Laboratório de Raios Cósmicos Prof. Fernando Barão. Apresentação do: LRCsimulator. Gonçalo Guiomar Miguel Orcinha

Transcription

1 Laboratório de Raios Cósmicos Prof. Fernando Barão Apresentação do: LRCsimulator Gonçalo Guiomar Miguel Orcinha

2 0. Plan for the presentation Scintillator Study Trapezoid Study Cosmic-ray Air Shower Study LRCsimulator Physics simulation framework based on root Graphics User Interface

3 LRCsimulator Development

4 1. Planing of the LRC simulator ROOT Requirements Geometry Material Properties Particle Tracking Particle Storage Event Display ROOT Framework Geometry Implementation Geometry Tracking Algorithm Track Visualization Histogram Manipulation and Plot Statistical Analysis

5 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Using ROOT geometry package: LRCscintillator Hamamatsu PMT R580 PMMA 100 cm x 50 cm x 1 cm LRCtelescope 3 x Scintillator 1 Cerenkov Tank Phillips PMT XP2020 LRCarray 3 x Scintillator Positions: (0,0,0), (10,0,0) (0,10,0)

6 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Detector Efficiency vs Sci Emission Absorption Coeff vs Sci Emission Reflectivity

7 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCphysProperties (Physical Properties Library) Refraction Index Scintillation Emission Absorption Coefficient Detector Efficiency Reflectivity Specularity Coef Diffusion Angle LMCmatProperties (Pointer Linking Library) LMCmaterials (Creates and links the materials) TGeoMaterial Cerenkov Properties LMCgeomN (Geometry Creator) TGeoNode TGeoVolume TGeoMaterial

8 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCgeomN (geometry) TGeoManager (geometry management tool) Monte Carlo (i.e. direction, impact) TParticle (particle storage tool) LMCpropagator (main propagation) PropParticle PropOpticalPhoton User Commands (i.e. verbose, tracking) LMCsteps (trajectory storage tool)

9 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Monte Carlo TParticle LMCpropagator (main propagation) TGeoMaterial Who are you? Particle properties (m, q, E, v, p...) Where are you? Physical processes inside that node (dedx, Cer, Det...) Are you crossing a boundary? Where to? Boundary interaction (Ref, Tra, Abs...)

10 Geometry Material Properties Particle Tracking Trajectory Storage Event Display PropParticle (until particle leave geometry) Coarse Stepping Fine Stepping

11 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Scintillation (Monte-Carlo) γ

12 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Photon Absorption (Monte-Carlo)

13 Geometry Material Properties Particle Tracking Trajectory Storage Event Display PropOpticalPhoton (just for optical photons) Transmission Specular Reflection Non-specular Reflection θ i θ i θ r θ i θ rand θ t

14 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Conductor Reflectivity Hecht, Optics (2002)

15 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCstep (propagation storage tool) Initial and final point Initial energy Energy lost Secundary particles i -ΔE γ γ γ γ γ f Node Volume and material

16 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Trajectory Storage LMCevent LMCstep LMCparticle LMCstepsimple LMCtrack

17 1. Status - Implemented Physical Processes Interaction with matter Bethe-Bloch Cherenkov Radiation Optical Photons Reflection Transmission Absorption Non-Specular Reflection Materials Scintillation Absorption Reflectivity Specularity Coding philosophy Scalability

18 LRCscintillator Study

19 2. Scintillator Study Scintillator study: 1. Exposing the geometry to cosmic rays 2. Compilation of data (from the LMCsteps) 3. Data analysis

20 2. Scintillator Study Random Generation over Surface Simulation conditions: Scintillation detector 100 cm x 50 cm x 1cm PMMA BC480 Hamamatsu R580 PMT Muon Angular Distribution 5000 primaries Including propagation of secundaries (scintillation photons)

21 2. Scintillator Study PMMA Scintillation Spectrum

22 2. Scintillator Study Causes for efficiency Absorption

23 2. Scintillator Study PMMA Absorption and Propagation The PMMA absorption spectrum is the main (but not the only) cause for the optical path length of the photons.

24 2. Scintillator Study Reflections and Direct Collection

25 2. Scintillator Study Aluminium Reflectivity Hecht, Optics (2002)

26 2. Scintillator Study Aluminium Reflectivity The second contribution to photon absorption is aluminium absorption.

27 2. Scintillator Study Aluminium Reflectivity

28 2. Scintillator Study Aluminium Reflectivity Premature death!

29 2. Scintillator Study PMT Quantum Efficiency To increase simulation velocity, the quantum efficiency was applied to the scintillated photons before propagation to the PMT.

30 2. Scintillator Study Total Collected Signal

31 2. Scintillator Study Collection Signal Definitions: Represents the geometrical efficiency of the detector. It s the ratio between the number of photons that were detected versus all the photons that are detectable. Represents the TOTAL efficiency.

32 2. Scintillator Study Collection Efficiency Y (cm)

33 2. Scintillator Study Collection Efficiency X (cm)

34 2. Scintillator Study Detection Efficiency Y (cm)

35 2. Scintillator Study Results The simulation led us to the following results: Single particle sensitivity Efficiency has exponencial dependency on distance to PMT Very low efficiency LRCsim provides detailed information about the performance of a certain detector geometry

36 2. Scintillator Study Solutions We thought of some solutions for the shortcomings of the detector: Reduce the dimentions Increasing of direct detection Reduced the likelhood of absorption Change the configuration all together to include 2 detectors Remove systematic errors Reduce dark current detections Remove directional bias Does not remove position efficiency

37 2.1 Trapezoidal Geometry Study Why? The previous configuration has some issues: Its efficiency is dependent on the position of impact of the CR. A directional bias is created due to the position of the PMT. A lot of photons are lost due to the high number of reflections. Creating a simetric configuration increases the efficiency but it does not guarantee Creating an open geometry gives us a higher number of directly detected photons, reducing the photon absorption. Having two PMT s still allows us to eliminate the dependency on position Y (cm)

38 2.1 Trapezoidal Geometry Study Primary generation Simulation conditions: Scintillation detector 40 cm x 40 cm x 1cm PMMA BC480 2x Hamamatsu R580 PMT Base is light-difusive and top is specularly difusive. Muon Angular Distribution 5000 primaries With propagation of secundaries (scintillation photons)

39 2.1 Trapezoidal Geometry Study Scintillated Photons

40 2.1 Trapezoidal Geometry Study Collected Photons Some improvements: Radial symmetry in the collection of photoelectrons. Higher number of photoelectrons

41 2.1 Trapezoidal Geometry Study - Reflections

42 2.1 Trapezoidal Geometry Study Signal for each detector

43 2.1 Trapezoidal Geometry Study Geometric Efficiency

44 2.1 Trapezoidal Geometry Study Total efficiency

45 2.1 Trapezoidal Geometry Study Signal study

46 2.1 Trapezoid Study Results

47 2.1 Trapezoid Study Results We were able to conclude that: By changing the geometry, we can collect a larger number of photoelectrons. Efficiency is mostly flat Efficiency is higher than the Scintillator efficiency

48 GUI Graphical User Interface (event display)

49 GUI

50 GUI

51 GUI Graphics User Interface: 5 geometries already implemented Scalable to any number of geometries; Geometry explorer (Zoom and motion through root keybindings); Can show how the geometry is built in its logical volumes Able to perform real time simulation of propagation through a geometry, tracking both the primary and secondary particles. Simulations are configurable Primary: Energy lost, Cerenkov Secondary: Aluminium Absorption and selection of events per maximum lenght Information about the simulation is shown in a text box

52 GUI DEMO

53 LRCarray Study

54 3. LRCarray Study LRCarray study: 1. Atmosphere and first interaction 2. Parametrization of the shower 3. Dimensioning the problem 4. Running the simulation with the apropriate trigger 5. Data Analysis 6. Calculation of the rate of events detected 7. Influence of array dimension on the rate of events

55 3. LRCarray Study Shower Parametrization Depth Z X max h 0 θ X (depth)

56 3. LRCarray Study Shower Parametrization Cross Section arxiv:hep-ph/ arxiv:

57 3. LRCarray Study Shower Parametrization Cross Section 0 Z Z u l i θ Z i l

58 3. LRCarray Study Shower Parametrization Cross Section

59 3. LRCarray Study Shower Parametrization Cross Section

60 3. LRCarray Study Shower Parametrization Cross Section

61 3. LRCarray Study Shower Longitudinal Parametrization Greisen, K., Prog. Cosmic Ray Physics 3 (1965) 1.

62 3. LRCarray Study Shower Lateral Distribution K. Kamata, J. Nishimura, Prog. Theoret. Phys. Suppl. 6 (1958) 93. Dependencies Incidence angle (θ) Inicial energy (E i ) Age parameter (s) Radial simetry (r)

63 3. LRCarray Study Shower Parametrization Coordinates Z Z θ Z_align Z_align X Y Y X X_align Y_align ϕ

64 3. LRCarray Study Shower Parametrization Coordinates Z Z θ Z_plane Z_plane X Y_plane Y Y X X_plane ϕ

65 3. LRCarray Study Shower Parametrization Coordinates Y Y_impact Z ϕ P Core_Position X_impact Lab/Detector Frame X

66 3. LRCarray Study Shower Parametrization Coordinates Y_align Y Z Z_align ϕ ϕ P Core_Position Lab/Detector Frame X X_align

67 3. LRCarray Study Shower Parametrization Coordinates Shower Z_align X_plane θ P_align Y_align

68 3. LRCarray Study Shower Parametrization Coordinates Z_plane Z_align X_plane Z_align θ P_plane Y_plane ΔZ P_align Y_align

69 3. LRCarray Study Shower Lateral Distribution

70 3. LRCarray Study Shower Lateral Distribution

71 3. LRCarray Study Shower Lateral Distribution

72 3. LRCarray Study Array Dimensions 10 m 2 50 m 10 m

73 3. LRCarray Study Detector Size as a function of shower size

74 3. LRCarray Study Detector Size as a function of shower size

75 3. LRCarray Study Detector Size as a function of shower size

76 3. LRCarray Study Detector Size as a function of shower size All points are at d < 20m to any detector.

77 3. LRCarray Study Detector Size as a function of shower size Not Detected Detected

78 3. LRCarray Study Shower Size Study

79 3. LRCarray Study Simulation Conditions Simulation conditions Cosmic Ray Distribution Dimensions Exposed area: 2000 m x 2000 m Characteristic dimension: 10 m Trigger condition 1 particle on each detector Number of events 10 9 events 10 m 10 m 2 50 m

80 3. LRCarray Study Primary Generation

81 3. LRCarray Study Detection Map Total No flutuations R = 500 m No flutuations no angular dispersion

82 3. LRCarray Study Array Efficiency

83 3. LRCarray Study Array Efficiency Detailed Simulation

84 3. LRCarray Study Acceptance Calculation dωdacos(θ)

85 3. LRCarray Study Contributions

86 3. LRCarray Study Preliminary Results

87 3. Array Study Results

88 3. Array Study Results 20 m x 20 m

89 3. Array Study Comparison of arrays

90 3. Array Study Comparison of arrays Detector area diminshes with node distance.

91 3. Array Study Comparison of arrays The simulations led us to the following results: The scintillator detector sensitivity makes it a good candidate for node detector in the array; Our array of detectors allows for a big acceptance but introduces a cutoff energy for which Cosmic Rays with lower energy cannot be seen (depends on the trigger condition); The rate of events is highly dependent on low energy cosmic rays, due to their abundance at such energies; From the comparison of the 2 arrays we can see the dependence on node distance, increasing the distance between detectors does not increase detector size, it decreases it. The uncertainty at lower energies indicates a necessity for a longer simulation. Even though the number of events is large, the detector area in the lower regime e a lot smaller than the total area which makes those

92 Appendix A Code Implementations

93 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCscintillator Implementation

94 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCgeomN Implementation

95 Geometry Material Properties Particle Tracking Trajectory Storage Event Display Material Implementation

96 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCstep Class

97 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCstepsimple Class

98 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCtrack Class Z coord (5) Z sign (1) Y coord (5) Y sign (1) X coord (5) X sign (1) Inter (1) 8 bytes per point Range = [ , ] [cm]

99 Geometry Material Properties Particle Tracking Trajectory Storage Event Display X = cm Y = cm Z = cm Interaction Kind = 3 (Absorption)

100 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCevent Class

101 Geometry Material Properties Particle Tracking Trajectory Storage Event Display LMCparticle Class

102 1. Coding Example Main Propagation Implementation rscintillator.c Implementation Geometry ROOT geometry manager Physical Interactions

103 1. Coding Example Main Propagation Implementation Position Generation Collection of Secundaries

104 1. Coding Example Main Propagation Implementation Propagation of Secundaries Gathering Physical Information