AERA - Why everybody should start listening to radio 1 Florian Briechle 25/09/19
Overview Why is Radio? ➔ Production of Radio Emission How is Radio? ➔ Detector Principles of AERA What can we do with Radio? ➔ Results from Radio How will Radio be? ➔ Outlook 2 Florian Briechle 25/09/19
Alan Watson on Radio... “During the London Conference, Greisen gave an invited paper (‘Highlights in Air Showers 1965’) which was insightful and influential and is still well-worth reading. Amongst the topics he discussed was the detection of air showers using the radio method which had just been demonstrated. Greisen commented ‘The technique is barely in its infancy.... We feel confident it is a significant breakthrough and further study will reveal ways of obtaining information about showers not available by other means’. His prediction would eventually turn out to be correct but it was to be an infancy lasting nearly 40 years.” Alan Watson approves! 3 Florian Briechle 25/09/19
Radio emission mechanisms 1 st order: geomagnetic radiation ➔ Electrons/positrons deflected in Earth's magnetic field B ➔ Polarized into direction of Lorentz force ➔ Scales with angle between shower axis and B 2 nd order:charge excess / Askaryan effect ➔ Time varying net charge excess ➔ Electrons from air nucleus knocked out ➔ Positrons annihilate in shower front ➔ Radially polarized towards shower axis 4 Florian Briechle 25/09/19
What is AERA? 5 Florian Briechle 25/09/19
The Auger Engineering Radio Array World's largest radio detector for cosmic rays More than 150 autonomous radio stations on 17 km² Taking data since 2011 Coincident measurements with SD and FD Two different antenna types ➔ Log-periodic dipole LPDA Butterfly antenna antenna (LPDA) ➔ Butterfly antenna Two polarizations Sensitive in the range of 30 – 80 MHz 6 Florian Briechle 25/09/19
We also have drones! Octocopter 7 Florian Briechle | briechle@physik.rwth-aachen.de
Typical event Circles: AERA station Color: measured energy fluence ➔ No difference between measured signal in stations and fit Well performed fit Transform into v x B system to symmetrize event v: direction of shower B: Earth’s magnetic field 8 Florian Briechle | briechle@physik.rwth-aachen.de
Measuring with Radio Radio can measure all commonly used properties of cosmic primaries Energy: clear correlation between SD and RD RD observable Obtained via fit of event 9 Florian Briechle | briechle@physik.rwth-aachen.de
Example 2: Xmax Xmax: Measured footprint size is estimate for Xmax Distance to Xmax Radio observable (related to size of footprint) 10 Florian Briechle | briechle@physik.rwth-aachen.de
Especially useful for Horizontal air showers Extensive air showers with zenith angle θ > 60° Radio (and muons) reach ground EM and hadronic components die out earlier in atmosphere Inclined showers have larger footprint on ground up to tens of km² Can measure in regions where SD and FD are blind 11 Florian Briechle 25/09/19
Radio is used worldwide Tunka-Rex LOFAR AERA Arianne Ice-Top Interesting times for Radio detection! 12 Florian Briechle 25/09/19
What the future holds Radio officially part of AugerPrime First test stations already deployed RadioUpgrade antenna Some people expressing their joy working with Radio 13 Florian Briechle 25/09/19
… and also other experiments GRAND: Giant Radio Array for Neutrino Detection Observatory in China currently in testing, final size: 200000 km² with 200000 antennas Not feasible with SD or FD due to technological and money constraints 14 Florian Briechle 25/09/19
Summary and Outlook Radio detection has never looked as promising as now! Feasible alternative (or addition) to standard detection methods Cheap and easily handable Results from AERA show competitive results with SD and FD Future observatories will heavily use Radio Looking for PhD? We can always use more manpower :) (and if that did not already convince you, 15 Florian Briechle 25/09/19 we also have a Radio Meme WhatsApp)
Recommend
More recommend
