Simple Penning Ion Source for Laboratory Research and Development Applications

A simple Penning ion generator (PIG) that can be easily fabricated with simple machining skills and standard laboratory accessories is described. The PIG source uses an iron cathode body, samarium cobalt permanent magnet, stainless steel anode, and iron cathode faceplate to generate a plasma discharge that yields a continuous 1 mA beam of positively charged hydrogen ions at 1 mTorr of pressure. This operating condition requires 5.4 kV and 32.4 W of power. Operation with helium is similar to hydrogen. The ion source is being designed and investigated for use in a sealed-tube neutron generator; however, this ion source is thoroughly described so that it can be easily implemented by other researchers for other laboratory research and development applications

Efficiency Analysis of a Hall Thruster Operating with Krypton and Xenon

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76560/1/AIAA-19613-425.pd

Erosion Processes of the Discharge Cathode Assembly of Ring-Cusp Gridded Ion Thrusters

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77019/1/AIAA-2006-3558-252.pd

Dormant Cathode Erosion in a Multiple-Cathode Gridded Ion Thruster

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76860/1/AIAA-37031-330.pd

Measurement of 30-Centimeter Ion Thruster Discharge Cathode Erosion

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76209/1/AIAA-22982-649.pd

Recent progress and perspectives of space electric propulsion systems based on smart nanomaterials

Miniaturized spacecraft built from advanced nanomaterials are poised for unmanned space exploration. In this review, the authors examine the integration of nanotechnology in electric propulsion systems and propose the concept of self-healing and adaptive thrusters

Experimental Investigation of Formation Time in Single-Gap Pseudospark Discharge

Experiment results on the formation of pseudospark discharge in single-gap device are presented. The formation process is investigated by capacitive probes and shows two phases: a slow ignition phase and a fast current increasing phase. The ignition of the discharge is found to be synchronous with a high speed ionization wave propagating from cathode to anode. Transition to the high current phase is initiated when the ionization front reaches the anode side. The experimental results on four different gap widths are presented under different pressures. The characteristic time of the ignition phase of the discharge is decreased with increasing pressure in all four gap widths. The mean velocity of the observed ionization front varies from 5.4 × 10 to 1.7 × 103 cm µs?1 under the investigated pressures. In four gap widths, the velocity of the ionization front can be fitted by one given curve as an exponential decline function of E/P

Experimental Investigations of High Voltage Pulsed Pseudospark Discharge and Intense Electron Beams

A high voltage pulsed discharge device which can produce intense high energy electron beam named pseudospark is presented in this work. This discharge device is able to hold 10s of kV voltage, kA current and 10¹⁰ - -10¹¹ A/s current rising rate. The pseudospark device is also a simply-constructed source for intense electron beam with high energy. The presented experimental investigation is focused on the discharge properties of pseudospark and the plasma-produced electron beam characteristics for current and potential applications in aerospace problems. The discharge property results show the presented pseudospark device has the hold-off voltages up to 26 kV and discharge current of 2 kA with current rising rate of 1 × 10¹¹ A/sec. And the comparative study on various discharge configurations show the capability of pseudospark device to hold voltage and high current generation in short pulse can be further improved by the device geometric configuration, leading to higher pulsed load drive capability. The intense electron beam obtained from the multi-gap pseudospark device has a current up to 132.2 A, and electron number is varied from 4 x 10¹⁵ to 2 × 10¹⁶ in the presented operation voltage range obtained from 10s of cm 3 charged particle channel. The energy analysis on this pseudospark-produced electron beam displays the double-hump non-Maxwellian energy distribution. The maximum energy peak value varies from 900 eV to 6.3 keV under 4 kV to 12 kV discharge voltage. Specifically, comparison of the beam parameters obtained from pseudospark device and the electron beam requirement for a MHD channel indicates pseudospark is a promising electron source

Faraday Cup with Nanosecond Response and Adjustable Impedance for Fast Electron Beam Characterization

A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 ? standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a double-humped energy distribution