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LA ACES Neutron Detector (NeD)
Team Members: Ravi Chimmalgi Robert Giglio Shiloh Meyers Bradley Wood Louisiana State University LaAces Amateur Balloon Flight Program
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Cosmic Rays: Supernova Debris
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Cosmic Rays: Supernova Debris Cont
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Cosmic Rays: Coming to Earth
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Cosmic Rays: Cosmic Shower and Neutron Production
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Neutron Flux as Measured Aboard High Altitude Plane
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measuring Neutron Flux in Atmosphere: Science Goals
Measure neutron flux as a function of altitude. Differentiate neutrons from other interacting particles. Create a graphical representation to present neutron flux versus altitude. Give a definite statement on the safety issues present for airline passengers from the data found Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measuring Neutron Flux in Atmosphere: Scientific Requirements
Need to record at least one data point every 10 minutes, or an average of every ft (3.048 km) in order to reproduce the accuracy of previously observed data plots Payload instrumentation must function for at least 4 hrs Payload instrumentation must function at pressures as low as 10 mBars Payload instrumentation must function at atmospheric temperatures as low as -60 degrees Celsius Need to make measurements in altitude range of airline traffic (30000ft ft). Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measuring Neutrons at High Altitudes: Conditions
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Altitude vs Temperature
Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measuring Neutrons at High Altitudes: Detector
PMT Scintillation Plastic Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Detector Continued: Neutron Scatter
1 MeV ~500 keV to photons Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Detector Continued: Neutron Absorption
Alpha Deposition ~2.8 MeV Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Previous Data At Palestine, Texas
Ground = .002 neutrons cm^-2/s (10keV – 10 MeV) Max Balloon Altitude = .04 neutrons cm^-2/s ( MeV) Based on D. J. Forest and E. L. Chupp (1968). Upper Limit for the Solar Neutron Flux in the Energy Interval MeV. Kluwer Academic Publishers. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Overview of electronics
Photomultiplier & boron-doped scintillator used Produced By LA ACES Team F. N. H. S. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Light emitted by scintillator
How the PMT works Light emitted by scintillator PMT detects light & sends pulse to circuit Produced By LA ACES Team F. N. H. S. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Timing the Windows Pulses specific times apart
Circuit detects first pulse, closes window for 150ns Window opened for 20us Produced By LA ACES Team F. N. H. S. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Electronics block diagram
Produced By LA ACES Team F. N. H. S. Louisiana State University Physics and Astronomy Louisiana State University Physics and Astronomy
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Payload Overview Control Circuitry Sensor System Batteries & Holder
SolidWorks® Model of Mechanical Payload Control Circuitry Sensor System Batteries & Holder Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Insert (Front-side) Photo of Insert
Title, caption – vertical orientation Photo of Insert Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy 20
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Insert (Back-side) Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Weight PMT/ Scintillator sensor neutron detectors >2kg (2000g)
Our Total Weight: ~1100g Box 230 g Circuits 190 g Insert 90 g Power & Cables 210 g PMT 280 g Misc. 100g Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Three different programs: pre-flight, on- flight and post-flight.
Software Three different programs: pre-flight, on- flight and post-flight. Fail-Safe mechanism Sample rate = 10 sec Each data point = 13 bytes Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Pre-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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On-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Post-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Altitude readings from the GPS. Data analysis.
Flight Data Handling Used Term232 and Excel. Altitude readings from the GPS. Data analysis. - Neutron Count vs Altitude - Particle Count vs Altitude - Temperature vs Time Louisiana State University Physics and Astronomy Louisiana State University Physics and Astronomy
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Procedure of Data Analysis
Took ground level counts in Palestine Integrate data in 10 second intervals versus altitude Integrate data in 5 minute intervals Apply error deviation using following Poisson equations Louisiana State University Physics and Astronomy Louisiana State University Physics and Astronomy
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Ground Count Comparisons
Louisiana State University LaAces Amateur Balloon Flight Program
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Measured Neutron Flux vs Altitude (10 Sec)
Louisiana State University LaAces Amateur Balloon Flight Program
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Measured Neutron Flux vs Altitude (5 min)
Louisiana State University LaAces Amateur Balloon Flight Program
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Procedure of Data Analysis Cont
Compare data to previously recorded data Compare data to neutron radiation levels for biological organisms Louisiana State University Physics and Astronomy Louisiana State University Physics and Astronomy
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Predicted Neutron Flux vs Altitude
Predicted neutron flux as a function of altitude F. N. H. S. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measured Neutron Counts vs Altitude (5 min)
Louisiana State University LaAces Amateur Balloon Flight Program
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We Detected a Neutron Calibration Source
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We Detected a Neutron Calibration Source
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We Detected a Neutron Calibration Source
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Predicted Charged Particle Flux
Predicted measurements of cosmic ray flux given by LA ACE’s experiment FRED. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measured Charged Particle Flux
Charged Particle Counts Louisiana State University LaAces Amateur Balloon Flight Program
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Atmospheric Temperature
Predicted measurements of temperature given by LA ACE’s experiment TIC. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy
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Measured Internal Temperature vs Time
Louisiana State University LaAces Amateur Balloon Flight Program
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Biological Radiation in Equivalent Dosages
Equivalent dose measured in Sieverts 1 Sievert causes nauseation 2 Sieverts causes hair loss 6 Sieverts kills Conversion equation: DE = R(E) φ Louisiana State University LaAces Amateur Balloon Flight Program
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Neutron Dose vs Altitude
Louisiana State University LaAces Amateur Balloon Flight Program
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Charged Particle Counts Over Total Flight
Louisiana State University LaAces Amateur Balloon Flight Program
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Charged Particle Counts At Launch
Louisiana State University LaAces Amateur Balloon Flight Program
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Thank you Jim Adams and Mark Christl at Marshal Space Center
Dr. Erno Sajo Dr. Jeff Blackmon Columbia Scientific Ballooning Facility
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