91 research outputs found
The fast neutron and proton irradiation facility at the INFN Legnaro National Laboratory
The availability at the INFN Legnaro National Laboratory of two new accelerator systems, the 70 MeV cyclotron of the SPES project and the 5 MeV RFQ developed for the TRASCO project, makes it possible to build a suite of
neutron sources for a wide spectrum of different applications. This article focuses on the facility at the SPES cyclotron (NEPIR), which is in an advanced design phase. NEPIR will deliver quasi mono-energetic neutrons for multi-disciplinary applications and a complementary fast (En > 1 MeV) neutron field with a continuous energy
(atmospheric-like) spectrum for studying neutron-induced effects on materials, e.g., single event effects in electronics
LNL irradiation facilities for radiation damage studies on electronic devices
In this paper we will review the wide range of irradiation facilities installed at the INFN Legnaro National Laboratories and routinely used for radiation damage studies on silicon detectors, electronic components and systems. The SIRAD irradiation facility, dedicated to Single Event Effect (SEE) and bulk damage studies, is installed at the 14MV Tandem XTU accelerator and can deliver ion beams from H up to Au in the energy range from 28MeV to 300 MeV. An Ion Electron Emission Microscope, also installed at SIRAD, allows SEE testing with micrometric sensitivity. For total dose tests, two facilities are presently available: an X-rays source and a 60Co γ-ray source. The 7MV Van de Graaff CN accelerator provides 1H beams in the energy range 2–7MeV and currents up to few μA for both total dose and bulk damage studies. At this facility, very high dose rates (up to ∼100 krad/s (SiO2)) can be achieved. Finally, also neutron beams are available,
produced at the CN accelerator, by the reaction d + Be ⇒ n+B
Hydrogen maser clocks in space for solid-Earth research and time-transfer applications: Experiment overview and evaluation of Russian miniature sapphire loaded cavity
The Observatoire Cantonal de Neuchatel (ON) is developing for ESTEC a compact H-maser for space use based upon a miniature sapphire loaded microwave cavity, a technique pioneered at VNIIFTRI. Various contacts between West-European parties, headed by ESA, and the Russian parties, headed by ESA, led to the proposal for flying two H-masers on Meteor 3M, a Russian meteorology satellite in low polar orbit. The experiment will include two masers, one provided by ON and the other by VNIIFTRI. T/F transfer and precise positioning will be performed by both a microwave link, using PRARE equipment, and an optical link, using LASSO-like equipment. The main objectives of the experiment are precise orbit determination and point positioning for geodetic/geophysical research, ultra-accurate time comparison and dissemination as well as in-orbit demonstration of operation and performance of H-masers. Within the scope of a preliminary space H-maser development phase performed for ESTEC at ON in preparation to the joint experiment, a Russian miniature sapphire loaded microwave cavity, on loan from VNIIFTRI, was evaluated in a full-size EFOS hydrogen maser built by ON. The experimental evaluation confirmed the theoretical expectation that with a hydrogen storage volume of only 0.65 liter an atomic quality factor of 1.5 x 10(exp 9) can be obtained for a -105 dBm output power. This represents a theoretical Allan deviation of 1.7 x 10(exp -15) averaged on a 1000 s time interval. From a full-size design to a compact one, therefore, the sacrifice in performance due to the reduction of the storage volume is very small
The Phase 0 of the NEPIR project at LNL
NEPIR (Neutron and Proton Irradiation facility) is the project of a new irradiation facility at INFN Legnaro National Laboratories (LNL). The facility will exploit the LNL 35-70 MeV high current proton cyclotron of the SPES complex, to feed two different compact neutron sources in order to generate high flux neutron beams with different energy spectra: quasi-monoenergetic neutron beams and atmospheric-like neutrons. This contribution focuses on the first stage of the construction of the facility: the NEPIR Phase 0, financed and in an advanced design phase. It will use a Be neutron production target capable of delivering up to ∼ 2 × 106 n cm−2 s −1
Fast neutron production at the LNL Tandem from the Li(N,xn)X reaction
Fast neutron beams are of relevance for many scientific and industrial
applications. This paper explores fast neutron production using a TANDEM
accelerator at the Legnaro National Laboratories, via an energetic ion beam (90
MeV ) onto a lithium target. The high energy models for nuclear
collision of FLUKA foresee large neutron yields for reactions of this kind. The
experiment aimed at validating the expected neutron yields from FLUKA
simulations, using two separate and independent set-ups: one based on the
multi-foil activation technique, and the other on the time of flight technique,
by using liquid scintillator detectors.
The results of the experiment show clear agreement of the measured spectra
with the FLUKA simulations, both in the shape and the magnitude of the neutron
flux at the measured positions. The neutron spectrum is centered around the 8
MeV range with mild tails, and a maximum neutron energy spanning up to 50 MeV.
These advantageous results provide a starting point in the development of
fast neutron beams based on high energy ion beams from medium-sized accelerator
facilities
Social patterning in grip strength and in its association with age; A cross sectional analysis using the UK Household Longitudinal Study (UKHLS)
Background: Grip strength in early adulthood and midlife is an important predictor of disability, morbidity and mortality in later life. Understanding social patterning in grip strength at different life stages could improve insight into inequalities in age-related decline and when in the life course interventions could prevent the emergence of inequalities. Methods: Using United Kingdom Household Longitudinal Study (UKHLS) data on 19,292 people aged 16 to 99, fractional polynomial models were fitted to identify which function of age best described its association with grip strength. Linear regressions were used to establish whether socio-economic position (SEP), as measured by maternal education, highest educational qualification and income, was associated with grip strength. To test whether the association between age and grip strength was modified by SEP, interactions between SEP and the age terms were added. Differentiation was used to identify the age at which grip strength was highest for men and women and predicted levels of grip strength at peak were compared. Results: SEP is significantly associated with grip strength on all SEP measures, except education for men. Grip strength is highest at a younger age, and less strong for all measures of disadvantage for women and most measures for men. Interaction terms were not statistically significant indicating that the association between age and grip strength was not modified by SEP. Grip strength peak was 29.3 kg at age 33 for women with disadvantaged childhood SEP compared with 30.2 kg at age 35 for women with advantaged childhood SEP. Conclusion: The SEP differences in age and level of peak grip strength could be indicative of decline in muscle strength beginning earlier and from a lower base for disadvantaged groups. This could impact on the capacity for healthy ageing for those with disadvantaged SEP
Effects of an H3R Antagonist on the Animal Model of Autism Induced by Prenatal Exposure to Valproic Acid
Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders primarily characterized by impaired social interaction and communication, and by restricted repetitive behaviors and interests. Ligands of histamine receptor 3 (H3R) are considered potential therapeutic agents for the treatment of different brain disorders and cognitive impairments. Considering this, the aim of the present study is to evaluate the actions of ciproxifan (CPX), an H3R antagonist, on the animal model of autism induced by prenatal exposure to valproic acid (VPA). Swiss mice were prenatally exposed to VPA on embryonic day 11 and assessed for social behavior, nociceptive threshold and repetitive behavior at 50 days of life. The treatment with CPX (3 mg/kg) or saline was administered 30 minutes before each behavioral test. The VPA group presented lower sociability index compared to VPA animals that were treated with CPX. Compared to the Control group, VPA animals presented a significantly higher nociceptive threshold, and treatment with CPX was not able to modify this parameter. In the marble burying test, the number of marbles buried by VPA animals was consistent with markedly repetitive behavior. VPA animals that received CPX buried a reduced amount of marbles. In summary, we report that an acute dose of CPX is able to attenuate sociability deficits and stereotypies present in the VPA model of autism. Our findings have the potential to help the investigations of both the molecular underpinnings of ASD and of possible treatments to ameliorate the ASD symptomatology, although more research is still necessary to corroborate and expand this initial data
- …