Raphael Krause, Florian Briechle, Martin Erdmann, Christian Glaser - - PowerPoint PPT Presentation

Raphael Krause, Florian Briechle, Martin Erdmann, Christian Glaser AERA Meeting at KIT February 2017

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Outline

 status calibration paper

submitted to JINST on 03.02. submitted to arxiv on 05.02. arXiv: 1702.01392

 calibration method

calibration setup using RPA example measurement LPDA pattern influence on CR signals

 LNA temperature dependency  summary

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Calibration Setup

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Measurement of |Hφ| and |Hθ|

|Hφ|: |Hy|: |Hz|: |Hθ| = cos(θ)|Hy| + sin(θ)|Hz|

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Uncertainties of |Hφ| at 55MHz and 42.5°

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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|Hφ| - Combined Results

 combination of 5 flights  simulation and measurement agree on a level of 10% 

• verall uncertainty at 55MHz and 42.5°: 7.9%

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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|Hφ| - Correction Factor

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Influence of Modified Pattern on

• ne Example Event

 Run: 101044, Event: 171743  signal measured in 9 stations at AERA  Θ = 30°, Φ = 14°  E =1.1 * 1018 eV

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Influence of Modified Pattern on

• ne Example Event

 up to 7% higher amplitude in EW at station with highest SNR  total energy fluence at station with highest SNR: 141 eV/m2 → 156 eV/m2 

• verall radiation energy:

7.96 MeV → 8.54 MeV EW

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Uncertainty of the Electric Field

 uncertainty of the calibration

what is the impact of the calibration uncertainty on the reconstructed electric field?

 uncertainty of the simulation

how stable is the simulation of the VEL to different ground conditions or environmental effects?

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Antenna Pattern Simulation

 standard simulation:

conductivity: σ = 1.3 mS/m relative permittivity: εr = 5.5

 new simulations:

σ = 0.5 mS/m … 5 mS/m εr = 2 … 10 elec. box included

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Antenna Pattern Simulation

 conductivity nearly no influence on antenna VEL  influence of permittivity and elec. box: %-level

permittivity conductivity

• elec. box

standard standard standard

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Influence of Box and Ground on Antenna VEL

 influence of ground: %-level  influence of box: small comp. to permittivity

permittivity: box: εr=2 εr=10

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Uncertainty of Energy Fluence

 use bandpass limited Dirac pulse adjusted according to the geomagnetic emission → E  VEL shifted by overall uncertainties/simulation → Hup, Hdown  calculate Uup, Udown using Hup, Hdown  reconstruct Eup, Edown from Uup, Udown using H  uncertainty from difference between Eup, Edown

permittivity: calibration:

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Uncertainty of Energy Fluence

 uncertainty increases with Θ

 due to larger uncertainties of |Hθ|

 azimuthal pattern

 at Φ=90° and Φ=270°: |Hφ| contributes only

quadratic

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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LNA Temperature Dependency

sensor LNA

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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LNA Temperature Dependency

a [dB/K]

55 MHz

50 25

Time [h]

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Summary

 great effort to calibrate AERA with small uncertainties

 measurement of the LPDA antenna VEL |Hφ| and |Hθ|  simulation and measurement agree on a 10% level in |Hφ|  AERA calibration uncertainty of |Hφ| at 55MHz and 42.5°: 7.9%  influence on one comsic-ray signal  uncertainties propagated to square root of energy fluence: 9.4% in median with Θ<60°

 FAL Calibration Paper:

 submitted to JINST on 03.02.  submitted to Arxiv on 05.02. arXiv: 1702.01392

 LPDA LNA temperature dependency: -0.01(7) dB/K

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Backup

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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• H: relation of voltage to incoming e-field
• horizontal antenna most sensitive to zenith direction

Vector Effective Length

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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Scientific Goals

 precise knowledge of the antenna response essential to reconstruct the electric field emitted by cosmic rays  setup using an octocopter delivers an overall calibration with high statistics  aim for the smallest systematic uncertainties with the

• ctocopter calibration method

direct impact on the energy scale given by AERA for Auger! (see talk F. Briechle)

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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|Hφ| - Reproducibility

 three measurements performed at different days  measurements agree on a 15% level

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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|Hθ| - Combined Results



• verall uncertainties at 55MHz and 42.5°: 11.7%

 simulation and measurement agree on a level of 20%

AERA Meeting Karlsruhe Raphael Krause | RWTH Aachen University | 08.02.2017

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|Hθ| - Correction Factor