Abstract: A heatable cell for photoacoustic tests. The cell includes a specimen chamber which is connected with the microphone chamber of a detector microphone, and is provided with a specimen receiving portion and light admission window located across therefrom. A recess is located in the chamber closure and serves as the specimen receiving portion. The sealing surface of the chamber closure is sealingly pressed against a sealing surface of the chamber. At least one heating winding is provided on the chamber and/or on the chamber closure, and a thin-wall connecting tube having poor heat conducting characteristics is provided between the specimen chamber and the microphone chamber, which is arranged lower than the specimen chamber to prevent convection.

Abstract: The cylindrical peripheral wall (5) of a rotating hollow body mounted on a haft (1) driven by an electric motor within the stem casing of an X-ray tube is cooled with water supplied and removed respectively through co-axial ducts in the drive shaft, distributed by radial ducts in one end face of the rotary body to a ring duct and gathered from a ring duct at the other end face through another set of radial ducts leading back to the shaft. Between the two ring ducts the cooling medium flows through helical cooling ducts running parallel to each other and at an angle of about 15.degree. to the edge boundaries of the cylindrical operating surface. These ducts are formed on the outside by the anode peripheral wall material itself and on the inside by a stainless steel insert. The anode is degassed when its structure is soldered or brazed together in high vacuum at 1000.degree. C.