(3) Interaction of high energy photons with matter - LUTH

More documents

Recommendations

Info

a little excursion: Feynman diagrams Introduction to Feynman diagrams: http://www2.slac.stanford.edu/vvc/theory/feynman.html Compton scattering calculation: http://www.phys.ualberta.ca/~gingrich/phys512/latex2html/node102.html A. Zech, Instrumentation in High Energy Astrophysics 22
Pair Production in photon-photon collisions (1) Another important mechanism for e + -e - pair production occurs when a photon of very high energy interacts with an ambient photon (extragal. background light, starlight, CMB...). What is the threshold energy required for this process ? We assume that two photons collide and produce a particle-antiparticle pair at rest: k = [ 1 1 c , 1 c i1 ] ; k2 = [ 2 c , 2 c i2 ] ; p1 = [m c,0] ; p = [mc ,0] 2 We use 4-momentum conservation and the following scalar identities: Thus: k 1 ⋅k 1 = k 2 ⋅k 2 = 0 p 1 ⋅p 1 = p 2 ⋅p 2 = p 1 ⋅p 2 = m 2 c 2 k 1 k 2 = p 1 p 2 k 1k 2 2 = p 1p 2 2 k 1 ⋅k 1 2k 1 ⋅k 2 k 2 ⋅k 2 = p 1 ⋅p 1 2p 1 ⋅p 2 p 2 ⋅p 2 A. Zech, Instrumentation in High Energy Astrophysics 23
Page 1 and 2: (3) Interaction of high energy phot
Page 3 and 4: Photoelectric Absorption Edges The
Page 5 and 6: Compton Scattering The Compton effe
Page 7 and 8: Thomson and Compton scattering cros
Page 9 and 10: Thomson and Compton scattering cros
Page 11 and 12: Compton scattering - energy transfe
Page 13 and 14: Inverse Compton Scattering A. Zech,
Page 15 and 16: Inverse Compton Scattering - energy
Page 17 and 18: Electron-Positron Pair Production -
Page 19 and 20: Electron-Positron Pair Production i
Page 21: Electron-Positron Pair Production i
Page 25 and 26: Pair Production in photon-photon co
Page 27 and 28: Comparison of photon cross-sections
Page 29 and 30: Excitation of Resonances - the GZK
Page 31 and 32: Proportional Counters & Geiger Coun
Page 33 and 34: Delta Rays The generation of second
Page 35 and 36: Mass Spectrometer Mass spectrometer
Page 37 and 38: Time Projection Chamber (TPC) The m
Page 39 and 40: Spark Chambers (2) A. Zech, Instrum
Page 41 and 42: Semiconductors as Solid State Detec
Page 43 and 44: Semiconductors (2) - pn-junctions f
Page 45 and 46: Recording with a three-phase CCD: C

(3) Interaction of high energy photons with matter - LUTH

Create successful ePaper yourself

Delete template?

Save as template?