171,153 research outputs found
Prediction of energy resolution in the JUNO experiment
No full textThis paper presents an energy resolution study of the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of the liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The results of this study reveal an energy resolution of 2.95% at 1 MeV. Furthermore, this study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection. Moreover, it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.peerReviewe
Juno-UVS approach observations of Jupiter's auroras.
No full textJuno ultraviolet spectrograph (UVS) observations of Jupiter's aurora obtained during approach are presented. Prior to the bow shock crossing on 24 June 2016, the Juno approach provided a rare opportunity to correlate local solar wind conditions with Jovian auroral emissions. Some of Jupiter's auroral emissions are expected to be controlled or modified by local solar wind conditions. Here we compare synoptic Juno-UVS observations of Jupiter's auroral emissions, acquired during 3-29 June 2016, with in situ solar wind observations, and related Jupiter observations from Earth. Four large auroral brightening events are evident in the synoptic data, in which the total emitted auroral power increases by a factor of 3-4 for a few hours. Only one of these brightening events correlates well with large transient increases in solar wind ram pressure. The brightening events which are not associated with the solar wind generally have a risetime of ~2 h and a decay time of ~5 h
Mass testing and characterization of 20-inch PMTs for JUNO
No full textMain goal of the JUNO experiment is to determine the neutrino mass ordering using a 20 kt liquid-scintillator detector. Its key feature is an excellent energy resolution of at least 3% at 1 MeV, for which its instruments need to meet a certain quality and thus have to be fully characterized. More than 20,000 20-inch PMTs have been received and assessed by JUNO after a detailed testing program which began in 2017 and elapsed for about four years. Based on this mass characterization and a set of specific requirements, a good quality of all accepted PMTs could be ascertained. This paper presents the performed testing procedure with the designed testing systems as well as the statistical characteristics of all 20-inch PMTs intended to be used in the JUNO experiment, covering more than fifteen performance parameters including the photocathode uniformity. This constitutes the largest sample of 20-inch PMTs ever produced and studied in detail to date, i.e. 15,000 of the newly developed 20-inch MCP-PMTs from Northern Night Vision Technology Co. (NNVT) and 5000 of dynode PMTs from Hamamatsu Photonics K. K.(HPK).peerReviewe
Potential to identify neutrino mass ordering with reactor antineutrinos at JUNO
No full textThe Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment under construction in South China. This paper presents an updated estimate of JUNO's sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants. This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angle θ23. The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory (TAO) detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site, local and global nuclear reactors, JUNO and TAO detector responses, expected event rates and spectra of signals and backgrounds, and systematic uncertainties of analysis inputs. We find that a 3σ median sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years × 26.6 GW thermal power.peerReviewe
Juno and Oswego concert flier, Kansas House, Arlington, Virginia, November 20, 1999
No full textAn advertising flier promoting a concert by the punk rock bands Juno and Oswego. The concert occurred on Saturday, November 20, 1999 at the Kansas House in Arlington, Virginia. The flier was illustrated and designed by Ryan Nelson of Oswego
Juno-UVS Approach Observations of Jupiter's Auroras
No full textpeer reviewedJuno-UVS observations of Jupiter's aurora obtained during approach are presented. Prior to the bow-shock crossing on 24 June 2016, the Juno approach provided a rare opportunity to correlate local solar wind conditions with Jovian auroral emissions. Some of Jupiter's auroral emissions are expected to be controlled or modified by local solar wind conditions. Here we compare synoptic Juno-UVS observations of Jupiter's auroral emissions, acquired during 3-29 June 2016, with in situ solar wind observations, and related Jupiter observations from Earth. Four large auroral brightening events are evident in the synoptic data, in which the total emitted auroral power increases by a factor of 3-4 for a few hours. Only one of these brightening events correlates well with large transient increases in solar wind ram pressure. The brightening events which are not associated with the solar wind generally have a rise time of ~2 hours and a decay time of ~5 hours
The JUNO experiment
No full textInternational audienceThe Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector aiming at the measurement of anti-neutrinos issued from nuclear reactors at a 53 km distance, having as primary goal the determination of the neutrino mass hierarhcy. The detector will be located 1800 m.w.e. underground and consists of a 20 kiloton liquid scintillator contained in a 35.4 m diameter acrylic sphere, instrumented by more than 17000 20 inch PMTs ensuring a 77% photocatode coverage. The required energy resolution to discriminate between the hierarchies at the 3–4 σ C.L. in about 6 years of data taking is 3% at 1 MeV. To achieve such a precision, severe constraints on the detector components quality are set: the PMTs need a quantum efficiency of more than 27% and the attenuation length of the liquid has to be better than 20 m (at 430 nm). The precise measurement of the antineutrino spectrum will allow to reduce the uncertainty below 1% on solar oscillation parameters. The international collaboration of JUNO was established in 2014, the civil construction started in 2015 and the R&D of the detectors is ongoing. The expected start of data taking is set for 2020
Fluorescence emission of the JUNO liquid scintillator
No full textJUNO is a huge neutrino detector that will use 20 kton of organic liquid scintillator as its detection medium. The scintillator is a mixture of linear alkyl benzene (LAB), 2.5 g/L of 2,5-diphenyloxazole (PPO) and 3 mg/L of 1,4-Bis(2-methylstyryl)benzene (Bis-MSB). The main goal of JUNO is to determine the Neutrino Mass Ordering [1–3]. In order to achieve this purpose, good energy and position reconstruction is required, hence a complete understanding of the optical characteristics of the liquid scintillator is mandatory. In this paper we present the first measurements on the JUNO scintillator emission spectrum, absorption length and fluorescence time distribution performed respectively with a spectrofluorimeter, a spectrophotometer and a custom made setup of the liquid scintillator produced by the JUNO purification plants
Fluorescence emission of the JUNO liquid scintillator
No full textJUNO is a huge neutrino detector that will use 20 kton of organic liquid scintillator as its detection medium. The scintillator is a mixture of linear alkyl benzene (LAB), 2.5 g/L of 2,5-diphenyloxazole (PPO) and 3 mg/L of 1,4-Bis(2-methylstyryl)benzene (Bis-MSB). The main goal of JUNO is to determine the Neutrino Mass Ordering [1-3]. In order to achieve this purpose, good energy and position reconstruction is required, hence a complete understanding of the optical characteristics of the liquid scintillator is mandatory. In this paper we present the first measurements on the JUNO scintillator emission spectrum, absorption length and fluorescence time distribution performed respectively with a spectrofluorimeter, a spectrophotometer and a custom made setup of the liquid scintillator produced by the JUNO purification plants
Caryedes juno
No full textCaryedes juno (Sharp, 1885) Bruchus juno Sharp 1885: 443 (description, distribution). Pseudopachymerus juno: Pic 1913b: 11 (catalog). Caryedes juno: Blackwelder 1946: 758 (checklist); Kingsolver and Whitehead 1974: 399 (lectotype designation, redescription, male genitalia, species-group, key, figures, distribution, host plant); Johnson and Kingsolver 1981: 416 (checklist); Udayagiri and Wadhi 1989: 74 (catalog); Romero and Johnson 2004: 623 (checklist); de Lorea-Barocio et al. 2006: 517 (checklist); Mart´ınez-Sánchez et al. 2017 (checklist). Pseudopachymerus (Falsobruchus) gounellei Pic 1923: 15 (description, distribution) New synonymy. Caryedes gounellei: Blackwelder 1946: 758 (checklist); Kingsolver and Whitehead 1974: 399 (species-group, notes); Udayagiri and Wadhi 1989: 73 (catalog). Type Material. Bruchus juno (2, BMNH). Lectotype designated by Kingsolver and Whitehead (1974), male, "[handwritten, with fixed specimen] Bruchus boops juno \ Type (³) D. S. \ David. Chiriqui. \ Champion." "[circular label with dark blue border, printed] LECTO- \ TYPE" "[circular label, red border, facing down, printed] TYPE" "[printed] David, Chiriqui. \ Champion." "[printed] B. C. A. Col. V. \ Bruchus \ juno, \ Sharp." "[label facing down, printed] Sharp Coll. \ 1905-313."; 1 paralectotype female "[circular label, light blue border, printed] PARA- \ LECTO- \ TYPE" "[printed] David, Chiriqui, \ Champion" "[printed] B. C. A. Col. V. \ Bruchus \ juno, \ Sharp.". Sharp (1885) mentioned that four specimens were studied for the description. However, we received only two specimens from the BMNH, with collecting label data identical to the information given in the original description (" Chiriqui, Champion "). Pseudopachymerus (Falsobruchus) gounellei (4, MNHN): Lectotype, here designated, male "[handwritten] Pernambuco \ (Bresil)" "[handwritten] Bresil \ (gounellei)" "[handwritten, red] type" "[handwritten] Falsobruchus \ gounellei \ n sp" "[printed, red] HOLOTYPE " "[printed] MUSÉUM PARIS \ 1958 \ Coll. M. PIC" "gounellei [handwritten] \ det. [printed] 70 Pic [handwritten] \ J. M. Kingsolver [printed]" " Caryedes [handwritten] \ juno [handwritten] \ (Sharp, 1885) [handwritten] \ Ribeiro-Costa, C. S. det. 200 [printed] 7 [handwritten]" "vial with genitalia" " Lectotype / Pseudopachymerus (Falsobruchus) gounellei Pic, 1923 / design. I. R. Jorge"; 1 paralectotype female "[handwritten] Pernambuco \ Bresil \ (gounellei)" "[printed] MUSÉUM PARIS \ 1958 \ Coll. M. PIC" "[printed, red] PARATYPE " " Paralectotype / Pseudopachymerus (Falsobruchus) gounellei Pic, 1923 / design. I. R. Jorge"; 1 paralectotype female "[handwritten] Pernambuco \ (Bresil)" "[printed] MUSÉUM PARIS \ 1958 \ Coll. M. PIC" "[printed, red] PARATYPE " " Paralectotype / Pseudopachymerus (Falsobruchus) gounellei Pic, 1923 / design. I. R. Jorge"; 1 paralectotype female "[printed] MUSÉUM PARIS \ 1958 \ Coll. M. PIC" "[printed, red] PARATYPE " " Paralectotype / Pseudopachymerus (Falsobruchus) gounellei Pic, 1923 / design. I. R. Jorge". Four specimens were received from the MNHN, with locality data identical to the information given in Pic' s original description (" Brazil, Pernambuco ") except for one of the specimens, which does not have locality labels associated with it. This specimen, which also does not have Pic' s handwritten label, has the museum label recognizing it as part of Pic' s collection (similar to Fig. 1, label "[printed] MUSÉUM PARIS \ 1958 \ Coll. M. PIC"), and was prepared in a similar manner as the other syntypes. While reviewing C. juno, Kingsolver and Whitehead (1974) reported that this species has a contrasting dark patch on the metepisternum, a characteristic that is less developed in C. gounellei, a representative of the South American fauna. This difference is considered by us to be intraspecific variation. Consequently, P. (Falsobruchus) gounellei is here deemed a new junior synonym of B. juno. The male with Pic' s label "type" is here designated as the lectotype of P. gounellei.Published as part of Jorge, Isaac Reis & Ribeiro-Costa, Cibele Stramare, 2019, New Synonymies and Lectotype Designations for the Neotropical Seed Beetle Genus Caryedes Hummel, 1827 (Coleoptera: Chrysomelidae: Bruchinae), pp. 321-328 in The Coleopterists Bulletin 73 (2) on pages 325-326, DOI: 10.1649/0010-065X-73.2.321, http://zenodo.org/record/483691
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