Surface Wave Propagation Preliminary work developing a method for surface wave detection

1. Surface Wave Propagation Preliminary work developing a method for surface wave detection Amy Zheng Andrew Johnanneson

2. Ultrahigh Energy Neutrino Detection • Particles with velocity > will emit radiation due to the Askaryan effect [1] • Detection is difficult due to internally reflected waves dying off quickly[2]

3. Surface Waves as an Detection Tool • Radiation from Askaryan cascade is trapped in Air-dielectric layer between ice and firn[2] • In tandem with existing experiments RICE [3] and ANITA [4]

4. Why Use Surface Waves? • Surface waves travel between two mediums[5] • Amplitudes fall at the rate • Attenuation length times > bulk waves • ~800 times more efficient than bulk waves • If detection is viable, expanding existing experiments would be far less expensive • Surface waves may carry information about neutrinos and their interactions with ice better than the current method

5. Procedure • 1 sending + 2 receiving antennas displayed waveshape • Physically moved antennas to determine wavelength and thus index of refraction

6. Example Antenna Placements • “Air” • “Surface” • “In”

7. Translating to refractive index (1) Definition of Refractive Index (2) Sellmeier Equation

8. Refractive Index of Air Single or Half λ λ (cm) Calculated (2) 1000MHz & 1500MHz n=1.000273[6]

9. Refractive Index of Water (rms) Single or Half λ λ (cm) Calculated (2) n~1.3333[7]

10. Refractive Index of NaCl (rms) Single or Half λ λ (cm) Calculated (2) n~1.544[8]

11. Refractive Index of Granulated Fused Silica (sand) Single or Half λ λ (cm) Calculated (2)1000MHz n= 1.73251 [9] Calculated (2) 1500MHz n= 1.73317

12. Refractive Index of Granulated Fused Silica (sand) Multiple λ λ (cm) Calculated (2) 1000MHz n= 1.73251 [9] Calculated (2) 1500MHz n= 1.73317

13. Measurement Complications • Mechanical water waves appeared to alter EM waveform • Imprecise measurements due to hand & eye observation • Sand and water tend to collect in the connectors • Angular error from planar disparity • Waveforms disappeared & reappeared on and off • Waveforms constantly shift amplitude • Background EM noise & reflections often interfered

14. Future Steps • Experiment using ice as a medium • Change antenna size; more precision • Change experimental scale

15. References • [1] G.A. Askaryan, Sov. Phys. JETP 14, 441 (1961) • [2]J.P. Ralston, Phys. Rev. D 71, 011503 (2005) • [3] RICE Collaboration, I. Kravchenkoet al., Astropart. Phys. 19, 15 (2003); S. Razzaque, Sseunarine, D.Z. Besson, D.W. McKay, J.P. Ralston, and D. Seckel, Phys. Rev. D 65, 103002 (2002); Phys. Rev. D 69, 047101 (2004). • [4] For information on ANITA, see http://www.phys.hawaii.edu/anita/. • [5] J. P. Ralston “An Experiment to Detect Surface Waves on Polar Ice” (2005) • [6] Philip E. Ciddor. Refractive index of air: new equations for the visible and near infrared, Appl. Optics 35, 1566-1573 (1996) doi:10.1364/AO.35.001566 • [7]P. Schiebener, J. Straub, J.M.H. LeveltSengers and J.S. Gallagher, J. Phys. Chem. Ref. Data 19, 677, (1990) • [8] Faughn, Jerry S., Raymond A. Serway. College Physics, 6th Edition. Toronto: Brooks/Cole, 2003: 692. • [9] I. H. Malitson. Interspecimen Comparison of the Refractive Index of Fused Silica, J. Opt. Soc. Am. 55, 1205-1208 (1965) doi:10.1364/JOSA.55.001205 • [misc] Colloquium Notes from John P. Ralston • Refractive index calculations for relative reference only: • n found for granulated fused silica was found using Sellmeier constants for solid fused silica; granulation affects density. • Calculated n for water is for λ of 589.29 nm • Calculated n for NaCl is for λ of 589 nm

16. Acknowledgements • Dave Besson • Marie Piasecki • Carolyn Bandle

17. Any Questions?