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Mary Tsagri Home Country: Greece

Mary Tsagri Home Country: Greece. Past background: Education: Physics Degree Graduation: September 2008 – University of Patras, Greece Diploma thesis on Astroparticle Physics:

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Mary Tsagri Home Country: Greece

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  1. Mary Tsagri Home Country: Greece MC-PAD Midterm Review Past background: Education: Physics Degree Graduation: September 2008 – University of Patras, Greece Diploma thesis on Astroparticle Physics: “Astrophysical Signatures For Axion or Axion-like Particles – A Summary” CERN Summer Student, June - September 2008 Summer Student at Max-Planck-Institut für Plasmaphysik (IPP), September 2008 CAST experiment at CERN since July 2007 Present status: Start Date: December 2008 Host institute: CERN MC-PAD project: P12 (ESR) “Optimization of Monte Carlo Tools and Comparison with Benchmark Data” Supervisor: Dr. John Apostolakis Thesis advisor and University: Prof. Els Koffeman – University of Amsterdam

  2. Introduction:Geant4 / Garfield: An Interface MC-PAD Midterm Review • Simulation of neutrons (Geant4) and the deposit of secondary γ's and charged particles (Garfield) • Significant neutron background in many LHC and sLHC detector experiments • Need to model the impact of neutrons on the performance of gaseous detectors

  3. Technical Progress • A. Validation of neutron cross sections in noble gases • Aim: Improve the performance and reliability of Geant • Comparison of Geant4 and established databases MC-PAD Midterm Review • B. Validation of Low Energy EM physics models

  4. Natural composition of Argon Elastic XS MC-PAD Midterm Review Geant4: Red JEF-2.2: Black JEFF-3.0: Green ENDF/B-VII.0: Blue JEFF-3.1: Purple Non-elastic XS • Agreement between Geant4and the: JEF 2.2 / JEFF 3.0libraries at all energy regions. Differences of the factor 2-20 with “new” libraries • Results are available also for: Ca, He, H, Kr, • O and Xe. Geant4 follows JEF-2.2 library for • most elements. • Moreover, neutron cross sections from • recent libraries are being prepared. Rad. Capture XS

  5. Technical Progress A. Validation of neutron cross sections in noble gases MC-PAD Midterm Review • Validation of Low Energy EM Physics Models in gaseous detectors (Geant4, HEED & FLUKA) • Non Elastic Scattering of neutrons emits γ's and charged particles. • Standard EM in Geant4 emits no secondaries < ~1 keV • Low energy EM in Geant4 include: atomic/molecular quantum effects • (inner shell ionization, emission of Auger e- and fluorescence γ, etc.)

  6. Ionization Energy Loss 1 MeV e- in 1.5 cm of natural Argon ? MC-PAD Midterm Review G4_emstandard_opt3G4_emlivermore G4_PAI HEED_PAIR • Overall shape of the ionization loss spectra is in good agreement • Livermore model should not be used in the energy range 1MeV - 5GeV, due to lack of data • Found a shoulder in Geant4 and we are investigating it together with experts

  7. Comparison between Geant4, HEED and FLUKA e- : 500MeV/c in natural Argon Red: Geant4: <Energy> : 4.45 keV Blue: HEED: <Energy> : 4.13 keV Green: FLUKA: <Energy> : 4.17 keV MC-PAD Midterm Review • General features: rather similar making the identification of the “shoulder” mandatory • In search of beam data (a micromegas detector with appropriate thickness and good • energy resolution (~20%) in a high energy beam)

  8. Attended Trainings / Meetings: MC-PAD Midterm Review Network Training Events: • 1st Training Event on Electronics, AGH Cracow - September 2009 • 2nd Training Event on Detector Simulation and Data Analysis, DESY Hamburg - January 2010 • 3rd Network Training Event on Processing and Radiation Hardness of Solid State Detectors, Ljubljana - September 2010 • MC-PAD KICK-OFF Meeting, CERN - January 2009

  9. Attended Trainings / Meetings: MC-PAD Midterm Review Schools / Courses: • École Geant4,Annecy, France, November 2008 • 8thFluka Course, Demokritos, Athens, Greece, March 2009 • Topical lectures on SUSY models, Nikhef, Amsterdam, December 2009 • C++ Part 1 - Hands-On Introduction, CERN, October 2009 • C++ Part 2 - Object-Oriented & Generic Programming, CERN, November 2009 • 1st EIROforum School on Instrumentation, CERN, May 2009 • General and Professional French Courses, Geneva Workshops / Meetings: • 6th Geant4 Space User's Workshop, Madrid, Spain, May 2009 • RD51 mini week, CERN, February 2010

  10. Dissemination: MC-PAD Midterm Review • Internal note for university of Amsterdam, December 2009 • ~ 20 reports/updates in team meetings • Presentation in RD51 Mini Week at CERN, February 2010 • Posters (Uploaded in Activity Log): 1. 1st Training Event on Electronics, AGH Cracow – September 2009 2. Marie Curie Poster Exhibition "Training for Europe”, CERN, September 2010

  11. Milestones/deliverables: MC-PAD Midterm Review

  12. Thank you MC-PAD Midterm Review

  13. Backup Slides … MC-PAD Midterm Review

  14. Interaction of neutrons with matter A. Elastic Scattering • Energy of recoiling nucleus absorbed by medium. B. Non Elastic Scattering • Energy of recoiling nucleus absorbed by medium. nucleus Total Energy Unchanged neutron MC-PAD Midterm Review γ-ray ⇝ nucleus Radiative Capture simple transmutation neutron Inelastic Scattering (> ~1 MeV) intermediate excited state γ-ray ⇝

  15. Validation of neutron cross sections for noble gases ALICE TPC • Neutron energies of interest: • Thermal neutrons up to 20 MeV • These are the energies most relevant to the physical • background in LHC and sLHC experiments • e.g. ATLAS : ~ 1014 n/cm2/year = 107 n/cm2/sec • Slow neutron flux: ~ 109 n/cm2/sec for L=1034 /cm2/sec • Compared Geant4 code with established databases • (ENDF, JEFF, JENDL) using JANIS Software Package. • http://www.nea.fr/janis/ MC-PAD Midterm Review http://tuprints.ulb.tu-darmstadt.de/epda/000690/thesis_part3.pdf “Neutrons - scatter off nuclei ...just like WIMPs!”

  16. 500 MeV/c e- in 1.5 cm of Ar:CO2 [80:20] MC-PAD Midterm Review G4_emstandard_opt0 G4_emstandard_opt3 G4_emlivermore G4_empenelope G4_PAI HEED_PAI HEED_PAIR

  17. MC-PAD Midterm Review doi:10.1016/0029-554X(76)90626-1

  18. Definition of reaction types (MT Numbers): 1 (n,total) Neutron total cross section 2 (z,z0) elastic 3 (z, non-elastic) Nonelastic neutron cross section. Sum of MT=4, 5, 16-18, 22-26, 28-37, 41-42, 102-116 22 (z,na) The cross section for the production of a neutron and alpha particle plus a residual. 4 (z,n) Cross section for the production of one neutron in the exit channel. Sum of the MT=50-91. 16 (z,2n) Cross section for producing two neutrons and a residual. 17 (z,3n) Cross section for producing three neutrons and a residual 102 (z,y) Radiative capture cross section. 50 (y,nO) The cross section for the production of a neutron, leaving the residual nucleus in the ground state. 51 (z,nl) Cross section to the first excited state of the residual nucleus. 5 (z,anything) The cross section for the sum of all reactions not given explicitly in another MT number. 10 (z,continuum) Total continuum cross section. This sum cross section includes all continuum reactions and excludes all 33 (z,nt) Cross section for the production of one neutron and one triton plus a residual . . . ( …851 MT numbers) MC-PAD Midterm Review

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