Abstract
This paper describes a new method for momentum reconstruction of charged particles using multiple Coulomb scatterings in a nuclear emulsion detector with a layered structure of nuclear ...emulsion films and target materials. The method utilizes the scattering angles of particles precisely measured in the emulsion films. The method is based on the maximum likelihood to include the new information on the decrease of the energy as the particle travels through the detector. According to the Monte Carlo simulations, this method can measure momentum with a resolution of 10% for muons of ${500}\, {\rm MeV}/c$ passing through the detector perpendicularly. The momentum resolution is evaluated to be 10–20%, depending on the momentum and emission angle of the particle. By accounting for the effect of the energy decrease, the momentum can be reconstructed correctly with less bias, particularly in the low-momentum region. We apply this method to measure the momentum of muon tracks detected in the Neutrino Interaction research with Nuclear emulsion and J-PARC Accelerator (NINJA) experiment where the momentum is also measured independently by using the track range. The two measurements agree well within experimental uncertainties, verifying the method experimentally. This method will extend the measurable phase space of muons and hadrons in the NINJA experiment.
Performance of multi-pixel photon counters for the T2K near detectors Yokoyama, M.; Minamino, A.; Gomi, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2010, Volume:
622, Issue:
3
Journal Article
Peer reviewed
Open access
We have developed a Multi-Pixel Photon Counter (MPPC) for the neutrino detectors of T2K experiment. About 64,000 MPPCs have been produced and tested in about a year. In order to characterize a large ...number of MPPCs, we have developed a system that simultaneously measures 64 MPPCs with various bias voltage and temperature. The performance of MPPCs are found to satisfy the requirement of T2K experiment. In this paper, we present the performance of 17,686 MPPCs measured at Kyoto University.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
Fast neutrons are a large background to measurements of gamma-rays emitted from excited nuclei, such that detectors that can efficiently distinguish between the two are essential. In this ...paper we describe the separation of gamma-rays from neutrons with the pulse shape information of the CsI(Tl) scintillator, using a fast neutron beam and several gamma-ray sources. We find that a figure of merit optimized for this separation takes on large and stable values (nearly 4) between 5 and 10 MeV of electron equivalent deposited energy, the region of most interest to the study of nuclear de-excitation gamma-rays. Accordingly, this work demonstrates the ability of CsI(Tl) scintillators to reject neutron backgrounds to gamma-ray measurements at these energies.
Measurement of the precise position of a high activity iridium-192 (192Ir) source during high-dose-rate (HDR) brachytherapy is desired to detect the mispositioning of the source and avoid incidents. ...Although real-time imaging of the source position using a high-energy gamma camera is a possible method for this purpose, electronics are saturated at small distances from the source because the 192Ir source activity is so high. To solve this problem, we developed a low-sensitivity high-resolution gamma camera. We used a 1-mm-thick cerium-doped yttrium aluminum perovskite (YA1O3: YAP(Ce)) scintillator plate to reduce sensitivity. The developed low-sensitivity gamma camera consists of this thin YAP(Ce) scintillator optically coupled to a flat panel photomultiplier tube (FP-PMT). It is encased in a 20-mm-thick tungsten shield with a 0.5-mm diameter pinhole collimator mounted on its head. The spatial resolution of the gamma camera at 100 mm from the 192Ir source was 3.3 mm FWHM and the sensitivity was 0.52 cps/MBq. The count rate of the camera was ∼180-k cps at 100 mm from the 212.4-GBq 192Ir source and real-time imaging of the 192Ir source was possible. With a 100-mm-thick water phantom positioned between the gamma camera and the 192Ir source, we decreased the count rate to half, but the 192Ir source images could be observed clearly. We conclude that the developed low-sensitivity high-resolution gamma camera system has the potential to be a new real-time imaging system for HDR brachytherapy.
Abstract
A high-pressure xenon gas time projection chamber, with a unique cellular readout structure based on electroluminescence, has been developed for a large-scale neutrinoless double-beta decay ...search. In order to evaluate the detector performance and validate its design, a 180 L size prototype is being constructed and its commissioning with partial detector has been performed. The obtained energy resolution at 4.0 bar is 1.73 $\pm$ 0.07% (FWHM) at 511 keV. The energy resolution at the $^{136}$Xe neutrinoless double-beta decay $Q$-value is estimated to be between 0.79 and 1.52% (FWHM) by extrapolation. Reconstructed event topologies show patterns peculiar to the track endpoint that can be used to distinguish $0\nu\beta\beta$ signals from gamma-ray backgrounds.
The angular dependence of columnar recombination in xenon (Xe) gas, if observed for low energy nuclear tracks, can be used for a direction-sensitive dark matter search. We measured both scintillation ...and ionization yields to study columnar recombination for 5.4 MeV alpha particles in a high pressure gas detector filled with Xe gas at a pressure of 8 atm. Because the recombination photons are emitted several microseconds after de-excitation, the scintillation photons are separated into fast and slow components. While the fast component is not dependent on the track angle relative to the drift electric field, the slow component increases when the track is aligned with the electric field. This result indicates that the track angle relative to the electric field can be reconstructed from the scintillation time profile.
OBJECTIVE:It is well known that the renin angiotensin system (RAS) plays a pivotal role in the development of diabetic nephropathy (DMN). Recent genome-wide association studies have identified a ...number of common genetic variants associated with blood pressure variation in east Asians. One of such loci is angiotensinase A (ENPEP), which converts the angiotensin II to angiotensin III in the RAS. We therefore tested the hypothesis that genetic variants of ENPEP could show significant association with prevalence of DMN.
DESIGN AND METHOD:We enrolled consecutive 345 subjects who had consulted our hospitals for type 2 diabetes. They consisted of cases with nephropathy (57.1 %) and controls (42.9%). Genomic DNA was isolated from human leukocytes by QIAamp kit. Genotypes were assayed with genomic DNA for a C/T variant of ENPEP (rs6825911) using the StepOnePlus real-time PCR system by TaqMan method. Association between the genetic variant and the prevalence of DMN was tested.
RESULTS:The numbers of individuals with each genotype of ENPEP were as follows (CC, CT and TT)64, 93 and 40 for cases and 29, 84 and 35 for controls. Accordingly, the risk for DMN was 1.39 (95% confidence interval; 1.02–1.88), p = 0.03 for allelic comparison and also p = 0.03 for Armitageʼs trend test. Thus, a significant association with DMN was observed for the ENPEP variant with 1.4 times risk.
CONCLUSIONS:Thus, it is found that a genetic variant of ENPEP may have a significant impact on the onset of DMN.
For noble gas Time Projection Chambers (TPCs) in the field of rare event searches, operation of high voltage to generate an electric field is a key point. We designed a new structure of electrodes to ...shape a strong and uniform drift field without electric discharge, in which electrodes of two different radius are used. We also developed Cockcroft-Walton voltage multiplier as a high voltage generator inside a pressure vessel. We achieved −30.0 kV output and examined such kind of voltage generator is feasible as a high voltage supplier in a TPC.
The CDF Silicon Vertex Trigger Ashmanskas, Bill; Barchiesi, A.; Bardi, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Volume:
518, Issue:
1
Journal Article
Peer reviewed
Open access
The Collider Detector at Fermilab (CDF) experiment's Silicon Vertex Trigger (SVT) is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a
15
μs
...pipeline. SVT's
35
μm
impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common interboard data link, and a universal “Merger” board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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![[OP.6D.04] ASSOCIATION STUD...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0263-6352/small "[OP.6D.04] ASSOCIATION STUDY OF ANGIOTENSINASE A (ENPEP) GENOTYPE WITH DIABETIC NEPHROPATHY")
