1. Development of Position Sensitive Detector Jong-kyu Cheon Radiation Physics Lab.

2. Contents Interaction of Radiation and Materials Process of PSD measurements Construction of Electronics Advantage & Disadvantage Some application Plan for future

3. Interaction of Radiation(gamma ray or X-ray) and Materials - Photo-electric effects - Compton scattering - Pair production 10.110100 E[Mev] Z P.E C.S P.P Produce electrons!

4. X-ray Detection Materials All kinds of material can be used in X-ray detection(cross-section depend on atomic number) Main gases for X-ray detection  Ar(w= 26eV), Kr(w= 24eV), Xe(w=22eV) Quenching gases  CH 4, CO 2, C 2 H 6, C 3 H 8

5. Thermal Neutron Detection Materials 3 He + n  3 H + p + 0.77 MeV 6 Li + n  3 H+ 4 He + 4.79MeV 10 B + n  7 Li* + 4 He +2.31 MeV(94%)  7 Li + 4 He + 2.79 MeV(6%) 157 Gd + n  Gd* +  (0.07-0.18MeV) 235 U + n  fission fragments + ~80MeV 239 Pu + n  fission fragments + ~80MeV

6. Process of measurements by Delay line Detector Anode wires applied HV Cathode (collect cations) Incident beam (X-ray, Neutron, etc) + - + - + - + - Ionization of gas atoms Electron avalanche +++ + + + + + + Measure the timing between 2 signals to find position of beam

7. Fabrication of PSD

8. 1D Neutron PSD Neutron Monitor 1D & 2D X-ray PSD2D Large Neutron PSD

9. Construction of Electronics PSD PreAmp. Discriminator Time to Digtal Converter PC Matching impedance Analog to Logic sig. Find timing between 2 signal High Voltage

10. Advantage & Disadvantage Advantage Measure diffraction pattern at once. experiment more quickly. Disadvantage Expensive system

11. Some Applications Small Angle X-ray Scattering at Pohang Light Source Small Angle X-ray Scattering of Chicken tendon

12. X-ray diffraction patterns of polyprophilene

13. Plan for future HIPD(High Intensity Powder Diffractometer) - Integrated 8 PSD Curved PSD PSD system, For High Speed Signal Processing.

14. The end