1000 hours of testing on a 10 kilowatt Hall effect thruster

Over the last two decades, numerous experimental and numerical efforts have examined physical phenomena in plasma discharge devices. The physical mechanisms that govern the anomalous electron diffusion from the cathode to the anode in the Hall Effect Thruster (HET) are not fully understood. This work used 1-D numerical method to improve our understanding and gain insight into the effect of the anomalous electron diffusion in the HET. To this end, numerical solutions are compared with various experimental HET performance measurements and the effects of anomalous electron diffusion are analyzed. The relationships between the anomalous electron diffusion and important parameters of the HET are also studied quantitatively. The work identifies the cathode mass flow rate fraction, radial magnetic field distribution, and discharge voltage as significant factors that affect anomalous electron diffusion. Additionally, the study demonstrates a computational process to determine the radial magnetic field distribution required to achieve specific thruster performance goals.

show abstract

“…The T-220 is a 10-kW HET and its outer diameter is 220 mm [25]. The operating conditions and geometry are summarized in Table 5.…”

Section: Study With the T-220 Hetmentioning

confidence: 99%

Study on Anomalous Electron Diffusion in the Hall Effect Thruster

Kwon¹,

Walker²,

Mavris³

2014

International Journal of Aeronautical and Space Sciences

View full text Add to dashboard Cite

show abstract

“…45,49,50 Shown schematically in Fig. 4, the probe consisted of a 1.94-cm-diam collection electrode enclosed within a 3.20-cm-diam guard ring.…”

Section: Faraday Probementioning

confidence: 99%

“…45 On initial exposure to vacuum, the thruster was operated for at least 2 h to allow for outgassing of thruster components. Thrust measurements were typically conducted at constant voltage and flow rate, in intervals of about 30 min, following the outgassing procedure.…”

Section: Thrust Standmentioning

confidence: 99%

High-Specific Impulse Hall Thrusters, Part 2: Efficiency Analysis

Hofer¹,

Gallimore

2006

Journal of Propulsion and Power

View full text Add to dashboard Cite

A laboratory-model Hall thruster with a magnetic circuit designed for high-specific impulse (2000-3000 s) was evaluated to determine how current density and magnetic field affect thruster operation. Results have shown for the first time that a minimum current density and optimum magnetic field shape exist at which efficiency will monotonically increase with specific impulse. At the nominal mass flow rate of 10 mg/s and between discharge voltages of 300 and 1000 V, total specific impulse and total efficiency ranged from 1600 to 3400 s and 51 to 61%, respectively. Comparison with a similar thruster showed how efficiency can be optimized for specific impulse by varying the shape of the magnetic field. Plume divergence decreased from a maximum of 48 deg at 400 V to a minimum of 35 deg at 1000 V, but increased between 300 and 400 V as the likely result of a large increase in discharge current oscillations. The breathing-mode frequency continuously increased with voltage, from 14.5 kHz at 300 V to 22 kHz at 1000 V, in contrast to other Hall thrusters where a sharp decrease of the breathing-mode frequency was found to coincide with increasing electron current and decreasing efficiency. These findings suggest that efficient, high-specific impulse operation was enabled through the regulation of the electron current with the applied magnetic field. η t = total efficiency θ = azimuthal coordinate direction ∇ z B r = axial gradient of the centerline radial magnetic field Nomenclature

show abstract

“…10 A cylindrical lens was used to create a plane of light, which was NASAfTM-2003-2 11879 2 projected on the guard ring and anode electrode. At the intersection of the object and light plane, a line of light was produced.…”

Section: Apparatus and Proceduresmentioning

confidence: 99%