Dr. George H. Miley, Hugo Leon, Atanu Khan, Ben Ulmen, Guilherme Amadio, William Matisiak, George Chen, Paul Keutelian. Comments About Current Plasma Studies at UIUC. Research . Description of the IEC Jet Thruster Concept. Spherical plasma diode Ground potential on an outer sphere
IEC Jet design potential - cover a wide range of powers with good efficiency while providing plasma jet that can start with large diameter but be narrowed directionally to focus.
Analogous to planar electrostatic ion thruster "folded" into spherical form.
Electrical efficiency match conventional plasma thrusters;
reduced erosion giving long life time
reduced propellant leakage losses
high power-to-weight ratio
Low gas leakage & good heat removal make it possible to scale the design to low power or high power.Application of Jet Mode for Thrust
Higher densities and temperatures in the central core plasma, but increased losses due to Bremsstrahlung radiation still negligible .
Energy expenditure per ion for IEC device has not been established experimentally, but can be estimated.
IEC ion thruster - totally new concept:
little testing has been carried out on it
exact performance is not firmly established
several issues need to be investigated experimentally and theoretically to develop a reliable thruster for high power applications.
directly applicable to many basic underlying thruster issues
Performance of the IEC thruster is dependent on three major processes: ionization, microchannel formation and, redirection of ions into the plasma jet.
The exact thrust and velocity of the plasma jet as well as power losses due to ionization, thermal radiation, Bremsstrahlung radiation, and grid dissipation need to be measured in the experimental device.Performance & Design
Schematic diagram of glow discharge set up: 1-vacuum chamber; 2-cathode support, 3 – cathode, 4- Mo anode with holes; 5-15 m thick Be-foil; 6-CR-39 detectors; 7-discharge zone supply; 8-scintillator/X-ray detector.
DD-reaction enhancement factor calculated with formula (4) for the Ti target during deuteron bombardment with accelerator  (curve 1) and glow discharge (curve 2). The solid parts of the curves are corresponded to the deuteron energy ranges where DD-reaction yield was measured experimentally.
Experimental yield of 3.0 MeV protons at 0.8 < Ed < 2.45 keV, normalized to that at Ed = 2.45 keV. The bare cross-section corresponded to Bosch and Halle approximation to Ed 2.45 keV is marked by a solid line. The dashed line is a DD-reaction yield =in accordance with a screening potential value Ue = 610 eV.
Comparison of High Current, Low Energy D Accelerator and Pulsed GD
*The accelerator uses a Duoplasmatron (Ed = 50 keV) ion source, decelerating system and magnetic focusing installation ].
**Power supply given a periodic rectangular current pulse. The pulse duration can vary within 100 - 600 μs. The distance between cathode and anode is varied between 4.0 and 6.0 mm.
Ion Injection can be used to achieve low background pressure, enabling Beam-Beam reactions. An RF Ion Gun developed earlier at UIUC forms the basis for this concept.
A schematic of the Ion BeamTM is shown on the right. The photo on the left shows a 3-D mm hole cut into solid stainless ball placed 20 cm from the nozzle of the Ion BeamTM.
Specific Impulse Variations for a (a) manned Mars mission; (b) Triton sample return mission