Geant4 Simulations for the Radon Electric Dipole Moment Search at

More documents

Recommendations

Info

Figure 3.5: Cross section of the simulated EDM cell, oven, magnet and µMetal shielding. The cell and cylindrical oven wall composed of PYREX glass with the oven caps constructed of delrin. The simulated magnetic coil was designed to fit tightly around the EDM oven, with a thickness matching that of 24 AWG wire. The thickness of the µMetal was user-defined in the GUGI program. 3.5 RnEDM Geant4 Geometry The simulated geometry for the RnEDM experiment consists of a ring of eight GRIFFIN detectors around an EDM cell and oven (see Figure 3.1). The eight GRIF- FINdetectors areclose-packed in their highest efficiency mode asshown inFigure2.9. 3.5.1 Cell and Oven Design The design for the RnEDM experiment has not been finalized. The experiment will, however, consist of a few basic components; including a cell, oven, magnetic coil and magnetic shielding. The spherical cell and cylindrical oven were bothconstructed of PYREX glass in the Geant4 simulation. The cell was located inside the oven and was 1 mm thick with an inner radius of 1 cm. The oven was 5 mm thick with an inner 54
of radius 10 cm, allowing the GRIFFIN detectors to be close-packed in their highest efficiency mode with an inner radius of 11 cm. The oven caps were constructed of delrin and were 22 cm in diameter and 1 cm thick. The optional solenoidal magnet was constructed of pure copper and designed to tightly fit around the oven. The thickness of the cylinder was equivalent to 24 AWG wire. Finally, the µMetal was given a user-defined thickness and it was placed tightly around the magnet. A cross section of this setup is shown in Figure 3.5. While this does not represent the final designoftheRnEDMexperiment, itdoesincludethekeycomponentsthatwillscatter and absorb γ rays with variable thickness that enable scattering studies as a function of component thickness. 3.5.2 LaBr 3 (Ce) Scintillator The LaBr 3 (Ce) scintillator material is used in the construction of Saint-Gobain’s BrilLanCe 380 detector. The BrilLanCe 380 scintillator has excellent fast timing properties (∼200 ps) and offers a better energy resolution when compared to a standard NaI(Tl) detector [41]. The impressive count rate capability of LaBr 3 (Ce) could give a strong advantage over HPGe in the RnEDM experiment. The sensitivity of the EDM measurement will be statistics limited and will be determined by the number of photopeak events detected. The higher count rate capability of LaBr 3 (Ce) could thus lead to greater sensitivity. However, to observe the EDM signal, the time structure of a single γ-ray transition needs to be monitored precisely, and the energy resolution of HPGe is much better than LaBr 3 (Ce). Using LaBr 3 (Ce) to identify individual transitions in the decay of 223 Rn may be difficult or impossible. Geant4 simulations of the BrilLanCe 380 detector were performed as part if this work (Section 4.3), to study the sensitivity achieved with LaBr 3 (Ce) energy resolution. 55
Page 1 and 2:
GEANT4 SIMULATIONS FOR THE RADON EL
Page 3 and 4:
Dictated but not read. i
Page 5 and 6:
Contents Acknowledgements ii 1 Intr
Page 7 and 8:
4 Results 60 4.1 γ-Ray Spectroscop
Page 9 and 10:
List of Figures 1.1 An illustration
Page 11 and 12:
Chapter 1 Introduction Thesearchfor
Page 13 and 14: ˆP ր ˆT ց Figure 1.1: An illust
Page 15 and 16: 1.1.1 CP Violation Following the ob
Page 17 and 18: Figure 1.2: Experimental upper limi
Page 19 and 20: Figure 1.3: Illustration of the dou
Page 21 and 22: Chapter 2 RnEDM Experiment at TRIUM
Page 23 and 24: Figure 2.1: A schematic of the ISAC
Page 25 and 26: a measurement cell. The RnEDM exper
Page 27 and 28: NMR techniques, and supplementing s
Page 29 and 30: Occupied Orbitals Fine Structure Hy
Page 31 and 32: energy levels are separated accordi
Page 33 and 34: (σ + ) along the axis of the B fie
Page 35 and 36: atom and absorbed by another. Radia
Page 37 and 38: anaverageof120kHzphotopeakcountrate
Page 39 and 40: Figure 2.7: One GRIFFIN/TIGRESS HPG
Page 41 and 42: (a) One GRIFFIN detector in the HPG
Page 43 and 44: 3.1 Introduction 3.1.1 Previous Wor
Page 45 and 46: energies, branching ratios, emissio
Page 47 and 48: used around the measurement cell in
Page 49 and 50: 3.2.5 Simulated Data Thecodewaswrit
Page 51 and 52: lower its total energy. Internal co
Page 53 and 54: 10000 1000 2 χ red = 1.21 t 1/2 =
Page 55 and 56: as [47] I(E) = G 2π 3 7 c 6 | M i
Page 57 and 58: was to use an average X-ray energy
Page 59 and 60: 1.5 1.4 1.3 1.2 P = 100% P = 75% P
Page 61 and 62: where (a b c d | e f) are Clebsch-G
Page 63: 2 2 1.5 J i = 5/2, J f = 5/2 J i =
Page 67 and 68: (a) Screenshot showing the detector
Page 69 and 70: 3.6.2 Output Data and Sort Codes Th
Page 71 and 72: (user-defined option), secondly toa
Page 73 and 74: 30 Absolute Efficiency (%) 25 20 15
Page 75 and 76: 11 10 9 8 7 6 5 4 3 2 1 0 1e+06 Cou
Page 77 and 78: 4.2.1 Multipolarity Effects The sha
Page 79 and 80: Figure 4.7: The time projections an
Page 81 and 82: distribution, this average intensit
Page 83 and 84: Table 4.1: The fit results for the
Page 85 and 86: 12 10 linear regression: y = 0.2243
Page 87 and 88: 15 Linear Counts (e+04) 10 5 0 1e+0
Page 89 and 90: Chapter 5 Conclusions and Future Di
Page 91 and 92: simulated given sufficient parent a
Page 93 and 94: Appendix A Figure A.1: Simulated de
Page 95 and 96: Figure A.3: Simulated decay scheme
Page 97 and 98: Figure A.5: Simulated decay scheme
Page 99 and 100: 6 out = (1/(1+∆ˆ2))*(f(k,jf,L1,L
Page 101 and 102: 44 return; 45 end 46 if abs(m) > j
Page 103 and 104: 1 % LegendreP.m 2 function P = Lege
Page 105 and 106: 39 xx(i+1,j+1) = r(i+1,1)*sin((i*re
Page 107 and 108: 11 %warning('m1 + m2 + m3 must equa
Page 109 and 110: 23 end 24 % ////////// 25 j1 = J1;
Page 111 and 112: 33 if L1 == L2 && ∆ == 0 34 title
Page 113 and 114: Bibliography [1] J. M. Pendlebury a
Page 115 and 116:
[25] P. G. Bricault, M. Dombsky, Je
Page 117:
[47] RichardA.Dunlap. An introducti
show all

Geant4 Simulations for the Radon Electric Dipole Moment Search at

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?