The afternoon poster session included over twenty exhibitors presenting their work on important issues in vacuum electronics. There was an eclectic array of posters covering everything from the peniotron to frequency multiplier grid arrays. Industry, academia and government institutions were all well represented. There was excellent participation from the Far East with representatives traveling from Korea and Taiwan to present posters on PIC codes for magnetron analysis and properties of high-pressure discharge in plasma-panel displays.

Several posters were presented on electron devices including a tunable klystron, a multiple beam klystron, peniotron, magnetron, and microwave power module. Several microwave components were discussed in papers on electron guns for sheet beam klystrons, low back flow collector design, and rf window designs for wideband and high power applications.

Posters related to systems included the work presented by the group from DTI on solid-state high voltage modulators used to operate high power vacuum devices. The switching power supply and solid-state modulator used in the AN/SPG-60, the 50 kilovolt switches used in the test stand for the AN/SPS-49 klystrons and the replacement power supply and arc detection system for the C-band TWT driven MIR radar were all mentioned in the poster. The aptly named "magic modulator" which produces 65 kilovolts switching at up to 400 kilohertz was discussed in this poster as well.

The modulator for the Next Linear Collider, which will operate at 500 kV and 265 amps with 3.2 microsecond pulses at 180 hertz was presented in a separate poster. This hybrid modulator utilizes a solid state switch and a pulse transformer. Two other design approaches, one utilizing a transformerless hard switch and another using a Marx Bank were also presented.

Several posters relating to the modeling and performance of electron guns were displayed. These included the poster of the sheet beam klystron gun that is being developed for the Stanford Linear Accelerator by Calabazas Creek Research. The objective is to develop a sheet beam cathode that will operate at 415 kilovolts and 250 amps. This design is required to alleviate the space charge issues that arise and which limit the current that can be generated at high voltages. Posters were presented on the negative grid gun and on predicting electron gun life expectancy, both by representatives of CPI, Inc. Semicon hosted a presentation of acceptance and workmanship issues related to cathode manufacturing.

Device modeling was a theme that was well covered in the poster session. There were posters covering CFA noise, and modeling of a rising-sun magnetron oscillator. There was also a late entry poster describing recent successful results obtained in modeling a helix device using HFSS.

The diverse expertise represented in the material presented at the afternoon poster session was impressive. Individuals from the Stanford Linear Accelerator Center, University of California Davis, Fermi National Accelerator Laboratory, Kwangwoon University, Ajou University Suwon, and Seoul University, Seoul, Korea, National Chiao University and Chung-Shan Institute of Science and Technology, Taiwan were contributors to the session. Industry representation was lead by Calabazas Creek Research, Communications and Power Industries, KMW of Kyungki-do, Korea, Semicon and Diversified Technologies. Other participants represented Defense Science and Technology, Portsmouth, U.K. and Microwave and Antenna Systems, Malvern, U.K.

Judging from the interactions that occurred during the afternoon poster session, the exhibit was a success. Access to the researchers was excellent and a dissemination of the current state of the art was achieved. We look forward to the next IVEC with anticipation of advances to be made in the coming year.