2. RADAR Detection of Extensive Air Showers Nils Scharf III. Physikalisches Institut A Bad Honnef31.08.2007 Nils Scharf III. Physikalisches Institut A Bad Honnef31.08.2007

3. RADAR Detection of EAS2 Outline Cosmic Rays and the Auger Observatory RADAR Principles Test Setup First Results Conclusion

4. RADAR Detection of EAS3 Open questions:  Composition  Origin  Propagation of UHECR Measure Extensive Air Showers generated by cosmic rays Cosmic Rays

5. RADAR Detection of EAS4 The Auger Observatory 1480 deployed 1400 filled 1364 taking data 082407 ~ 85% All 4 fluorescence buildings complete, each with 6 telescopes AIM: 1600 tanks

6. RADAR Detection of EAS5 Detection Methods Surface detector  Water Cherenkov detector  Samples secondary particles on ground level  Nearly 100 % duty cycle Surface detector  Water Cherenkov detector  Samples secondary particles on ground level  Nearly 100 % duty cycle Fluorescence detector  Measures fluorescence light  Samples shower development  Very sensitive, works only in moonless nights -> 15 % duty cycle Fluorescence detector  Measures fluorescence light  Samples shower development  Very sensitive, works only in moonless nights -> 15 % duty cycle

7. RADAR Detection of EAS6 RADAR Radio Detecting and Ranging Possible sources for reflection / scattering:  Metallic objects Airplane monitoring, Car velocity measurements  Regions of high ion density Lightning RADAR Atmospheric Probing (Ionized regions in the Atmosphere) Ionization trails of Meteors  Used as long range communication channel (commercial and by radio amateurs)  Used for meteor science

8. RADAR Detection of EAS7 Monostatic:  Transmitter and receiver close to each other (ideal same antenna)  Area around transmitter is monitored

9. RADAR Detection of EAS8 Bistatic / Forward Scatter  Great distance between transmitter and receiver  Area between transmitter and receiver is monitored  Use of existing transmitters possible

10. RADAR Detection of EAS9 Properties of RADAR for EAS Large monitored volume (several km 3 ) Nearly 100 % duty cycle Active scanning of shower  Monitoring longitudinal shower development  Detection of horizontal showers Relatively simple detection method  Low budget and low maintenance

11. RADAR Detection of EAS10 Test Setup - Airplanes Use local transmitter (i.e. TV station) Radio waves reflected on moving airplanes -> Doppler shift Monitor original and Doppler shifted signal

12. RADAR Detection of EAS11 Power Supply for Preamplifier and Receiver Sound card 96 kHz 16bit sampling To antenna Preamplifier DAQ Receiver

13. RADAR Detection of EAS12 144 MHz Receiver Bandwidth freq amp Demodulation Receiver frequency 144 MHz Receiver bandwidth 3 kHz Radio waves with frequencies from 144.000 MHz to 144.003 MHz received Output Sound waves with frequencies from 0 Hz to 3000 Hz

14. RADAR Detection of EAS13

15. RADAR Detection of EAS14 Meteor scatter Meteor Ionization Column

16. RADAR Detection of EAS15 Comparison EAS – Meteors Meteors  Velocity: ~ 70 km/s  Altitude: 80 km to 120 km  Energy: ~ 0.1 J  Ionization column radius: ~ 10 m  Signal duration: 10 ms – 5 s EAS  Velocity: nearly c  Altitude: 0 km to 20 km  Energy: 0.1 J (10 18 eV)  Ionization column radius: ~ 10 m  Signal duration: 20 µs – 20 ms

17. RADAR Detection of EAS16 Test Setup for Meteor scatter Needed:  Transmitter with continuous transmission / high pulse rate below radio horizon of receiver ( distance greater than 500 km)  No local transmitter in used frequency range (noise reduction)

18. RADAR Detection of EAS17 Transmitter site in southern Norway Frequency 144 478 000 Hz Power 120 W Continuous transmission Distance 810 km Matching antenna and receiver for beacon frequency

19. RADAR Detection of EAS18 First Results - Meteor scatter Receiver Bandwidth Local transmitter Expected MS signals in this range

20. RADAR Detection of EAS19

21. RADAR Detection of EAS20

22. RADAR Detection of EAS21 First Results - Sound Just 3 examples: different signal types, sometimes only distinguishable by listening to them

23. RADAR Detection of EAS22 Results Meteor scatter signals with durations between 0.01 s and 3.5 s found Hourly rate between 10 and 20 (higher with active meteor shower) Simple setup working

24. RADAR Detection of EAS23 Outlook Measurements in coincidence with existing shower detectors Upgrade hardware (higher sampling rate) to detect expected very short EAS signals Antenna Array

25. RADAR Detection of EAS24 Conclusion RADAR is possible new detection method for EAS -> additional information on shower development Detection of meteor scatter with simple setup established Several groups are working on EAS detection by RADAR