The cooling systems of the calorimeters and tracking sub-detectors of the L3 experiment

Due to the compact geometry of the tracking sub-detectors and calorimeters of the L3 experiment, a large amount of heat (about 28 kW) is dissipated in a small volume and partly in hardly reachable locations. This heat, if not removed, would result in malfunctioning of these sub-detectors and even in their components damaging. Heat transfer to near irrigating cooling fluid (water, silicon oil) proved to be an efficient way to reach the required temperature stability and uniformity during long periods of data acquisition. Safe working conditions were obtained thanks to a newly developed leakless system. In this paper, we describe the studies and tests performed to achieve these goals.