SearcharxivSearch

arXiv · 2503.00968

Simulation of the Background from $^{13}$C$(\alpha, n)^{16}$O Reaction in the JUNO Scintillator

JUNO Collaboration·Thomas Adam·Kai Adamowicz·Shakeel Ahmad·Rizwan Ahmed·Sebastiano Aiello·Fengpeng An·Costas Andreopoulos·Giuseppe Andronico·Nikolay Anfimov·Vito Antonelli·Tatiana Antoshkina·João Pedro Athayde Marcondes de André·Didier Auguste·Weidong Bai·Nikita Balashov·Andrea Barresi·Davide Basilico·Eric Baussan·Marco Beretta·Antonio Bergnoli·Nikita Bessonov·Daniel Bick·Lukas Bieger·Svetlana Biktemerova·Thilo Birkenfeld·Simon Blyth·Anastasia Bolshakova·Mathieu Bongrand·Matteo Borghesi·Dominique Breton·Augusto Brigatti·Riccardo Brugnera·Riccardo Bruno·Marcel Büchner·Antonio Budano·Jose Busto·Anatael Cabrera·Barbara Caccianiga·Hao Cai·Xiao Cai·Yanke Cai·Zhiyan Cai·Stéphane Callier·Steven Calvez·Antonio Cammi·Chuanya Cao·Guofu Cao·Jun Cao·Yaoqi Cao·Rossella Caruso·Cédric Cerna·Vanessa Cerrone·Jinfan Chang·Yun Chang·Auttakit Chatrabhuti·Chao Chen·Guoming Chen·Jiahui Chen·Jian Chen·Jing Chen·Junyou Chen·Pingping Chen·Shaomin Chen·Shiqiang Chen·Xin Chen·Yiming Chen·Yixue Chen·Yu Chen·Ze Chen·Zhangming Chen·Zhiyuan Chen·Jie Cheng·Yaping Cheng·Yu Chin Cheng·Alexander Chepurnov·Alexey Chetverikov·Davide Chiesa·Pietro Chimenti·Po-Lin Chou·Ziliang Chu·Artem Chukanov·Gérard Claverie·Catia Clementi·Barbara Clerbaux·Claudio Coletta·Selma Conforti Di Lorenzo·Simon Csakli·Chenyang Cui·Olivia Dalager·Christophe De La Taille·Zhi Deng·Ziyan Deng·Xiaoyu Ding·Xuefeng Ding·Yayun Ding·Bayu Dirgantara·Carsten Dittrich·Sergey Dmitrievsky·David Doerflinger

Abstract

Large-scale organic liquid scintillator detectors are highly efficient in the detection of MeV-scale electron antineutrinos. These signal events can be detected through inverse beta decay on protons, which produce a positron accompanied by a neutron. A noteworthy background for antineutrinos coming from nuclear power reactors and from the depths of the Earth (geoneutrinos) is generated by ($\alpha, n$) reactions. In organic liquid scintillator detectors, $\alpha$ particles emitted from intrinsic contaminants such as $^{238}$U, $^{232}$Th, and $^{210}$Pb/$^{210}$Po, can be captured on $^{13}$C nuclei, followed by the emission of a MeV-scale neutron. Three distinct interaction mechanisms can produce prompt energy depositions preceding the delayed neutron capture, leading to a pair of events correlated in space and time within the detector. Thus, ($\alpha, n$) reactions represent an indistinguishable background in liquid scintillator-based antineutrino detectors, where their expected rate and energy spectrum are typically evaluated via Monte Carlo simulations. This work presents results from the open-source SaG4n software, used to calculate the expected energy depositions from the neutron and any associated de-excitation products. Also simulated is a detailed detector response to these interactions, using a dedicated Geant4-based simulation software from the JUNO experiment. An expected measurable $^{13}$C$(\alpha, n)^{16}$O event rate and reconstructed prompt energy spectrum with associated uncertainties, are presented in the context of JUNO, however, the methods and results are applicable and relevant to other organic liquid scintillator neutrino detectors.

Explore related subjects

Keep this discovery

BibTeXRIS

JUNO Collaboration, Thomas Adam, Kai Adamowicz, Shakeel Ahmad, Rizwan Ahmed, Sebastiano Aiello, Fengpeng An, Costas Andreopoulos, Giuseppe Andronico, Nikolay Anfimov, Vito Antonelli, Tatiana Antoshkina, João Pedro Athayde Marcondes de André, Didier Auguste, Weidong Bai, Nikita Balashov, Andrea Barresi, Davide Basilico, Eric Baussan, Marco Beretta, Antonio Bergnoli, Nikita Bessonov, Daniel Bick, Lukas Bieger, Svetlana Biktemerova, Thilo Birkenfeld, Simon Blyth, Anastasia Bolshakova, Mathieu Bongrand, Matteo Borghesi, Dominique Breton, Augusto Brigatti, Riccardo Brugnera, Riccardo Bruno, Marcel Büchner, Antonio Budano, Jose Busto, Anatael Cabrera, Barbara Caccianiga, Hao Cai, Xiao Cai, Yanke Cai, Zhiyan Cai, Stéphane Callier, Steven Calvez, Antonio Cammi, Chuanya Cao, Guofu Cao, Jun Cao, Yaoqi Cao, Rossella Caruso, Cédric Cerna, Vanessa Cerrone, Jinfan Chang, Yun Chang, Auttakit Chatrabhuti, Chao Chen, Guoming Chen, Jiahui Chen, Jian Chen, Jing Chen, Junyou Chen, Pingping Chen, Shaomin Chen, Shiqiang Chen, Xin Chen, Yiming Chen, Yixue Chen, Yu Chen, Ze Chen, Zhangming Chen, Zhiyuan Chen, Jie Cheng, Yaping Cheng, Yu Chin Cheng, Alexander Chepurnov, Alexey Chetverikov, Davide Chiesa, Pietro Chimenti, Po-Lin Chou, Ziliang Chu, Artem Chukanov, Gérard Claverie, Catia Clementi, Barbara Clerbaux, Claudio Coletta, Selma Conforti Di Lorenzo, Simon Csakli, Chenyang Cui, Olivia Dalager, Christophe De La Taille, Zhi Deng, Ziyan Deng, Xiaoyu Ding, Xuefeng Ding, Yayun Ding, Bayu Dirgantara, Carsten Dittrich, Sergey Dmitrievsky, David Doerflinger. 2025-03-02. Simulation of the Background from $^{13}$C$(\alpha, n)^{16}$O Reaction in the JUNO Scintillator. https://arxiv.org/abs/2503.00968

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

High-Speed Semi-FE Readout Module for ATLAS MDT at HL-LHC: Design and Production-Level Characterization

The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) introduces increased demands on the ATLAS Muon Spectrometer, particularly in terms of data throughput, timing distribution and system reliability. The Phase-II Chamber Service Module (CSM) is a key component of the upgraded Monitored Drift Tube (MDT) trigger and readout system, providing a high-speed interface between the front-end electronics and the backend systems. This paper describes the design and implementation of the Phase-II CSM, together with its validation. The results show that the CSM supports two independent optical uplinks, each operating at a line rate of 10.24 Gbps, together with clock distribution and slow control in the expected operating environment. Integration with small-diameter MDT (sMDT) chambers and tests with the prototype L0MDT trigger system are also presented. The CSM boards are now in production and will be used for installation and integration during the upcoming LHC Long Shutdown.

physics.ins-det

Spectral Discrimination of Deposited Gamma-Ray Energies in a Simulated CeBr$_3$ Scintillator

We show that wavelength measurements of individual detected optical photons may provide additional information about gamma-ray energy deposited in a CeBr$_3$ crystal when the detected-photon-count distributions overlap for nearby gamma-ray energies. Monoenergetic 662 and 629 keV gammas are used in a Geant4 simulation of a $25\times25\times20~\mathrm{mm^3}$ CeBr$_3$ crystal. Assuming a light yield of $6.0\times10^4$ photons/MeV, a wavelength-independent photon-detection efficiency of 30%, and a wavelength resolution of $\sigma_{\lambda}=40$ nm, we find that the fraction of photons reconstructed above 385 nm gives an event-level separation of $\sim$ 2 standard deviations between the 662 and 629 keV event populations selected within the same $\sim$ 1%-wide detected-photon-count interval. No timing or reconstructed interaction-position information is used. The result demonstrates, within the present simulation model, that event-dependent optical spectra can retain energy information beyond an undifferentiated photon count.

physics.ins-det

Operation of a negative ion gas time projection chamber without electronegative fill gases

The high fidelity reconstruction of particle tracks in micropatterned gaseous time projection chambers renders this technology ideal for future rare-event searches, including direction-sensitive dark matter experiments. Large drift distances are typically required for such experiments, so that the overall spatial resolution is limited by diffusion. Negative ion drift exhibits lower diffusion than electron drift and is thus an attractive option for realising a large-scale detector. The use of electronegative gases to create negative ions introduces technical challenges, most notably a reduction in gain when compared to conventional gas mixtures. In this study, we demonstrate a new method for negative ion generation via dissociative electron attachment using the conventional molecular fill gas CF$_4$. Our optical measurements of negative ion drift indicate electron attachment lengths of $<$1 mm and comparable gain to electron avalanches. The individual negative ion avalanches were also time-resolved, allowing the number of ions reaching the readout to be counted. We measure an improved energy resolution by single ion counting, relative to an integrated electron avalanche signal measured under identical gain conditions.

physics.ins-det