LA ACES Neutron Detector (NeD) Team Members: Ravi Chimmalgi Robert Giglio Shiloh Meyers Bradley Wood Louisiana State University LaAces Amateur Balloon Flight Program

Cosmic Rays: Supernova Debris http://upload.wikimedia.org/wikipedia/commons/thumb/4/43/Supernova-1987a.jpg/660px-Supernova-1987a.jpg Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Cosmic Rays: Supernova Debris Cont http://auger.cnrs.fr/presse/0197swordy2a.gif Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Cosmic Rays: Coming to Earth http://www.astroparticlephysics.nl/cosmic_rays.jpg Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Cosmic Rays: Cosmic Shower and Neutron Production Louisiana State University LaAces Amateur Balloon Flight Program http://neutronm.bartol.udel.edu/catch/cr2b.gif Louisiana State University Physics and Astronomy

Neutron Flux as Measured Aboard High Altitude Plane Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

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

Measuring Neutron Flux in Atmosphere: Scientific Requirements Need to record at least one data point every 10 minutes, or an average of every 10000 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- 40000ft). Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Measuring Neutrons at High Altitudes: Conditions http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.gif Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Altitude vs Temperature Louisiana State University LaAces Amateur Balloon Flight Program http://www.seungjoo.net/projects/may2006/image2/clip_image039.jpg Louisiana State University Physics and Astronomy

Measuring Neutrons at High Altitudes: Detector PMT Scintillation Plastic http://www.sphere.bc.ca/test/tubes/252-rca-6655a.jpg http://www.apace-science.com/eljen/images/plastic.jpg Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Detector Continued: Neutron Scatter 1 MeV ~500 keV to photons http://knowledgepublications.com/doe/images/DOE_Nuclear_Elastic_Scattering.gif Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Detector Continued: Neutron Absorption Alpha Deposition ~2.8 MeV Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Previous Data At Palestine, Texas Ground = .002 neutrons cm^-2/s (10keV – 10 MeV) Max Balloon Altitude = .04 neutrons cm^-2/s (20-120 MeV) Based on D. J. Forest and E. L. Chupp (1968). Upper Limit for the Solar Neutron Flux in the Energy Interval 20- 120 MeV. Kluwer Academic Publishers. Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

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

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

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

Electronics block diagram Produced By LA ACES Team F. N. H. S. Louisiana State University Physics and Astronomy Louisiana State University Physics and Astronomy

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

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

Insert (Back-side) Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

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

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

Pre-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

On-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

Post-flight Program Louisiana State University LaAces Amateur Balloon Flight Program Louisiana State University Physics and Astronomy

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

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

Ground Count Comparisons Louisiana State University LaAces Amateur Balloon Flight Program

Measured Neutron Flux vs Altitude (10 Sec) Louisiana State University LaAces Amateur Balloon Flight Program

Measured Neutron Flux vs Altitude (5 min) Louisiana State University LaAces Amateur Balloon Flight Program

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

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

Measured Neutron Counts vs Altitude (5 min) Louisiana State University LaAces Amateur Balloon Flight Program

We Detected a Neutron Calibration Source

We Detected a Neutron Calibration Source

We Detected a Neutron Calibration Source

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

Measured Charged Particle Flux Charged Particle Counts Louisiana State University LaAces Amateur Balloon Flight Program

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

Measured Internal Temperature vs Time Louisiana State University LaAces Amateur Balloon Flight Program

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

Neutron Dose vs Altitude Louisiana State University LaAces Amateur Balloon Flight Program

Charged Particle Counts Over Total Flight Louisiana State University LaAces Amateur Balloon Flight Program

Charged Particle Counts At Launch Louisiana State University LaAces Amateur Balloon Flight Program

Thank you Jim Adams and Mark Christl at Marshal Space Center Dr. Erno Sajo Dr. Jeff Blackmon Columbia Scientific Ballooning Facility