CsI calorimeter for the J-PARC KOTO experiment Sato, K.; Lee, J.W.; Banno, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2020, Letnik:
982, Številka:
C
Journal Article
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An electromagnetic calorimeter made of undoped CsI crystals is used in the J-PARC KOTO experiment to search for new physics beyond the standard model with the KL→π0νν̄ decay. The calorimeter is ...designed to operate in vacuum of 0.1 Pa and in a high-rate environment where the counting rate due to KL decays is O(100) kHz. A special method to calibrate the calorimeter during the data taking without using a tracking system for charged particles is reported. The energy, position, and timing resolutions of the calorimeter were evaluated in several beam tests, and the resolutions satisfy the required performance. The energy resolution with the total energy E is 0.66⊕1.81∕EGeV% in the inner region of the calorimeter.
The purpose of this work is to give a contribution to the construction of a comprehensive knowledge of the exposure levels to gradient magnetic fields (GMF) in terms of the weighed peak (WP), ...especially for 3 Tesla scanners for which there are still few works available in the literature. A new generation probe for the measurement of electromagnetic fields in the range of 1 Hz-400 kHz was used to assess the occupational exposure levels to the GMF for 1.5 and 3.0 Tesla MRI body scanners, using the method of the WP according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) approach. The probe was placed at a height of 1.1 m, close to the MRI scanners, where operators could stay during some medical procedures with particular issues. The measurements were performed for a set of typical acquisition sequences for body (liver) and head exams. The measured values of WP were in compliance with ICNIRP 2010 reference levels for occupational exposures.
The performance of the CsI electromagnetic calorimeter to be used for the J-PARC E14 KOTO experiment for a rare decay KL→π0νν¯ was studied by using a positron beam from an accelerator. The energy, ...timing, and position resolutions for energies up to 800MeV were measured. We also developed a new method to reconstruct the incident angle of photons based on the shower shape recorded with the calorimeter, and evaluated the method to suppress possible backgrounds for KL→π0νν¯ decay signals.
Background An impairment of glucose metabolism, contributing to the increased cardiovascular risk, has been shown in primary aldosteronism (PA). Insulin resistance is associated with nonalcoholic ...fatty liver disease (NAFLD) and may play a role in its pathophysiology. The aim of this study was to investigate the association between NAFLD and PA, and to identify determinants of NAFLD in this condition. Methods A total of 40 patients with PA, 40 sex-, age-, and body mass index matched patients with low-renin essential hypertension (LREH) and 40 normotensive subjects were studied. According to ultrasound detection of fatty liver, each group was subdivided in two subsets: with NAFLD and without NAFLD. Patients with diabetes, obesity, and hyperlipidemia were excluded. Results Prevalence of NAFLD in PA was similar to that observed in LREH patients, and higher (P < 0.01) than in normotensive controls. Serum potassium was lower in PA than in LREH patients with NAFLD (P < 0.001), while it was similar in PA and LREH patients without NAFLD. At univariate analysis, plasma aldosterone, homeostasis model assessment (HOMA) index and hypokalemia were determinants of NAFLD in PA (P < 0.05), while HOMA index was associated with NAFLD in LREH (P < 0.05). At multivariable analysis, only hypokalemia remained associated with NAFLD in PA (P = 0.02). Conclusions The results of this pilot study suggest that, in the absence of major risk factors for liver disease, NAFLD is a frequent finding in PA. Patients with PA and hypokalemia are more insulin resistant and have higher prevalence of NAFLD than those with normokalemia, indicating greater risk for metabolic and liver disease in this subgroup.
Germplasm bank characterization as well as adequate statistical methods allows the identification of divergent parents. Therefore, this study aimed to evaluate the genetic divergence among 56 ...accessions of grapevine of the Germplasm Collection at Instituto Agron´mico - IAC, characterized by eight quantitative traits. Multivariate analyses were used to quantify the divergence among the accessions. Euclidian distance, principal components and Tocher’s clustering method were applied. The Tocher’s method applied to the matrix of Euclidian distance with scores of principal components discriminated seven groups, with the first two comprised 69.64% and 17.86% respectively of total access. About 77,27% of the total variation was explained by the first two main components and 86,94% was explained by the three first main components obtained with eight components analysis. Thus, the multivariate analysis to study genetic diversity applied to the quantitative characters (Tocher’s clustering method and principal components) agreed among themselves, being efficient for analysis of the genetic diversity of germplasm of grapevine at IAC, which can be used for guidance in future crosses for breeding of this species. However, additional characteristics related to productivity, cycle and quality of most will be realized and added to these works of diversity.
The KOTO (
$K^0$
at Tokai) experiment aims to observe the CP-violating rare decay
$K_L \rightarrow \pi ^0 \nu \bar {\nu }$
by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam ...at the Japan Proton Accelerator Research Complex. The
$K_L$
flux is an essential parameter for the measurement of the branching fraction. Three
$K_L$
neutral decay modes,
$K_L \rightarrow 3\pi ^0$
,
$K_L \rightarrow 2\pi ^0$
, and
$K_L \rightarrow 2\gamma $
, were used to measure the
$K_L$
flux in the beam line in the 2013 KOTO engineering run. A Monte Carlo simulation was used to estimate the detector acceptance for these decays. Agreement was found between the simulation model and the experimental data, and the remaining systematic uncertainty was estimated at the 1.4% level. The
$K_L$
flux was measured as
$(4.183 \pm 0.017_{{\rm stat.}} \pm 0.059_{{\rm sys.}}) \times 10^7$
$K_L$
per
$2\times 10^{14}$
protons on a 66-mm-long Au target.
Diante a perspectiva de revitalização da vitivinicultura no Brasil, algumas restrições diante os produtores foram constatadas, sendo, a falta de conhecimento das cultivares de uvas para suco e vinho ...e seu comportamento nas condições climáticas regionais. Neste sentido, o objetivo do trabalho foi avaliar a produção, qualidade de frutos e a maturação da uva ‘Syrah’ em região subtropical. O experimento foi realizado na Fazenda Experimental da Unesp, em São Manuel-SP. Foi utilizado o delineamento inteiramente casualizados com cinco repetições de cinco plantas cada. As videiras da cultivar Syrah enxertadas no porta-enxerto ‘IAC 766’ se apresentavam em terceiro ano de produção, no espaçamento de 2,0 x 0,80 m e sustentadas sobre o sistema de espaldeira alta. A partir do início da maturação se estendendo até a colheita, foram coletadas semanalmente 100 bagas por parcela experimental para a avaliação da maturação, determinando-se os teores de sólidos solúveis (SS), acidez titulável (AT), pH e relação SS/AT. Por ocasião da colheita, avaliou-se: produção, produtividade, número de cachos por planta, massa fresca, comprimento e largura dos cachos, bagas e engaço e número de bagas por cacho. As características de produção, físicas e de maturação da uva ‘Syrah’, permite considerar que esta cultivar, nas condições subtropicais brasileiras, apresenta condições ideais de produção para elaboração de vinhos.
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