0000000000360491
AUTHOR
R. Dumont
showing 11 related works from this author
Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating
2017
We describe a new technique for the efficient generation of high-energy ions with electromagnetic ion cyclotron waves in multi-ion plasmas. The discussed ‘three-ion’ scenarios are especially suited for strong wave absorption by a very low number of resonant ions. To observe this effect, the plasma composition has to be properly adjusted, as prescribed by theory. We demonstrate the potential of the method on the world-largest plasma magnetic confinement device, JET (Joint European Torus, Culham, UK), and the high-magnetic-field tokamak Alcator C-Mod (Cambridge, USA). The obtained results demonstrate efficient acceleration of 3He ions to high energies in dedicated hydrogen–deuterium mixtures.…
Novel method for determination of tritium depth profiles in metallic samples
2019
Tritium accumulation in fusion reactor materials is considered a serious radiological issue, therefore a lot of effort has been concentrated on the development of radiometric techniques. A novel method, based on gradual dissolution, for the determination of the total tritium content and its depth profiles in metallic samples is demonstrated. This method allows for the measurement of tritium in metallic samples after their exposure to a hydrogen and tritium mixture, tritium containing plasma or after irradiation with neutrons resulting in tritium formation. In this method, successive layers of metal are removed using an appropriate etching agent in the controlled regime and the amount of evo…
Overview of the JET results
2015
Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in…
PCA3 como biomarcador de segunda línea en un programa de screening oportunista prospectivo, aleatorizado y controlado
2017
Resumen Objetivos Determinar el comportamiento del PCA3 como un marcador de segunda linea en un programa de cribado oportunista de cancer de prostata (CaP) y su comparacion con la calculadora de riesgo 3 del cribado aleatorizado europeo en cancer de prostata (ERSPC RC-3). Material y metodos Un total de 5.199 hombres de 40-75 anos se hicieron la prueba del antigeno prostatico especifico (PSA) y un tacto rectal (TR). Aquellos con TR normal y PSA ≥ 3 ng/ml se realizaron un PCA3. Todos los hombres con PCA3 ≥ 35 se hicieron biopsia inicial (BxI) —12 cilindros—. Aquellos con PCA3 Resultados PCA3 se testo en 838 hombres (16,1%). En los grupos PCA3(+) y PCA3(–), las tasas de deteccion global de CaP…
Comparison of the structure of the plasma-facing surface and tritium accumulation in beryllium tiles from JET ILW campaigns 2011-2012 and 2013-2014
2019
In this study, beryllium tiles from Joint European Torus (JET) vacuum vessel wall were analysed and compared regarding their position in the vacuum vessel and differences in the exploitation conditions during two campaigns of ITER-Like-Wall (ILW) in 2011-2012 (ILW1) and 2013-2014 (ILW2) Tritium content in beryllium samples were assessed. Two methods were used to measure tritium content in the samples - dissolution under controlled conditions and tritium thermal desorption. Prior to desorption and dissolution experiments, scanning electron microscopy and energy dispersive x-ray spectroscopy were used to study structure and chemical composition of plasma-facing-surfaces of the beryllium sampl…
Optimización de un programa de cribado oportunista de cáncer de próstata; ensayo aleatorizado prospectivo del papel del PSA y del PCA3 en uso secuenc…
2014
Resumen Objetivos Reducir el numero de biopsias (Bx) innecesarias en un programa de cribado oportunista en cancer de prostata (CaP). Material y metodos Estudio prospectivo y aleatorizado evaluando el PCA3 como biomarcador de segunda linea. De septiembre de 2010 a septiembre de 2012 2.366 hombres con edad en rango 40-74 anos, y mas de 10 anos de expectativa de vida, fueron estudiados mediante PSA y tacto rectal (TR), excluyendo los biopsiados previamente o con infeccion urinaria reciente. Ante un TR sospechoso y/o PSA > 3 ng/ml se les realizo un PCA3. A todos aquellos con PCA3 ≥ 35 se les realizo una Bx inicial (IBx) —12 cilindros—. Con PCA3 0,5 ng/ml a 6 meses o PSAv > 0,75 ng/ml/ano. Res…
Optimizing prostate cancer screening; prospective randomized controlled study of the role of PSA and PCA3 testing in a sequential manner in an opport…
2014
Abstract Objectives To reduce unnecessary biopsies (Bx) in an opportunistic screening programme of prostate cancer. Material and methods We performed a prospective evaluation of PCA3 as a second-line biomarker in an opportunistic screening for prostate cancer (PCa). From September 2010 until September 2012, 2,366 men, aged 40–74 years and with >10 years life expectancy, were initially screened with PSA/digital rectal examination (DRE). Men with previous Bx or with recent urine infections were excluded. Men with abnormal DRE and/or PSA > 3 ng/ml were submitted for PCA3. All men with PCA3 ≥ 35 underwent an initial biopsy (IBx) —12cores—. Men with PCA3 .5 ng/ml at 4-6months or PSAv > .75 ng/…
Assessment of the impact of herd management on sensorial quality of Charolais heifer meat
2004
International audience; Meat industry and some consumers often criticize beef meat because the organoleptic quality and tenderness are highly variable and difficult to predict. So, beef meat consumption could be penalized, by the marketing of an irregular quality product. * There are many livestock rearing methods in France to produce beef meat, depending on the region, the breed used, the feeding used (and so on).
Recent progress in L-H transition studies at JET: tritium, helium, hydrogen and deuterium
2022
Abstract We present an overview of results from a series of L–H transition experiments undertaken at JET since the installation of the ITER-like-wall (JET-ILW), with beryllium wall tiles and a tungsten divertor. Tritium, helium and deuterium plasmas have been investigated. Initial results in tritium show ohmic L–H transitions at low density and the power threshold for the L–H transition (P LH) is lower in tritium plasmas than in deuterium ones at low densities, while we still lack contrasted data to provide a scaling at high densities. In helium plasmas there is a notable shift of the density at which the power threshold is minimum ( n ¯ e , min ) to higher values relative to deuterium and …
Modelling of JET hybrid plasmas with emphasis on performance of combined ICRF and NBI heating
2018
International audience; During the 2015--2016 JET campaigns, many efforts have been devoted to the exploration of high-performance plasma scenarios envisaged for DT operation in JET. In this paper, we review various key recent hybrid discharges and model the combined ICRF NBI heating. These deuterium discharges with deuterium beams had the ICRF antenna frequency tuned to match the cyclotron frequency of minority H at the centre of the tokamak coinciding with the second harmonic cyclotron resonance of D. The modelling takes into account the synergy between ICRF and NBI heating through the second harmonic cyclotron resonance of D beam ions, allowing us to assess its impact on the neutron rate…
PCA3 as a second-line biomarker in a prospective controlled randomized opportunistic prostate cancer screening programme
2017
Objectives: PCA3 performance as a single second line biomarker is compared to the European Randomised Study of Screening for Prostate Cancer risk calculator model 3 (ERSPC RC-3) in an opportunistic screening in prostate cancer (PCa). Material and methods: 5,199 men, aged 40-75y, underwent prostate-specific antigen (PSA) screening and digital rectal examination (DRE). Men with a normal DRE and PSA >= 3 ng/ml had a PCA3 test done. All men with PCA3 >= 35 underwent an initial biopsy (IBx) 12 cores. Men with PCA3 = 3 ng/ml and DRE is normal, IBx could be avoided in 12.5% less than if ERSPC RC-3 is used and would reduce the false negative cases by 36.2%. At a FU of 21.7 months, this dual protoco…