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Author Gonzalez-Iglesias, D.; Gimeno, B.; Esperante, D.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster-Martinez, N.; Blanch, C.; Martinez, E.; Menendez, A.; Fuster, J.; Grudiev, A.
Title Non-resonant ultra-fast multipactor regime in dielectric-assist accelerating structures Type Journal Article
Year 2024 Publication Results in Physics Abbreviated Journal Results Phys.
Volume 56 Issue Pages 107245 - 12pp
Keywords Multipactor; Dielectric accelerating structures; RF particle accelerators; Plasma discharge
Abstract The objective of this work is the evaluation of the risk of suffering a multipactor discharge in an S-band dielectric-assist accelerating (DAA) structure for a compact low-energy linear particle accelerator dedicated to hadrontherapy treatments. A DAA structure consists of ultra-low loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure, with the advantage of having an extremely high quality factor and very high shunt impedance at room temperature, and it is therefore proposed as a potential alternative to conventional disk-loaded copper structures. However, it has been observed that these structures suffer from multipactor discharges. In fact, multipactor is one of the main problems of these devices, as it limits the maximum accelerating gradient. Because of this, the analysis of multipactor risk in the early design steps of DAA cavities is crucial to ensure the correct performance of the device after fabrication. In this paper, we present a comprehensive and detailed study of multipactor in our DAA design through numerical simulations performed with an in-house developed code based on the Monte-Carlo method. The phenomenology of the multipactor (resonant electron trajectories, electron flight time between impacts, etc.) is described in detail for different values of the accelerating gradient. It has been found that in these structures an ultra-fast non-resonant multipactor appears, which is different from the types of multipactor theoretically studied in the scientific literature. In addition, the effect of several low electron emission coatings on the multipactor threshold is investigated. Furthermore, a novel design based on the modification of the DAA cell geometry for multipactor mitigation is introduced, which shows a significant increase in the accelerating gradient handling capabilities of our prototype.
Address [Gonzalez-Iglesias, Daniel; Gimeno, Benito; Esperante, Daniel; Martinez-Reviriego, Pablo; Martin-Luna, Pablo; Fuster-Martinez, Nuria; Blanch, Cesar; Martinez, Eduardo; Menendez, Abraham; Fuster, Juan] CSIC UV, Inst Fis Corpuscular IF, c Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: daniel.gonzalez-iglesias@uv.es
Corporate Author Thesis
Publisher (up) Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-3797 ISBN Medium
Area Expedition Conference
Notes WOS:001133850600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5866
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Author Amaldi, U.; Bonomi, R.; Braccini, S.; Crescenti, M.; Degiovanni, A.; Garlasche, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pitta, G.; Puggioni, P.; Rosso, E.; Verdu-Andres, S.; Wegner, R.; Weiss, M.; Zennaro, R.
Title Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs Type Journal Article
Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 620 Issue 2-3 Pages 563-577
Keywords Medical accelerators; Linac; Cyclotron; Synchrotron; Cyclinac; Radiation oncology; Hadrontherapy; Particle therapy; Proton therapy; Carbon ion therapy; Dose delivery
Abstract Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and 'single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs.
Address [Amaldi, U.; Bonomi, R.; Braccini, S.; Crescenti, M.; Degiovanni, A.; Garlasche, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pitta, G.; Puggioni, P.; Rosso, E.; Andres, S. Verdu; Wegner, R.; Weiss, M.; Zennaro, R.] TERA Fdn, Novara, Italy, Email: Saverio.Braccini@cern.ch
Corporate Author Thesis
Publisher (up) 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 ISI:000280601700058 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 401
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Author Degiovanni, A.; Amaldi, U.; Bonomi, R.; Garlasche, M.; Garonna, A.; Verdu-Andres, S.; Wegner, R.
Title TERA high gradient test program of RF cavities for medical linear accelerators Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 657 Issue 1 Pages 55-58
Keywords Medical accelerators; Hadrontherapy; Cyclinac; Linac; RF cavity; Breakdown Rate
Abstract The scientific community and the medical industries are putting a considerable effort into the design of compact, reliable and cheap accelerators for hadrontherapy. Up to now only circular accelerators are used to deliver beams with energies suitable for the treatment of deep seated tumors. The TERA Foundation has proposed and designed a hadrontherapy facility based on the cyclinac concept: a high gradient linear accelerator placed downstream of a cyclotron used as an injector. The overall length of the linac, and therefore its final cost, is almost inversely proportional to the average accelerating gradient achieved in the linac. TERA, in collaboration with the CLIC RF group, has started a high gradient test program. The main goal is to study the high gradient behavior of prototype cavities and to determine the appropriate linac operating frequency considering important issues such as machine reliability and availability of distributed power sources. A preliminary test of a 3 GHz cavity has been carried out at the beginning of 2010, giving encouraging results. Further investigations are planned before the end of 2011. A set of 5.7 GHz cavities is under production and will be tested in a near future. The construction and test of a multi-cell structure is also foreseen.
Address [Degiovanni, A; Wegner, R] CERN, CH-1211 Geneva, Switzerland, Email: alberto.degiovanni@cern.ch
Corporate Author Thesis
Publisher (up) 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:000297085800010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 807
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Author Scandale, W. et al; Lari, L.
Title Optimization of the crystal assisted collimation of the SPS beam Type Journal Article
Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 726 Issue 1-3 Pages 182-186
Keywords Accelerator; Beam collimation; Crystal; Channeling
Abstract The possibility for optimization of crystal assisted collimation has been studied at the CERN SPS for stored beams of protons and Pb ions with 270 GeV/c per unit charge. A bent silicon crystal used as a primary collimator deflects halo particles in the channeling regime, directing them into a tungsten absorber. In channeling conditions a strong reduction of off-momentum particle numbers produced in the crystal and absorber, which form collimation leakage, has been observed in the first high dispersion (HD) area downstream. The present study shows that the collimation leakage is minimal for some values of the absorber offset relative to the crystal. The optimal offset value is larger for Pb ions because of their considerably larger ionization losses in the crystal, which cause large increases of particle betatron oscillation amplitudes. The optimal absorber offset allows obtaining maximal efficiency of crystal-assisted collimation.
Address [Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland, Email: alexander.taratin@cern.ch
Corporate Author Thesis
Publisher (up) 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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000326482200020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1694
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Author Scandale, W et al; Lari, L.
Title Deflection of high energy protons by multiple volume reflections in a modified multi-strip silicon deflector Type Journal Article
Year 2014 Publication Nuclear Instruments & Methods in Physics Research B Abbreviated Journal Nucl. Instrum. Methods Phys. Res. B
Volume 338 Issue Pages 108-111
Keywords Accelerator; Beam collimation; Crystal; Channeling; Volume reflection
Abstract The effect of multiple volume reflections in one crystal was observed in each of several bent silicon strips for 400 GeV/c protons. This considerably increased the particle deflections. Some particles were also deflected due to channeling in one of the subsequent strips. As a result, the incident beam was strongly spread because of opposite directions of the deflections. A modified multi-strip deflector produced by periodic grooves on the surface of a thick silicon plate was used for these measurements. This technique provides perfect mutual alignment between crystal strips. Such multi-strip deflector may be effective for collider beam halo collimation and a study is planned at the CERN SPS circulating beam.
Address [Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland
Corporate Author Thesis
Publisher (up) 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 0168-583x ISBN Medium
Area Expedition Conference
Notes WOS:000343390400016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1974
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Author de Salas, P.F.; Forero, D.V.; Ternes, C.A.; Tortola, M.; Valle, J.W.F.
Title Status of neutrino oscillations 2018: 3 sigma hint for normal mass ordering and improved CP sensitivity Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 782 Issue Pages 633-640
Keywords Neutrino mass and mixing; Neutrino oscillation; Solar and atmospheric neutrinos; Reactor and accelerator neutrinos; Neutrino telescopes
Abstract We present a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture, including new data which appeared since our previous analysis[1]. In this update we include new long-baseline neutrino data involving the antineutrino channel in T2K, as well as new data in the neutrino channel, data from NO nu A, as well as new reactor data, such as the Daya Bay 1230 days electron antineutrino disappearance spectrum data and the 1500 live days prompt spectrum from RENO, as well as new Double Chooz data. We also include atmospheric neutrino data from the IceCube DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we also update our solar oscillation analysis by including the 2055-day day/night spectrum from the fourth phase of the Super-Kamiokande experiment. With the new data we find a preference for the atmospheric angle in the upper octant for both neutrino mass orderings, with maximal mixing allowed at Delta chi(2)= 1.6 (3.2) for normal (inverted) ordering. We also obtain a strong preference for values of the CP phase delta in the range [pi, 2 pi], excluding values close to pi/2at more than 4 sigma. More remarkably, our global analysis shows a hint in favorof the normal mass ordering over the inverted one at more than 3 sigma. We discuss in detail the status of the mass ordering, CP violation and octant sensitivities, analyzing the interplay among the different neutrino data samples.
Address [de Salas, P. F.; Ternes, C. A.; Tortola, M.; Valle, J. W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cient Paterna,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: pabferde@ific.uv.es;
Corporate Author Thesis
Publisher (up) 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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000438486900094 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3665
Permanent link to this record
 

 
Author Marco-Hernandez, R.; Bau, M.; Ferrari, M.; Ferrari, V.; Pedersen, F.; Soby, L.
Title A Low-Noise Charge Amplifier for the ELENA Trajectory, Orbit, and Intensity Measurement System Type Journal Article
Year 2017 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 64 Issue 9 Pages 2465-2473
Keywords Beam position monitor (BPM); charge sensitive amplifier; instrumentation for accelerators; low-noise amplifier; particle accelerators; printed circuits
Abstract A low-noise head amplifier has been developed for the extra low energy antiproton ring beam trajectory, orbit, and intensity measurement system at CERN. This system is based on 24 double-electrode electrostatic beam position monitors installed around the ring. A head amplifier is placed close to each beam position monitor to amplify the electrode signals and generate a difference and a sum signal. These signals are sent to the digital acquisition system, about 50 m away from the ring, where they are digitized and further processed. The beam position can be measured by dividing the difference signal by the sum signal while the sum signal gives information relative to the beam intensity. The head amplifier consists of two discrete charge preamplifiers with junction field effect transistor (JFET) inputs, a sum and a difference stage, and two cable drivers. Special attention has been paid to the amplifier printed circuit board design to minimize the parasitic capacitances and inductances at the charge amplifier stages to meet the gain and noise requirements. The measurements carried out on the head amplifier showed a gain of 40.5 and 46.5 dB for the sum and difference outputs with a bandwidth from 200 Hz to 75 MHz and an input voltage noise density lower than 400 pV/v Hz. Twenty head amplifiers have been already installed in the ring and they have been used to detect the first beam signals during the first commissioning stage in November 2016.
Address [Marco-Hernandez, Ricardo; Pedersen, Flemming; Soby, Lars] CERN, CH-1217 Meyrin, Switzerland, Email: rmarco@ific.uv.es
Corporate Author Thesis
Publisher (up) 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 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000411029500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3298
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Author Millar, W.L. et al; Bañon Caballero, D.
Title High-Power Test of Two Prototype X-Band Accelerating Structures Based on SwissFEL Fabrication Technology Type Journal Article
Year 2023 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 70 Issue 1 Pages 1-19
Keywords Radio frequency; Life estimation; Temperature measurement; Wires; Electric breakdown; Brazing; Rendering (computer graphics); Acceleration; breakdown; high gradient; linear accelerator cavity (LINAC); radio frequency (RF); test facilities; vacuum arc; X-band
Abstract This article presents the design, construction, and high-power test of two $X$ -band radio frequency (RF) accelerating structures built as part of a collaboration between CERN and the Paul Scherrer Institute (PSI) for the compact linear collider (CLIC) study. The structures are a modified “tuning-free ” variant of an existing CERN design and were assembled using Swiss free electron laser (SwissFEL) production methods. The purpose of the study is two-fold. The first objective is to validate the RF properties and high-power performance of the tuning-free, vacuum brazed PSI technology. The second objective is to study the structures' high-gradient behavior to provide insight into the breakdown and conditioning phenomena as they apply to high-field devices in general. Low-power RF measurements showed that the structure field profiles were close to the design values, and both structures were conditioned to accelerating gradients in excess of 100 MV/m in CERN's high-gradient test facility. Measurements performed during the second structure test suggest that the breakdown rate (BDR) scales strongly with the accelerating gradient, with the best fit being a power law relation with an exponent of 31.14. In both cases, the test results indicate that stable, high-gradient operation is possible with tuning-free, vacuum brazed structures of this kind.
Address [Millar, William L. L.; Grudiev, Alexej; Wuensch, Walter; Lasheras, Nuria Catalan; McMonagle, Gerard; Volpi, Matteo; Paszkiewicz, Jan; Edwards, Amelia; Wegner, Rolf; Bursali, Hikmet; Woolley, Benjamin; Magazinik, Anastasiya; Syratchev, Igor; Vnuchenko, Anna; Pitman, Samantha; del Pozo Romano, Veronica; Caballero, David Banon] CERN, CH-1211 Geneva, Switzerland, Email: lee.millar@cern.ch
Corporate Author Thesis
Publisher (up) 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 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000920658600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5471
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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 (up) 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
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Author ATLAS Collaboration (Aad, G. et al); Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fassi, F.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; March, L.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.
Title Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run Type Journal Article
Year 2013 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 8 Issue Pages P07004 - 72pp
Keywords Pattern recognition, cluster finding, calibration and fitting methods; Performance of High Energy Physics Detectors; Accelerator modelling and simulations (multi-particle dynamics; single-particle dynamics); Analysis and statistical methods
Abstract This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstrates the importance of such event cleaning techniques for some new physics searches.
Address [Jackson, P.; Soni, N.] Univ Adelaide, Sch Chem & Phys, Adelaide, SA, Australia
Corporate Author Thesis
Publisher (up) 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:000322572900015 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1557
Permanent link to this record