After the second annual progress report to DOE in July 1990, we continued the experimental work for another liquid system. The mathematical model was also improved to include secondary effects due to drop deformation and charge redistribution on the deformed drop surface. Originally, we planned to study a mass transfer process after the hydrodynamic modelling. Due to difficulty in measuring drop concentration during oscillations, we decided to study a heat transfer process instead. Using the analogy between the mass transfer and the heat transfer, we can easily extend the results for the heat transfer study to the mass transfer problem.

After the second annual progress report to DOE in July 1990, we continued the experimental work for another liquid system. The mathematical model was also improved to include secondary effects due to drop deformation and charge redistribution on the deformed drop surface. Originally, we planned to study a mass transfer process after the hydrodynamic modelling. Due to difficulty in measuring drop concentration during oscillations, we decided to study a heat transfer process instead. Using the analogy between the mass transfer and the heat transfer, we can easily extend the results for the heat transfer study to the mass transfer problem.

The properties of YBa{sub 2}Cu{sub 3}O{sub 7-x} superconducting tapes designed and fabricated into SAFIRE-type, encapsulated, grounding links by the Ceramic Engineering Department at Clemson University are under investigation. Testing at the Savannah River Site will include gamma irradiation, vibration, and long-term evaluation. The gamma irradiation portion of testing has been completed. The long-term testing began in January and will continue. The vibration test has yet to be started.

The properties of YBa{sub 2}Cu{sub 3}O{sub 7-x} superconducting tapes designed and fabricated into SAFIRE-type, encapsulated, grounding links by the Ceramic Engineering Department at Clemson University are under investigation. Testing at the Savannah River Site will include gamma irradiation, vibration, and long-term evaluation. The gamma irradiation portion of testing has been completed. The long-term testing began in January and will continue. The vibration test has yet to be started.

Progress during the second year of this program has been noteworthy in both theoretical and experimental areas. Two experiments on a CARM oscillator were performed and analysed. The first long-pulse operation of a CARM oscillator was carried out, with output powers of approximately 100 kW and operating efficiencies of approximately 2%. Much has been learned from the analysis of the first two experiments, and both the amplifier and oscillator experiments planned for the next year will benefit substantially from the knowledge gained during these oscillator experiments. We have installed and tested an new electron gun made by Thompson Tubes Electroniques of France. This gun has now operated at up to 580 kV on our modulator; use of this gun for the upcoming CARM experiments should result in a significant increase in performance due to a much better beam quality and the capability of operation at a much higher voltage. In the theoretical area, Year II has seen substantial improvements to the MIT CARM codes. The amplifier and oscillator codes have been successfully benchmarked against other codes, linear theory, aid experimental work. This includes the development of multimode CARM amplifier linear and nonlinear theory, the theory of harmonic CARMs, and the …