K. Tauchi

A common data acquisition system for high-intensity beam experiments

The J-PARC facility, which will be ready in 2008, is being constructed to perform a number of experiments including nuclear physics, kaon decays and neutrino oscillation. The expected data acquisition rate ranges from 500 Hz to 10 kHz, which is significantly higher than those used in the existing small experiments at KEK. We have developed a new data acquisition system that can be used in a wide range of experiments at J-PARC. The system consists of a KEK-VME crate, a readout platform module and peripheral modules. The readout platform module is highly modularized, having four slots to install daughter cards for digitization and three PCI mezzanine card (PMC) slots for on-board data processing and other purposes. The performance of the platform module and a model setup of the data acquisition system are reported

Near muon range detector for the K2K experiment: Construction and performance

A muon range detector (MRD) has been constructed as a near detector for the KEK-to-Kamioka long-baseline neutrino experiment (K2K). It monitors the neutrino beam properties at the near site by measuring the energy, angle and production point of muons produced by charged-current neutrino interaction. The detector has been working stably since the start of the K2K experiment.

Modular pipeline readout electronics for the SuperBelle drift chamber

In order to explore new physics in B-meson decays we plan to upgrade the KEK B-factory to a luminosity of 5/spl times/10/sup 35/ cm/sup -2/ s/sup -1/. In parallel we are developing a new pipelined data acquisition system for the Belle detector to cope with higher trigger rates of up to 30 kHz and severe background conditions. In order to reduce development and maintenance costs, we have adopted a modular design for these new readout electronics. The chosen architecture consists of a common readout platform, upon which are mounted subdetector specific parts, customized to meet the readout requirements of each sub detector component. As an example of this new architecture, we present in this paper the design of drift chamber electronics. The drift chamber readout utilizes the AMT-3 time-to-digital converter chip, originally developed for the ATLAS experiment, which satisfies the performance requirement for current and future Belle drift chamber readout. A data transfer performance test with emulation modules, mounted on the common platform, shows that the new readout electronics works well at a more than 30 kHz input trigger rate.

A common data acquisition system for high intensity beam experiments

The J-PARC facility, which will be ready in 2008, is being constructed to perform a number of experiments including nuclear physics, kaon decays and neutrino oscillation. The expected data acquisition rate ranges from 500 Hz to 10 kHz, which is significantly higher than those used in the existing small experiments at KEK. We have developed a new data acquisition system that can be used in a wide range of experiments at J-PARC. The system consists of a KEK-VME crate, a readout platform module and peripheral modules. The readout platform module is highly modularized, having four slots to install daughter cards for digitization and three PCI mezzanine card (PMC) slots for on-board data processing and other purposes. The performance of the platform module and a model setup of the data acquisition system are reported

Performance of the AMT-3 based TDC system at Belle

The KEKB storage ring for a B-factory experiment at KEK, Japan, has been breaking the luminosity record of e+e- colliders. Now the luminosity reaches 1.6 times larger than the designed luminosity. The Belle detector at KEKB uses a traditional readout method based on the trigger and delay: almost all of the digitizer is the same FASTBUS TDC whose intrinsic deadtime is not negligible in a recent high luminosity condition. To accommodate more higher luminosity, we developed new pipelined TDC module and its intrinsic deadtime is smaller than 10% of the current TDC. We report the performance of this TDC module.

Performance of fine mesh photomultiplier tubes designed for an undoped CsI endcap photon detector

Abstract We have developed two types of fine-mesh photomultiplier tubes for an undoped-CsI endcap photon detector installed in a strong axial magnetic field. These photomultiplier tubes have ultraviolet-transmitting glass windows, backed by large-area bialkali photocathodes, in order to efficiently detect scintillation light from undoped-CsI crystals. A gain of more than 2 × 10 5 , in a magnetic field of 1.0 T, was obtained from these tubes with 19-stage fine-mesh dynodes. Gain drops caused by the magnetic field and by high anode currents were investigated. Several performance criteria of the tubes were studied: gain, quantum efficiency, linearity, noise, and transit time spread.

On-site background measurements for the J-PARC E56 experiment: A search for the sterile neutrino at J-PARC MLF

The J-PARC E56 experiment aims to search for sterile neutrinos at the J-PARC Materials and Life Science Experimental Facility (MLF). In order to examine the feasibility of the experiment, we measured the background rates of dierent detector candidate sites, which are located at the third oor of the MLF, using a detector consisting of plastic scintillators with a ducial

Front-end electronics of double SOI X-ray imaging sensors

We have developed monolithic CMOS pixel sensor using fully-depleted (FD) silicon-on-insulator (SOI) pixel process technology. The SOI substrates consist of high-resistivity silicon with p-n junctions and low-resistivity silicon layers for forming SOI-CMOS circuitry. Tungsten vias are used to make connections between p-n junctions in the silicon substrate and the first metal layers in the top-layer circuitry. Using this sensor construction, high sensor gain in small pixel areas can be achieved. In 2014, a high-resolution, integrated SOI pixel sensor, called INTPIX8, was developed with two types of substrates: a float-zone, p-type layer on a single SOI (SSOI) wafer and a Czochralski, p-type layer on a double SOI (DSOI) wafer. The X-ray spectra were obtained using Am-241 radiation source. The SSOI-based and DSOI-based sensors exhibited different levels of sensor gain and there were no large differences in the noise levels between them.

SOI monolithic pixel detector

We are developing monolithic pixel detector using fully-depleted (FD) silicon-on-insulator (SOI) pixel process technology. The SOI substrate is high resistivity silicon with p-n junctions and another layer is a low resistivity silicon for SOI-CMOS circuitry. Tungsten vias are used for the connection between two silicons. Since flip-chip bump bonding process is not used, high sensor gain in a small pixel area can be obtained. In 2010 and 2011, high-resolution integration-type SOI pixel sensors, DIPIX and INTPIX5, have been developed. The characterizations by evaluating pixel-to-pixel crosstalk, quantum efficiency (QE), dark noise, and energy resolution were done. A phase-contrast imaging was demonstrated using the INTPIX5 pixel sensor for an X-ray application. The current issues and future prospect are also discussed.

CsI endcap photon detector for a K/sup +//spl rarr//spl pi//sup +//spl nu//spl nu

We have constructed an endcap photon detector with undoped Cesium Iodide (CsI) crystals for K + →π + νν experiment E787 at Brookhaven National Laboratory (BNL). To reject backgrounds it is essential to have a photon detection system with high efficiency. Good resolution for timing and energy is critical for reducing accidental vetoes in a high-counting-rate environment. The endcap detector is located in a 1 T magnetic field. Fine-mesh photomultiplier tubes are attached directly to the crystals for efficient light collection, and the fast-decay component of the CsI light output is selected by optical filters. The tube gains are monitored with the light from a xenon flash lamp and from light pulsers. The pulse shapes are recorded by transient digitizers based on charged coupled devices (CCDs), which enables precise determination of timing of endcap signals. The construction and performance of the detector are described.The authors have constructed an endcap photon detector with undoped Cesium Iodide (CsI) crystals for K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} experiment E787 at Brookhaven National Laboratory (BNL). To reject backgrounds it is essential to have a photon detecting system with high efficiency. Good resolution for timing and energy is critical for reducing accidental vetoes in a high-counting-rate environment. The endcap detector is located in a 1 T magnetic field. Fine-mesh photomultiplier tubes are attached directly to the crystals for efficient light collection, and the fast-decay component of the CsI light output is selected by optical filters. The tube gains are monitored with the light from a xenon flash lamp and are monitored with the light from a xenon flash lamp and from light pulsers. The pulse shapes are recorded by transient digitizers based on charged coupled devices (CCDs), which enables precise determination of timing of endcap signals. The construction and performance of the detector are described.We have constructed an endcap photon detector with undoped cesium iodide (CsI) crystals for K/sup +//spl rarr//spl pi//sup +//spl nu//spl nu. >