4π detector at multi-TeV hadron collider

What experiments would be like at a multi-TeV hadron collider and the feasibility of a general-purpose detector to uncover new phenomena in such a high energy machine are described. Although much R and D is needed in almost every part, a 4π detector can be built and operated at the maximum luminosity of up to 1033 cm-2s-1. But the detector must be necessarily big and costly. The typical size is about (20 m)3, the weight is about 20 ktons, the number of channels is about 1/2 million, and the cost is about 250 M$. The construction will take as many years as that of the machine itself. An intense program of R and D on every aspect must be vigorously pursued. (Mori, K.)