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1.
Rev Sci Instrum ; 91(2): 023321, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-32113432

ABSTRACT

The Linear IFMIF (International Fusion Materials Irradiation Facility) Prototype Accelerator (LIPAc) is aiming at demonstrating the low energy section of a 40 MeV/125 mA IFMIF deuteron accelerator up to 9 MeV with a full beam current in cw operation. For such a high-power beam, the LIPAc injector is required to produce a 100 keV D+ beam with 140 mA and match it for injection into the Radio Frequency Quadrupole (RFQ) accelerator. The injector is designed by CEA-Saclay based on the high intensity light ion source (SILHI). In 2019, the commissioning of the RFQ to demonstrate the D+ beam acceleration at a low duty cycle (0.1%) was conducted. A nominal beam current of 125 mA D+ beam was accelerated up to 5 MeV through the RFQ successfully. The LIPAc injector fully satisfied the requirements for RFQ beam commissioning at the pulse mode.

2.
Rev Sci Instrum ; 90(11): 113324, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31779408

ABSTRACT

A Radio Frequency Quadrupole Cooler (RFQC) prototype was adapted for insertion into a high uniformity magnetic field, with Bz up to 0.2 T, to improve radial confinement. While the RFQC purpose is to reduce (by gas collisions) the energy spread and emittance of a beam of radioactive nuclei, to finely select ion mass in nuclear physics, the prototype is tested in a setup including a stable ion source, a pepper pot emittance meter, and two Faraday cups; this makes a precise characterization of the RFQC feasible. The ion extraction was studied in detail by simulations, both to match it to the emittance meter granularity and to verify the effect of the typical nonuniformity of the longitudinal electric field Ez inside the RFQC; an average motion description (including friction force from gas collisions) was used, introducing the ballistic and diffusive regimes. With a preliminary optimization of the electrode shape, buffer gas pressure pg, and radio frequency voltage, the ion beam can be extracted with a significant cooling margin.

3.
Rev Sci Instrum ; 87(2): 02B504, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26932057

ABSTRACT

Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component B(z) up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by B(z) and the rf voltage V(rf) (up to 1 kV at few MHz). Transport is provided by a static electric field E(z) (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on V(rf). The beamline design and the major parameters V(rf), B(z) (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

4.
Rev Sci Instrum ; 85(2): 02B905, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24593610

ABSTRACT

SPES (Selective Production of Exotic Species) is an INFN (Istituto Nazionale di Fisica Nucleare) project with the aim at producing and post-accelerating exotic beams to perform forefront research in nuclear physics. To allow post-acceleration of the radioactive ions, an ECR-based Charge Breeder (CB) developed on the basis of the Phoenix booster was chosen. The design of the complete beam line for the SPES-CB will be described: a system for stable 1+ beams production was included; special attention was paid to the medium resolution mass spectrometer after the CB to limit possible superposition of the exotic beams with the impurities present in the ECR plasma.

5.
Rev Sci Instrum ; 85(2): 02B909, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24593614

ABSTRACT

Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

6.
J Hum Nutr Diet ; 27(2): 162-7, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24387274

ABSTRACT

BACKGROUND: Measures of central adiposity such as waist circumference (PC) and sagittal abdominal diameter (SAD) are better predictors of metabolic complications than measures of total body fat. Thus, this study aimed to assess the relationship of different measures of WC and SAD with cardiometabolic risk factors in elderly men. METHODS: This is a cross-sectional study that included 69 men (aged 60-92 years old) enrolled in the Family Health Program of Viçosa, Minas Gerais, Brazil. The evaluations comprised anthropometric, biochemical and haemodynamic measurements. The WC (i.e., umbilical level; the narrowest waist; immediately above the iliac crests; and the midpoint between the last rib and iliac crest) and SAD (i.e., the narrowest point between the last rib and the iliac crest; higher abdominal diameter; umbilical level; and the midpoint between the iliac crests) were measured at different anatomical sites. Statistical analysis consisted of correlation coefficients between measures of abdominal adiposity and cardiometabolic risk factors. RESULTS: The strongest correlations were between the WC measured at the narrowest waist and triglycerides (TG), fasting blood glucose (FBG) and high-density lipoprotein cholesterol (HDL-C) levels, and between the SAD measured at the midpoint between the iliac crests and TG, FBG and HDL-C. CONCLUSIONS: SAD measured at the midpoint between the iliac crests and WC measured at the narrowest waist showed the best relationships with cardiometabolic risk factors in elderly men.


Subject(s)
Abdomen , Adiposity , Cardiovascular Diseases/etiology , Obesity, Abdominal/complications , Sagittal Abdominal Diameter , Waist Circumference , Aged , Aged, 80 and over , Anthropometry , Blood Glucose/metabolism , Brazil , Cardiovascular Diseases/blood , Cholesterol, HDL/blood , Cross-Sectional Studies , Humans , Male , Middle Aged , Obesity, Abdominal/blood , Risk Factors , Triglycerides/blood
7.
Article in English | MEDLINE | ID: mdl-12751839

ABSTRACT

In hemodialysis patients, oxidative stress results from an imbalance between the production of reactive oxygen species and antioxidant defense mechanisms. Recently, a new dialysis multi-layer membrane has been developed, by modifying the inner surface of regenerated cellulose to support a vitamin E coating. The aim of our study was to investigate the effects of hemodialysis treatment with vitamin E-modified membrane on anemia and erythropoietin requirement in a group of chronic uremic patients. Ten uremic, non diabetic, patients on standard bicarbonate dialysis were treated with vitamin E-bonded dialysis membrane for 12 months. Hematological parameters, erythropoietin requirement, serum vitamin E and serum malonyldialdehyde (MDA) were evaluated before starting the study and monthly. No significant changes in hemoglobin level, RBC count, hematocrit and EPO requirement were observed. Basal vitamin E levels were in the normal range (13.0 +/- 2.88 mg/L vs. 14.79 +/- 3.12 mg/L; NS). On the contrary, basal MDA levels were higher than those observed in the control group (1.87 +/- 0.36 vs. 1.13 +/- 0.18 mmol/mL; p < 0.01) and a significant decrease of MDA levels was found after 1 month of Excebrane treatment (1.39 +/- 0.25 nmol/mL; p < 0.02). In conclusion, the role of the "oxidative hemolysis" in the pathogenesis of anemia in CHD patients is still not clearly defined, but it could be of minor clinical relevance. Although the effectiveness of vitamin E-coated membranes as a scavenger of ROS allows a better control of intradialytic oxidative stress, it doesn't seem to contribute to clinical management of anemia in these patients.


Subject(s)
Anemia/prevention & control , Membranes, Artificial , Oxidative Stress/drug effects , Renal Dialysis/adverse effects , Uremia/therapy , Vitamin E/pharmacology , Adult , Aged , Anemia/drug therapy , Anemia/etiology , Cellulose , Erythropoietin/blood , Hematologic Tests , Humans , Lipid Peroxidation/drug effects , Male , Malondialdehyde/blood , Middle Aged , Renal Dialysis/instrumentation , Renal Dialysis/methods , Uremia/complications
8.
J Nephrol ; 14(4): 280-5, 2001.
Article in English | MEDLINE | ID: mdl-11506251

ABSTRACT

BACKGROUND: Several risk factors of IgA nephropathy (IgAN) have been identified, but their importance in predicting outcome is still controversial. METHODS: We conducted a retrospective study on 119 patients (pts) with IgAN. All had a follow-up of over five years (mean 134+/-56 months). For each patient we recorded age, 24h proteinuria, hematuria, renal function (RF), arterial hypertension (AH) and histological features. Multivariate analysis was done for predictive purposes (segmentation, using Chi-squared Automatic Interaction Detection-CHAID). RESULTS: AH at the time of renal biopsy was the principal and independent predicting factor: 30/50 (60%) hypertensive pts had serum creatinine > or =1.5 mg/dL at the end of follow-up compared to 9/69 (13%) pts with normal blood pressure. Age was a further predictive parameter: 21/28 (75%) pts with AH and age over 39 years had reduced RF at the last examination. In this subgroup, 18/19 (95%) with evidence of tubulo-interstitial lesions showed a decline of RF. CONCLUSIONS: AH and age alone are significant prognostic factors; tubulo-interstitial lesions are an additional pointer to poor outcome in these pts. The algorithm obtained with segmentation analysis may be a guideline for prognosis in single patients with IgA nephropathy.


Subject(s)
Glomerulonephritis, IGA/therapy , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Multivariate Analysis , Prognosis , Retrospective Studies , Treatment Outcome
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