Serial-bus based trigger timing distribution system
We have developed a serial-bus based trigger timing distribution system to handle the trigger and related timing signals over more than one thousand newly developed pipeline data acquisition modules for the Belle detector at the KEKB storage ring and for the SuperKEKB upgrade. The main idea is the use of 10-bit serial-bus lines over an inexpensive, compact and widely available enhanced category-5 shielded twist pair (STP) copper cable. The serial-bus is operated at 42.33 MHz, resulting in a 508 Mbps serial data transfer over the STP cable up to a distance of 15 m. The entire system consists of only three types of modules. The system is highly scalable by cascading switch modules over multiple stages: we use 4 stages to handle up to 4096 readout modules. We have proved that the basic technology is suitable for such an application. A two-step integration procedure before the full replacement is planned to integrate the system into the running Belle data acquisition system.
Data acquisition system for the Belle experiment
We built a data acquisition system for the Belle experiment at the KEK B-factory. The system is designed to record the signals from the detectors at 500 Hz trigger rate with a less than 10% dead time fraction. A typical event size is 30 kbyte, which corresponds to a data transfer rate of 15 Mbyte/s. The main components are two kinds of detector readout systems, an event builder, an online computer farm and a data storage system. The system has been reliably in operation at the design performance for a half year. We have completed cosmic-ray data taking for 2.5 months and started physics data taking on Jun. 1, 1999.
The REX-ISOLDE project
The Radioactive Beam Experiment REX-ISOLDE [1–3] is a pilot experiment at ISOLDE (CERN) testing the new concept of post acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In order to prepare the ions for the experiments singly charged radioactive ions from the on-line mass separator ISOLDE will be cooled and bunched in a Penning trap, charge bred in an electron beam ion source (EBIS) and finally accelerated in the LINAC. The LINAC consists of a radiofrequency quadrupole (RFQ) accelerator, which accelerates the ions up to 0.3 MeV/u, an interdigital H-type (IH) structure with a final energy between 1.1 and 1.2 MeV/u and three seven gap resonators, which allow the variation of the final energy. With an energy of the radioactive beams between 0.8 MeV/u and 2.2 MeV/u a wide range of experiments in the field of nuclear spectroscopy, astrophysics and solid state physics will be addressed by REX-ISOLDE.