Ionization Nexus for Discharge Research in the AtmosphereJ. Collins 3, V. Fernandez-Kim4, S. Harb 3, B. Stutzman 3, A. Linson 1, J. Ozenua 2, J. Villien4

LaACES Project

1 Department of Civil Engineering at Louisiana State University, Baton Rouge, LA 2 Department of Petroleum Engineering at Louisiana State University, Baton Rouge, LA 3 Department of Electrical and Computer Engineering at Louisiana State University, Baton Rouge, LA 4Department of Mechanical Engineering at Louisiana State University, Baton Rouge, LA

Abstract

Acknowledgements

Results

Conclusions

The goal of the Ionization Nexus for Discharge Research in the Atmosphere (I.N.D.R.A.) experiment was to measure the breakdown voltage of the atmosphere in an effort to validate Paschen’s Curve. Paschen’s Curve is a relationship between the breakdown voltage as a function of air pressure and the distance of the electrodes. Theoretically, a decrease in pressure should correspond to a decrease in breakdown voltage. I.N.D.R.A.’s goal was accomplished by using a spark generation system to create and detect a voltage breakdown across high voltage electrodes exposed to the atmospheric conditions to an altitude of 100,000 feet.

It was possible to determine the breakdown voltage of the atmosphere using INDRA’s spark gap system. The payload was successfully launched on May 20, 2014 from NASA’s Columbia Scientific Balloon Facility in Palestine, Texas. The decreasing pressure did show a correlation with increasing breakdown voltage on both the ascent and decent. This correlation was within 66% confidence, which was a mission goal. However, due to an unexpected dip in breakdown voltage, this experiment should be repeated to confirm results. Further work is also warranted to study the relationship between atmospheric humidity and temperature on breakdown voltage.

Payload Design

Arc Detection Board

Analysis

October 4, 2014

Supported by the Louisiana Space Consortium. Special thanks to the LaACES Staff: T. G. Guzik, D. Granger, M. Stewart, B. Ellison, C. Fava, J.P. Wefel, D. Browne, and the staff of the NASA Columbia Scientific Ballooning Facility

Software System Flowchart

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Prior to flight, the INDRA team created a table of expected results, mapped across the range of expected pressures for flight. The recorded flight data matched the general trend of our expected data: a decrease in pressure yielded a decrease in breakdown voltage. However, INDRA observed one notable exception to this trend, visible on the Ascent breakdown voltage curve. Although the exact cause for the dip is unknown, possible causes include condensation on the electrodes, dislodged foam, or signal interference from the arc discharges. The decent records match more closely with expected values.

Start: Initialize datavariables

ADC ReadRoutine

AtmosphericPressure

Check

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HVDC RampRoutine

EEPROMWrite routine

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Payload Containment Unit Design

Principle of OperationThe payload is controlled in real-time using a BASIC Stamp processor. A high voltage is applied across a pair of high voltage electrodes (the ‘spark gap’). The voltage is raised in 15V increments until the voltage exceeded the breakdown voltage of the atmosphere, which forms an arc between the electrodes. The payload then detects the arc and records the breakdown voltage into an onboard memory chip. The payload is constructed using lightweight foam and wood.

Spark Generation System