256 research outputs found
Influence of the magnetic filter field topology on the beam divergence at the ELISE test facility
The ELISE test facility hosts a RF negative ion source, equipped with an
extraction system which should deliver half the current foreseen for the ITER
Neutral Beam Injector, keeping the ratio of co-extracted electrons to ions
below 1. An important tool for the suppression of the co-extracted electrons is
the magnetic filter field, produced by a current flowing in the plasma grid,
the first grid of the 3 stage extraction system. To boost the source
performances new concepts for the production of the magnetic filter field have
been tested, combining the existing system with permanent magnets attached on
the source walls. The topologies of these new magnetic configurations influence
the beam particles trajectories in the extraction region, with consequences for
the overall beam optics. These effects will be characterized in this article by
studying the angular distribution of the beam particles, as measured by the
Beam Emission Spectroscopy (BES) diagnostic. The behavior of the beam will be
studied also through the measurements of the currents flowing on the grounded
grid (the third grid) and on the grid holder box surrounding its exit. The main
finding is that the broader component of the beam increases when the magnetic
field is strengthened by permanent magnets, i.e. in the cases in which most of
the co-extracted electrons are suppressed.Comment: 7 pages, 4 figures. Contributed paper for the NIBS 2016 conference.
Accepted manuscrip
Modeling and design of a BES diagnostic for the negative ion source NIO1
Consorzio RFX and INFN-LNL are building a flexible small ion source (NIO1)
capable of producing about 130 mA of H- ions accelerated at 60 KeV. Aim of the
experiment is to test and develop the instrumentation for SPIDER and MITICA,
the prototypes respectively of the negative ion sources and of the whole
neutral beam injectors which will operate in the ITER experiment. As SPIDER and
MITICA, NIO1 will be monitored with Beam Emission Spectroscopy (BES), a
non-invasive diagnostic based on the analysis of the spectrum of the
emission produced by the interaction of the energetic ions with the background
gas. Aim of BES is to monitor direction, divergence and uniformity of the ion
beam. The precision of these measurements depends on a number of factors
related to the physics of production and acceleration of the negative ions, to
the geometry of the beam and to the collection optics. These elements were
considered in a set of codes developed to identify the configuration of the
diagnostic which minimizes the measurement errors. The model was already used
to design the BES diagnostic for SPIDER and MITICA. The paper presents the
model and describes its application to design the BES diagnostic in NIO1.Comment: 3 pages, 3 figures. Contributed paper for the ICIS 2013 conference.
Accepted manuscrip
Beam characterization by means of emission spectroscopy in the ELISE test facility
The ELISE test facility at IPP Garching hosts a RF H-/D- ion source and an
acceleration system. Its target is to demonstrate the performance foreseen for
the ITER NBI system in terms of extracted current density (H/D), fraction of
co-extracted electrons and pulse duration. The size of the ELISE extraction
area is half that foreseen for the ITER NBI. This paper presents a detailed
study of the ELISE beam divergence and uniformity. In particular, it was
possible to describe the beam as the sum of two components at very different
divergence: about 2{\deg} vs. 5{\deg}{\div}7{\deg}. As test cases, the beam
properties have been measured as function of two source parameters. The first
one is the current flowing through the grid facing the plasma, the Plasma Grid,
in order to generate the magnetic filter field. The second one is the bias
current flowing between the Plasma Grid and the source walls. Both the filter
field and the bias current influence the fraction of co-extracted electrons,
but also the properties of the plasma just in front of the extraction system
and the beam properties. The divergence and the uniformity of the beam have
been measured by a Beam Emission Spectroscopy (BES) diagnostic; the detailed
analysis of the raw spectra collected by BES led to describing the beam with
two components of different divergence. This concept has been supported by the
information given by thermal imaging of the diagnostic calorimeter. Further
support to the proposed beam model has been found in the behavior of the
currents flowing in the acceleration system and beamline components; these
currents are given by the most divergent (charged) particles of the beam.Comment: 15 pages, 8 figures. Accepted manuscript (embargo expired
Reconfigurations in the university academic area and its impact on strategic management
El presente trabajo es el resultado de una investigación sobre los condicionantes que inciden en la toma de decisiones estratégicas del área académica universitaria. A partir de la realización de entrevistas en profundidad a informantes claves de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata, la cual constituye el foco de estudio, se ha considerado relevante exponer aquà los resultados de la percepción que tienen los miembros sobre la priorización de tales procesos decisorios. Se analizará a la luz del contexto actual de la Universidad Pública Argentina, del cual emergen múltiples variables situacionales que complejizan y afectan la calidad de la gestión estratégica.
El objetivo es poder generar información relevante que contribuya a la mejora en la planificación estratégica de la planta docente y permita optimizar la sostenibilidad de las polÃticas universitarias.
Se pretenderá resaltar la importancia de invertir tiempo en decisiones que tienen un profundo impacto de largo plazo en todos los actores, como asà también en establecer lineamientos claros que aseguren el desarrollo integral de la profesión docente.This work is the result of a study about conditioning factors in the strategic decision making processes at the university academic area. From in-depth interviews, made to important actors of the Faculty of Economic and Social Sciences of the National University of Mar del Plata, which is the focus of study, it has considered important to show here the results of the perceptions that members have about the prioritization of such decision-making processes. They will be analyzed in light of the changes that the Public University of Argentina is experiencing, where new variables emerge and make it difficult to think in the long term.
The objective is to produce relevant information that helps strategic management of the teaching team and make possible the sustainability of university policies. It pretends to show the importance of investing time on decisions that have profound long-term impact on all university actors. It is also important to establish clear guidelines that ensure the complete development of teaching profession.Facultad de Ciencias Económica
Reconfigurations in the university academic area and its impact on strategic management
El presente trabajo es el resultado de una investigación sobre los condicionantes que inciden en la toma de decisiones estratégicas del área académica universitaria. A partir de la realización de entrevistas en profundidad a informantes claves de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata, la cual constituye el foco de estudio, se ha considerado relevante exponer aquà los resultados de la percepción que tienen los miembros sobre la priorización de tales procesos decisorios. Se analizará a la luz del contexto actual de la Universidad Pública Argentina, del cual emergen múltiples variables situacionales que complejizan y afectan la calidad de la gestión estratégica.
El objetivo es poder generar información relevante que contribuya a la mejora en la planificación estratégica de la planta docente y permita optimizar la sostenibilidad de las polÃticas universitarias.
Se pretenderá resaltar la importancia de invertir tiempo en decisiones que tienen un profundo impacto de largo plazo en todos los actores, como asà también en establecer lineamientos claros que aseguren el desarrollo integral de la profesión docente.This work is the result of a study about conditioning factors in the strategic decision making processes at the university academic area. From in-depth interviews, made to important actors of the Faculty of Economic and Social Sciences of the National University of Mar del Plata, which is the focus of study, it has considered important to show here the results of the perceptions that members have about the prioritization of such decision-making processes. They will be analyzed in light of the changes that the Public University of Argentina is experiencing, where new variables emerge and make it difficult to think in the long term.
The objective is to produce relevant information that helps strategic management of the teaching team and make possible the sustainability of university policies. It pretends to show the importance of investing time on decisions that have profound long-term impact on all university actors. It is also important to establish clear guidelines that ensure the complete development of teaching profession.Facultad de Ciencias Económica
Characterization of Cs-free negative ion production in the ion source SPIDER by Cavity Ring-Down Spectroscopy
The Neutral beam Injectors of the ITER experiment will be based on negative
ion sources for the generation of beams composed by 1 MeV H/D particles. The
prototype of these sources is currently under testing in the SPIDER experiment,
part of the Neutral Beam Test Facility of Consorzio RFX, Padua, Italy. Among
the targets of the experimentation in SPIDER, it is of foremost importance to
maximize the beam current density extracted from the source acceleration
system. The SPIDER operating conditions can be optimized thanks to a Cavity
Ring-down Spectroscopy diagnostic, which is able to give line-integrated
measurements of negative ion density in proximity of the acceleration system
apertures. Regarding the diagnostic technique, this work presents a phenomenon
of drift in ring down time measurements, which develops in a time scale of few
hours. This issue may significantly affect negative ion density measurements
for plasma pulses of 1 h duration, as required by ITER. Causes and solutions
are discussed. Regarding the source performance, this paper presents how
negative ion density is influenced by the RF power used to sustain the plasma,
and by the magnetic filter field present in SPIDER to limit the amount of
co-extracted electrons. In this study, SPIDER was operated in hydrogen and
deuterium, in Cs-free conditions.Comment: 9 pages, 5 figures. Accepted manuscript of a published articl
Reconfigurations in the university academic area and its impact on strategic management
El presente trabajo es el resultado de una investigación sobre los condicionantes que inciden en la toma de decisiones estratégicas del área académica universitaria. A partir de la realización de entrevistas en profundidad a informantes claves de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata, la cual constituye el foco de estudio, se ha considerado relevante exponer aquà los resultados de la percepción que tienen los miembros sobre la priorización de tales procesos decisorios. Se analizará a la luz del contexto actual de la Universidad Pública Argentina, del cual emergen múltiples variables situacionales que complejizan y afectan la calidad de la gestión estratégica.
El objetivo es poder generar información relevante que contribuya a la mejora en la planificación estratégica de la planta docente y permita optimizar la sostenibilidad de las polÃticas universitarias.
Se pretenderá resaltar la importancia de invertir tiempo en decisiones que tienen un profundo impacto de largo plazo en todos los actores, como asà también en establecer lineamientos claros que aseguren el desarrollo integral de la profesión docente.This work is the result of a study about conditioning factors in the strategic decision making processes at the university academic area. From in-depth interviews, made to important actors of the Faculty of Economic and Social Sciences of the National University of Mar del Plata, which is the focus of study, it has considered important to show here the results of the perceptions that members have about the prioritization of such decision-making processes. They will be analyzed in light of the changes that the Public University of Argentina is experiencing, where new variables emerge and make it difficult to think in the long term.
The objective is to produce relevant information that helps strategic management of the teaching team and make possible the sustainability of university policies. It pretends to show the importance of investing time on decisions that have profound long-term impact on all university actors. It is also important to establish clear guidelines that ensure the complete development of teaching profession.Facultad de Ciencias Económica
Beamlet scraping and its influence on the beam divergence at the BATMAN Upgrade test facility
For the ITER fusion experiment, two neutral beam injectors are required for plasma heating and current drive. Each injector supplies a power of about 17 MW, obtained from neutralization of 40 A (46 A), 1 MeV (0.87 MeV) negative deuterium (hydrogen) ions. The full beam is composed of 1280 beamlets, formed in 16 beamlet groups, and strict requirements apply to the beamlet core divergence (<7 mrad). The test facility BATMAN Upgrade uses an ITER-like grid with one beamlet group, which consists of 70 apertures. In a joint campaign performed by IPP and Consorzio RFX to better assess the beam optics, the divergence of a single beamlet was compared to a group of beamlets at BATMAN Upgrade. The single beamlet is measured with a carbon fiber composite tile calorimeter and by beam emission spectroscopy, whereas the divergence of the group of beamlets is measured by beam emission spectroscopy only. When increasing the RF power at low extraction voltages, the divergence of the beamlet and of the group of beamlets is continuously decreasing and no inflection point toward an overperveant beam is found. At the same time, scraping of the extracted ion beam at the second grid (extraction grid) takes place at higher RF power, supported by the absence of the normally seen linear behavior between the measured negative ion density in the plasma close to the extraction system and the measured extracted ion current. Beside its influence on the divergence, beamlet scraping needs to be considered for the determination of the correct perveance and contributes to the measured coextracted electron current
XRCC2 R188H (rs3218536), XRCC3 T241M (rs861539) and R243H (rs77381814) single nucleotide polymorphisms in cervical cancer risk
Human Papillomavirus (HPV) is the main cause of cervical cancer and its precursor lesions. Transformation may be induced by several mechanisms, including oncogene activation and genome instability. Individual differences in DNA damage recognition and repair have been hypothesized to influence cervical cancer risk. The aim of this study was to evaluate whether the double strand break gene polymorphisms XRCC2 R188H G>A (rs3218536), XRCC3 T241M C>T (rs861539) and R243H G>A (rs77381814) are associated to cervical cancer in Argentine women. A case control study consisting of 322 samples (205 cases and 117 controls) was carried out. HPV DNA detection was performed by PCR and genotyping of positive samples by EIA (enzyme immunoassay). XRCC2 and 3 polymorphisms were determined by pyrosequencing. The HPV-adjusted odds ratio (OR) of XRCC2 188 GG/AG genotypes was OR = 2.4 (CI = 1.1-4.9, p = 0.02) for cervical cancer. In contrast, there was no increased risk for cervical cancer with XRCC3 241 TT/CC genotypes (OR = 0.48; CI = 0.2-1; p = 0.1) or XRCC3 241 CT/CC (OR = 0.87; CI = 0.52-1.4; p = 0.6). Regarding XRCC3 R243H, the G allele was almost fixed in the population studied. In conclusion, although the sample size was modest, the present data indicate a statistical association between cervical cancer and XRCC2 R188H polymorphism. Future studies are needed to confirm these findings.Fil: Perez, Luis Orlando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Crivaro, Andrea Natalia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Barbisan, Gisela. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Poleri, LucÃa Belén. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Golijow, Carlos Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin
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