The First Flight of EUSO Balloon
a prototype of JEM-EUSO
Jim Adamsa, Evgeny Kuznetsova, Matthew Rodencala, Jurgen Sawatzkia, Mark Christlb,
Lawrence Weinckec and Johannes Eserc for the EUSO Collaboration
aUniversity
of Alabama in Huntsville
bNASA Marshall Space Fight Center
cColorado School of Mines
10/13-15/2014
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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
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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
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Fresnel Optics
•
•
•
•
•
Entrance Aperture: 1 m2
Field of View: 12
Focal Spot: ~7 mm diameter
Resolution: ~500 m at sea level
Estimated throughput: 50%
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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
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Infrared Camera
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
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• Frame Rate: 0.0125 Hz
• Bispectral: 10.8 & 12 μm
• FoV: 45
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Balloon flight Operations
• Flight: ~5 hours at 38 km altitude
• Field of view on the ground: ~250 m2
• Energy threshold: ~5X1017 eV
No cosmic rays expected
• Forced trigger at 20 Hz
• Laser used to simulate horizontal EASs
• Flashers used to simulate vertical EASs
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Helicopter Under-flight for Calibration
A Bell 212 helicopter carrying
a UV flasher and a UV laser
was flown under EUSOBALLOON 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.
•
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Laser System:
Energy 9-16 mJ
EAS equivalent ~ 1020 eV
Polarization randomized
GPS synchronized
J. Eser, L. Wiencke
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Laser pulses fired
from helicopter
while under the
balloon
Laser Beam
Calibration
(pre and post flight)
J. Eser, L. Wiencke
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The Flashers
Firing Sequence
UV LED
• UV LED
• Laser
• Xenon Flasher
Xenon Lamp Holder
with mounted filters
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UV LED Calibration Characteristics
Projected number of photoelectrons at focal pixel versus control voltage.
Calibration curve was measured before and after flight in Canada
October 1 -10, 2014
JEM-EUSO Workshop - Toulouse
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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.
October 1 -10, 2014
JEM-EUSO Workshop - Toulouse
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Inside the Helicopter
Flasher Controller
Laser
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Helicopter Operations
Johannes Eser operated the
laser and the flasher via a
single-board computer he
programmed
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Matthew Rodencal directed the
pilots to fly under the balloon
using a balloon tracker system he
developed.
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Tracking Beacons on EUSO-BALLOON
Redundant Trackers on EUSO BALLOON
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Quarter-wave HAM Antenna on
the landing fame at the bottom of
EUSO-BALLOON
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Balloon Track (blue)
Helicopter Track (Red)
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Helicopter Viewed from the Balloon
Circumscribed Circle
Inscribed Circle
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Appearance of Ideal Focal Spot
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
Prepared by Jörg Bayer & Alejandro Guzman
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Video Clip from EUSO BALLOON
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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
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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)
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The End
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Helicopter Track
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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.
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V1.0 8/30 2014
Balloon
EUSOBalloon
Field of View
38 km
Timmins Campaign
August 24/25th
2014
Timmins CN
Flasher,
LED
3 km
Laser
Bell 212 Helicopter
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