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National Research Centre” Kurchatov Institute”. European Organization for Nuclear Research. DPA calculations in irradiated graphite collimator materials under 7 TeV and 450 GeV proton beams. A.I.Ryazanov , E.V.Semenov and A.Ferrari. 0 6 .03.2015, CERN , Geneva , Switzerland.
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National Research Centre” Kurchatov Institute” European Organization for Nuclear Research DPA calculations in irradiated graphite collimator materials under 7TeV and 450 GeV proton beams A.I.Ryazanov, E.V.Semenov and A.Ferrari 06.03.2015, CERN, Geneva, Switzerland
Energy flux of secondary protons formed in graphite at different distances along the beam of 7 TeV protons 2 06.03.2015, CERN, Geneva, Switzerland
Energy flux of secondary electrons formed in graphite at different distances along the beam of 7 TeV protons 3 06.03.2015, CERN, Geneva, Switzerland
Energy flux of secondary charged pi-mesons formed in graphite at different distances along the beam of 7 TeV protons 4 06.03.2015, CERN, Geneva, Switzerland
Cumulative energy flux of secondary neutrons formed in graphite at different distances along the beam 7 TeV protons 5 06.03.2015, CERN, Geneva, Switzerland
Displacement cross-section - Differential cross-section of secondary particles (neutrons and others) with kinetic energy E to interact with target graphite atom, that will have energy T. ν (T) is the cascade function (number of collisions created by primary knock-on atom with energy T), i is the index of summation over various nuclear reaction channels. 6 06.03.2015, CERN, Geneva, Switzerland
Cascade function -displacement energy, - Bohr radius, and are atomic masses of incident and target atoms, respectively, and are atomic numbers of incident and target atoms, respectively, 8 06.03.2015, CERN, Geneva, Switzerland
The crystal structure of graphite showing theABAB stacking sequence of graphene planes in whichthe carbon atoms have threefold coordination. The value of Edlies between 24 and 60 eV. (Ed =25eV) 06.03.2015, CERN, Geneva, Switzerland
Differential cross-section of electrons and charged pions McKinley and Feshbach formula for low-Z materials 10 06.03.2015, CERN, Geneva, Switzerland
Displacement cross-section of secondary neutronsformed in graphite under 7 TeV proton beam irradiation 11 06.03.2015, CERN, Geneva, Switzerland
Displacement generation rate of point defect production Gd = np is the total number of protons in a bunch(1.1*1011), τ is the time gap between bunches (26 ns), Ф(Е) is the energy spectrum of secondary particles having energy E and interacting with graphite atoms, σd (E) is the cross section of defect formation with the secondary particle energy E. 12 06.03.2015, CERN, Geneva, Switzerland
Displacement rate of DPA produced by secondary protons at different distances along the beam of 7 TeV protons per each bunch 13 06.03.2015, CERN, Geneva, Switzerland
Displacement rate of DPA produced by secondary pions at different distances along the beam of 7 TeV protons per each bunch 14 06.03.2015, CERN, Geneva, Switzerland
Displacement rate of DPA produced by secondary neutrons under 7 TeV proton beam irradiation per each bunch 15 06.03.2015, CERN, Geneva, Switzerland
The spectrum of pions (π-) produced in graphite at different distances along the beam of 450 GeV protons (FLUKA) 16 06.03.2015, CERN, Geneva, Switzerland
Displacement cross sections for secondary pions with energies up to 450 GeV in graphite 17 06.03.2015, CERN, Geneva, Switzerland
Cross section of defect formation for secondaryπ–mesons in graphite near 450 GeV proton beam
Generation rate of primary radiation point defects (DPA) in graphite versus energy of pions at different distances along the beam of 450 GeV protons per each bunch 19 06.03.2015, CERN, Geneva, Switzerland
The spectrum of secondary relativistic electrons produced in graphite at different distances along the beam of 450 GeV protons (FLUKA) 20 06.03.2015, CERN, Geneva, Switzerland
Displacement cross sections for secondary electrons with energies up to 450 GeV in graphite 21 06.03.2015, CERN, Geneva, Switzerland
Generation rate of primary radiation point defects (DPA) in graphite versus energy of secondary electrons at different distances along the beam of 450 GeV protons per each bunch 22 06.03.2015, CERN, Geneva, Switzerland
Energy spectra of secondary neutrons formed as a resultof interaction of 450 GeV proton beam with graphitealong beam axis 23 06.03.2015, CERN, Geneva, Switzerland
Generation rate of point defect formation (DPA) under irradiation by secondary neutrons along axis of 450 GeV proton beam 24 06.03.2015, CERN, Geneva, Switzerland
Conclusion • Maximum of displacement rates for 7 TeV protons correspond to the following secondary particles: • Protons – 0.012 dpa/s per proton bunch • Pions – 0.11 dpa/s per proton bunch • Neutrons – 0.018 dpa/s per proton bunch • Maximum of displacement rates for 450 GeV protons correspond to the following secondary particles: • Electrons – 4e-3 dpa/s per proton bunch • Pions – 4.3e-3 dpa/s per proton bunch • Neutrons – 4e-3 dpa/s per proton bunch 25 06.03.2015, CERN, Geneva, Switzerland