| 摘要 |
A radiation energy beam for example a laser beam (5) is directed coaxially onto a conical mirror (3) such that the beam is deflected to the radiation field which forms an angle with and extends around the axis of the conical mirror. An annular internally reflecting frusto-conical mirror (1) receives the radiation field and deflects same onto a second annular frusto-conical internally reflecting mirror (2) which deflects the radiation field toward the axis of the mirror (2). An article (6,8,9) having a circumferential area to be treated by means of the field, is placed with its circumferential area coaxial with the mirror (2) such that the circumferential area is hit by the field (50). The circumferential area of the article can consist of a tubular thermoplastics sleeve (8) which tightly surrounds the thermoplastic tube (9) to which the sleeve is to be heat sealed. |
