Publications by Daniel George Courtney

Charge Neutralization and Direct Thrust Measurements from Bipolar Pairs of Ionic- Electrospray Thrusters

lectrospray (ES) thrusters are unique in their ability to emit both positive and negative beams, each contributing similarly to thrust. Spacecraft charging could be prevented without a dedicated neutralizer if currents of simultaneously emitted opposing po ...

2017

Comparing Direct and Indirect Thrust Measurements from Passively Fed and Highly Ionic Electrospray Thrusters

Herbert Shea, Simon Dandavino, Daniel George Courtney

Highly ionic beams of several hundred microampere per squared centimeter have been measured from porous glass ionic liquid electrospray sources fabricated using a conventional mill. The thrust output from three prototype devices, two emitting the ionic liq ...

American Institute of Aeronautics and Astronautics2016

Influences of porous reservoir Laplace pressure on emissions from passively fed ionic liquid electrospray sources

Herbert Shea, Daniel George Courtney

Passively fed ionic liquid electrospray sources are capable of efficiently emitting a variety of ion beams with promising applications to spacecraft propulsion and as focused ion beams. Practical devices will require integrated or coupled ionic liquid rese ...

AIP American Institute of Physics2015

A 10 nN resolution thrust-stand for micro-propulsion devices

Herbert Shea, Subha Chakraborty, Daniel George Courtney

We report on the development of a nano-Newton thrust-stand that can measure up to 100 μN thrust from different types of microthrusters with 10 nN resolution. The compact thrust-stand measures the impingement force of the particles emitted from a microthrus ...

American Institute of Physics2015

Fragmentation in Time-of-Flight Spectrometry-Based Calculations of Ionic Electrospray Thruster Performance

Herbert Shea, Daniel George Courtney

A method has been presented for accounting for ion fragmentation that occurs within the nonzero field of an ionic electrospray thruster. Given the complexities associated with direct thrust measurements, indirect means (and time-of-flight (TOF) in particul ...

American Institute of Aeronautics and Astronautics2015

Microfabricated electrospray emitter arrays with integrated extractor and accelerator electrodes for the propulsion of small spacecraft

Herbert Shea, Caglar Ataman, Simon Dandavino, Daniel George Courtney, Subha Chakraborty

Microfabricated electrospray thrusters could revolutionize the spacecraft industry by providing efficient propulsion capabilities to micro and nano satellites (1–100 kg). We present the modeling, design, fabrication and characterization of a new generation ...

Iop Publishing Ltd2014

A ToF-MS with a Highly Efficient Electrostatic Ion Guide for Characterization of Ionic Liquid Electrospray Sources

Herbert Shea, Caglar Ataman, Simon Dandavino, Subha Chakraborty, Daniel George Courtney

We report on the development of a time-of-flight (ToF) mass spectrometer with a highly efficient electrostatic ion guide for enhancing detectability in ToF mass spectrometry. This 65-cm long ion guide consists of 13 cascaded stages of Einzel lens to collec ...

Springer2014