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Author NEXT Collaboration (Lorca, D. et al); Martin-Albo, J.; Laing, A.; Ferrario, P.; Gomez-Cadenas, J.J.; Alvarez, V.; Carcel, S.; Cervera-Villanueva, A.; Diaz, J.; Liubarsky, I.; Martinez, A.; Monrabal, F.; Monserrate, M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.
Title Characterisation of NEXT-DEMO using xenon K-alpha X-rays Type Journal Article
Year 2014 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 9 Issue Pages P10007 - 20pp
Keywords (down) Charge transport, multiplication and electroluminescence in rare gases and liquids; Double-beta decay detectors; Time projection chambers
Abstract The NEXT experiment aims to observe the neutrinoless double beta decay of Xe-136 in a high-pressure xenon gas TPC using electroluminescence (EL) to amplify the signal from ionization. Understanding the response of the detector is imperative in achieving a consistent and well understood energy measurement. The abundance of xenon K-shell X-ray emission during data taking has been identified as a multitool for the characterisation of the fundamental parameters of the gas as well as the equalisation of the response of the detector. The NEXT-DEMO prototype is a similar to 1.5 kg volume TPC filled with natural xenon. It employs an array of 19 PMTs as an energy plane and of 256 SiPMs as a tracking plane with the TPC light tube and SiPM surfaces being coated with tetraphenyl butadiene (TPB) which acts as a wavelength shifter for the VUV scintillation light produced by xenon. This paper presents the measurement of the properties of the drift of electrons in the TPC, the effects of the EL production region, and the extraction of position dependent correction constants using K-alpha X-ray deposits. These constants were used to equalise the response of the detector to deposits left by gammas from Na-22.
Address [Lorca, D.; Martin-Albo, J.; Laing, A.; Ferrario, P.; Gomez-Cadenas, J. J.; Alvarez, V.; Carcel, S.; Cervera, A.; Diaz, J.; Liubarsky, I.; Martinez, A.; Monrabal, F.; Monserrate, M.; Munoz Vidal, J.; Nebot-Guinot, M.; Rodriguez, J.; Serra, L.; Simon, A.; Sorel, M.; Yahlali, N.] CSIC, Inst Fis Corpuscular IFIC, Valencia 46980, Spain, Email: david.lorca@ific.uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000345858500050 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2055
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Author Capozziello, S.; Harko, T.; Lobo, F.S.N.; Olmo, G.J.; Vignolo, S.
Title The Cauchy problem in hybrid metric-Palatini f(X)-gravity Type Journal Article
Year 2014 Publication International Journal of Geometric Methods in Modern Physics Abbreviated Journal Int. J. Geom. Methods Mod. Phys.
Volume 11 Issue 5 Pages 1450042 - 12pp
Keywords (down) Cauchy problem; modified gravity; hybrid metric-Palatini gravity
Abstract The well-formulation and the well-posedness of the Cauchy problem are discussed for hybrid metric-Palatini gravity, a recently proposed modified gravitational theory consisting of adding to the Einstein-Hilbert Lagrangian an f(R)-term constructed a la Palatini. The theory can be recast as a scalar-tensor one predicting the existence of a light long-range scalar field that evades the local Solar System tests and is able to modify galactic and cosmological dynamics, leading to the late-time cosmic acceleration. In this work, adopting generalized harmonic coordinates, we show that the initial value problem can always be well-formulated and, furthermore, can be well-posed depending on the adopted matter sources.
Address [Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Sci Fis, Naples, Italy, Email: capozzie@na.infn.it;
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0219-8878 ISBN Medium
Area Expedition Conference
Notes WOS:000336527100003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1813
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Author Pujades, M.C.; Granero, D.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Papagiannis, P.; Siebert, F.A.
Title Air-kerma evaluation at the maze entrance of HDR brachytherapy facilities Type Journal Article
Year 2014 Publication Journal of Radiological Protection Abbreviated Journal J. Radiol. Prot.
Volume 34 Issue 4 Pages 741-753
Keywords (down) bunker; shielding; NCRP 151; brachytherapy; Monte Carlo
Abstract In the absence of procedures for evaluating the design of brachytherapy (BT) facilities for radiation protection purposes, the methodology used for external beam radiotherapy facilities is often adapted. The purpose of this study is to adapt the NCRP 151 methodology for estimating the air-kerma rate at the door in BT facilities. Such methodology was checked against Monte Carlo (MC) techniques using the code Geant4. Five different facility designs were studied for Ir-192 and Co-60 HDR applications to account for several different bunker layouts. For the estimation of the lead thickness needed at the door, the use of transmission data for the real spectra at the door instead of the ones emitted by Ir-192 and Co-60 will reduce the lead thickness by a factor of five for Ir-192 and ten for Co-60. This will significantly lighten the door and hence simplify construction and operating requirements for all bunkers. The adaptation proposed in this study to estimate the air-kerma rate at the door depends on the complexity of the maze: it provides good results for bunkers with a maze (i.e. similar to those used for linacs for which the NCRP 151 methodology was developed) but fails for less conventional designs. For those facilities, a specific Monte Carlo study is in order for reasons of safety and cost-effectiveness.
Address [Pujades, M. C.] Natl Ctr Dosimetry CND, Valencia, Spain, Email: mpuclau@gmail.com
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0952-4746 ISBN Medium
Area Expedition Conference
Notes WOS:000345895800005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2031
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Author Koolen, B.B.; Vidal-Sicart, S.; Benlloch, J.M.; Olmos, R.A.V.
Title Evaluating heterogeneity of primary tumor 18 F-FDG uptake in breast cancer with a dedicated breast PET ( MAMMI): a feasibility study based on correlation with PET/CT Type Journal Article
Year 2014 Publication Nuclear Medicine Communications Abbreviated Journal Nucl. Med. Commun.
Volume 35 Issue 5 Pages 446-452
Keywords (down) breast cancer; F-18-FDG; heterogeneity; MAMMI; PET
Abstract PurposeThe aim of the study was to evaluate the heterogeneity of primary tumor F-18-fluorodeoxyglucose (F-18-FDG) uptake in breast cancer patients using a dedicated breast PET.Patients and methodsA positron emission tomography/computed tomography (PET/CT) of the thorax was performed 60 min after administration of 180-240 MBq of F-18-FDG in patients with breast cancer. Subsequently, 110 min after injection, a scan was taken with a dedicated high-resolution breast PET [MAMmography with Molecular Imaging (MAMMI)]. Both procedures were performed with the patients in the prone position. Four-point scores were used to compare the intensity (0: none; 1: mild; 2: moderate; 3: high) and heterogeneity (0: none; 1: mild; 2: moderate; 3: high) of F-18-FDG uptake between PET/CT and MAMMI images.ResultsThirty-five patients in whom the primary tumor was visualized on both scans were included in this analysis. The mean primary tumor size was 35.1 mm (range 10-108 mm). The mean intensity score was similar on both devices (2.4 for PET/CT and 2.3 for MAMMI; P=0.439), but the mean heterogeneity score on MAMMI images was significantly higher (PET/CT 1.9 vs. MAMMI 2.3; P=0.005). MAMMI showed a higher heterogeneity score in 11 (31%) of 35 patients, especially in tumors with moderate or high intensity. Significantly higher heterogeneity scores on both PET/CT and MAMMI were seen in large tumors (P=0.005 and 0.014, respectively) and in tumors with high intensity scores (P=0.012 and P<0.001, respectively).ConclusionHeterogeneous tumor F-18-FDG uptake in breast cancer is frequently observed, particularly in large tumors with intense F-18-FDG uptake. It is more often seen on MAMMI PET than on conventional PET/CT. Although the observed heterogeneity should be proven histopathologically, this finding offers a rationale for F-18-FDG-guided biopsies.
Address [Koolen, Bas B.; Vidal-Sicart, Sergi; Olmos, Renato A. Valdes] Antoni van Leeuwenhoek Hosp, Netherlands Canc Inst, Dept Nucl Med, NL-1066 CX Amsterdam, Netherlands, Email: b.koolen@nki.nl
Corporate Author Thesis
Publisher Lippincott Williams & Wilkins Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0143-3636 ISBN Medium
Area Expedition Conference
Notes WOS:000334103800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1763
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Author Celis, A.; Fuentes-Martin, J.; Serodio, H.
Title A class of invisible axion models with FCNCs at tree level Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue 12 Pages 167 - 53pp
Keywords (down) Beyond Standard Model; CP violation; Global Symmetries
Abstract We build a class of invisible axion models with tree-level Flavor Changing Neutral Currents completely controlled by the fermion mixing matrices. The scalar sector of these models contains three-Higgs doublets and a complex scalar gauge singlet, with the same fermionic content as in the Standard Model. A horizontal Peccei-Quinn symmetry provides a solution to the strong CP problem and predicts the existence of a very light and weakly coupled pseudo-Goldstone boson, the invisible axion or familon. A phenomenological analysis is performed taking into account familon searches in rare kaon and muon decays, astrophysical considerations and axion searches via axion-photon conversion. Drastic differences are found in the axion properties of different models due to the strong hierarchy of the CKM matrix, making some of the models considered much more constrained than others. We also obtain that a rich variety of these models avoid the domain wall problem. A possible mechanism to protect the solution to the strong CP problem against gravitational effects is also discussed.
Address [Celis, Alejandro; Fuentes-Martin, Javier] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: alejandro.celis@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:000347160000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2067
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