000077195 001__ 77195 000077195 005__ 20200716101520.0 000077195 0247_ $$2doi$$a10.1007/JHEP01(2019)027 000077195 0248_ $$2sideral$$a110455 000077195 037__ $$aART-2019-110455 000077195 041__ $$aeng 000077195 100__ $$aHenriques, C.A.O. 000077195 245__ $$aElectroluminescence TPCs at the thermal diffusion limit 000077195 260__ $$c2019 000077195 5060_ $$aAccess copy available to the general public$$fUnrestricted 000077195 5203_ $$aThe NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the 136Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 mm/m for pure xenon down to 2.5 mm/m using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate the possibility to have an electroluminescence TPC operating very close to the thermal diffusion limit without jeopardizing the TPC performance, if CO2 or CH4 are chosen as additives.[Figure not available: see fulltext.] 000077195 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/SEV-2014-0398$$9info:eu-repo/grantAgreement/ES/MINECO/MDM-2016-0692$$9info:eu-repo/grantAgreement/ES/MINECO/FIS2014-53371-C04$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 740055-MELODIC$$9info:eu-repo/grantAgreement/EC/H2020/740055/EU/Molecule for low diffusion TPCs for rare event searches/MELODIC$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 690575-InvisiblesPlus$$9info:eu-repo/grantAgreement/EC/H2020/690575/EU/InvisiblesPlus/InvisiblesPlus$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 674896-ELUSIVES$$9info:eu-repo/grantAgreement/EC/H2020/674896/EU/The Elusives Enterprise: Asymmetries of the Invisible Universe/ELUSIVES$$9info:eu-repo/grantAgreement/EC/FP7/339787/EU/Towards the NEXT generation of bb0nu experimets/NEXT 000077195 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000077195 590__ $$a5.875$$b2019 000077195 591__ $$aPHYSICS, PARTICLES & FIELDS$$b4 / 29 = 0.138$$c2019$$dQ1$$eT1 000077195 592__ $$a0.948$$b2019 000077195 593__ $$aNuclear and High Energy Physics$$c2019$$dQ2 000077195 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000077195 700__ $$aMonteiro, C.M.B. 000077195 700__ $$aGonzález-Díaz, D. 000077195 700__ $$aAzevedo, C.D.R. 000077195 700__ $$aFreitas, E.D.C. 000077195 700__ $$aMano, R.D.P. 000077195 700__ $$aJorge, M.R. 000077195 700__ $$aFernandes, A.F.M. 000077195 700__ $$aGómez-Cadenas, J.J. 000077195 700__ $$aFernandes, L.M.P. 000077195 700__ $$aAdams, C. 000077195 700__ $$aÁlvarez, V. 000077195 700__ $$aArazi, L. 000077195 700__ $$aBailey, K. 000077195 700__ $$aBallester, F. 000077195 700__ $$aBenlloch-Rodríguez, J.M. 000077195 700__ $$aBorges, F.I.G.M. 000077195 700__ $$aBotas, A. 000077195 700__ $$aCárcel, S. 000077195 700__ $$aCarrión, J.V. 000077195 700__ $$0(orcid)0000-0002-6948-5101$$aCebrián, S.$$uUniversidad de Zaragoza 000077195 700__ $$aConde, C.A.N. 000077195 700__ $$aDíaz, J. 000077195 700__ $$aDiesburg, M. 000077195 700__ $$aEscada, J. 000077195 700__ $$aEsteve, R. 000077195 700__ $$aFelkai, R. 000077195 700__ $$aFerrario, P. 000077195 700__ $$aFerreira, A.L. 000077195 700__ $$aGenerowicz, J. 000077195 700__ $$aGoldschmidt, A. 000077195 700__ $$aGuenette, R. 000077195 700__ $$aGutiérrez, R.M. 000077195 700__ $$aHafidi, K. 000077195 700__ $$aHauptman, J. 000077195 700__ $$aHernandez, A.I. 000077195 700__ $$aHernando Morata, J.A. 000077195 700__ $$aHerrero, V. 000077195 700__ $$aJohnston, S. 000077195 700__ $$aJones, B.J.P. 000077195 700__ $$aKekic, M. 000077195 700__ $$aLabarga, L. 000077195 700__ $$aLaing, A. 000077195 700__ $$aLebrun, P. 000077195 700__ $$aLópez-March, N. 000077195 700__ $$aLosada, M. 000077195 700__ $$aMartín-Albo, J. 000077195 700__ $$aMartínez, A. 000077195 700__ $$aMartínez-Lema, G. 000077195 700__ $$aMcDonald, A. 000077195 700__ $$aMonrabal, F. 000077195 700__ $$aMora, F.J. 000077195 700__ $$aMuñoz Vidal, J. 000077195 700__ $$aMusti, M. 000077195 700__ $$aNebot-Guinot, M. 000077195 700__ $$aNovella, P. 000077195 700__ $$aNygren, D.R. 000077195 700__ $$aPalmeiro, B. 000077195 700__ $$aPara, A. 000077195 700__ $$aPérez, J. 000077195 700__ $$aPsihas, F. 000077195 700__ $$aQuerol, M. 000077195 700__ $$aRenner, J. 000077195 700__ $$aRepond, J. 000077195 700__ $$aRiordan, S. 000077195 700__ $$aRipoll, L. 000077195 700__ $$aRodríguez, J. 000077195 700__ $$aRogers, L. 000077195 700__ $$aRomo-Luque, C. 000077195 700__ $$aSantos, F.P. 000077195 700__ $$ados Santos, J.M.F. 000077195 700__ $$aSimón, A. 000077195 700__ $$aSofka, C. 000077195 700__ $$aSorel, M. 000077195 700__ $$aStiegler, T. 000077195 700__ $$aToledo, J.F. 000077195 700__ $$aTorrent, J. 000077195 700__ $$aVeloso, J.F.C.A. 000077195 700__ $$aWebb, R. 000077195 700__ $$aWhite, J.T. 000077195 700__ $$aYahlali, N. 000077195 7102_ $$12004$$2390$$aUniversidad de Zaragoza$$bDpto. Física Teórica$$cÁrea Física Atóm.Molec.y Nucl. 000077195 773__ $$g2019, 1 (2019), 27 [23 pp]$$pJ. high energy phys.$$tJournal of High Energy Physics$$x1126-6708 000077195 8564_ $$s439184$$uhttps://zaguan.unizar.es/record/77195/files/texto_completo.pdf$$yVersión publicada 000077195 8564_ $$s12145$$uhttps://zaguan.unizar.es/record/77195/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000077195 909CO $$ooai:zaguan.unizar.es:77195$$particulos$$pdriver 000077195 951__ $$a2020-07-16-09:26:51 000077195 980__ $$aARTICLE