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1.
J Acoust Soc Am ; 151(1): 180, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35105033

RESUMO

This paper investigates the performance of one-eighth Spherical Fraction Microphone Array through experimental measurement to analyze acoustic scenes in one-eighth of space. The array geometry is designed to be placed in a room corner at the junction of three acoustically rigid walls. Two prototypes are built with 8 and 16 microphones, respectively. The sampling strategy is discussed and a spatial aliasing analysis is carried out both analytically and by numerical simulations. The array performances are evaluated through Spherical Fraction Beamforming (SFB). This approach is based on the decomposition of the acoustic pressure field in a rigid bounded domain. The localization angular error and Directivity Index criterion are evaluated for both arrays. In a first experiment, the arrays are mounted in an eighth of space built inside an anechoic room. The results are compared with simulation and show consistency. The theoretical limitations of SFB in a rigid bounded one-eighth of space are retrieved experimentally. These limitations are also observed in a real configuration: an office room. Further investigations on SFB are also conducted in the case of a virtual scene constructed with two sound sources.

2.
Phytopathology ; 109(6): 916-931, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30852973

RESUMO

Vitis vinifera is affected by many diseases every year, depending on causal agents, susceptibility of cultivars, and climate region. Some are caused by a single agent, such as gray mold caused by Botrytis cinerea or powdery mildew caused by Erysiphe necator. Others result from the actions of a complex of pathogens such as grapevine trunk diseases (GTDs). GTDs are presently among the most devastating diseases in viticulture worldwide because both the economic losses and the long-term sustainability of vineyards are strongly affected. The complexity of GTDs results from the diversity of associated fungi, the undetermined period of latency within the vine (asymptomatic status), the erratic foliar symptom expression from one year to the next, and, probably correlated with all of these points, the lack of efficient strategies to control them. Distinct methods can be beneficial to improve our knowledge of GTDs. In vitro bioassays with cell suspensions, calli, foliar discs, full leaves, or plantlets, and in vivo natural bioassays with cuttings, grafted plants in the greenhouse, or artificially infected ones in the vineyard, can be applied by using progressive integrative levels of in vitro and in vivo, depending on the information searched. In this review, the methods available to understand GTDs are described in terms of experimental procedures, main obtained results, and deliverable prospects. The advantages and disadvantages of each model are also discussed.


Assuntos
Ascomicetos , Vitis , Doenças das Plantas , Folhas de Planta , Vitis/microbiologia
3.
World J Surg ; 42(1): 143-152, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28785839

RESUMO

OBJECTIVE: To evaluate the natural history of MEN1-related bronchial endocrine tumors (br-NETs) and to determine their histological characteristics, survival and causes of death. br-NETs frequency ranges from 3 to 13% and may reach 32% depending on the number of patients evaluated and on the criteria required for diagnosis. METHODS: The 1023-patient series of symptomatic MEN1 patients followed up in a median of 48.7 [35.5-59.6] years by the Groupe d'étude des Tumeurs Endocrines was analyzed using time-to-event techniques. RESULTS: br-NETs were found in 51 patients (4.8%, [95% CI 3.6-6.2%]) and were discovered by imaging in 86% of cases (CT scan, Octreoscan, Chest X-ray, MRI). Median age at diagnosis was 45 years [28-66]. Histological examination showed 27 (53%) typical carcinoids (TC), 16 (31%) atypical carcinoids (AC), 2 (4%) large cell neuroendocrine carcinomas (LCNEC), 3(6%) small cell neuroendocrine carcinomas (SCLC), 3(6%) TC associated with AC. Overall survival was not different from the rest of the cohort (HR 0.29, [95% CI 0.02-5.14]). AC tended to have a worse prognosis than TC (p = 0.08). Seven deaths were directly related to br-NETs (three AC, three SCLC and one LCNEC). Patients who underwent surgery survived longer (p = 10-4) and were metastasis free, while 8 of 14 non-operated patients were metastatic. There were no operative deaths. CONCLUSIONS: Around 5% of MEN1 patients develop br-NETs. br-NETs do not decrease overall survival in MEN1 patients, but poorly differentiated and aggressive br-NETs can cause death. br-NETs must be screened carefully. A biopsy is essential to operate on patients in time.


Assuntos
Neoplasias Brônquicas/patologia , Neoplasia Endócrina Múltipla Tipo 1/patologia , Tumores Neuroendócrinos/patologia , Adulto , Idoso , Neoplasias Brônquicas/diagnóstico , Neoplasias Brônquicas/mortalidade , Causas de Morte , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasia Endócrina Múltipla Tipo 1/diagnóstico , Neoplasia Endócrina Múltipla Tipo 1/mortalidade , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/mortalidade , Análise de Sobrevida
4.
J Acoust Soc Am ; 141(4): 2315, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28464683

RESUMO

Sound field reproduction is aimed at the reconstruction of a sound pressure field in an extended area using dense loudspeaker arrays. In some circumstances, sound field reproduction is targeted at the reproduction of a sound field captured using microphone arrays. Although methods and algorithms already exist to convert microphone array recordings to loudspeaker array signals, one remaining research question is how to control the spatial sparsity in the resulting loudspeaker array signals and what would be the resulting practical advantages. Sparsity is an interesting feature for spatial audio since it can drastically reduce the number of concurrently active reproduction sources and, therefore, increase the spatial contrast of the solution at the expense of a difference between the target and reproduced sound fields. In this paper, the application of the elastic-net cost function to sound field reproduction is compared to the lasso cost function. It is shown that the elastic-net can induce solution sparsity and overcomes limitations of the lasso: The elastic-net solves the non-uniqueness of the lasso solution, induces source clustering in the sparse solution, and provides a smoother solution within the activated source clusters.

5.
Rev Sci Instrum ; 87(2): 02B508, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26932061

RESUMO

In the framework of the SPIRAL1 upgrade under progress at the GANIL lab, the charge breeder based on a LPSC Phoenix ECRIS, first tested at ISOLDE has been modified to benefit of the last enhancements of this device from the 1+/n+ community. The modifications mainly concern the 1 + optics, vacuum techniques, and the RF-buffer gas injection into the charge breeder. Prior to its installation in the midst of the low energy beam line of the SPIRAL1 facility, it has been decided to qualify its performances and several operation modes at the test bench of LPSC lab. This contribution shall present preliminary results of experiments conducted at LPSC concerning the 1 + to n+ conversion efficiencies for noble gases as well as for alkali elements and the corresponding transformation times.

6.
Eur J Endocrinol ; 173(6): 819-26, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26392472

RESUMO

BACKGROUND: MEN1, which is secondary to the mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Most studies demonstrated the absence of direct genotype-phenotype correlations. The existence of a higher risk of death in the Groupe d'étude des Tumeurs Endocrines-cohort associated with a mutation in the JunD interacting domain suggests heterogeneity across families in disease expressivity. This study aims to assess the existence of modifying genetic factors by estimating the intrafamilial correlations and heritability of the six main tumor types in MEN1. METHODS: The study included 797 patients from 265 kindred and studied seven phenotypic criteria: parathyroid and pancreatic neuroendocrine tumors (NETs) and pituitary, adrenal, bronchial, and thymic (thNET) tumors and the presence of metastasis. Intrafamilial correlations and heritability estimates were calculated from family tree data using specific validated statistical analysis software. RESULTS: Intrafamilial correlations were significant and decreased along parental degrees distance for pituitary, adrenal and thNETs. The heritability of these three tumor types was consistently strong and significant with 64% (s.e.m.=0.13; P<0.001) for pituitary tumor, 65% (s.e.m.=0.21; P<0.001) for adrenal tumors, and 97% (s.e.m.=0.41; P=0.006) for thNETs. CONCLUSION: The present study shows the existence of modifying genetic factors for thymus, adrenal, and pituitary MEN1 tumor types. The identification of at-risk subgroups of individuals within cohorts is the first step toward personalization of care. Next generation sequencing on this subset of tumors will help identify the molecular basis of MEN1 variable genetic expressivity.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Neoplasias Brônquicas/genética , Neoplasia Endócrina Múltipla Tipo 1/genética , Tumores Neuroendócrinos/genética , Neoplasias Pancreáticas/genética , Neoplasias das Paratireoides/genética , Neoplasias Hipofisárias/genética , Neoplasias do Timo/genética , Adolescente , Neoplasias das Glândulas Suprarrenais/epidemiologia , Adulto , Distribuição por Idade , Neoplasias Brônquicas/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/epidemiologia , Neoplasias Pancreáticas/epidemiologia , Neoplasias das Paratireoides/epidemiologia , Linhagem , Neoplasias Hipofisárias/epidemiologia , Neoplasias do Timo/epidemiologia , Adulto Jovem
7.
Diabetes Metab ; 41(1): 37-44, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25277526

RESUMO

AIM: Our study assessed the distribution of physical activity during various typical tasks of daily life in adults with type 2 diabetes (T2D), a population typified by low physical activity. METHODS: We investigated the duration and intensity of physical activity in four domains (work, leisure, transportation and domestic), and how individual determinants might influence the repartition. The long-form International Physical Activity Questionnaire (IPAQ) was administered to participants from the échantillon national témoin représentatif des personnes diabétiques (ENTRED), a study of French adults with T2D (n=724, 65% men, age 62±10y, BMI 29±5kg.m(-2), HbA1c 7.1±1.1%), and the associations between sociodemographic/clinical characteristics and categories of physical activity intensity (low, moderate or high) were examined by logistic regression. RESULTS: The median total physical activity was 2079 [Q1=893, Q3=3915]MET-min·week(-1). The main contributors to total physical activity were domestic chores, followed by leisure-time activities and transportation (median: 630, 347 and 198MET-min·week(-1), respectively). Absence of cardiovascular complications (OR=1.87, 95% CI=1.01-3.47), age<65y (OR=2.28, 95% CI=1.30-4.01) and better self-perceived health (OR=2.12, 95% CI=1.18-3.83) were associated with more physical activity. In all patient subgroups (defined by category of physical activity intensity or stratified by determinants of physical activity level), domestic chores were always the main contributor to total physical activity (P<0.0001). CONCLUSION: Domestic chores are the predominant routine whereby adults with T2D engage in physical activity. This emphasizes the vast potential for promoting voluntary leisure-time physical activity in this population.


Assuntos
Atividades Cotidianas , Diabetes Mellitus Tipo 2/epidemiologia , Atividade Motora/fisiologia , Idoso , Índice de Massa Corporal , Estudos Transversais , Exercício Físico , Feminino , França/epidemiologia , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Inquéritos e Questionários
8.
Opt Express ; 22(24): 29554-67, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25606888

RESUMO

A differential profilometry technique is adapted to the problem of measuring the roughness of hollow glass fibres by use of immersion objectives and index-matching liquid. The technique can achieve picometer level sensitivity. Cross validation with AFM measurements is obtained through use of vitreous silica step calibration samples. Measurements on the inner surfaces of fibre-sized glass capillaries drawn from high purity suprasil F300 tubes show a sub-nanometer roughness, and the roughness power spectrum measured in the range [5 · 10(-3) m(-1) 10(-1) m(-1)] is consistent with the description of the glass surface as a superposition of frozen capillary waves. The surface roughness spectrum of two capillary tubes of differing compositions can be quantitatively distinguished.


Assuntos
Vidro/química , Interferometria/instrumentação , Íons , Dióxido de Silício/química , Propriedades de Superfície
9.
Theor Appl Genet ; 126(10): 2575-86, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23907359

RESUMO

Sugarcane cultivars are interspecific hybrids with an aneuploid, highly heterozygous polyploid genome. The complexity of the sugarcane genome is the main obstacle to the use of marker-assisted selection in sugarcane breeding. Given the promising results of recent studies of plant genomic selection, we explored the feasibility of genomic selection in this complex polyploid crop. Genetic values were predicted in two independent panels, each composed of 167 accessions representing sugarcane genetic diversity worldwide. Accessions were genotyped with 1,499 DArT markers. One panel was phenotyped in Reunion Island and the other in Guadeloupe. Ten traits concerning sugar and bagasse contents, digestibility and composition of the bagasse, plant morphology, and disease resistance were used. We used four statistical predictive models: bayesian LASSO, ridge regression, reproducing kernel Hilbert space, and partial least square regression. The accuracy of the predictions was assessed through the correlation between observed and predicted genetic values by cross validation within each panel and between the two panels. We observed equivalent accuracy among the four predictive models for a given trait, and marked differences were observed among traits. Depending on the trait concerned, within-panel cross validation yielded median correlations ranging from 0.29 to 0.62 in the Reunion Island panel and from 0.11 to 0.5 in the Guadeloupe panel. Cross validation between panels yielded correlations ranging from 0.13 for smut resistance to 0.55 for brix. This level of correlations is promising for future implementations. Our results provide the first validation of genomic selection in sugarcane.


Assuntos
Genoma de Planta/genética , Genômica/métodos , Saccharum/genética , Seleção Genética , Marcadores Genéticos , Variação Genética , Desequilíbrio de Ligação/genética , Modelos Genéticos , Fenótipo , Análise de Componente Principal
10.
Diabetes Res Clin Pract ; 101(2): 226-35, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23831112

RESUMO

AIM: Diabetes is known to impair health-related quality of life (HrQol). Our aim was to analyse a comprehensive set of potential determinants of HrQol in a large sample of patients with diabetes. METHODS: This study is based on the ENTRED 2007 study, a representative sample of adults (18 years and older) with diabetes. Data were extracted from postal self-reported questionnaires (from patients and medical practitioners) and from reimbursements from the National health insurance data system. HrQol was assessed with the MOS SF-12 for mental (MCS) and physical (PCS) component summaries. Multivariate linear regression models were used to analyse the variables associated with HrQol. RESULTS: SF-12 MCS and PCS were available in 2832 patients with T2DM, with a mean age 64 years (1715 males, 56%). Lower income, severe hypoglycaemic episodes, hospitalisation ≥24 h, instrumental daily living (IADL) restriction, low satisfaction for social support and an HbA1c within the 8.1-10.0% range were associated with lower MCS rating, whereas an older age and male gender were associated with higher MCS. Older age, female sex, higher BMI, lower income, insulin treatment, macrovascular complications, severe hypoglycaemic episodes, hospitalisation ≥24 h, and IADL restriction were associated with lower PCS values whereas having no need for social support was associated with higher PCS values. DISCUSSION: HrQol associated factors are multiple but mainly linked with socio-demographic factors, diabetes complications and satisfaction for social support. A patient centred approach should be tested to prevent impairment of HrQol and thus to decrease the burden of diabetes. Assessment of social support should be included.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Idoso , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Apoio Social , Inquéritos e Questionários
11.
Diabetes Metab ; 39(2): 139-47, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23219072

RESUMO

AIM: This study estimated the prevalence of symptoms evocative of obstructive sleep apneoa (OSA) in patients with type 2 diabetes and the proportion of those with evidence of a previous diagnosis or diagnostic procedure. METHODS: In ENTRED 2007, 8926 people reimbursed for at least three antidiabetic agents within the last 12 months were randomly selected, and 3894 answered a self-administered questionnaire. Symptoms evocative of OSA were defined as frequent snoring with excessive daytime sleepiness and/or witnessed sleep apneoa. Patients were considered to have evidence of a previous diagnostic procedure if they reported an OSA diagnosis or had a sleep recording done, or if a sleep recording was found in the hospital discharge or medical claims database, or if they were currently being treated with nocturnal ventilation. RESULTS: The patients' mean age was 66 years. Around 8.5% reported being diagnosed with OSA, 4.2% were treated with nocturnal ventilation and 16% had symptoms evocative of OSA. Being male, obesity, high blood pressure, insulin treatment, living with a partner, lower educational level and financial difficulties were all associated with symptoms suggestive of OSA. Overall, 13% had evidence of a previous diagnostic procedure, and the rate was 35% among those with symptoms evocative of OSA. CONCLUSION: OSA is underdiagnosed in French diabetic patients, while the prevalence of symptoms is high. Only 13% of the study population and 35% of those with symptoms suggestive of OSA had benefited from a diagnostic procedure. It is of the utmost importance to better diagnose OSA in the diabetic population.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Programas de Rastreamento , Obesidade/complicações , Apneia Obstrutiva do Sono/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Escolaridade , Feminino , França/epidemiologia , Humanos , Hipertensão/epidemiologia , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/epidemiologia , Prevalência , Qualidade de Vida , Fatores de Risco , Distribuição por Sexo , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/epidemiologia , Ronco/epidemiologia , Classe Social , Inquéritos e Questionários
13.
Rev Sci Instrum ; 83(2): 02A911, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22380252

RESUMO

The upgrade of the "Système de Production d'Ions Radioactifs en Ligne" phase I (SPIRAL I) installed at the "Grand Accélérateur National d'Ions Lourds" (GANIL) situated at Caen, France, is in progress and should be ready by 2014. In parallel, the first part of SPIRAL II facility is currently under construction. The global status of the upgrade is presented: goal, radioactive ion production systems, modification of the production cave and impact of the current safety re-evaluation of GANIL.

14.
Plant Dis ; 96(7): 924-934, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30727208

RESUMO

A new study on the development of foliar symptoms of esca was carried out from 2004 to 2006 in five mature vineyards in Aquitaine, France. Symptoms were monitored for severity and changes over time. Initial foliar symptoms were characterized by the presence of drying zones or discolorations (reddening or yellowing), which are symptoms that have also been attributed to Black Dead Arm (BDA). Then, the less-severely affected leaves persisted throughout the summer and developed into typical "tiger-stripe" symptoms of esca. The most severely symptomatic leaves fell soon after symptoms appeared. Severely diseased vines showed typical apoplectic or acute forms of esca that did not differ from the severe BDA forms. The appearance of leafsymptomatic vines increased uniformly over time, reaching a maximum incidence by the end of July. A second survey in 41 European and Lebanese vineyards showed that longitudinal discolorations were visible under the bark of 95% of the vines showing foliar esca symptoms. These wood symptoms, also previously attributed to BDA, appeared as xylem orange-brown stripes. Thus, foliar symptoms of esca showed transitory phases which overlapped with some BDA descriptions. Most of these symptoms, in the west-palearctic regions that were investigated, were commonly associated with the presence of one or several xylem discolorations.

15.
Eur J Endocrinol ; 164(4): 457-65, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21270112

RESUMO

BACKGROUND: Pituitary stalk interruption syndrome (PSIS) is a particular entity in the population of patients with hypopituitarism. Only rare cases have a known genetic cause. OBJECTIVES: i) To compare subgroups with or without extra-pituitary malformations (EPM) in a cohort of PSIS patients to identify predictive factors of evolution, ii) to determine the incidence of mutations of the known pituitary transcription factor genes in PSIS. Study design We analyzed features of 83 PSIS patients from 80 pedigrees and screened HESX1, LHX4, OTX2, and SOX3 genes. RESULTS: PSIS had a male predominance and was rarely familial (5%). Pituitary hypoplasia was observed only in the group with EPM. Multiple hormone deficits were observed significantly more often with versus without EPM (87.5 vs 69.5% respectively). Posterior pituitary location along the stalk was a significant protective factor regarding severity of hormonal phenotype. A novel HESX1 causative mutation was found in a consanguineous family, and two LHX4 mutations were present in familial PSIS. CONCLUSION: PSIS patients with EPM had a more severe hormonal disorder and pituitary imaging status, suggesting an antenatal origin. HESX1 or LHX4 mutations accounted for <5% of cases and were found in consanguineous or familial cases.


Assuntos
Proteínas de Homeodomínio/genética , Hipófise/anormalidades , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Proteínas com Homeodomínio LIM , Imageamento por Ressonância Magnética , Masculino , Mutação , Fatores de Transcrição Otx/genética , Hipófise/patologia , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição/genética
16.
J Dairy Sci ; 93(10): 4961-75, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20855031

RESUMO

The objective of the study was to evaluate performance of classic (global) and innovative (local) calibration techniques to monitor cattle diet, based on fecal near infrared reflectance spectroscopy (NIRS). A 3-yr on-farm survey (2005-2008) was carried out in Vietnam and La Reunion Island to collect animal, feed intake, and feces excretion data. Feed and feces were scanned by a Foss NIRsystem 5000 monochromator (Foss, Hillerød, Denmark) to estimate diet characteristics and nutrient digestibility. A data set including 1,322 diet-fecal pairs was built and used to perform global and local calibrations. Global equations gave satisfactory accuracy [coefficient of determination (R(2)) >0.8, 10% ≤ relative standard error of prediction (RSEP) ≤20%], whereas local equations gave good accuracy (R(2) >0.8, RSEP <10%) or excellent accuracy (R(2) >0.9, RSEP <10%) for the prediction of diet intake, quality, and digestibility. When validating the equations using the external individual data, both techniques were robust, with similar RSEP (8%) and R(2) (0.82) values. The predictive performance of global and local equations was improved (RSEP = 5% and R(2)=0.90) when averaged animal data from farm, visit, and similar milk production were used. In particular, local equations reduced RSEP by 43% and increased R(2) by 15%, on average, compared with those obtained from individual data. The low RSEP (4%), high R(2) (0.96), and good ratio performance deviation (RPD=5) illustrated the excellent accuracy and robustness of the local equations. Findings suggest the ability of fecal NIRS to successfully and more accurately predict diet properties (intake, quality, and digestibility) with local calibration techniques compared with classic global techniques, especially on an averaged data set. Local calibration techniques represent an alternative promising method and potentially a decision support tool to decide whether diets meet dairy cattle requirements or need to be modified.


Assuntos
Ração Animal/normas , Dieta/veterinária , Fezes/química , Espectroscopia de Luz Próxima ao Infravermelho/veterinária , Fenômenos Fisiológicos da Nutrição Animal , Animais , Calibragem , Bovinos , Dieta/normas , França , Valor Nutritivo , Controle de Qualidade , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Vietnã
17.
Rev Sci Instrum ; 81(2): 02A908, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20225406

RESUMO

Development of new radioactive beams, and thus of new target ion sources (TISs) for isotope-separator-on-line production systems are in progress at GANIL for the SPIRAL 2 project. The efficiency and time response measurements of each step in the production process are crucial to predict and maximize the available yields, in particular, for short lived isotopes. This paper presents a method for measuring these quantities that makes use of a stable alkali chopped beam of controlled intensity. This method was applied to surface ionization source test for high efficiency. Results of recent experiments are presented that include ionization efficiency measurements for Cs, Rb, K, Na, and Li with a graphite and rhenium ionizer and dwell time of these alkalis on graphite. The results enabled to design a first surface ionization source prototype which will be installed in the SPIRAL 2 TIS.

18.
Rev Sci Instrum ; 81(2): 02A904, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192402

RESUMO

The production of radioactive ions using the Isotope Separation On-Line method gives rise, in most cases, to singly charged ions. In order to perform experiments with postaccelerated radioactive ion beams, these ions have to be multicharged. We describe here a new compact design for a charge breeder that will be coupled to the production target of SPIRAL1 at GANIL. We present recent results obtained offline with stable alkali ions (Na, K, Rb, and Cs) on the SIRa test bench. Particularly, 1(+) to N(+) conversion efficiencies and conversion times are presented. Several points have been identified for the improvements of the present performances.

19.
Rev Sci Instrum ; 81(2): 02A909, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192406

RESUMO

In the frame of the SPIRAL II (Système de Production d'Ions Radioactifs Accélérés en Ligne Partie II) project, several developments of stable and radioactive ion production systems have been started up. In parallel, GANIL has the ambition to preserve the existing stable and radioactive beams and also to increase its range by offering new ones. In order to identify the best directions for this development, a new group called GANISOL has been formed. Its preliminary conclusions and the latest developments at GANIL are presented.

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