S. Guatelli, J. Brown, S. Incerti, V. Ivanchenko, L. Pandola Geant4 Collaboration Workshop 2015
K. Amako et al, IEEE TNS, 52(4), 910- 918, 2005. Comparison of ◦ Attenuation coefficients Stopping Power and Range of e - , p and With respect to NIST The project is to have systematic regression tests on gamma ray processes trunk/verification/electromagnetic/atten ◦ uation
Elements to test: Be (Z=4), C(Z=6), O(Z=8) ,Al (Z=13), Ar (Z=18), Ca (Z=20), Fe(Z=26), Cu(Z=29), Ge (Z=32), Ag (Z=47), Xe (Z=54), Ce(Z=58), Gd (Z=64), W(Z=74), Au(Z=79), Pb (Z=82), Bi (Z=83), U(Z=92) Compounds to test: Water, BGO, PMMA, other plastic phantoms used in radiotherapy Quality Assurance Attenuation coeff. to test ◦ Total ◦ Rayleigh scattering ◦ Photoelectric effect ◦ Compton scattering ◦ Gamma conversion
User application ◦ Calculate attenu nuati tion on coeffic fficients ients ◦ The cut is fixed 1/10 of the target thickness ◦ Physics cs lists: - EMStandard_opt0 Photon beam - EMStandard_opt3 - EMStandard_opt4 - Livermore - Penelope o Same simulation parameters for the alternative physics lists o Comparison: % % differ eren ence ce: abs((NIST- Geant4/NIST)*100) x 𝑂 = 𝑂 0 𝑓 −μ𝑦 o Regress gression ion testin ing: G4 10.0 and 10.1
Reference NIST data have 1-5% error Z Rayl yl Phot otoel oel Compto ton Conv nvers ersion ion Tota tal 4 Livermore and Livermore: x Livermore: x Livermore:x Livermore:x Penelope: 1 Penelope: x Std_opt4 : x Penelope: x Penelope: x and 1.5 keV, Std_opt0 and opt3: diff Penelope: E< ~5 keV Std_opt3: x Std_opt0: 4 keV-40 then ok 3 keV <E < 1MeV Std_opt0 and opt3: E< Std_opt4:x keV Std_opt4: x 6 keV Std_opt3: 4 keV-10 keV Std_opt4:x 13 Livermore: 1- Livermore: x Livermore: x Livermore:x Livermore:x 8 keV Penelope: x Penelope: 1 keV- 10 Penelope: x Penelope: x Penelope: 1-8 Std_opt0: x keV Std_opt0:x Std_opt0: 15 keV<E< keV Std_opt3: x Std_opt3 and opt0: Std_opt3: x 150 keV Std_opt4: x 1keV- 15 keV Std_opt4: x Std_opt3: x Std_opt4: x Std_opt4:x 20 Livermore and Livermore: x Runnin ing Livermore:x Livermore: x Penelope: Penelope: x opt3 Penelope: x Penelope: x below 15 keV Std_opt0 and opt3: 1-3 Std_opt3: x Std_opt0: 30 keV-200 MeV Std_opt0:x keV Std_opt4: x Std_opt4: x Std_opt3: x Just first point for Std_opt4: x penelope, opt0, opt3 and opt4 26 Livermore and Livermore: x Livermore: x Livermore:x Livermore: x Penelope: Penelope: x Penelope: E< 8 keV Penelope: x Penelope: x below 20 keV Std_opt0:x Std_opt3 and opt0: E< Std_opt0:x Std_opt0: 40 keV- Std_opt3: x 10 keV Std_opt3: x 200keV Std_opt4: x Std_opt4: x Std_opt4: x Std_opt3: x Std_opt4: x 32 Livermore and Livermore: x Livermore: x Livermore:x Livermore: x Penelope: Penelope: x Penelope : 1keV< E< Penelope: x Penelope: x below 40 keV Std_opt3 and opt0: 20 10 keV Std_opt3: x Std_opt0: 50 keV – MeV-1GeV Std_opt3 and opt0: 1 Std_opt4: x 300 keV Std_opt4: x keV < E< 10 keV Just first point for Std_opt3: x Std_opt4: x penelope, opt0, Std_opt4: x opt3 X: agreement within 5% red: differences > 5 %
green: differences < 5% red: differences > 5% Reference NIST data have 1-5% error Z Rayl Photoe toele lectric tric Compton on Conve vers rsion ion Total 47 Livermor Livermore: x Livermore: x Livermore:x e: x Penelope: x Penelope: E < 8 keV Penelope: x Livermore: x Penelope: Std_opt4: x Std_opt0: diff up to 10% E< 5 keV Std_opt0:x Penelope: x x Std_opt3: diff up to 10% E< 5 keV Std_opt3: x Std_opt0: 15 keV- Std_opt0 and std_ opt3 Std_opt4: x Std_opt4: x 300keV up to 10% differences between 5% Std_opt3: x and 20% for E> ~ 50 Std_opt4: x MeV 74 Livermor The statis istic tic needs to Livermore: x running Livermore: x e: be improve oved d : runnin ing Penelope: E < 20 keV Penelope: x different Std_opt0: E< 10 keV Std_opt0: 15 keV- Penelope: Std_opt3: E< 10 keV 600keV up to 10% different Std_opt4: x Std_opt3:1 keV-10 keV Std_opt4: x 79 runnin ing runnin ing Livermore: x Livermore:x Livermore, Penelope and Penelope: E < 20 keV Penelope: x opt4 liv: 2.248 keV and Std_opt0: E< 1.5 keV Std_opt0:x 2.507 keV (values just Std_opt3: E< 1.5 keV Std_opt3: x after the M edges) Std_opt4: x Std_opt4: x opt0: 1 keV – 600 keV: differences > 5% opt3: 1 keV – 5 keV differences > 5%
Reference NIST data have 1-5% error Material ial Rayl Photoe toele lectric tric Compton on Conve vers rsion ion Total s Water Livermore: < Livermore: x Livermore: x Livermore: x Livermore: x 5 keV Penelope: x Penelope: E < Penelope: x Penelope: x Penelope: < Std_opt0: x 10 keV Std_opt3: x Std_opt0: x 5 keV Std_opt3: x Std_opt0: E< Std_opt4: x Std_opt3: x Std_opt4: x 10 keV Std_opt4: x Std_opt3: E< 10 keV Std_opt4: x BGO Runnin ing g Livermore: x runnin ing Livermore: x Livermore: x liver ermore ore Penelope: x Penelope: x Penelope: x Std_opt0: 1keV – 5keV Std_opt3: x Std_opt0: 1 keV – 4 keV and 40 keV – 500 Std_opt3: 1keV – 5keV Std_opt4: x keV Std_opt4: x Std_opt3: 1keV – 5 keV Std_opt4: x green: differences < 5% red: differences > 5%
In the last year, added: ◦ New materials ◦ Rayleigh scattering ◦ Regression test ◦ Standard_option0 Regression test: Geant4 10.1 agrees with Geant4 10.0 within statistical error bars. In general good agreement with NIST (within 5%, which is the NIST uncertainty). Penelope approach, Standard Option 0 and 3 Compton scattering report differences below ~20 keV, where this process is negligible
Significant differences observed. % Difference Geant4-NIST NIST uncertainty (5%) Be Ca W % Difference Livermore Penelope The continued lines are the statistical uncertainties of Geant4 simulations ( green: Penelope, black: Livermore)
Livermore Rayleigh scattering model is different from NIST. ◦ This is known for Livermore approach K. Amako et al, IEEE TNS, 52(4), 910-918, 2005. To be investigated for Penelope, however Penelope and Livermore seem to agree NIST Further investigation required EPDL97 (Livermore approach)
Finish the materials Repeat with next Geant4 public release. ◦ The tests have been automatised from execution to analysis. ◦ The tests are ran on UOW High Performance Computing Facility ( ~ 100 CPUs available per day) Statistical analysis to do (Chi-squared, Kolmogorov- Smirnov)
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