NOVELTY - The device has a collection unit (11) with a collection tube (21) placed on supports (23), which is formed by an inner absorber tube and an outer envelope tube, and reflectors (15, 15') directing radiation toward the collection tube. A set of vacuum pumps maintain the collection tube space between the inner absorber tube and the outer envelope tube at a pressure between 5asterisk10-1 - 5asterisk10-2 mbar when the device is operative. The outer envelope tube is formed by multiple segments that are united by joints.    USE - Radiation heat collection device.    ADVANTAGE - The device enables providing robust, controllable thermoelectric plants to ensure a minimum level of inoperativity, thus allowing for flexible, cost-optimized production and exploitation. The device provides thermoelectric plants to increase the interception factor, the effective surface in the absorber element and the yield. The device eliminates glass-to-metal-seal (GTMS) welds and reduces the shaded space per meter to provide greater effective surface. The device eliminates getter for hydrogen control. The possibility of fixed supports results in high optical yield, so that the dilation is absorbed at the end. The absorber tubes with a non-cylindrical geometry and an oval geometry improve the yield. The device is easy to assemble and to process. Gasifications are not required for high vacuum levels. The need for highly airtight joints is eliminated. The lower stresses to fatigue reduce the breaking of glass. The GTMS welds are not required and lower stresses are borne at the ends, so that the thickness of the glass outer envelope tube is reduced. The optical yield can be improved by better transmittance. The active management of the vacuum and the presence of hydrogen allow finding the location at each time and monitoring the evolution. The device is easy to manufacture. The device eliminates the need of using Getter systems and vacuum control elements in the closed chamber. The device provides greater precision of the position of the absorber tube with respect to the theoretical focal point.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a collection unit of a heat collection device.    Collection unit (11)    Reflectors (15, 15')    Central area of the guiding structure (17)    Collection tube (21)    Support (23)