JUNO Conceptual Design Report

The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine the neutrino mass hierarchy using an underground liquid scintillator detector. It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants in Guangdong, China. The experimental hall, spanning more than 50 meters, is under a granite mountain of over 700 m overburden. Within six years of running, the detection of reactor antineutrinos can resolve the neutrino mass hierarchy at a confidence level of 3-4$\sigma$, and determine neutrino oscillation parameters $\sin^2\theta_{12}$, $\Delta m^2_{21}$, and $|\Delta m^2_{ee}|$ to an accuracy of better than 1%. The JUNO detector can be also used to study terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard Model. The central detector contains 20,000 tons liquid scintillator with an acrylic sphere of 35 m in diameter. $\sim$17,000 508-mm diameter PMTs with high quantum efficiency provide $\sim$75% optical coverage. The current choice of the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of detected photoelectrons per MeV is larger than 1,100 and the energy resolution is expected to be 3% at 1 MeV. The calibration system is designed to deploy multiple sources to cover the entire energy range of reactor antineutrinos, and to achieve a full-volume position coverage inside the detector. The veto system is used for muon detection, muon induced background study and reduction. It consists of a Water Cherenkov detector and a Top Tracker system. The readout system, the detector control system and the offline system insure efficient and stable data acquisition and processing.Comment: 328 pages, 211 figure

NICA/MPD Electromagnetic Calorimeter based on Multipixel Avalanche Photodetector

A Multi Purpose Detector (MPD) is being constructed for the Heavy-Ion Collider at Dubna (NICA). One of the important components of MPD setup is an Electromagnetic Calorimeter, which will operate in the magnetic field of MPD solenoid and provide good energy and space resolution to detect particles in the energy range from ~100 MeV to few GeV. For this purpose the, so-called, “shashlyk” sampling structure with the fiber readout to the silicon Multi Pixel Avalanche Photodetector is used. The genuine design is similar to the one developed by us for COMPASS experiment but a number of important modifications have been introduced to better meet MPD resolution, large volume thermo-stabilization and other requirements. These details are presented in the report along with the beam test results obtained with the MPD/NICA module prototypes

Tests of the module array of the ECAL0 electromagnetic calorimeter for the COMPASS experiment with the electron beam at ELSA

The array of 3 × 3 modules of the electromagnetic calorimeter ECAL0 of the COMPASS experiment at CERN has been tested with an electron beam of the ELSA (Germany) facility. The dependence of the response and the energy resolution of the calorimeter from the angle of incidence of the electron beam has been studied. A good agreement between the experimental data and the results of Monte Carlo simulation has been obtained. It will significantly expand the use of simulation to optimize event reconstruction algorithms

Kysy asiantuntijalta riippuvuuksista : julkinen neuvontapalsta A-klinikkasäätiön Päihdelinkissä

Päihdelinkki on A-klinikkasäätiön ylläpitämä internetpalvelu päihteistä ja riippuvuuksista. Päihdelin-kissä on tarjottu henkilökohtaista verkkoneuvontaa vuodesta 1998 lähtien. Loppuvuodesta 2008 Päihde-linkin keskustelualueelle perustettiin julkinen neuvontapalsta, asiantuntijapalsta, joka oli toiminnassa 7.10-30.11.2008. Palstalle pystyi kirjoittamaan kysymyksen, johon asiantuntijat kävivät vastaamassa noin viikon kuluessa. Kysymysten kirjoittaminen ja lukeminen ei vaatinut rekisteröitymistä, vaan ky-symykset vastauksineen olivat kaikkien palstan kävijöiden nähtävissä. Palstan vastaajina toimi kahdek-san päihdealan ammattilaista. Tämän opinnäytetyön tarkoituksena oli kuvata palstan toimintaa ja sinne tulleita kysymyksiä: mitä aihealuetta palstalle tulleet kysymykset käsittelivät, koskivatko kysymykset kysyjän omaa vai jonkun läheisen tilannetta ja mitä kysyjä kysymyksellään palstalta haki. Tämän lisäksi tarkoituksena oli myös selvittää vastaajien näkemyksiä ja kokemuksia julkisesta neuvontapalvelusta. Opinnäytetyöni on triangulaatiotutkimus. Aineistona käytin palstalle tulleita kysymyksiä sekä materiaalia, jonka keräsin lähettämällä sähköisen kyselylomakkeen palstan vastaajille. Analyysimenetelminä käytin aineistolähtöistä sisällönanalyysiä ja tilastollisia menetelmiä, kuten ristiintaulukointia. Palstalle lähetettiin yhteensä 52 kysymystä. Suurin osa kysymyksistä käsitteli alkoholinkäyttöä, mutta kysymyksiä tuli runsaasti myös huumeista ja lääkkeistä. Kysymyksistä lähes kaksi kolmannesta koski kysyjän omaa tilannetta ja eniten kysymyksillä haettiin tukea omien valintojen tekemiseen. Myös faktatietoa päihteistä ja neuvoja riippuvuusongelman ratkaisemiseksi haettiin. Koska tulokset koskevat vain yksittäistä tapausta, ei niitä voida yleistää koskemaan kaikkia julkisia neuvontapalstoja. Tarpeen olisikin tutkia, haetaanko muiltakin julkisilta neuvontapalstoilta näitä samoja asioita. Sähköiseen kyselyyn vastasi viisi palstan vastaajaa. Palstan tekninen toteutus onnistui hyvin, lukuun ottamatta kysymysten varausjärjestelmää, joka koettiin aluksi hieman sekavaksi. Vastaajien mielestä julkinen neuvontapalsta on hyvä lisäpalvelu, mutta sitä ei ole tarpeen tarjota jatkuvasti. Palstan avulla voidaan auttaa useampia kuin henkilökohtaisella neuvontapalvelulla, sillä kysymyksiä vastauksineen voi lukea myös ne, jotka eivät itse uskalla kysyä. Toisten samankaltaisen tilanteen huomaaminen voi rohkaista ottamaan itsekin yhteyttä tai hakemaan muulla tavalla apua.AddictionLink is an online service maintained by the A-Clinic Foundation, which deals with drugs and addictions. AddictionLink has offered online advice for individuals since 1998. At the end of 2008 an open advice site, an expert advice column, was created on the AddictionLink's discussion site. This expert column was in operation from 7.10.2008 until 30.11.2008. People could write questions to this site which the experts would reply within a week. Creating questions for the experts and reading the column did not require registration; all questions and answers were available for all visitors. The expert board consisted of eight trained specialists working with substance abusers. The goal of this study was to describe the function of the column and the questions it received: what did the questions that were received deal with, did the questions concern the situation of the person posing the question or someone else, and what sort of an end result people were hoping for. In addition to this, one of the main purposes was to discover what kind of ideas and experiences the respondents had on the public advice services. The study was conducted by triangular research. The material consisted of questions sent to the ad-vice column as well as material collected by sending an online questionnaire to those replying to the questions. The methods of analysis were material-based content analysis and statistical methods such as cross tabulation. In total, there were 52 questions sent to the column. Most of the questions dealt with the use of al-cohol, but there were also a great deal of questions on narcotics and prescription medicines. Two thirds of the questions were from people experiencing the problems - they were mostly concerned with getting support for making their own choices. There were also requests for factual information on narcotics and help on how to solve substance abuse problems. Because the results of the questionnaire only dealt with one particular case at a time, they could not be generalised to depict all public advice columns. In order to do generalisations it would be necessary to see if other advice columns receive similar questions. The online questionnaire was answered by five of the experts. The technical implementation was a success, with the exception of the booking system for the questions, which was considered confusing at first. The experts thought that a public advice column was a good extra service but it would not be ne-cessary to have it available all the time. More people can be helped with the column than with an indi-vidual advice service, because its questions and answers can also be read by those who dare not pose any questions of their own. Finding out that others are in a similar situation may encourage people to get in touch with experts or seek help in other ways

Optimization of the JUNO liquid scintillator composition using a Daya Bay antineutrino detector

To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and <0.01 mg/L to 4 g/L and 13 mg/L, respectively. The numbers of total detected photoelectrons suggest that, with the optically purified solvent, the bis-MSB concentration does not need to be more than 4 mg/L. To bridge the one order of magnitude in the detector size difference between Daya Bay and JUNO, the Daya Bay data were used to tune the parameters of a newly developed optical model. Then, the model and tuned parameters were used in the JUNO simulation. This enabled to determine the optimal composition for the JUNO LS: purified solvent LAB with 2.5 g/L PPO, and 1 to 4 mg/L bis-MSB

JUNO sensitivity to low energy atmospheric neutrino spectra

Atmospheric neutrinos are one of the most relevant natural neutrino sources that can be exploited to infer properties about cosmic rays and neutrino oscillations. The Jiangmen Underground Neutrino Observatory (JUNO) experiment, a 20 kton liquid scintillator detector with excellent energy resolution is currently under construction in China. JUNO will be able to detect several atmospheric neutrinos per day given the large volume. A study on the JUNO detection and reconstruction capabilities of atmospheric $\nu_e$ and $\nu_\mu$ fluxes is presented in this paper. In this study, a sample of atmospheric neutrino Monte Carlo events has been generated, starting from theoretical models, and then processed by the detector simulation. The excellent timing resolution of the 3'' PMT light detection system of JUNO detector and the much higher light yield for scintillation over Cherenkov allow to measure the time structure of the scintillation light with very high precision. Since $\nu_e$ and $\nu_\mu$ interactions produce a slightly different light pattern, the different time evolution of light allows to discriminate the flavor of primary neutrinos. A probabilistic unfolding method has been used, in order to infer the primary neutrino energy spectrum from the detector experimental observables. The simulated spectrum has been reconstructed between 100 MeV and 10 GeV, showing a great potential of the detector in the atmospheric low energy region