UNT

31. Acknowlegements Special thanks to Jerry Duggan Mangal Dhoubhadel Lucas Phinney Contact information: weathers@unt.edu