We report that the measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of ...Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.
A high-capacity (128-line) photonic space-division switching system prototype has been developed. All of the developments on polarization-independent LiNbO/sub 3/ matrix switches, semiconductor ...optical amplifiers for network loss compensation and three-dimensional optical interconnections for multi-stage switching networks combine to enlarge line capacity. The system is devised to provide both HDTV distribution services that require nonblocking connections and TV phone services that do not necessarily require these connections. It is confirmed that the system has been operating in providing 150 Mbps TV phone services and 600 Mbps HDTV distribution services with high stability. Thus, the system proves to be promising for STM broadband switching systems capable of providing high-speed continuous dense bit-stream services. The system, in concert with an ATM broadband switching system, could provide a full range of cost-effective broadband services from POTS (plain old telephone services) to HDTV.< >
