Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment
- Plasma Physics Group, Institute of Applied Physics, Goethe University, Frankfurt am Main 60438 (Germany)
We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH{sub 2} with 2.8% H{sub 2} served as the discharge medium. H{sub 2} was chosen in order to observe the broadening of the H{sub β} emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 10{sup 16} cm{sup −3}. Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.
- OSTI ID:
- 22408376
- Journal Information:
- Physics of Plasmas, Vol. 22, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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