1. The First Flight of EUSO Balloon a prototype of JEM-EUSO Jim Adams a, Evgeny Kuznetsov a, Matthew Rodencal a, Jurgen Sawatzki a, Mark Christl b, Lawrence Weincke c and Johannes Eser c for the EUSO Collaboration a University of Alabama in Huntsville b NASA Marshall Space Fight Center c Colorado School of Mines 10/13-15/2014UHECR 20141

2. Objectives for the first flight of EUSO-BALLOON: Test and mature JEM-EUSO technology Detect the UV signals from the helicopter and use them to calibrate EUSO-BALLOON Measure the UV background 10/13-15/2014UHECR 20142

3. EUSO BALLOON Design Video Camera  very high speed  very sensitive Focal Surface  Photon Detection Module (PDM) from JEM-EUSO IR Camera  Bispectral 10.8 & 12 μm  waterproof  measures the color-temperature of clouds 10/13-15/2014UHECR 20143

4. Fresnel Optics Entrance Aperture: 1 m 2 Field of View: 12  Focal Spot: ~7 mm diameter Resolution: ~500 m at sea level Estimated throughput: 50% 10/13-15/2014UHECR 20144

5. Photon Detection Module 36 Multi-anode photomultiplier tubes (MAPMTs) – 64 anodes each 2304 pixels, total Each MAPMT is covered by a UV filter (300-400 nm) Framing time: 2.5  s 10/13-15/2014UHECR 20145

6. Infrared Camera Frame Rate: 0.0125 Hz Bispectral: 10.8 & 12 μm FoV: 45  10/13-15/2014UHECR 20146 The extensive air showers (EASs) from extreme energy cosmic rays extend deep into the troposphere. An infrared camera is needed to monitor for interference from clouds. This camera will be used to: Measure cloud cover Determine cloud top altitudes With these measurements: Dead-time can be estimated

7. Balloon flight Operations Flight: ~5 hours at 38 km altitude Field of view on the ground: ~250 m 2 Energy threshold: ~5X10 17 eV  No cosmic rays expected Forced trigger at 20 Hz Laser used to simulate horizontal EASs Flashers used to simulate vertical EASs 10/13-15/2014UHECR 20147

8. Helicopter Under-flight for Calibration 10/13-15/2014UHECR 20148 A Bell 212 helicopter carrying a UV flasher and a UV laser was flown under EUSO- BALLOON on a helicopter at an altitude of ~3.2 km for 2.5 hours on August 24/25. The laser and flashers were fired at 19 Hz.

9. 9 J. Eser, L. Wiencke Laser System: Energy 9-16 mJ EAS equivalent ~ 10 20 eV Polarization randomized GPS synchronized

10. 10 Laser pulses fired from helicopter while under the balloon Laser Beam Calibration (pre and post flight) J. Eser, L. Wiencke

11. The Flashers 10/13-15/2014UHECR 201411 UV LED Xenon Lamp Holder with mounted filters Firing Sequence UV LED Laser Xenon Flasher

12. October 1 -10, 2014JEM-EUSO Workshop - Toulouse12 UV LED Calibration Characteristics Projected number of photoelectrons at focal pixel versus control voltage. Calibration curve was measured before and after flight in Canada

13. October 1 -10, 2014JEM-EUSO Workshop - Toulouse13 Calibration of the Xenon Flasher Projected number of photoelectrons at focal PDM pixel at 4 high voltage settings. Integrated number of photoelectrons over 8 consecutive GTU time frames. Calibration was conducted after the flight in Canada.

14. Inside the Helicopter 10/13-15/2014UHECR 201414 Flasher Controller Laser

15. Helicopter Operations 10/13-15/2014UHECR 201415 Johannes Eser operated the laser and the flasher via a single-board computer he programmed Matthew Rodencal directed the pilots to fly under the balloon using a balloon tracker system he developed.

16. Tracking Beacons on EUSO-BALLOON 10/13-15/2014UHECR 201416 Redundant Trackers on EUSO BALLOON Quarter-wave HAM Antenna on the landing fame at the bottom of EUSO-BALLOON

17. Balloon Track (blue) Helicopter Track (Red) 10/13-15/2014UHECR 201417

18. Helicopter Viewed from the Balloon 10/13-15/2014UHECR 201418 Circumscribed Circle Inscribed Circle

19. Appearance of Ideal Focal Spot 10/13-15/2014UHECR 201419 Prepared by Jörg Bayer & Alejandro Guzman Flasher and Laser Firing Sequence LED Flasher (70  s) Laser – 7 ns pulse (FOV crossing time 25  s) Xe Flasher (~50  s) Video Clip – 320  s Cadence – 20 clips/sec

20. Video Clip from EUSO BALLOON 10/13-15/2014UHECR 201420

21. Data Analysis Plans Use the onboard magnetometer and other data to find the orientation of EUSO BALLOON – Determine the position of the helicopter image on the focal surface versus time – Identify flashes from the helicopter – Calibrate EUSO Balloon at many places on the focal surface Search the video clips for flashes not from the helicopter Measure the ambient background light level during the flight 10/13-15/2014UHECR 201421

22. Plans for the Next Flight Objectives – Detect the first cosmic ray EAS signals from above – Search for EAS-like background flashes Instrument Upgrades – Add a cosmic ray self-trigger – Add a third lens for chromatic correction and improved focus Possible Flight Operation – Launch from New Zealand – Land in South America (Southern Patagonia) 10/13-15/2014UHECR 201422

23. The End 10/13-15/2014UHECR 201423

24. Helicopter Track 10/13-15/2014UHECR 201424

25. JEM-EUSO Mission Objective: Find the accelerators of the most energetic particles in the universe and discover how they work. Measure extensive air showers in the atmosphere Reconstruct the energy and arrival direction of each particle. Very large high-speed and wide-angle video camera to capture video clips of the nitrogen fluorescence in the atmosphere from extensive air showers caused by extreme energy cosmic rays. 10/13-15/2014UHECR 201425

26. Balloon EUSO- Balloon 38 km Field of View Timmins Campaign August 24/25 th 2014 Timmins CN 3 km Laser Flasher, LED V1.0 8/30 2014 Bell 212 Helicopter

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