Search

Demand for zircon and titanium minerals is increasing and Victoria is well placed to capitalise on this interest. It has large, undeveloped high grade mineral sands deposits in the Murray and Gippsland Basins, excellent infrastructure for supplying power and transport, and the government is in the process of streamlining and improving mineral resource legislation. The Murray Basin is estimated to hold resources of more than 140 000 000 t TiO2 and 40 000 000 t zircon in two main types of deposit: coarse-grained, linear strandline accumulations and finer-grained Wimmera Industrial Minerals (WIM)-style deposits. Coarse-grained deposits have grades of 5% to 20% heavy mineral but are of relatively low tonnage. They are currently being mined for zircon and rutile, having produced 117 314 tonnes rutile, 90 671 t zircon and 27 904 t ilmenite in 2010. The WIM-style deposits could be extremely favourable for future development in the current economic conditions; heavy mineral grades are lower than those of the coarse-grained deposits, but tonnages are higher and the ore has a favourable mineral assemblage. The very fine-grained nature of the deposits, however, could present difficulties in recovery and upgrading., Demand for zircon and titanium minerals is increasing and Victoria is well placed to capitalise on this interest. It has large, undeveloped high grade mineral sands deposits in the Murray and Gippsland Basins, excellent infrastructure for supplying power and transport, and the government is in the process of streamlining and improving mineral resource legislation. The Murray Basin is estimated to hold resources of more than 140 000 000 t TiO2 and 40 000 000 t zircon in two main types of deposit: coarse-grained, linear strandline accumulations and finer-grained Wimmera Industrial Minerals (WIM)-style deposits. Coarse-grained deposits have grades of 5% to 20% heavy mineral but are of relatively low tonnage. They are currently being mined for zircon and rutile, having produced 117 314 tonnes rutile, 90 671 t zircon and 27 904 t ilmenite in 2010. The WIM-style deposits could be extremely favourable for future development in the current economic conditions; heavy mineral grades are lower than those of the coarse-grained deposits, but tonnages are higher and the ore has a favourable mineral assemblage. The very fine-grained nature of the deposits, however, could present difficulties in recovery and upgrading.

A radiation-hard CMOS/SOS technology has been used to fabricate a complex LSI circuit containing over 2200 transistors. The circuit is an eight bit wide arithmetic and logic unit (ALU) slice. This paper describes the results of electrical, temperature, and radiation tests on the ALU circuit. An instruction cycle-time of less than 240 ns was achieved for nominal operation at +11V and 25 C. This time increases to 300 ns at 125 C. After irradiation to 1 mega rad. (SI) under bias, operation was degraded only slightly. The 25 C and 125 C postradiation cycle times were within 320 and 360 ns, respectively. Radiation tolerance from part to part and lot to lot excellent, thus demonstrating the applicability of radiation hard CMOS/SOS to LSI circuitry. (Author), Presented at the Conference on Magnetism and Magnetic Materials (23rd) 8-11 Nov 77, Minneapolis, MN.

This report summarizes the results of Phase I of a three-phase program to develop and verify hardening techniques in Complementary-Symmetry/Metal Oxide Semiconductor (CMOS) Large Scale Integrated (LSI) circuits fabricated with Silicon-on-Sapphire (SOS) technology. The Phase I study examined, experimentally, the effects of threshold voltage shifts on the electrical performance and transient radiation response in basic CMOS/SOS circuits. Simple CMOS/SOS test circuits, including an inverter, a 2-input NAND gate and a 2-input NOR gate, were fabricated with a 5 x 5-matrix of p-channel and n-channel threshold voltages. Results of electrical measurements are reported which show the variations that can be expected in electrical operation of these circuits, arising from the matrix of threshold voltage combinations. These threshold voltages can result from exposure to ionizing radiation or instability in the gate insulator material. Results of transient radiation measurements are reported which show the transient failure levels that can be expected in CMOS/SOS circuits and the significance of different threshold voltage combinations and sapphire photoresistive effects on the transient radiation hardness. (Author), See also Volume 2, AD-A021 644.