Possible benefit of longer $L^*$ for detectors at ILC

Abstract

In the present design of ILC, $L^*$, the distance between the interaction point (IP) and the front surface of the final focusing magnet (QD0), is 4.1 m. The QD0 is supported from the detector platform by a cantilever type support or from the detector itself. This design could cause several difficulties in smooth operation of ILC or in maintenance of detectors. These difficulties could be mitigated by adopting longer $L^*$ optics. In this article, we discuss possible benefit of longer $L^*$ for detectors.