A tubular radiation absorbing device (1) designed for a solar heating
application is described. The tubular radiation absorbing device has a
metal central tube (3) and a glass tubular jacket (2) surrounding the
central tube (3). A folding bellows (11) is connected between the central
tube (3) and the tubular jacket (2), so that the tubular jacket and the
central tube are movable relative to each other. A connecting element
(20) connects an inner end of the folding bellows (11) with the central
tube (3) and extends from the inner end of the folding bellows (11)
through an inner annular space (30) between the folding bellows (11) and
the central tube (3). The connecting element includes at least a part of
a hydrogen window (50). A getter (6) is arranged in an outer annular
space (33) between the folding bellows (11) and the tubular jacket (2).