Planar Dynode Multipliers for High-Speed Counting

The WX 30006 and WX 5009, whose characteristic are summarized in Table I, are just two representatives of a whole family of high-speed tubes which can be constructed using the building blocks at hand. Many trade offs ar possible allowing one to design a tube tailore to a specific application. All tubes incorporating planar dynode multipliers have several features in common, some of which are enumerate below: 1. Uniform and close spacing of dynodes in a plane parallel geometry, combined with high voltage per stage, allowing a substantial reduction in transit time fluctuations as wel as total transit time. 2. Absence of positive ion feedback (owing to the compartmentalized structure of the tube) resulting in virtual eliminatio of after pulses. 3. Ability to operate in the presenc of relatively intense magnetic fields because of the close spacings, high voltages, and guardring effect of the kovar mounting flanges. All TSE tubes have operated effectively in axial fields in excess of 1200 gauss, and there is no reason to suspect that the gain would suffe appreciably even in axial fields of 20 Kilogauss. There are, however, two possible limitation n the usefulness of these tubes which frankly require further investigation: 1. At present the life of these devices is only imperfectly understood. 2. The high voltage required for operating these tubes will in many cases pose problems which require some imagination for their solution.