1 / 17

Atmospheric Radio Soundings in Argentina - Effects of Air Density Variations -

Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft. Atmospheric Radio Soundings in Argentina - Effects of Air Density Variations -. Bianca Keilhauer. Tokyo, February 26th, 2004. Data Acquisition. Auger Fluorescence Detector measures longitudinal shower development

ila-riley
Télécharger la présentation

Atmospheric Radio Soundings in Argentina - Effects of Air Density Variations -

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. Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft Atmospheric Radio Soundings in Argentina - Effects of Air Density Variations - Bianca Keilhauer Tokyo, February 26th, 2004

  2. Data Acquisition • Auger Fluorescence Detector measures longitudinal shower development • Atmospheric parameter affect the development and detection at every height • ⇒ Knowledge of atmospheric profiles is required • Radiosonde measurements in each season are performed: • 61 successful launches in total • Average reached altitude ≈ 20 km a.s.l. (maximum was 28 km a.s.l.) • Roughly every 20 m a set of data (h, p, T, u, wind) • Used DFM-97 GPS sondes (www.graw.de) • Accuracy: T < 0.2 K p < 1.0 hPa (range 200 hPa to 1080 hPa) < 0.5 hPa (range 5 hPa to 200 hPa) u < 5%

  3. Important Effects of Atmospheric Profiles on the Auger FD shower data • Atmospheric depth to geom. height • Fluorescence light production • fl. yieldλ(p,T) • Fluorescence light transmission • τ (p,T) fluorescence photons X to h Fe p Fe p Fl. Yield transmission telescope atmosph. depth height

  4. atmospheric depth: air density: ⇒height and time dependent height (km a.s.l.) 10 8 6 5 4 3 2 particle number (x 109) Geometrical Effect atmospheric depth (g/cm²) Fe p 1019eV / 0° US Std. atmosphere

  5. Atmospheric Depth Profiles Max. of Fe-ind. 1019eV, 60o shower in US-StdA averaged measured profiles: • distortion of longitudinal shower profiles • shift of position of shower maximum

  6. Difference in Atmospheric Depth within seasons winter, July / August 2003 summer, January / February 2003

  7. Longitudinal Shower Development - Energy Deposit - average of 100 simulated showers ⇒ same EAS in Ne(X) for all atmospheres ⇒Δhmax= 436 m between winter I and summer atmosphere

  8. Difference in Energy Deposit same EAS inNe(X) for all atmospheres

  9. Fluorescence Yield for a 1.4 MeV electron, vertical incidence • EAS excites N2 – molecules in air • de-excitation partly via fluorescence light emission (λ≈ 300 -400 nm) • fl. yield ~ local energy deposit

  10. both EAS 60°, 1019eV, p-ind. in summer, Fe-ind. in winter I: → Δhmax= 350 m vertical height difference 8.0 km 8.35 km both 8.1 km Position of Shower Maximum - Fluorescence Yield - both EAS in US-StdA, 60°, 1019eV: → Δhmax= 800 m vertical height difference 7.6 km 8.4 km same EAS inNe(X) for all atmospheres

  11. Xmax distribution for Fe-ind. showers with 60° ⇒ increase of Xmax distribution by approx. 25 % same EAS inNe(X) for all atmospheres

  12. Photons at the telescope Fe, 1019eV, 60°, same EAS inNe(X) for all atmospheres

  13. Photons at the telescope Fe, 1019eV, 60°, same EAS inNe(X) for all atmospheres

  14. Summary • Atmospheric conditions influence the:- Shower development - Fluorescence light emission - Light transmission • EAS profiles are shifted and distorted: - Xmax position - Energy reconstruction - Distribution of Xmax broadened in dependence of incidence angle (more important for Fe-ind. EAS than for p-ind. ) • Fluorescence yield is height and (p,T) - dependent

  15. Difference of Atmospheric Depth Profiles for pressure at ground: 825.0 ± 0.2 hPa, 829.0 ± 0.2 hPa, 826.0 ± 0.2 hPa, 834.5 ± 0.2 hPa

  16. Atmospheric Depth Distribution at 2400 m for the individual profiles measured in Argentina

  17. Atmospheric Depth Distribution at 8400 m for the individual profiles measured in Argentina

More Related