In memoriam Dr. Walter P. Dyke (1914–1995)

IN MEMORIAM Dr. Walter P. Dyke (1914-1995) Dr. Walter Dyke believed that the field emission cathode was a unique electron source with desirable properties, and he believed in his ability to characterize the field emitter and to determine and fulfill the requirements for achieving controlled, stable, and long-life field electron emission, at the high intensity levels needed to improve the performance of a broad variety of devices, from high-power, very high frequency microwave tubes to fine focus electron optical devices to superpower flash X-ray systems and compact, high-voltage X-ray systems for medical radiology. This was the central goal of his professional career. Dr. Dyke started teaching physics and doing field emission research at Linfield College in 1948. He founded and directed Linfield Research Institute in 1955. He founded Field Emission Corporation in 1958 and directed Femcor until 1973 when it was acquired by Hewlett Packard (HP) who were particularly interested in medical radiography. Dr. Dyke was general manager of the McMinnville division of HP until 1975, when he retired from HP to devote more time to his responsibilities as trustee of the Murdock Foundation. But he remained interested in work on field emission devices and had regular contacts with Linfield Research Institute, Oregon Graduate Institute and FEI Co. until his death last February at the age of 80. In his late years, Dr. Dyke was satisfied with his accomplishments, particularly in flash X-ray, but he was disappointed that he had not been able to more fully develop applications of field emission in other areas. However, Dr. Dyke created and directed the group in McMinnville who pioneered in understanding, controlling and enhancing the performance of field emission cathodes. He organized the first Field Emission Symposium at Linfield College in 1952, and his classic papers in the 50's and 60's laid a solid foundation that other groups have built on in recent years. The fact that several hundred people are now actively engaged in device-oriented field emission work testifies to the validity of Dr. Dyke's vision and to the value and significance of his work. F. Charbonnier Linfield Research Institute