Stable dee-shaped plasmas with a height-to-width ratio of approximately 1.5 have been obtained in Doublet III. The maximum achievable plasma current increased with elongation and a 1-MA stable discharge was achieved at the greatest elongation. A maximum line-averaged density of 6.8 × 1013 cm−3 was attained. Metal impurity contamination was not serious in the high-density discharges.