Search results for "ilmaisimet"

GEM-TPC-ilmaisimen testimittausten datan analyysi

2017

GEM-TPC-ilmaisin on kaasutäytteinen hiukkasilmaisin, jolla pystytään mittaaamaan hyvin pieniä sähköisiä signaaleja ja niiden syntypaikkaa ilmaisimessa. Näitä ilmaisimia tullaan tulevaisuudessa käyttämään mm. FAIRtutkimuslaitoksen Super-FRS-nimisessä fragmenttiseparaattorissa. Tässä tutkielmassa analysoin kesällä 2016 GEM-TPC:llä GSI:ssä suoritettuja ilmaisintestimittauksia ROOT-ohjelmiston avulla. Alkuun kerron, miksi GEM-TPC-ilmaisin on lähdetty suunnittelemaan, minkälaisia mittauksia ja missä sillä on tarkoitus tehdä. Tutkielman loppupuolella analysoin testimittausten tuloksia. GSI:ssä GEM-TPC:tä testattiin Xe- ja C-suihkujen avulla. Tässä tutkielmassa perehdyn syvemmin C-suihkusta tehtyi…

A focus on selected perspectives of the NUMEN project

2022

Abstract The use of double charge exchange reactions is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The strategy adopted in the experimental campaigns performed at INFN - Laboratori Nazionali del Sud and in the analysis methods within the NUMEN project is briefly described, emphasizing the advantages of the multi-channel approach to nuclear reaction data analysis. An overview on the research and development activities on the MAGNEX magnetic spectrometer is also given, with a focus on the chosen technological solutions for the focal plane de…

Prospects for detecting the diffuse supernova neutrino background with JUNO

2022

We present the detection potential for the diffuse supernova neutrino background (DSNB) at the Jiangmen Underground Neutrino Observatory (JUNO), using the inverse-beta-decay (IBD) detection channel on free protons. We employ the latest information on the DSNB flux predictions, and investigate in detail the background and its reduction for the DSNB search at JUNO. The atmospheric neutrino induced neutral current (NC) background turns out to be the most critical background, whose uncertainty is carefully evaluated from both the spread of model predictions and an envisaged in situ measurement. We also make a careful study on the background suppression with the pulse shape discrimination (PSD) …

Sub-percent precision measurement of neutrino oscillation parameters with JUNO

2022

Feasibility and physics potential of detecting 8B solar neutrinos at JUNO

2021

The Jiangmen Underground Neutrino Observatory (JUNO) features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector. Some of JUNO's features make it an excellent location for B-8 solar neutrino measurements, such as its low-energy threshold, high energy resolution compared with water Cherenkov detectors, and much larger target mass compared with previous liquid scintillator detectors. In this paper, we present a comprehensive assessment of JUNO's potential for detecting B solar neutrinos via the neutrino-electron elastic scattering process. A reduced 2 MeV threshold for the recoil electron energy is found to be achievable, assuming that the intrinsic radioactive …

Improved stability of black silicon detectors using aluminum oxide surface passivation

2021

Publisher Copyright: © 2021 ESA and CNES We have studied how high-energy electron irradiation (12 MeV, total dose 66 krad(Si)) and long term humidity exposure (75%, 75 °C, 500 hours) influence the induced junction black silicon or planar photodiode characteristics. In our case, the induced junction is formed using n-type silicon and atomic-layer deposited aluminum oxide (Al2O3), which contains a large negative fixed charge. We compare the results with corresponding planar pn-junction detectors passivated with either with silicon dioxide (SiO2) or Al2O3. The results show that the induced junction detectors remain stable as their responsivity remains nearly unaffected during the electron beam…

Position sensitive plastic scintillator for beta particle detection

2022

A new segmented plastic scintillator detector Tuike has been developed for recoil-beta tagging experiments at the Accelerator Laboratory of the University of Jyväskylä. The detector consists of individual plastic scintillator bars arranged in two orthogonal layers, and the scintillation light is detected using silicon photomultipliers. Performance of the new detector was tested using fusion-evaporation reaction 40Ca(36Ar, pn)74Rb, and the results are discussed here. It was found that for beta particles seen in the main silicon detector, Tuike can tag high-energy beta particles with a 48(10)% efficiency. An energy calibration method using Compton edges of gamma ray transitions is described i…

Improved calculations of β decay backgrounds to new physics in liquid xenon detectors

2020

We present high-precision theoretical predictions for the electron energy spectra for the ground-state to ground-state β decays of 214Pb, 212Pb, and 85Kr most relevant to the background of liquid xenon dark matter detectors. The effects of nuclear structure on the spectral shapes are taken into account using large-scale shell-model calculations. Final spectra also include atomic screening and exchange effects. The impact of nuclear structure effects on the 214Pb and 212Pb spectra below ≈100 keV, pertinent for several searches for new physics, are found to be comparatively larger than those from the atomic effects alone. We find that the full calculation for 214Pb (212Pb) predicts 15.0%–23.2…

Thermoelectric radiation detector based on a superconductor-ferromagnet junction : Calorimetric regime

2018

We study the use of a thermoelectric junction as a thermal radiation detector in the calorimetric regime, where single radiation bursts can be separated in time domain. We focus especially on the case of a large thermoelectric figure of merit $ZT$ affecting significantly for example the relevant thermal time scales. This work is motivated by the use of hybrid superconductor/ferromagnet systems in creating an unprecedentedly high low-temperature $ZT$ even exceeding unity. Besides constructing a very general noise model which takes into account cross correlations between charge and heat noise, we show how the detector signal can be efficiently multiplexed by the use of resonant LC circuits gi…

Hypersensitive tunable Josephson escape sensor for gigahertz astronomy

2020

Sensitive photon detection in the gigahertz band constitutes the cornerstone to study different phenomena in astronomy, such as radio burst sources, galaxy formation, cosmic microwave background, axions, comets, gigahertz-peaked spectrum radio sources and supermassive black holes. Nowadays, state of the art detectors for astrophysics are mainly based on transition edge sensors and kinetic inductance detectors. Overall, most sensible nanobolometers so far are superconducting detectors showing a noise equivalent power (NEP) as low as 2x10-20 W/Hz1/2. Yet, fast thermometry at the nanoscale was demonstrated as well with Josephson junctions through switching current measurements. In general, det…