Achievement of Broad Acceleration Profile for Launching Active Transient Internal Probes
Abstract
The Transient Internal Probe (TIP) is a diagnostic for the direct measurement of internal local magnetic or electric fields with high spatial and temporal resolution (1 cm, 1 MHz). A two-stage light-gas gun launches an optic probe at high velocity (1.5 km/s ∼ 1.8 km/s) so that the probe can transit the plasma before severe ablation occurs. The polarization change of a light, retroreflected after double-pass through the probe, provides one component of the field measurements along a chord of a plasma. A Faraday rotator glass or a Pockels cell has been used for the present passive optic probes. Active probes, currently in development, utilizing on-board sensor and electronics will allow measurements of multi-parameters including 3-D magnetic- and electric fields, plasma temperature, and density. The frequency-modulated sensor information will be transmitted to the remote detector using a LED or a laser diode. At issue is whether the on-board microelectronic components will survive the high acceleration during launch. A recent study emonstrated the survivability of a standard size electronic circuitry on ∼ 25 mm diameter circuit board, launched in a rail-gun at ∼ 1 × 10^6 m/s^2 (0.1 Mg¡¯s). [1] Considering the size of the TIP probes, ( ∼ 5 mm in diameter) it is believed the TIP active probes with surface-mount electronic components will survive much higher accelerations, up to 2 × 10^6 m/s^2 or more. Experimental and numerical studies of the TIP light gas gun have been performed to achieve a launch condition that lowers the peak acceleration and broadens the acceleration profile of the probe. [1] K. A. Schroder et al, IEEE Transactions on Magnetics, 35(1), Jan. 1999
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2003
- Bibcode:
- 2003APS..DPPBP1018K