138 research outputs found
The monitoring system for the aerogel Cherenkov counter of the BELLE detector
We report on a design and performances of a monitoring system developed for
the aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists
of blue LEDs, a diffuser box, and optical distributors which distribute the LED
light to the ACC modules. The employed LED (NSPB series) has been observed to
have high reliability on the long term stability and the temprature dependence.
The diffuser box is employed to reduce the intrinsic non-uniformity of the LED
light intensity. The overall performances of the present monitoring system on
uniformity and intensity of the light output have been found to satisfy all the
requirements for the monitoring.Comment: 24 pages, LaTeX, 13 eps figures, to be published in Nucl. Instrum.
and Meth. A. Postscript file (4.5 MB) is available at
http://www-hep.phys.saga-u.ac.jp/~murakami/paper/xxx_accmon.p
On the Connection Between the Stability of Multidimensional Positive Systems and the Stability of Switched Positive Systems
In this work, we study the connection of the stability of multidimensional positive systems with the stability of switched positive systems. In a previous work, we showed that the stability of a multidimensional positive system implies the stability of a related switched positive system. Here, we investigate the reciprocal implication
Results of the Excitation Test of the LHD Helical Coils Cooled by Subcooled Helium
Large helical device, the largest superconducting stellarator, has been operated for the research of fusion plasma since 1998. The toroidal field of almost 3 T is produced by a pair of pool-cooled helical coils, in the innermost layers of which a normal-zone had been induced several times at the bottom of the coil at higher currents than 11.0 kA. Since the field is not the highest there, the local cooling conditions are probably deteriorated by bubbles gathered by buoyancy. In order to improve the cryogenic stability by subcooling, an additional cooler with two-stage cold compressors was installed at the inlet of the coil in 2006. The inlet and outlet temperatures of the coils were successfully lowered to 3.2 K and 3.8 K, respectively, with a mass flow of 50 g/s. In spite of a half charging rate to reduce AC losses, a normal-zone was induced near the top of the coil at 11.45 kA. It propagated to one side and stopped near the inner equator, where the field is the highest. In comparison with the stability tests with a model coil, the local temperatures of the innermost layers near the top is considered to have been raised up to almost the saturated temperature of 4.4 K by charging. The excitation method was revised to waiting cool-down at 11.0 kA, and the excitations up to 11.5 kA have been attained
Prescription sequence symmetry analysis: assessing risk, temporality, and consistency for adverse drug reactions across datasets in five countries
published_or_final_versio
Monte-Carlo Simulation for an Aerogel Cherenkov Counter
We have developed a Monte-Carlo simulation code for an aerogel \v Cerenkov
Counter which is operated under a strong magnetic field such as 1.5T. This code
consists of two parts: photon transportation inside aerogel tiles, and
one-dimensional amplification in a fine-mesh photomultiplier tube. It simulates
the output photoelectron yields as accurately as 5% with only a single free
parameter. This code is applied to simulations for a B-Factory
particle-identification system.Comment: 40 pages, latex(article), 19 figure
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