|CERN AC Note (2000-03)-General description of the CNGS Project|
|3. Underground structures|
The target chamber will be a cylindrical structure 115 m long with a diameter of 6.50 m. At the upstream end it widens out to a diameter of 8.50 m over a length of 15 m and will be linked to the proton beam tunnel by a junction tunnel 8 m long and 9 m in diameter. The access tunnel will be linked to the proton beam tunnel via the same junction.
Running parallel to the target chamber will be a service gallery 148 m long with a diameter of 3.40 m. The target chamber and the service tunnel are to be linked by six cross-passages 1.80 m in diameter allowing access to the target chamber for workers and power connections
|Figure 13: The target chamber and its annexes|
3.5 The decay tunnel
The decay tunnel will join the lower end of the target chamber and the upper end of the chamber for the hadron stop. It will be 992 m long with an internal height and width of 3.10 m. It will house a steel pipe with an internal diameter of 2.45 m, made of 6 m long sections welded in situ. The space between the steel pipe and the tunnel wall will be filled with concrete. There will be no access for persons or equipment between the target chamber and the hadron stop chamber.