1 / 28

Advancements in Ultra-High Energy Cosmic Ray Detection and Propagation Mechanisms

This paper explores recent advancements in the detection of ultra-high energy cosmic rays (UHECRs) and the associated propagation mechanisms in various mediums. It discusses detector strategies, including optical, radio, and acoustic methods, and examines factors such as decay processes, event rates, and interaction cross-sections. The research also addresses the challenges of measuring event types, background signals, and the opacity of the Earth at high energies. Additionally, it highlights the effectiveness of different detectors like IceCube and Auger in capturing and analyzing cosmic ray events.

avidan
Download Presentation

Advancements in Ultra-High Energy Cosmic Ray Detection and Propagation Mechanisms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. D. Seckel, Univ. of Delaware

  2. Topics • Why … • Detector Scale • Event rate: flux, cross-section • Area/Volume etc. • Threshold • Detector Strategy • Optical • Radio concept • Coherent Radiation from Showers • Radio • Acoustic

  3. Extreme Sources NRAO/AUI

  4. UHE Propagation & GZK process CMBR is opaque ?? Galactic SN shock Extra Galactic

  5. “top down” models • Decay/annihilation of defects • Decay of super heavy particles

  6. 1.9 Expectations for n-flux

  7. Event Rates • Rate vs incident flux

  8. Rate v. local flux

  9. Propagation • G is Greens function, determined by solving Boltzman eq. or MC techniques • Includes absorption, downscattering, regeneration, etc • Assume directivity G

  10. Effective Area • For simple propagation

  11. Cross-sections CTEQ-4 • Above PeV, neutrino=anti-neutrino. growth • of parton distribution in nucleon, CC ~ 2 NC • The Earth becomes opaque at high energy. • Uncertainty ~ 25% CTEQ-4 v. 6 (Aramo et al.)

  12. 1.9 Detector scale: 1 km3 v. 1000 km3 15 18

  13. Detector Strategy • Event types • Visible energy • Signals: optical, radio, acoustic • Attenuation • In-situ/Remote • Medium/Location

  14. Event types

  15. Inelasticity EMC effect

  16. Shower Detection Attenuation Length is critical

  17. In-situ v. Remote

  18. Medium & Location – (of better known efforts – several more)

  19. Optical scenarios • IceCube • Auger • Ocean Observer

  20. IceCube • A bit small – low energy • Low rates • Small acceptance from below • Cosmic Ray Background – muon bundles (veto by IceTop ?) • May have “useful” rate up to ~10 PeV • Measure s ?

  21. IceCube II Upward showers! (Hussain, Mckay, Marfatia, Seckel)

  22. Contained or Uncontained (Yoshida) Events with the same energy ~ 30PeV contained High npe: 107 npe uncontained Low npe: 1000 npe

  23. NPE Distribution Distribution difference between the signals and background! GZK m GZK t Atmospheric m

  24. Zenith Angle Distribution down • Signals peak at horizontal direction • Background distribute over down-going region up GZK m GZK t Atmospheric m

  25. Event Rate with 80 strings GZK m GZK t Atmospheric m GZK m GZK t Atmospheric m IceCube Preliminary GZK m0.35events/year GZK t0.31 events/year Atmospheric m0.033events/year GZK: S. Yoshida et. al. (1997) ApJ 479:547 (m=4, Zmax=4)

  26. AUGER (Let them speak…) • Upward tau’s • Earth skimming • Surface detector • Flourescence detector • Rock density, but area suppressed by projection • Downward events • New showers observed deep in atmosphere • Thin target density

  27. Ocean Observer • Concept only • Cf. OWL, EUSO air shower detection • Pros: • 100 x light yield of flourescence • Compact spot – fast hot pixel • 10 x target mass • Cons: • Interface • Sea conditions • No track

  28. Break • Remainder of detection summary contained in 2nd talk. • Includes discussion of radio technique, and overview of radio experiments.

More Related