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KIT – The Research University in the Helmholtz Association
Karlsruhe Institute of Technology (KIT), Institut für Kernphysik, Karlsruhe, Germany
www.kit.edu
Frank G. Schröder
Overview on Radio Detection of Air Showers
2 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Accurate measurement of energy and Xmax around the clock
Radio
Advantages of radio technique
3 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
arXiv:
1607.08781
4 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Emission mechanisms
Askaryan effect ~ 10%geomagnetic effect ~ 90%
5 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Conical radio emission with asymmetric footprint
CoREAS simulations By T. Huege et al., ARENA2012
shower
inclination:
q = 45°
43 – 74 MHz
6 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
3.4 – 4.2 GHz
Geomagnetic emission at Cherenkov ring
GHz emission beamed into narrow cone
CROME @ KIT
7 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Do simulations describe reality?
CoREAS (+ other codes) reproduce measured amplitudes within ~20% uncertainty
Tunka-Rex Coll.,Nucl. Instr. Meth. A 802 (2015) 89
LOPES Coll.,Astropart. Phys. 75 (2016) 72
(CoREAS)
(CoREAS)
8 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
1st Answer: How well do we understand the radio emission?
To a level of 10-20%
better than for muon content of air-showers
similarly good as fluorescence detection, but various systematics are not yet
extensively studied
Open questions for becoming even better
What is the impact of atmospheric humidity?
Is the proportionality with geomagnetic field exact?
How exactly behaves the emission for near-horizontal showers?
9 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Jelley et al Nature 1965,
R. A. Porter MSc Thesis 1967
Experiments: First Detection
Qualitative features discovered 50 years
ago, but measurements lacking accuracy
10 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Location of selected experiments and geomagnetic field
11 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
1 km
CODALEMA3
(57)
Compilation by A. Zilles
Designs of modern radio arrays(mostly externally triggered)
12 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
30 dipole antennas
40 – 80 MHz, east-west / north-south
Trigger by KASCADE
LOPES setup (map of 2009)
13 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Detectors: antennas
Many working solutions with only slight differences in
threshold (typical 1017 eV) and frequency band (typical 30-80 MHz)
accuracy (systematic uncertainties, e.g., due to ground conditions)
SALLA at
Tunka-Rex LPDA at Augerinverted v-dipole at LOPESButterfly at
CODALEMA
14 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
15 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Direction
example: LOPES
Energy
example: AERA and others
Shower maximum
example: LOFAR + Tunka-Rex
Reconstruction of shower parameters
16 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Cross-correlation of traces after time shift according to arrival direction
Direction precision ~ 0.5° (by comparing LOPES to KASCADE)
Interferometric beamforming at LOPES
LOPES Coll., Astroparticle Physics 50-52 (2013) 76 + Nature 435 (2005) 313
cross-
correlation
total power
17 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
750 m
Auger Engineering Radio Array
153 autonomous stations on 17 km²
18 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
750 m
LPDA
Auger Engineering Radio Array
153 autonomous stations on 17 km²
19 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Butterfly
750 m
LPDA
Auger Engineering Radio Array
153 autonomous stations on 17 km²
20 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Energy reconstruction by AERA
Total energy in radio signal scales quadratically with electro-mag. shower energy
slope = 1.98 ± 0.04
16 MeV
energy
resolution:
17%
Pierre Auger Coll.,
PRL 116 (2016) 241101
21 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Moscow experiment:
Vernov et al. (1968)
LOPES Coll., AIP Conf. Proc.
1535 (2013) 78
Tunka-Rex,JCAP 01 (2016) 052
Similar energy precision by other experiments
+ several other
experiments
22 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Several 100 antennas on several 100 m²
Low band: 10-90 MHz
High band: 110-190 MHz
LOFAR superterp, the Netherlands
23 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
High precision by intensive simulations
Pick the one of many simulations describing data best
very high precision < 20 g/cm²
provided no unknown systematics: competitive with fluorescence
LOFAR Coll, PRD 90 (2014) 082003
24 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
25 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Bildquelle: Wikimedia
Irkutsk
26 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
27 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Layout of Tunka-Rex
Array layout
200 m spacing in 1 km² inner area
Fully analyzed: Oct 2012 – Apr 2014
Year Stations Trigger
2012 19 Tunka-133
2013 25 Tunka-133
2014 timing problem
2015 44 Tunka-133
+ Grande
2016 63since Nov.
Tunka-133
+ Grande
28 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
One of several methods: slope of lateral distribution
Shower maximum: proof by Tunka-Rex
Tunka-Rex Coll.,
JCAP 01 (2016) 052
precision:
40 g/cm²
29 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
CoREAS takes situation of each experiment into account
Alternative way: Ratio of measured to simulated amplitude
30 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Tunka-Rex + LOPES Colls.,
PLB 763 (2016) 179
Comparing
energy scales
via radio
31 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
2nd Answer: What is the accuracy for shower observables?
Accuracy competitive to fluorescence technique
direction < 0.5°
energy < 20% (precision + scale)
Xmax < 20 g/cm² (with high antenna density)
Next steps currently under investigation
Can we reach an energy accuracy of 5-10%?
Can we achieve 20 g/cm² Xmax resolution with sparse arrays?
Can we exploit composition sensitivity beyond Xmax?
32 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
3rd Answer: What ideas and plans are there beyond Xmax?
Neutrino search above 1016 eV
radio arrays in and on ice – ARA, ARIANNA
Ultimate precision around 1017 eV
the low-frequency core of the Square Kilometer Array (SKA)
Highest apertures for 1020 eV
huge arrays for inclined showers (GRAND), satellites, the Moon
cosmic rays and neutrinos
33 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
ARA Collaboration ARIANNA Collaboration
Neutrino-induced showers in ice
34 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
S.W. Barwick,
PoS (ICRC2015) 027
35 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
T. Huege et al.,
ICRC 2015, Den Haag
antenna stations
particle detectors
The Square Kilometer Array: ultra high precision
Phase 1: ~ 60,000 antennas on ½ km²
Scintillator array planned for E > 1016 eV
36 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
P. Gorham, et al.
(ANITA Coll.)
Cosmic-Ray detection by ANITA
37 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Enables large-scale, sparse antenna arrays for reasonable costs
Huge footprint for inclined showers
vertical
50°
75°
E = 1018 eV
CoREAS simulationAuger measurement
E = 3.6.1018 eV, q = 75.7°
Pierre Auger Collaboration, PoS (ICRC2015) 615
38 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Composition sensitivity for inclined showers
Only radio emission + muons survive for inclined showers
Complementary information on shower primary particle type
39 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
more in arXiv: 1607.08781
Conclusion
Significant progress in last years
radio is on the way to a standard technique
emission understood to at least 10 - 20 % accuracy
Competitive accuracy for air shower parameters
direction < 0.5°
energy < 20% (precision + scale)
Xmax < 20 g/cm² (with high antenna density)
Radio ideal for particle-detector arrays at E >1017 eV
enhancement of accuracy for cosmic rays
neutrino search
40 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Backup
41 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Scintillation counters
Inside underground
Muon detector
Scintillation counters
Inside surface
particle detectorEntrance to
muon detector
Electronic
box
Tunka-133 and Tunka-Grande at TAIGA
ECRS 2014
Tunka Coll.
Cosmic Rays
Tunka-133
Tunka-Grande
Tunka-Rex
Gamma Rays
HiSCORE
IACT
Muon detectors
as veto
42 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
30-80 MHz
Using data acquisition of
Tunka-133 / Tunka-Grande
Tunka-Rex signal chain
43 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Digitally shift all traces
according to arrival time of
hyperbolic wavefront
Cross-correlation of antennas
Interferometric beamforming at LOPES
LOPES Coll.,
44 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Cherenkov ring (predicted by Allan 1971)
45 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Relative strength of Askaryan effect
46 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Hyperbolic radio wavefront
Hyperbolic shape seen by LOPES and LOFAR
Slight east-west asymmetry not yet confirmed
LOPES Coll., JCAP 09 (2014) 025
LOFAR measurementAstropp. 61 (2015) 22
CoREAS for LOPES
r1°- 2°
47 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Efficiency of Tunka-Rex standard reconstruction
48 08 December 2016 Radio Detection of Cosmic RaysYachay, Ecuador
frank.schroeder@kit.edu
Institut für Kernphysik
Amplitude calibration
Commercial reference
source also used by
LOPES and LOFAR
Common amplitude scale
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