Development of Position Sensitive Detector Jong-kyu Cheon Radiation Physics Lab.
Contents Interaction of Radiation and Materials Process of PSD measurements Construction of Electronics Advantage & Disadvantage Some application Plan for future
Interaction of Radiation(gamma ray or X-ray) and Materials - Photo-electric effects - Compton scattering - Pair production E[Mev] Z P.E C.S P.P Produce electrons!
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
Thermal Neutron Detection Materials 3 He + n 3 H + p MeV 6 Li + n 3 H+ 4 He MeV 10 B + n 7 Li* + 4 He MeV(94%) 7 Li + 4 He MeV(6%) 157 Gd + n Gd* + ( MeV) 235 U + n fission fragments + ~80MeV 239 Pu + n fission fragments + ~80MeV
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
Fabrication of PSD
1D Neutron PSD Neutron Monitor 1D & 2D X-ray PSD2D Large Neutron PSD
Construction of Electronics PSD PreAmp. Discriminator Time to Digtal Converter PC Matching impedance Analog to Logic sig. Find timing between 2 signal High Voltage
Advantage & Disadvantage Advantage Measure diffraction pattern at once. experiment more quickly. Disadvantage Expensive system
Some Applications Small Angle X-ray Scattering at Pohang Light Source Small Angle X-ray Scattering of Chicken tendon
X-ray diffraction patterns of polyprophilene
Plan for future HIPD(High Intensity Powder Diffractometer) - Integrated 8 PSD Curved PSD PSD system, For High Speed Signal Processing.
The end