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Author Gomez-Cadenas, J.J.; Benlloch-Rodriguez, J.M.; Ferrario, P.
Title Application of scintillating properties of liquid xenon and silicon photomultiplier technology to medical imaging Type Journal Article
Year 2016 Publication Spectrochimica Acta Part B Abbreviated Journal Spectroc. Acta Pt. B
Volume 118 Issue Pages (up) 6-13
Keywords PET; TOF; Liquid xenon; Energy resolution; High sensitivity; Coincidence resolution time (CRT); SiPMs
Abstract We describe a new positron emission time-of-flight apparatus using liquid xenon. The detector is based in a liquid xenon scintillating cell. The cell shape and dimensions can be optimized depending on the intended application. In its simplest form, the liquid xenon scintillating cell is a box in which two faces are covered by silicon photomultipliers and the others by a reflecting material such as Teflon. It is a compact, homogenous and highly efficient detector which shares many of the desirable properties of monolithic crystals, with the added advantage of high yield and fast scintillation offered by liquid xenon. Our initial studies suggest that good energy and spatial resolution comparable with that achieved by lutetium oxyorthosilicate crystals can be obtained with a detector based in liquid xenon scintillating cells. In addition, the system can potentially achieve an excellent coincidence resolving time of better than 100 ps.
Address [Gomez-Cadenas, J. J.; Benlloch-Rodriguez, J. M.; Ferrario, Paola] Univ Valencia, CSIC, IFIC, E-46003 Valencia, Spain, Email: gomez@mail.cern.ch
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547 ISBN Medium
Area Expedition Conference
Notes WOS:000374073300002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2631
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Author NEXT Collaboration (Trindade, A.M.F. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Ferrario, P.; Gomez-Cadenas, J.J.; Laing, A.; Liubarsky, I; Lopez-March, N.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Simon, A.; Sorel, M.; Torrent, J.; Yahlali, N.
Title Study of the loss of xenon scintillation in xenon-trimethylamine mixtures Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 905 Issue Pages (up) 22-28
Keywords Gaseous radiation detectors; Noble gas mixtures; Molecular additives; VUV absorption
Abstract This work investigates the capability of TMA ((CH3)(3)N) molecules to shift the wavelength of Xe VUV emission (160-188 nm) to a longer, more manageable, wavelength (260-350 nm). Light emitted from a Xe lamp was passed through a gas chamber filled with Xe-TMA mixtures at 800 Torr and detected with a photomultiplier tube. Using bandpass filters in the proper transmission ranges, no reemitted light was observed experimentally. Considering the detection limit of the experimental system, if reemission by TMA molecules occurs, it is below 0.3% of the scintillation absorbed in the 160-188 nm range. An absorption coefficient value for xenon VUV light by TMA of 0.43 +/- 0.03 cm(-1) Torr(-1) was also obtained. These results can be especially important for experiments considering TMA as a molecular additive to Xe in large volume optical time projection chambers.
Address [Trindade, A. M. F.; Escada, J.; Cortez, A. F., V; Borges, F. I. G. M.; Santos, F. P.; Conde, C. A. N.] LIP Lab Instrumentacao & Fis Expt Particulas, Coimbra, Portugal, Email: Kalexandre.trindade@coimbra.lip.pt
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000444425700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3730
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Author NEXT Collaboration (Henriques, C.A.O. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Laing, A.; Lopez-March, N.; Martinez, A.; Martinez-Lema, G.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Romo-Luque, C.; Simon, A.; Sorel, M.; Yahlali, N.
Title Electroluminescence TPCs at the thermal diffusion limit Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages (up) 027 - 23pp
Keywords Dark Matter and Double Beta Decay (experiments); Photon production; Particle correlations and fluctuations; Rare decay
Abstract The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the Xe-136 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 for pure xenon down to 2.5 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.
Address [Henriques, C. A. O.; Monteiro, C. M. B.; Freitas, E. D. C.; Mano, R. D. P.; Jorge, M. R.; Fernandes, A. F. M.; Fernandes, L. M. P.; dos Santos, J. M. F.] Univ Coimbra, Phys Dept, LIBPhys, Rua Larga, P-3004516 Coimbra, Portugal, Email: pancho@gian.fis.uc.pt
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000455157300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3873
Permanent link to this record
 

 
Author NEXT Collaboration (Fernandes, A.F.M. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Herrero, P.; Kekic, M.; Lopez-March, N.; Martinez-Lema, G.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Romo-Luque, C.; Sorel, M.; Uson, A.; Yahlali, N.
Title Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages (up) 034 - 18pp
Keywords Particle correlations and fluctuations; Photon production; Dark Matter and Double Beta Decay (experiments); Rare decay
Abstract High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe-He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by similar to 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: cristinam@uc.pt
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000525257400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4366
Permanent link to this record
 

 
Author NEXT Collaboration (Novella, P. et al); Palmeiro, B.; Sorel, M.; Uson, A.; Alvarez, V; Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Herrero, P.; Kekic, M.; Lopez-March, N.; Martinez-Lema, G.; Muñoz Vidal, J.; Querol, M.; Renner, J.; Romo-Luque, C.; Yahlali, N.
Title Radiogenic backgrounds in the NEXT double beta decay experiment Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages (up) 051 - 26pp
Keywords Dark Matter and Double Beta Decay (experiments)
Abstract Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterraneo de Canfranc with xenon depleted in Xe-136 are analyzed to derive a total background rate of (0.84 +/- 0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of Co-60, K-40, Bi-214 and Tl-208 to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25 +/- 0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5 sigma after 1 year of data taking. The background measurement in a Q(beta beta)+/- 100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75 +/- 0.12) events.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: pau.novella@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000491469000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4183
Permanent link to this record
 

 
Author NEXT Collaboration (Ferrario, P. et al); Benlloch-Rodriguez, J.M.; Kekic, M.; Renner, J.; Uson, A.; Alvarez, V.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Herrero, P.; Lopez-March, N.; Martinez-Lema, G.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Romo-Luque, C.; Sorel, M.; Yahlali, N.
Title Demonstration of the event identification capabilities of the NEXT-White detector Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages (up) 052 - 20pp
Keywords Dark Matter and Double Beta Decay (experiments)
Abstract In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a Th-228 calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 +/- 1.5(stat) +/- 0.3(sys) % for a background acceptance of 20.6 +/- 0.4(stat) +/- 0.3(sys)% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: paola.ferrario@dipc.org
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000509259700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4260
Permanent link to this record
 

 
Author NEXT Collaboration (Felkai, R. et al); Sorel, M.; Lopez-March, N.; Gomez-Cadenas, J.J.; Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Ferrario, P.; Laing, A.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Romo-Luque, C.; Rodriguez, J.; Simon, A.; Torrent, J.; Yahlali, N.
Title Helium-Xenon mixtures to improve the topological signature in high pressure gas xenon TPCs Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 905 Issue Pages (up) 82-90
Keywords Helium; Xenon; Double-beta decay; TPC; Low diffusion; Electroluminescence
Abstract Within the framework of xenon-based double beta decay experiments, we propose the possibility to improve the background rejection of an electroluminescent Time Projection Chamber (EL TPC) by reducing the diffusion of the drifting electrons while keeping nearly intact the energy resolution of a pure xenon EL TPC. Based on state-of-the-art microscopic simulations, a substantial addition of helium, around 10 or 15 %, may reduce drastically the transverse diffusion down to 2.5 mm/root m from the 10.5 mm/root m of pure xenon. The longitudinal diffusion remains around 4 mm/root m. Light production studies have been performed as well. They show that the relative variation in energy resolution introduced by such a change does not exceed a few percent, which leaves the energy resolution practically unchanged. The technical caveats of using photomultipliers close to an helium atmosphere are also discussed in detail.
Address [Adams, C.; Guenette, R.; Martin-Albo, J.] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA, Email: francesc.monrabalcapilla@uta.edu
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000444425700010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3731
Permanent link to this record
 

 
Author NEXT Collaboration (Novella, P. et al); Palmeiro, B.; Simon, A.; Sorel, M.; Martinez-Lema, G.; Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Laing, A.; Lopez-March, N.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Romo-Luque, C.; Yahlali, N.
Title Measurement of radon-induced backgrounds in the NEXT double beta decay experiment Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages (up) 112 - 27pp
Keywords Dark Matter and Double Beta Decay (experiments)
Abstract The measurement of the internal Rn-222 activity in the NEXT-White detector during the so-called Run-II period with Xe-136-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by Rn-222 and its alpha-emitting progeny. The specific activity is measured to be (38.1 +/- 2.2 (stat.) +/- 5.9 (syst.)) mBq/m(3). Radon-induced electrons have also been characterized from the decay of the Bi-214 daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.1 counts/yr in the neutrinoless double beta decay sample.
Address [Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: sorel@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000448191500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3779
Permanent link to this record
 

 
Author NEXT Collaboration (Azevedo, C.D.R. et al); Gomez-Cadenas, J.J.; Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Ferrario, P.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.
Title Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 877 Issue Pages (up) 157-172
Keywords Optical TPCs; Microscopic simulation; Xenon scintillation
Abstract We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.
Address [Azevedo, C. D. R.] Univ Aveiro, I3N, Phys Dept, Aveiro, Portugal, Email: Diego.Gonzalez.Diaz@usc.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000415128000022 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3371
Permanent link to this record
 

 
Author NEXT Collaboration (Kekic, M. et al); Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Martinez-Lema, G.; Martinez-Vara, M.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Romo-Luque, C.; Sorel, M.; Uson, A.; Yahlali, N.
Title Demonstration of background rejection using deep convolutional neural networks in the NEXT experiment Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages (up) 189 - 22pp
Keywords Dark Matter and Double Beta Decay (experiments)
Abstract Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in Xe-136. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a Th-228 calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses.
Address [Hauptman, J.; Nygren, D. R.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: marija.kekic@usc.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000616730800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4729
Permanent link to this record