The generation of thermal muons by laser ionization of muonium (μ+e−) confined in multi-layer silica aerogel structures is simulated. Thermal muonium generated inside the silica aerogel is emitted ...into the sandwiched vacuum regions between the aerogel layers separated by a few millimeters. The model for muonium emission is validated against emission measurements from single aerogel samples. The efficiency of thermal muon generation in this configuration is predicted to increase by several times compared with a single-layer design.
Abstract
A small-momentum-width muon beam, so-called ultra-slow muon beam, can be generated by laser ionization of muonium. To realize efficient ultra-slow muon generation, the Lyman-alpha and below ...360 nm coherent light are required to resonantly excite the muonium from the ground state to 2
p
and sequentially ionizes excited muonium to the unbound state. At the J-PARC MLF Ultra-Slow Muon beamline, we have successfully generated Lyman-alpha coherent light exceeding 10 μJ using an all-solid-state laser and high-efficiency vacuum ultraviolet light generation technologies. In this paper, we will describe the intense Lyman-alpha light source.
ATLAS fast physics monitoring: TADA Sabato, G; Elsing, M; Gumpert, C ...
Journal of physics. Conference series,
10/2017, Letnik:
898, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The ATLAS experiment at the LHC has been recording data from proton-proton collisions with 13 TeV center-of-mass energy since spring 2015. The collaboration is using a fast physics monitoring ...framework (TADA) to automatically perform a broad range of fast searches for early signs of new physics and to monitor the data quality across the year with the full analysis level calibrations applied to the rapidly growing data. TADA is designed to provide fast feedback directly after the collected data has been fully calibrated and processed at the Tier-0. The system can monitor a large range of physics channels, offline data quality and physics performance quantities. TADA output is available on a website accessible by the whole collaboration. It gets updated twice a day with the data from newly processed runs. Hints of potentially interesting physics signals or performance issues identified in this way are reported to be followed up by physics or combined performance groups. The note reports as well about the technical aspects of TADA: the software structure to obtain the input TAG files, the framework workflow and structure, the webpage and its implementation.
XMASS-I was unique experiment, as single phase, large volume liquid xenon detector observation was carried out during Nov. 20, 2013 to Feb. 1, 2019. Including WIMP dark matter searches, many rare ...event search results by using XMASS-I data were reported so far, such as dark photon, axion, axion-like particle, double electron capture. After the end of the long stable data acquisition, analysis for WIMP dark matter searches with full data set was processed. The analysis with total accumulated live time of 1590.9 days for the normal threshold trigger(> 1 keVee) and 768.8 days for the low threshold trigger (>0.5keVee) with 832kg of liquid xenon have been done. Two search analyses were done with almost 5 years long stable data set. One is the fiducial volume analysis in which nuclear recoil signal was searched in the detector’s fiducial volume, which contained 97kg of liquid xenon. The other is the annual modulation analysis which signal was searched on all target volumes of 832kg. In addition to nuclear recoil signal, signal from bremsstrahlung effect and Migdal effect were also searched in the modulation analysis. In the present circumstance for the dark matter searches, search by various methods is becoming more important than ever. The results from XMASS-I full data set are unique and very valuable results.
Correct prediction of flood extents in urban catchments has become a challenging issue. The traditional urban drainage models that consider only the sewerage-network are able to simulate the drainage ...system correctly until there is no overflow from the network inlet or manhole. When such overflows exist due to insufficient drainage capacity of downstream pipes or channels, it becomes difficult to reproduce the actual flood extents using these traditional one-phase simulation techniques. On the other hand, the traditional 2D models that simulate the surface flooding resulting from rainfall and/or levee break do not consider the sewerage network. As a result, the correct flooding situation is rarely addressed from those available traditional 1D and 2D models. This paper presents an integrated model that simultaneously simulates the sewerage network, river network and 2D mesh network to get correct flood extents. The model has been successfully applied into the Tenpaku basin (Nagoya, Japan), which experienced severe flooding with a maximum flood depth more than 1.5 m on September 11, 2000 when heavy rainfall, 580 mm in 28 hrs (return period > 100 yr), occurred over the catchments. Close agreements between the simulated flood depths and observed data ensure that the present integrated modeling approach is able to reproduce the urban flooding situation accurately, which rarely can be obtained through the traditional 1D and 2D modeling approaches.
We launched the research project in order to build a scientific and technological framework for comprehensively assessing and framing policies to restore the environment of a semi-closed coastal ...water area substantially affected by surrounding river basins. Setting Mikawa Bay and its river basins as the target field, first we chose N and P as primary materials that play substantial roles in the ecosystem of the water area, and then estimated the latest four-decade transition in composition of the materials and their supply to the bay. Comparing the transition and the time series of direct impacts on the water area with the environmental deterioration of the bay, we identified a scenario composed of four stages to explain the deterioration process with respect to material cycles, and validated it with a water/material movement simulation model. By defining 'good material cycle' as the state under which oxygen deficient water is much less likely to expand in the water area, and by using the scale of oxygen deficient water as a common index to measure the environmental soundness, we materialized the aforementioned framework, whereby the best mix between policies to be executed in river basins and a coastal water area can be examined.
Utilization of dietary protein in vitamin B12 (B12)-deficient rats was evaluated by determinating the content of plasma protein, urinary excretion of nitrogen compounds, and nitrogen-balance after ...the rats were fed on a beta12-deficient soy bean protein diet by pair-feeding for 100 days. The severe beta12-deficiency was confirmed in rats by a remarkable increase in urinary methylmalonic acid excretion and a remarkable decrease in the hepatic beta12 level. Growth of B12-deficient rats was significantly retarded as compared both with ad libitum-feeding control rats and pair-feeding control rats. The growth retardation due to B12-deficiency was alleviated by the administration of 1/microgram/day of CN-B12 for 30 days. Plasma total protein and albumin levels in rats fed on a B12-deficient diet decreased, compared with those in pair-feeding control, and increase in urea-nitrogen was observed. The excretion of urinary nitrogen compounds, such as urea-nitrogen, allantoin, and creatinine, was significantly depressed by B12-deficiency compared with those in pair-feeding control The administration of CN-B12 to B12-deficient rats for 30 days resulted in the recovery of the changes in plasma proteins and urinary excretion of nitrogen compounds. The above redepressed the utilization of dietary protein in rats. Moreover, the decrease in urinary urea-nitrogen excretion was supposed to be due to the adaptation by the depression of the dietary protein utilization.
The study deals with forging type rapid prototyping system that automates metal hammering done by an industrial robot. In order to automate metal hammering work, a CAD/CAM system is required to ...define product shapes and generate tool paths. However, the hammering process differs from the cutting process in that the hammering errors accumulate. Thus, unsuitable work methods threaten to cause both deterioration of work accuracy and sheet metal fractures. However, the relationship between the effects of errors and hammering results has not yet been fully defined. Hence, in this report, the effects of hammering direction on product shape is taken up to make these relationships clear, and a method to improving work accuracy is proposed in order to reduce the potential source of errors. Finally, the usefulness of the devised method is confirmed experimentally.
The JHF-Kamioka neutrino experiment Nakaya, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2003, Letnik:
503, Številka:
1
Journal Article
Recenzirano
We propose the JHF-Kamioka neutrino experiment to study the mass and mixing of leptons to great precision through neutrino oscillation. The experiment uses a high intensity narrow-band neutrino beam ...produced by JHF, Japan Hadron Facility, and the world largest water Cherenkov detector, Super-Kamiokande. The main physics goals are: (1) to discover ν
μ→ν
e oscillation with a mixing angle,
θ
13, down to 0.006, (2) to measure the oscillation parameters in ν
μ→ν
μ oscillation with a precision of 1% for the mixing angle and 10
−4eV
2 for the mass square difference, and (3) to confirm ν
μ→ν
τ or to eliminate ν
μ→ν
s by measuring the neutral current events. The experiment can extend the physics potential to measure CP violation in neutrino oscillation for the CP-violation phase (
δ) down to 10–20°, by upgrading the JHF accelerator to
4
MW
and by constructing a new
1
Mton
water Cherenkov detector, Hyper-Kamiokande. The experiment is planned to start in 2007 at the same time of completing the JHF accelerator complex.
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