GB850312A - High-power x-ray tube - Google Patents

Abstract

850,312. X-ray tubes. LICENTIA PATENTVERWALTUNGS G.m.b.H. Jan. 2, 1957 [Jan. 2, 1956; April 7, 1956], No. 188/57. Class 39(1). An X-ray tube anode serving at the same time as a window, provided with liquid cooling and so dimensioned that its specific loading is not more than 40 W/mm<SP>2</SP> while the total anode loading is at least 2 Kw, is divided into individual sections by line-shaped or stripshaped reinforcements. In the construction shown the anode window 11, e.g. of copper, has a part-cylindrical surface and the cathode consists of a plurality of parallel heating coils 6 connected in parallel and having their axes on a cylindrical surface coaxial with the anode surface. A Wehnelt cylinder 20 modifies the shape of the equipotential planes such as 8 to prevent electrons impinging on the frame 22 of the anode window 11. The latter is provided with ribs 12 dividing the surface into a number of portions each opposite one of the cathode coils 6. The ribs 12 may be extended to the outer wall 18, e.g. of aluminium, thus dividing the cooling space into sections each of which may have its own connections at the points indicated by crosses 16. Alternatively the anode window 11 and/or the outer wall 18 may be corrugated and welded together to provide a plurality of cooling passages, Figs. 5-9 (not shown). In an alternative construction Fig. 1 (not shown), the anode window is a heat disc backed by a thin sheet of a heavy metal such as gold and divided into individual sections by ribs which project towards an outer cooling jacket. The cathode is a wire wound spirally to follow the surface of a section of a sphere. The anode window may also be curved to form a section of a sphere. The size of the radiation field may be varied for purposes of economy when irradiating objects of different sizes by providing a plurality of exchangeable cathode and/or anode systems or by electrostatically shielding or switching cathode filaments or parts thereof.