Initial performance of the COSINE-100 experiment Adhikari, G.; Adhikari, P.; de Souza, E. Barbosa ...
The European physical journal. C, Particles and fields,
02/2018, Letnik:
78, Številka:
2
Journal Article
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COSINE is a dark matter search experiment based on an array of low background NaI(Tl) crystals located at the Yangyang underground laboratory. The assembly of COSINE-100 was completed in the summer ...of 2016 and the detector is currently collecting physics quality data aimed at reproducing the DAMA/LIBRA experiment that reported an annual modulation signal. Stable operation has been achieved and will continue for at least 2 years. Here, we describe the design of COSINE-100, including the shielding arrangement, the configuration of the NaI(Tl) crystal detection elements, the veto systems, and the associated operational systems, and we show the current performance of the experiment.
We present the first search for a dark matter annual modulation signal in the Southern Hemisphere conducted with NaI(Tl) detectors, performed by the DM-Ice17 experiment. Nuclear recoils from dark ...matter interactions are expected to yield an annually modulated signal independent of location within the Earth’s hemispheres. DM-Ice17, the first step in the DM-Ice experimental program, consists of 17 kg of NaI(Tl) located at the South Pole under 2200 m.w.e. overburden of Antarctic glacial ice. Taken over 3.6 years for a total exposure of 60.8 kg yr, DM-Ice17 data are consistent with no modulation in the energy range of 4–20 keV, providing the strongest limits on weakly interacting massive particle dark matter from a direct detection experiment located in the Southern Hemisphere. The successful deployment and stable long-term operation of DM-Ice17 establishes the South Pole ice as a viable location for future dark matter searches and in particular for a high-sensitivity NaI(Tl) dark matter experiment to directly test the DAMA/LIBRA claim of the observation of dark matter.
In a continuing investigation of the potential for reproductive and developmental toxicity of molybdenum (Mo), consequent to the previous published OECD studies 1,2 and as directed by the European ...Chemicals Agency 3, a supplemental rat GLP-compliant Prenatal Developmental Toxicity (PNDT) study was conducted to investigate higher dose levels of sodium molybdate dihydrate (SMD) in an identical study design (OECD 414)4 to Murray et al. 2014a 1, at dietary concentrations calculated to provide target Mo levels of 80 and 120mg/kg bw/day (the maximum-tolerated dose). There was no effect on post-implantation loss, litter size, sex ratio or the incidence of external, visceral or skeletal fetal malformations or variations. Fetal weight was reduced proportionate to maternal dose. Minimal differences observed in the ossification status of some extremities of fetuses from females receiving 120mg Mo/kg bw/day were confirmed as transient by skeletal examination of PND 21 pups from a further group of females receiving the same dose regime. There was no evidence of copper depletion in serum, placenta or liver.
A benchmark dose evaluation using continuous and dichotomous approaches by combining the fetal body weight data from this study and the previous study determined that the BMD05 ranged from 47 to 57mg Mo/kg bw/day, depending on the modelling approach and the BMDL05 estimates ranged from 37 to 47mg Mo/kg bw/day. These levels are considered a more statistically robust point of departure for risk assessment for reproductive effects than the established NOAEL of 40mg Mo/kg bw/day.
•Molybdenum in the diet does not adversely affect the incidence of fetal anomalies•Dose level selection for OECD 414 studies according to ECHA 2022 advice document•BMD05 and BMDL05 ranges for fetal weight are higher than the established NOAEL
We report the measurement of muons and muon-induced phosphorescence in DM-Ice17, a NaI(Tl) direct detection dark matter experiment at the South Pole. Muon interactions in the crystal are identified ...by their observed pulse shape and large energy depositions. The measured muon rate in DM-Ice17 is 2.93+ or -0.04 mu /crystal/day with a modulation amplitude of 12.3+ or -1.7%, consistent with expectation. Following muon interactions, we observe long-lived phosphorescence in the NaI(Tl) crystals with a decay time of 5.5+ or -0.5s. The prompt energy deposited by a muon is correlated to the amount of delayed phosphorescence, the brightest of which consist of tens of millions of photons. These photons are distributed over tens of seconds with a rate and arrival timing that do not mimic a scintillation signal above 2keV sub(ee). While the properties of phosphorescence vary among individual crystals, the annually modulating signal observed by DAMA cannot be accounted for by phosphorescence with the characteristics observed in DM-Ice17.
Over one-third of cancer cases are attributable to modifiable risk factors. Because health-related behaviors are often established at adolescence, it is important that adolescents understand the ...risks and lifestyle decisions that may reduce their chances of developing cancer. This study aims to identify the levels of cancer awareness of adolescents in Australia.
Paper questionnaires were used to collect information about baseline levels of cancer awareness. These questionnaires included socio-demographic questions and the Cancer Awareness Measure (CAM) with slight modifications to ensure their suitability for the Australian adolescent population. Students aged 11 to 19 years were recruited from 13 Australian high schools between 2016 and 2019.
A total of 766 adolescents (58% female, mean age = 14.5 years) completed the questionnaires. Adolescents' cancer awareness was low. Adolescents who knew someone with cancer recognized significantly more cancer risk factors and cancer warning signs than those who did not know someone with cancer (t (756) = 2.35, p = .019; t (747) = 5.57, p = .001). Those from high Index of Community Socio-Educational Advantage (ICSEA) schools significantly recognized more cancer risk factors than those from low ICSEA schools (t (764) = 2.42, p = .016). Females recognized significantly more warning signs than males (t (583) = 3.11, p = .002) and students from senior high school grades recognized more warning signs than those from junior grades (t (754) = 2.24, p = .02). Most adolescents (78%) were aware of skin cancer as one of the most common cancers in Australia, however half or less were aware of other common cancers. Although most adolescents would seek medical help in the presence of possible cancer symptoms as soon as possible, approximately 20% of them would not see a doctor promptly. Emotional barriers were the most common reasons to delay seeing a doctor (56%), for example "being worried about hearing bad news" (27%).
Australian adolescents show poor awareness of cancer risk factors and cancer warning signs. A number of demographic and experience factors were found to be related to lower cancer awareness. Education is essential to raise cancer awareness, promote healthy lifestyles from adolescence and avoid a preventable cancer diagnosis.
Narrowing and other changes in retinal arterioles may reflect damage due to hypertension, which may predict stroke and other cardiovascular diseases independently of blood pressure level. Newly ...developed quantitative methods of assessing retinal narrowing are used to determine whether this sign is related only to current blood pressure or whether it also independently reflects the effects of previous blood pressure. Retinal photography was performed at the third examination of Atherosclerosis Risk in Communities (ARIC) Study in 1993-1995, and results are presented for the 9,300 nondiabetic participants aged 50-71 years. Generalized narrowing of smaller arterioles was strongly and monotonically related to current blood pressure in men and women, whether they were taking antihypertensive medications or not, and, independent of current blood pressure, was consistently and monotonically related to blood pressure levels measured 3 and 6 years before the retinal assessment. Arteriovenous nicking was also independently related to both current and previous blood pressures. The patterns of association suggested that these signs reflect both transient and persisting structural effects of elevated blood pressure, in agreement with the scant pathologic literature available. The findings suggest that retinal assessment may be useful for research on the microvascular contributions to clinical cardiovascular diseases.
The Micro-X sounding rocket is a NASA funded X-ray telescope payload that completed its first flight on July 22, 2018. This event marked the first operation of Transition Edge Sensors (TESs) and ...their SQUID-based multiplexing readout system in space. Unfortunately, due to an attitude control system pointing failure, the rocket was spinning during its 5 min observation period and no scientific data was collected. However, data collected from the internal calibration source marked a partial success for the payload and offers a unique opportunity to study the response of TESs and SQUIDs in space. Of particular interest is the magnetic field response of the NIST MUX06a SQUID readout system to tumbling through Earth’s magnetic field. We present a model to explain the baseline response of the SQUIDs, which lead to a subset of pixels failing to “lock” for the full observational period. Future flights of the Micro-X rocket will include the NIST MUX18b SQUID system with dramatically reduced sensitivity to magnetic fields.
Micro-X is an X-ray sounding rocket payload that had its first flight on July 22, 2018. The goals of the first flight were to operate a transition edge sensor X-ray microcalorimeter array in space ...and take a high-resolution spectrum of the Cassiopeia A supernova remnant. The first flight was considered a partial success. The array and its time-division multiplexing readout system were successfully operated in space, but due to a failure in the attitude control system, no time on-target was acquired. A re-flight has been scheduled for summer 2022. Since the first flight, modifications have been made to the detector systems to improve noise and reduce the susceptibility to magnetic fields. The three-stage SQUID circuit, NIST MUX06a, has been replaced by a two-stage SQUID circuit, NIST MUX18b. The initial laboratory results for the new detector system will be presented in this paper.
Micro-X is a sounding rocket-borne instrument that uses a microcalorimeter array to perform high-resolution X-ray spectroscopy. This instrument flew for the first time on July 22nd, 2018, from the ...White Sands Missile Range, USA. This flight marks the first successful operation of a transition-edge sensor array and its time-division multiplexing readout system in space. This launch was dedicated to the observation of the supernova remnant Cassiopeia A. A failure in the attitude control system prevented the rocket from pointing and led to no time on target. The onboard calibration source provided X-rays in flight, and it is used to compare detector performance during preflight integration, flight, and after the successful post-flight recovery. This calibration data demonstrate the capabilities of the detector in a space environment as well as its potential for future flight.
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