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.
Belle DAQ system upgrade at 2001
Abstract We renewed the data acquisition system for the Belle experiment. Previous data acquisition system, which has been used since December 1998, did not have level 2 trigger facility. To improve the data reduction factor and total throughput, we replaced event builder, online computer farm and the storage system. The event builder and online computer farm are unified into one system. This event building farm uses commodity hardware and newly appended level 2 trigger functionality. This data acquisition system started its operation since last autumn and is very stable. We took 36 fb −1 with new DAQ system, it had already overtaken 30 fb −1 that is total amount of previous DAQ system.
New Low-Profile Applicators for Local Heating of Tissues
A new type of low-profile applicator is described giving efficient power transfer to tissue with low leakage. It consists of a resonant element spaced from a ground plane by low-loss material having high relative permittivity and some relative permeability. This combination is covered by similar material which can be placed in direct contact with the tissue to be heated, or separated from it by a water bolus as required. Laboratory measurements using phantom materials show that these applicators are well matched and produce well defined and relatively uniform heating profiles. Applicators having maximum dimensions of 3-15 cm covering the frequency range 1000-100 MHz, respectively, are described. Penetration depths of at least 4 cm at 100-200 MHz are achieved. Tests on anesthetised pigs and some clinical assessment have confirmed the usefulness of this compact low-frequency type of applicator and have shown that performance compares favorably with that of other recently reported types. The design can be optimized for treatment of specific sites, and suitable choice of dimensions and electrical characteristics of the layer material allow the low-profile concept to be extended over a wide range of operating frequencies.