Low- and intermediate-beta, 352-MHz superconducting half-wave resonators for high power hadron acceleration

Two prototypes of superconducting, 352 MHz coaxial half-wave resonators with β=0.17 and β=0.31 have been designed, constructed, and tested at INFN-LNL, in the framework of the SPES and EURISOL DS projects. Main features of these double-wall, 2-gap structures are compactness, mechanical stability, and easy installation in different kinds of cryostats. Their acceleration capabilities are similar to the ones of Spoke resonators with similar β. These cavities are being developed for acceleration of high power hadron beams in the 5–100  MeV/u energy range

Endothelial function and urine albumin levels among asymptomatic Mexican-Americans and non-Hispanic whites

<p>Abstract</p> <p>Background-</p> <p>Mexican-Americans (MA) exhibit increases in various cardiovascular disease (CVD) risk factors compared to non-Hispanic Whites (NHW), yet are reported to have lower CVD mortality rates. Our aim was to help explain this apparent paradox by evaluating endothelial function and urine albumin levels in MA and NHW.</p> <p>Methods-</p> <p>One hundred-five MA and 100 NHW adults were studied by brachial artery flow-mediated dilatation (FMD), blood and urine tests. Participants were studied by ultrasound-determined brachial artery flow-mediated dilatation (FMD), blood and urine tests, at a single visit.</p> <p>Results-</p> <p>Despite higher BMI and triglycerides in MA, MA demonstrated higher FMD than did NHW (9.1 ± 7.3% vs. 7.1 ± 6.3%, p < 0.04). Among MA, urinary albumin was consistently lower in participants with FMD ≥ 7% FMD versus < 7% FMD (p < 0.006). In multivariate analyses in MA men, urinary albumin was inversely related to FMD (r = -0.26, p < 0.05), as were BMI and systolic blood pressure. In MA women, urinary albumin:creatinine ratio was an independent inverse predictor of FMD (p < 0.05 ).</p> <p>Conclusion-</p> <p>To our knowledge, this is the first study to analyze, in asymptomatic adults, the relation of MA and NHW ethnicity to FMD and urine albumin levels. The findings confirm ethnic differences in these important subclinical CVD measures.</p

Status of the high power, solid-state RF amplifier development at laboratori nazionali di legnaro

The development of high power, unconditionally stable solid-state amplifiers for superconducting low-beta cavities, performed at Laboratori Nazionali di Legnaro in the framework of the EURISOL Design Study and in collaboration with Synchrotron Soleil [1], has led to the construction and testing of two newly designed 10 kW units that can be used both individually or coupled together to obtain a 20 kW source. This family of amplifiers, based on parallel assemblies of 300 W modules equipped with mosfets and individual circulators, gives the possibility of operating in any matching conditions and also, at a reduced power, in case of failure of one mosfet. Characteristics of amplifiers and high power combiner will be described, and their performance and test results will be reported

D4 - Half Wave Resonators developments

This document reports on the development of the half wave resonators and its associated cold tuning syste

B cell secretion and insulin sensitivity in hypertensive and normotensive obese subjects

To test the hypothesis that in obesity hypertension is associated with more pronounced hyperinsulinaemia and insulin resistance we compared plasma insulin levels and insulin sensitivity in a group of 6 obese subjects with untreated hypertension and in a group of 6 obese subjects with normal blood pressure. The two groups were similar for sex, age, body mass index and glucose tolerance. Six nonobese subjects served as controls. The study consisted of a 2-h hyperglycaemic clamp (steady-state plasma glucose = 11 mmol/l) and a 15-min insulin tolerance test (0.1 U/kg body wt). During hyperglycaemic clamp, insulin and C-peptide plasma levels were similar in normotensive and hypertensive obese subjects: the area under the plasma insulin curve was 36,000 +/- 3000 pmol/l X 120 min in the former and 34,000 +/- 1000 pmol/l X 120 min in the latter; the area under the plasma C-peptide curve was 298,000 +/- 26,000 pmol/l X 120 min in the former and 246,000 +/- 26,000 pmol/l X 120 min in the latter (P = n.s.). The ratio M/I between the amount of glucose metabolized (M) and the mean plasma insulin levels (I) during hyperglycaemic clamp was similar in the two groups: 0.59 +/- 0.09 in normotensive and 0.58 +/- 0.08 mg/min X m2 per pmol/l in hypertensive obese subjects (P = n.s.). Also the rate coefficient of glucose disappearance from plasma (K(itt)) after i.v. insulin injection was similar in the two groups (4.08 +/- 0.51 vs. 3.87 +/- 0.53 per cent/min).(ABSTRACT TRUNCATED AT 250 WORDS

Deliverable D3 - Low- and Medium-beta linac

The present document describes the Low- and Medium-beta section of the EURISOL DS Driver Accelerator. This section consists of a superconducting linac, based on Half-Wave (HWR) and SPOKE type resonators, preceded by a short, normal-conducting MEBT (Medium Energy Beam Transport) section that performs input beam matching. The scope of this linac is to bring the beams of H-, D+ and 3He++ produced by the Ion Injector (Deliverable D-5) to the energy and beam parameters required for injection in the superconducting High-beta linac (Deliverable D4-High beta linac). The present beam dynamics design reaches the goal of accelerating the required high current beams to the design energy (about 100 MeV/A, depending on the ion species), with minimum emittance growth and with low losses, using realistic and cost-effective, although innovative, technological solutions. The Low- and Medium-beta linac layout is described, together with the fundamental parameters and characteristics of its components and the system performance

LOW- AND INTERMEDIATE-BETA, 352 MHZ SUPERCONDUCTING HALF-WAVE RESONATORS FOR HIGH POWER HADRON ACCELERATION

Contribution to EPAC 2006 about EURISOL Half-wave resonator