X-RAY TUBE WITH NEEDLE-LIKE ANODE

Mieczysław Słapa1, Włodzimierz Straś1, Marek Traczyk1, Jerzy Dora2, Mirosław Snopek1, Ryszard Gutowski3, Wojciech Drabik1

1The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk, Poland,
2Power Dora System, 110, S. Wyszynskiego Str., 50-307 Wroclaw, Poland,
3Uniquant, 14/9, Batalionu Parasol Str., 01-118 Warsaw, Poland


An X-ray tube with a needle-like anode (NAXT) built in our Laboratory, its design and basic operating parameters are presented. The process of electron beam forming and influence of external and internal magnetic fields is discussed. The tube properties essential from the point of view of its application in X-ray generators as well as disadvantageous thermal effects caused by flow of heat generated in the tube target to irradiated objects are discussed. The tube is almost a point-like source of X radiation emitted into 4p geometry; the dose-rates are on the order of 1 Gy/min at the distance of 10 mm from the anode cap. Preliminary tests show the tube may be useful in brachytherapy of cancer tumors of diameter up to 30 mm. The tube may also be an interesting device in widely understood field of irradiation techniques.