Initial boronization of PBX-M using ablation from solid boronized probes
- Princeton Univ., NJ (United States); and others
Boronization was performed by plasma ablation of two solid boronized target probes. Probe-1, in a mushroom shape, consisted of a 10.7% boronized two-dimensional carbon-carbon composite containing 3.6 g of boron in a B[sub 4]C binder. Probe-2, in a rectangular shape, consisted of an 86% boronized graphite felt composite containing 19.5 g of 40-[mu]m boron particles. Probe-1 boronization deposited [approximately]26 monolayers of boron. After boronization with Probe-1, the loop voltage in 1-MW neutral-beam-heated plasmas decreased 27%, and volt-second consumption decreased 20%. Strong peripheral spectral lines from low-Z elements decreased by factors of [approximately]5. The central oxygen density decreased 15 to 20%. Carbon levels initially increased during boronization but were significantly reduced after boronization. The total radiated power during neutral beam injection decreased by 43%. Probe-2 boronization deposited [approximately]70 monolayers. Probe-2 boronization exhibited similar improved plasma conditions, but for some parameters, a smaller percentage change occurred because of the previous boronization with Probe-1. The ablation rates of both probes were consistent with front-face temperatures above the boron melting point. The results demonstrate the performance of two different boronized probe materials and the relative simplicity and effectiveness of solid target boronization as a convenient, real-time impurity control technique. 20 refs., 10 figs., 1 tab.
- OSTI ID:
- 6751715
- Journal Information:
- Fusion Technology; (United States), Vol. 25:4; ISSN 0748-1896
- Country of Publication:
- United States
- Language:
- English
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