[1199] | 1 | Prepared by R.Kokoulin, May 22nd, 2000 |
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| 2 | |
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| 3 | Brief summary of G4 muon activity, May 2nd - May 23rd, 2000 |
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| 4 | S.Kelner, R.Kokoulin, M.Maire, A.Rybin, L.Urban |
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| 5 | |
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| 6 | 1. G4 muon tests |
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| 7 | The test procedure of the verification of muon interaction simulation which allows to check |
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| 8 | both mean free path calculation and energy transfer sampling has been suggested and |
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| 9 | implemented. |
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| 10 | First test results revealed appreciable deviations of the distributions of the energy loss from |
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| 11 | theoretical dependencies (for bremsstrahlung, pair production, nuclear interaction). Several bugs |
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| 12 | have been found and eliminated; it has greatly improved the agreement. |
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| 13 | The program of further G4 muon tests has been prepared and agreed, including thin target |
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| 14 | tests (extending the set of materials, energies, and increasing statistics), and thick target |
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| 15 | simulation which will allow to verify the consistency of consideration of restricted continuous |
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| 16 | energy loss. |
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| 17 | |
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| 18 | 2. Refinement of the processes already implemented |
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| 19 | Simple formulae and algorithm for sampling photon and muon angles in muon |
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| 20 | bremsstrahlung have been suggested and prepared for implementation in G4. It will be coded in |
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| 21 | the nearest days. |
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| 22 | Final states for other processes (pair production, photonuclear interaction) have been |
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| 23 | clarified, fixed and introduced into documentation. |
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| 24 | Logical scheme of a consistent inclusion of bremsstrahlung correction in high-energy knock- |
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| 25 | on electron production and ionisation energy loss is prepared. |
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| 26 | List of questions concerning the validity of multiple scattering model has been compiled. |
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| 27 | After answering these questions, the "calibration" simulation of MCS for high-energy muons can |
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| 28 | be performed. |
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| 29 | |
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| 30 | 3. Documentation |
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| 31 | Sections concerning three basic muon interaction processes (bremsstrahlung, pair production, |
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| 32 | photonuclear interaction) for PRM (Phys. Ref. Manual) have been extended, updated and |
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| 33 | corrected. |
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| 34 | Suggestions for improvements for the section in PRM about muon ionisation, and also |
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| 35 | comments and corrections for "Electromagnetic Physics" gallery have been prepared. |
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| 36 | |
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| 37 | 4. Extension of the muon interactions in G4 |
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| 38 | List of muon processes for further inclusion in G4 has been discussed. The processes of |
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| 39 | interest are: muon pair production by photon, muon pair production by muon, diffractive |
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| 40 | bremsstrahlung (which leads to a difference in positive/negative muon energy loss). Refinement |
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| 41 | of multiple scattering and introduction of the screening correction to bremsstrahlung and pair |
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| 42 | production based on recent calculations of radiation logarithm in HF model are also important |
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| 43 | and can improve the accuracy of G4-based simulations. The level of theoretical knowledge of |
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| 44 | these processes is sufficient for their implementation into algorithms and codes. |
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| 45 | Theoretical clarification of LPM and Coulomb corrections for electron pair production by |
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| 46 | muons is needed; these are important both for accelerator and high-energy cosmic ray |
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| 47 | applications. |
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