Foil cycling technique for the VESUVIO spectrometer operating in the resonance detector configuration

Abstract

This article reports a novel experimental technique, namely, the foil cycling technique, developed on the VESUVIO spectrometer ͑ISIS spallation source͒ operating in the resonance detector configuration. It is shown that with a proper use of two foils of the same neutron absorbing material it is possible, in a double energy analysis process, to narrow the width of the instrumental resolution of a spectrometer operating in the resonance detector configuration and to achieve an effective subtraction of the neutron and gamma backgrounds. Preliminary experimental results, obtained from deep inelastic neutron scattering measurements on lead, zirconium hydride, and deuterium chloride samples, are presented.

Temperature dependence of the zero point kinetic energy in ice and water above room temperature

“…At each scattering angle the energy of the scattered neutrons, E 1 , is selected by using Au analyzer foils (E 1 ¼ 4897 meV). For forward scattering angles, such as those used for proton studies, the instrument operates using the Foil Cycling (FC) technique [46], accessing the kinematical range: 25 Å À1 6 q 6 600 Å À1 , and 2.5 eV 6 hx r 6 30 eV, where…”

Quantum effects in water: proton kinetic energy maxima in stable and supercooled liquid

“…The occurrence of Bragg's peaks in the thermal neutron energy range was constantly monitored, during data acquisition, to check for freezing. Two platinum temperature sensors, placed in the aluminum can walls close to the sample, monitored heat release due to ice formation when the sample was below 273 K. No Bragg's peaks signals nor latent heat release signals due to solidification were observed for the two measurements at T = 272.15 K and T = 272.95 K. Experimental data have been recorded by 64 fixed-angle detectors in the Resonance Detector configuration [19,20] employing the Foil Cycling technique (FCT) [21]. Data have been corrected for multiple scattering, aluminum and oxygen signals.…”

Deep inelastic neutron scattering on 207Pb and NaHF2 as a test of a detectors array on the VESUVIO spectrometer

“…For more experimental and theoretical details about the FCT, the reader is referred to Refs. [23,24].…”

“…It has to be stressed that these experiments represent the first attempt to use the RD configuration and the FCT with an array of detectors. Indeed, previous measurements with the FCT were performed by using only one or a couple of RD units [23]. The aim is a preliminary investigation of the capabilities of such a device, for a routine use in the user research program of the VESUVIO instrument.…”

“…A recent development for DINS measurements on VESUVIO is the Foil Cycling Technique (FCT) [23] which was found to improve the spectrometer resolution, providing an appreciable counting efficiency and a good neutron and gamma background subtraction method [23,24].…”