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Author Berenguer, A.; Coves, A.; Gimeno, B.; Bronchalo, E.; Boria, V.E.
Title Experimental Study of the Multipactor Effect in a Partially Dielectric-Loaded Rectangular Waveguide Type Journal Article
Year 2019 Publication IEEE Microwave and Wireless Components Letters Abbreviated Journal IEEE Microw. Wirel. Compon. Lett.
Volume 29 Issue 9 Pages 595-597
Keywords Dielectric; multipactor effect; rectangular waveguide; RF breakdown; Secondary Electron Yield (SEY); waveguide transformer
Abstract This letter presents the experimental study of the multipactor threshold in a partially dielectric-loaded rectangular waveguide, whose results validate a multipactor model recently developed by the authors, which includes the charge distribution appearing on the dielectric surface during the multipactor discharge. First, the variation of the multipactor RF voltage threshold has been theoretically analyzed in different waveguide configurations: in an empty waveguide, and also in the cases of a one-sided and two-sided dielectric-loaded waveguides. To reach this aim, an in-house Monte Carlo simulation tool has been developed. The Secondary Electron Yield (SEY) of the metallic and dielectric materials used in the numerical simulations have been measured experimentally. Finally, an aluminum WR-75 symmetric E-plane rectangular waveguide transformer has been designed and fabricated, in which several multipaction tests have been carried out to validate the in-house software tool, demonstrating an excellent agreement between the simulation results and the experimental data.
Address [Berenguer, Andres; Coves, Angela; Bronchalo, Enrique] Univ Miguel Hernandez Elche, Dept Commun Engn, Elche 03202, Spain, Email: angela.coves@umh.es
Corporate Author Thesis
Publisher Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1531-1309 ISBN Medium
Area Expedition Conference
Notes WOS:000489754400009 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4170
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Author Coves, A.; Maestre, H.; Archiles, R.; Andres, M.V.; Gimeno, B.
Title Surface-Impedance Formulation for Hollow-Core Waveguides Based on Subwavelength Gratings Type Journal Article
Year 2022 Publication IEEE Access Abbreviated Journal IEEE Access
Volume 10 Issue Pages 18843-18854
Keywords Electromagnetic waveguides; Optical waveguides; Planar waveguides; Gratings; Surface waves; Surface impedance; Optical surface waves; Surface impedance; hollow-core waveguide; surface-relief grating
Abstract A rigorous Surface Impedance (SI) formulation for planar waveguides is presented. This modal technique splits the modal analysis of the waveguide in two steps. First, we obtain the modes characteristic equations as a function of the SI and, second, we need to obtain the surface impedance values using either analytical or numerical methods. We validate the technique by comparison with well-known analytical cases: the parallel-plate waveguide with losses and the dielectric slab waveguide. Then, we analyze an optical hollow-core waveguide defined by two high-contrast subwavelength gratings validating our results by comparison with reported values. Finally, we show the potential of our formulation with the analysis of a THz hollow-core waveguide defined by two surface-relief subwavelength gratings, including material losses in our formulation.
Address [Coves, Angela; Maestre, Haroldo] Univ Miguel Hernandez Elche, Dept Commun Engn I3E, Elche 03202, Spain, Email: angela.coves@umh.es
Corporate Author Thesis
Publisher Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-3536 ISBN Medium
Area Expedition Conference
Notes WOS:000760714900001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5139
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Author Albiol, F.; Corbi, A.; Albiol, A.
Title Densitometric Radiographic Imaging With Contour Sensors Type Journal Article
Year 2019 Publication IEEE Access Abbreviated Journal IEEE Access
Volume 7 Issue Pages 18902-18914
Keywords Conventional X-ray imaging; contour data; densitometric images; dynamic range; depth information
Abstract We present the technical/physical foundations of a new imaging technique that combines ordinary radiographic information (generated by conventional X-ray settings) with the patient's volume to derive densitometric images. Traditionally, these images provide quantitative information about tissues densities. In our approach, they graphically enhance either soft or bony regions. After measuring the patient's volume with contour recognition devices, the physical traversed lengths within it (as the Roentgen beam intersects the patient) are calculated and pixel-wise associated with the original radiograph (X). In order to derive this map of lengths (L), the camera equations of the X-ray system and the contour sensor are determined. The patient's surface is also translated to the point-of-view of the X-ray beam and all its entrance/exit points are sought with the help of ray-casting methods. The derived L is applied to X as a physical operation (subtraction), obtaining soft tissue-(D-S) or bone-enhanced (D'(B)) figures. In the D-S type, the contained graphical information can be linearly mapped to the average electronic density (traversed by the X-ray beam). This feature represents an interesting proof-of-concept of associating density data to radiographs, but most important, their intensity histogram is objectively compressed, i.e., the dynamic range is more shrunk (compared against the corresponding X). This leads to other advantages: improvement in the visibility of border/edge areas (high gradient), extended manual window level/width manipulations during screening, and immediate correction of underexposed X instances. In the D-B' type, high-density elements are highlighted and easier to discern. All these results can be achieved with low-energy beam exposures, saving costs and dose. Future work will deepen this clinical side of our research. In contrast with other image-based modifiers, the proposed method is grounded on the measurement of a physical entity: the span of the X-ray beam within a body while undertaking a radiographic examination.
Address [Albiol, Francisco; Corbi, Alberto] CSIC, Inst Fis Corpuscular, Paterna 46980, Spain, Email: kiko@ific.uv.es
Corporate Author Thesis
Publisher Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-3536 ISBN Medium
Area Expedition Conference
Notes WOS:000459591800001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3920
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Author Casas, F.; Oteo, J.A.; Ros, J.
Title Unitary transformations depending on a small parameter Type Journal Article
Year 2012 Publication Proceedings of the Royal Society A Abbreviated Journal Proc. R. Soc. A
Volume 468 Issue 2139 Pages 685-700
Keywords perturbation theory; quantum mechanics; unitary transformation; Magnus expansion
Abstract We formulate a unitary perturbation theory for quantum mechanics inspired by the Lie-Deprit formulation of canonical transformations. The original Hamiltonian is converted into a solvable one by a transformation obtained through a Magnus expansion. This ensures unitarity at every order in a small parameter. A comparison with the standard perturbation theory is provided. We work out the scheme up to order ten with some simple examples.
Address [Oteo, J. A.; Ros, J.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: rosj@uv.es
Corporate Author Thesis
Publisher Royal Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1364-5021 ISBN Medium
Area Expedition Conference
Notes WOS:000300185400005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 893
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Author Verdu-Andres, S.; Amaldi, U.; Faus-Golfe, A.
Title CABOTO, a high-gradient linac for hadrontherapy Type Journal Article
Year 2013 Publication Journal of Radiation Research Abbreviated Journal J. Radiat. Res.
Volume 54 Issue Pages 155-161
Keywords hadrontherapy; high-gradient linac; cyclinac; carbon ion therapy; multipainting
Abstract The field of hadrontherapy has grown rapidly in recent years. At present the therapeutic beam is provided by a cyclotron or a synchrotron, but neither cyclotrons nor synchrotrons present the best performances for hadrontherapy. The new generation of accelerators for hadrontherapy should allow fast active energy modulation and have a high repetition rate, so that moving organs can be appropriately treated in a reasonable time. In addition, a reduction of the dimensions and cost of the accelerators for hadrontherapy would make the acquisition and operation of a hadrontherapy facility more affordable, which would translate into great benefits for the potential hadrontherapy patients. The 'cyclinac', an accelerator concept that combines a cyclotron with a high-frequency linear accelerator (linac), is a fast-cycling machine specifically conceived to allow for fast active energy modulation. The present paper focuses on CABOTO (CArbon BOoster for Therapy in Oncology), a compact, efficient high-frequency linac that can accelerate C6+ ions and H-2 molecules from 150-410 MeV/u in similar to 24 m. The paper presents the latest design of CABOTO and discusses its performances.
Address [Verdu-Andres, Silvia; Amaldi, Ugo] Fdn Tera, I-28100 Novara, Italy, Email: sverdu@bnl.gov
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0449-3060 ISBN Medium
Area Expedition Conference
Notes WOS:000321463900021 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1506
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Author Ros, A.; Lerche, C.W.; Sebastia, A.; Sanchez, F.; Benlloch, J.M.
Title Retroreflector arrays for better light collection efficiency of gamma-ray imaging detectors with continuous scintillation crystals without DOI misestimation Type Journal Article
Year 2014 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 9 Issue Pages P04009 - 14pp
Keywords Gamma detectors (scintillators, CZT, HPG, HgI etc); Interaction of radiation with matter; Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA); Detector design and construction technologies and materials
Abstract A method to improve light collection efficiency of gamma-ray imaging detectors by using retroreflector arrays has been tested, simulations of the behaviour of the scintillation light illuminating the retroreflector surface have been made. Measurements including retroreflector arrays in the setup have also been taken. For the measurements, positron emission tomography (PET) detectors with continuous scintillation crystals have been used. Each detector module consists of a continuous LSO-scintillator of dimensions 49x49x10 mm(3) and a H8500 position-sensitive photo-multiplier (PSPMT) from Hamamatsu. By using a continuous scintillation crystal, the scintillation light distribution has not been destroyed and the energy, the centroids along the x- and y-direction and the depth of interaction (DOI) can be estimated. Simulations have also been run taking into account the use of continuous scintillation crystals. Due to the geometry of the continuous scintillation crystals in comparison with pixelated crystals, a good light collection efficiency is necessary to correctly reconstruct the impact point of the gamma-ray. The aim of this study is to investigate whether micro-machine retro-reflectors improve light yield without misestimation of the impact point. The results shows an improvement on the energy and centroid resolutions without worsening the depth of interaction resolution. Therefore it can be concluded that using retroreflector arrays at the entrance side of the scintillation crystal improves light collection efficiency without worsening the impact point estimation.
Address [Ros, A.] Inst Fis Corpuscular IFIC, Valencia 46980, Spain, Email: anrogar2@i3m.upv.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:000336123800049 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1798
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Author Carrio, F.; Kim, H.Y.; Moreno, P.; Reed, R.; Sandrock, C.; Schettino, V.; Shalyugin, A.; Solans, C.; Souza, J.; Usai, G.; Valero, A.
Title Design of an FPGA-based embedded system for the ATLAS Tile Calorimeter front-end electronics test-bench Type Journal Article
Year 2014 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 9 Issue Pages C03023 - 12pp
Keywords Detector control systems (detector and experiment monitoring and slow-control systems, architecture, hardware, algorithms; databases); Data acquisition concepts; Digital electronic circuits
Abstract The portable test-bench for the certification of the ATLAS tile hadronic calorimeter front-end electronics has been redesigned for the present Long Shutdown (LS1) of LHC, improving its portability and expanding its functionalities. This paper presents a new test-bench based on a Xilinx Virtex-5 FPGA that implements an embedded system using a PowerPC 440 microprocessor hard core and custom IP cores. A light Linux version runs on the PowerPC microprocessor and handles the IP cores which implement the different functionalities needed to perform the desired tests such as TTCvi emulation, G-Link decoding, ADC control and data reception.
Address [Carrio, F.; Valero, A.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46980 Paterna, Spain, Email: fernando.carrio@cern.ch
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:000336123200023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1801
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Author ATLAS Tile Calorimeter Community (Abdallah, J. et al); Calderon, D.; Castillo Gimenez, V.; Costelo, J.; Ferrer, A.; Fullana, E.; Gonzalez, V.; Higon-Rodriguez, E.; Poveda, J.; Ruiz, A.; Salvachua, B.; Sanchis, E.; Solans, C.; Torres, J.; Valero, A.; Valls Ferrer, J.A.
Title Mechanical construction and installation of the ATLAS tile calorimeter Type Journal Article
Year 2013 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 8 Issue Pages T11001 - 26pp
Keywords Detector design and construction technologies and materials; Calorimeters
Abstract This paper summarises the mechanical construction and installation of the Tile Calorimeter for the ATLAS experiment at the Large Hadron Collider in CERN, Switzerland. The Tile Calorimeter is a sampling calorimeter using scintillator as the sensitive detector and steel as the absorber and covers the central region of the ATLAS experiment up to pseudorapidities +/- 1.7. The mechanical construction of the Tile Calorimeter occurred over a period of about 10 years beginning in 1995 with the completion of the Technical Design Report and ending in 2006 with the installation of the final module in the ATLAS cavern. During this period approximately 2600 metric tons of steel were transformed into a laminated structure to form the absorber of the sampling calorimeter. Following instrumentation and testing, which is described elsewhere, the modules were installed in the ATLAS cavern with a remarkable accuracy for a structure of this size and weight.
Address [Abdallah, J.; Calderon, D.; Castillo, M. V.; Costello, J.; Ferrer, A.; Fullana, E.; Gonzalez, V.; Higon, E.; Poveda, J.; Ruiz, A.; Salvachua, B.; Sanchis, E.; Solans, C.; Torres, J.; Valero, A.; Valls, J. A.] Univ Valencia, CSIC, Ctr Mixto, IFIC, E-46100 Valencia, Spain, Email: Proudfoot@anl.gov
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:000329193500038 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1696
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Author Resta-Lopez, J.
Title Nonlinear protection of beam delivery systems for multi-TeV linear colliders Type Journal Article
Year 2013 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 8 Issue Pages P11010 - 19pp
Keywords Beam Optics; Beam dynamics; Accelerator Subsystems and Technologies; Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics)
Abstract The post-linac energy collimation system of future e(+)e(-) multi-TeV linear colliders is designed to fulfil an essential function of protection of the Beam Delivery System (BDS) against miss-steered or errant beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This condition makes the design of the energy collimation system especially challenging, if we take into account the need to dispose of an unprecedented transverse beam energy density per beam of the order of GJ/mm(2), when assuming the nominal CLIC beam parameters at 3 TeV centre-of-mass energy, which translates into an extremely high damage potential of uncontrolled beams. This leads to research activities involving new collimator materials and novel collimation techniques. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a multipole magnet pair for energy collimation. In order to preserve an acceptable luminosity performance, we carefully study the general conditions for self-cancellation of optical aberrations between two multipoles. This nonlinear optics scheme is adapted to the requirements of the post-linac energy collimation system for the CLIC BDS, and its performance is investigated by means of beam tracking simulations. Although applied to the CLIC case, this nonlinear protection system could be adapted to other future colliders.
Address Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, Inst Invest Paterna, Valencia 46071, Spain, Email: resta@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:000329193500035 Approved no
Is ISI yes International Collaboration
Call Number IFIC @ pastor @ Serial 1697
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Author Alesini, D.; Boni, R.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.; Palumbo, L.; Spizzo, V.; Mostacci, A.; Campogiani, G.; Persichelli, S.; Enomoto, A.; Higo, T.; Kakihara, K.; Kamitani, T.; Matsumoto, S.; Sugimura, T.; Yokoyama, K.; Verdu-Andres, S.
Title The C-Band accelerating structures for SPARC photoinjector energy upgrade Type Journal Article
Year 2013 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 8 Issue Pages P05004 - 24pp
Keywords Acceleration cavities and magnets superconducting (high-temperature superconductor; radiation hardened magnets; normal-conducting; permanent magnet devices; wigglers and undulators); Accelerator Subsystems and Technologies; Instrumentation for FEL
Abstract The use of C-Band structures for electron acceleration and production of high quality beams has been proposed and adopted in several linac projects all over the world. The two main projects that adopted such type of structures are the Japanese Free Electron Laser (FEL) project in Spring-8 and the SwissFEL project at Paul Scherrer Institute (PSI). Also the energy upgrade of the SPARC photo-injector at LNF-INFN (Italy) from 150 to more than 240 MeV will be done by replacing a low gradient S-Band accelerating structure with two C-band structures. The structures are Traveling Wave (TW) and Constant Impedance (CI), have symmetric axial input couplers and have been optimized to work with a SLED RF input pulse. The paper presents the design criteria of the structures, the realization procedure and the low and high power RF test results on a prototype. The high power tests have been carried out by the Frascati INFN Laboratories in close collaboration with the Japanese Laboratory KEK. Experimental results confirmed the feasibility of the operation of the prototype at 50 MV/m with about 10(6) breakdowns per pulse per meter. Such high gradients have not been reached before in C-Band systems and demonstrated the possibility to use C-band accelerators, if needed, at such high field level. The results of the internal inspection of the structure after the high power test are also presented.
Address [Alesini, D.; Boni, R.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.] Ist Nazl Fis Nucl, LNF, I-00044 Rome, Italy, Email: alesini@lnf.infn.it
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:000320726000014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1512
Permanent link to this record