Measurement of neutron total cross sections at the VESUVIO spectrometer

Robledo, José Ignacio; Dawidowski, J.; Damián, José Ignacio Márquez; Škoro, G.; Bovo, Claudio; Romanelli, Giovanni

doi:10.1016/j.nima.2020.164096

Cited by 24 publications

(37 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the treatment of neutron transmission data, a bespoke VesuvioTransmission algorithm, implemented in the MantidPlot computational environment, was employed [29,31,32,34]. In the case of high-resolution neutron diffraction data recorded on VESUVIO, the VesuvioD-iffractionReduction algorithm, a part of the MantidPlot environment, was used [28,59].…”

Section: Neutron Scattering Experimentsmentioning

confidence: 99%

“…With the sample composition Moreover, the clearly observed increase in the magnitudes of the plateau regions of the transmission curves with the increasing temperature signifies a systematic decrease of the sample scattering power with temperature. The scattering power is defined as a product of the sample number density, its thickness, and the total free scattering neutron cross-section weighted by the sample composition [29,31,32,34]. With the sample composition being constant over the entire temperature range under investigation, as evidenced by the NCS data analysis (see Figure 5), the only plausible explanation for such a systematic trend in sample scattering power is that the average sample number density decreases with increasing temperature.…”

Section: Glass Transition By Neutron Experimentsmentioning

confidence: 99%

“…Traditionally, the core technique employed at VESUVIO has been neutron Compton scattering (NCS) [19][20][21][22][23]. Due to the recent upgrades in the instrumentation, sample environment, and software [19,20,24,[26][27][28][29][30], VESUVIO has become a very versatile tool, enabling concurrent measurements using techniques such as NCS, energy-dependent neutron transmission [29,[31][32][33][34][35][36][37][38][39], neutron diffraction [30,40,41], and gamma spectroscopy [24,[42][43][44][45]. The aforementioned techniques, especially when applied concurrently, enable the investigation of a plethora of physical and chemical properties of condensed matter systems.…”

Section: Introductionmentioning

confidence: 99%

“…Neutron transmission on VESUVIO covers a vast range of incident neutron energies, from a fraction of a millielectronvolt up to thousands of electron volts. The initial part of the transmission curve, corresponding to the incident neutron energies in the range 1 meV to 1 eV, is shaped by a wide range of different types of excitations, from local to the long-range ones [29,36,49]. Moreover, owing to the capability of VESUVIO to detect the second part of the transmission curve, corresponding to the incident neutron energies above a few eV, the regime of the Impulse Approximation (IA) is reached, where each neutron transmission curve reaches a plateau with the magnitude of transmission determined solely by the product of the sample thickness, its number density, and the total free scattering cross-section weighted by the sample stoichiometry [21,22,29,31,[34][35][36]39,49].…”

Section: Introductionmentioning

confidence: 99%

“…The initial part of the transmission curve, corresponding to the incident neutron energies in the range 1 meV to 1 eV, is shaped by a wide range of different types of excitations, from local to the long-range ones [29,36,49]. Moreover, owing to the capability of VESUVIO to detect the second part of the transmission curve, corresponding to the incident neutron energies above a few eV, the regime of the Impulse Approximation (IA) is reached, where each neutron transmission curve reaches a plateau with the magnitude of transmission determined solely by the product of the sample thickness, its number density, and the total free scattering cross-section weighted by the sample stoichiometry [21,22,29,31,[34][35][36]39,49]. This last unique feature of VESUVIO enables measurements of changes of density in different regions of phase diagrams of condensed matter systems and molecules, particularly important in the context of the glass transition.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Glass Transition in Rice Pasta as Observed by Combined Neutron Scattering and Time-Domain NMR

2021

View full text Add to dashboard Cite

Experimental protocols aiming at the characterisation of glass transition often suffer from ambiguity. The ambition of the present study is to describe the glass transition in a complex, micro heterogeneous system, the dry rice pasta, in a most unambiguous manner, minimising the influence of technique-specific bias. To this end, we apply an unprecedented combination of experimental techniques. Apart from the usually used NMR and DSC, we employ, in a concurrent manner, neutron transmission, diffraction, and Compton scattering. This enables us to investigate the glass transition over a range of spatio-temporal scales that stretches over seven orders of magnitude. The results obtained by neutron diffraction and DSC reveal that dry rice pasta is almost entirely amorphous. Moreover, the glass transition is evidenced by neutron transmission and diffraction data and manifested as a significant decrease of the average sample number density in the temperature range between 40 and 60 °C. At the microscopic level, our NMR, neutron transmission and Compton scattering results provide evidence of changes in the secondary structure of the starch within the dry rice pasta accompanying the glass transition, whereby the long-range order provided by the polymer structure within the starch present in the dry rice pasta is partially lost.

show abstract

Section: Neutron Scattering Experimentsmentioning

confidence: 99%

Section: Glass Transition By Neutron Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Glass Transition in Rice Pasta as Observed by Combined Neutron Scattering and Time-Domain NMR

2021

View full text Add to dashboard Cite

show abstract

Fluorinated borono‐phenylalanine for optimizing BNCT: Enhancing boron absorption against hydrogen scattering for thermal neutrons

Romanelli,

Capuani,

Onorati

et al. 2023

Medical Physics

View full text Add to dashboard Cite

BackgroundBoron‐containing compounds, such as 4‐borono‐phenylalanine (BPA) are used as drugs for cancer treatment in the framework of Boron Neutron Capture Therapy (BNCT). Neutron irradiation of boron‐rich compounds delivered to cancer cells triggers nuclear reactions that destroy cancer cells.PurposeWe provide a modeling of the thermal neutron cross section of BPA, a drug used in Boron Neutron Capture Therapy (BNCT), to quantify the competing contributions of boron absorption against hydrogen scattering, for optimizing BNCT by minimizing the latter.MethodsWe perform the experimental determination of the total neutron scattering cross section of BPA at thermal and epithermal neutron energies using neutron transmission measurements. We isolate the contribution related to the incoherent scattering by hydrogen atoms as a function of the neutron energy by means of the Average Functional Group Approximation, and we calculate the probability for a neutron of being absorbed as a function of the neutron energy both for BPA and for its variants where either one or all four aromatic hydrogen atoms are substituted by 19F, and both for the samples with natural occurrence or enriched concentration of 10B.ResultsWhile referring to the already available literature for in vivo use of fluorinated BPA, we show that fluorine‐rich variants of BPA increase the probability of neutrons being captured by the molecule. As the higher absorption efficiency of fluorinated BPA does not depend on whether the molecule is used in vivo or not, our results are promising for the higher efficiency of the boron neutron capture treatment.ConclusionsOur results suggest a new advantage using fluorinated compounds for BNCT, in their optimized interaction with neutrons, in addition to their already known capability to be used for monitoring and pharmacokinetics studies using 19F‐Nuclear Magnetic Resonance or in 18F‐Positron Emission Tomography.

show abstract