Operation of an Annular Helicon Plasma Source

Palmer, Douglas D.; Walker, Mitchell L. R.

doi:10.2514/6.2008-4926

Cited by 4 publications

(9 citation statements)

References 7 publications

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“…As helicon antenna devices are in operation 11,12 as prototypes for a high-efficiency ion source and for an electric propulsion thruster, a better determination of what is happening within the waveguide is warranted.…”

Section: ͑14͒mentioning

confidence: 99%

Comment on “Plasma ionization by annularly bounded helicon waves” [Phys. Plasmas 13, 063501 (2006)]

Johnson¹

2009

Physics of Plasmas

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The neoclassical calculation of the helicon wave theory contains a fundamental flaw. Use is made of a proportional relationship between the magnetic field and its curl to derive the Helmholtz equation describing helicon wave propagation; however, by the fundamental theorem of Stokes, the curl of the magnetic field must be perpendicular to that portion of the field contributing to the local curl. Reexamination of the equations of motion indicates that only electromagnetic waves propagate through a stationary region of constant pressure in a fully ionized, neutral medium.

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Section: ͑14͒mentioning

confidence: 99%

Comment on “Plasma ionization by annularly bounded helicon waves” [Phys. Plasmas 13, 063501 (2006)]

Johnson¹

2009

Physics of Plasmas

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“…1,12,13 Helicon sources launch RF waves along an axial magnetic field to couple to the plasma. 1,[12][13][14] Ionization occurs within a closed insulator, which prevents erosion of the RF antenna as a failure mechanism. Helicon sources have been operated in cylindrical and staged configurations on argon, xenon, and many other propellants.…”

Section: Nomenclaturementioning

confidence: 99%

“…Helicon sources have been operated in cylindrical and staged configurations on argon, xenon, and many other propellants. [12][13][14][15][16][17][18][19] In each case, the majority of the plasma is confined to the center of the device due to the strong axial magnetic field. Recent investigations show that the Pyrex insulator experiences etch rates of zero for argon ion temperatures below 200 eV.…”

Section: Nomenclaturementioning

confidence: 99%

“…Many investigations show that inductive plasmas have linear increases in ion number density, followed by a large jump in ion number density as the devices shifts to helicon mode. 1,13,14,16,19 Figure 10 shows that the electron temperature reaches high values at low RF power settings, however once a new power coupling mode is reached, the electron temperatures decrease because the device no longer uses large amounts of power to heat electrons. 12,20 A high ion number density with cold electrons is optimal for a propulsion device, because this minimizes the energy is lost heat electrons, and maximizes the number of ions available for acceleration.…”

Section: Gauss 250 Gauss 500 Gauss 750 Gauss 1gaussmentioning

confidence: 99%

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Performance Analysis of a Medium-Power Helicon Thruster

Palmer¹,

Walker²,

Manete³

et al. 2008

44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

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A medium-power helicon thruster (MPHT) is an electric propulsion device that uses a helicon plasma source to achieve specific impulses of up to 1500 s with argon propellant. 1 The Center of Studies and Activities for Space (CISAS) has created a prototype design, and the Georgia Institute of Technology (GA Tech) has designed and built a nominally 1.5-kW MPHT that sustains high density, steady-state plasma over a range of operating conditions. All tests are performed in the GA Tech vacuum test facility at an operating pressure less than 3.1 x 10-5 Torr-Ar. Ion number density, electron temperature, and electron energy distribution function measurements are taken with an RF-compensated Langmuir probe as a function of RF frequency (2-15 MHz), RF forward power (0-1.5 kW), magnetic field strength (0-1100 Gauss), and argon mass flow rate (0.74-4.45 mg/s). The maximum ion number density is 8.0 x 10 18 m-3. The measurements are compared with several known helicon plasma sources. Experimental characterization of this device allows validation of the 1-D and 2-D codes developed at CISAS, which simulate plasma acceleration during vacuum expansion.

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“…HE space industry is expected to develop safer and cheaper space transportation equipment by accelerating the entry of private entrepreneurial companies. In particular, small rockets are required for accelerating the launch demands of small satellites [1,2]. However, as body size decreases due to the restriction of internal area, various protuberances, such as feed pipes, cable ducts, auxiliary devices, and cameras, must be arranged outside of vehicles.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Investigations of Slender Body Side Force with Asymmetric Protuberances

Kawauchi

Harada

Kitamura

et al. 2019

Journal of Spacecraft and Rockets

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Typical space transportation vehicles have various asymmetric protuberant devices on their surfaces, such as cable ducts and side jet motors. Such protuberances, when arranged asymmetrically with respect to the vehicle axis, are known to cause asymmetric vortices that produce side force. In this study, to understand effects of side force and its associated flow fields, both wind tunnel tests and numerical calculations for a slender body with an asymmetric protuberance were conducted at a wind speed of Mach 1.5. The results of computed aerodynamic coefficients are in good agreement with the experimental results and detailed flow structures are provided. In particular, the results revealed that side force was generated by two factors. It linearly increased as vortices detached from the body and nonlinearly increased based on the effects of secondary vortex scale as the angle of attack increased. Additionally, the axial position and azimuthal angle (angle along the circumferential direction around the body axis) of the protuberance strongly influenced side force characteristics. First, the side force was significantly higher when the protuberance was installed in a forward axial position. Second, when the protuberance was installed on the leeward side of the slender body (upper side), the side force increased with the angle of attack. These results are not limited to the presented configuration and can be applied to other rocket designs for cost reduction and safety enhancement.

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Operation of an Annular Helicon Plasma Source

Cited by 4 publications

References 7 publications

Comment on “Plasma ionization by annularly bounded helicon waves” [Phys. Plasmas 13, 063501 (2006)]

Comment on “Plasma ionization by annularly bounded helicon waves” [Phys. Plasmas 13, 063501 (2006)]

Performance Analysis of a Medium-Power Helicon Thruster

Experimental and Numerical Investigations of Slender Body Side Force with Asymmetric Protuberances

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