The O–H stretching band in ice Ih derived via eV neutron spectroscopy on VESUVIO using the new very low angle detector bank

VLAD for epithermal neutron scattering experiments at large energy transfers

“…where k 0 and k 1 are the neutron incident and final wave-vectors, respectively, σ tot is the total scattering cross section and The results of the VLAD prototype measurements on ice [16,21] are in good agreement with previous results [18] and hence confirming the feasibility of the HINS approach with a physically interesting sample. …”

“…In Ref. [16] it is shown that a thicker crystal, i.e. higher efficiency, do not improve the signal to background ratio, which is optimized with a lower level threshold at about 600 keV.…”

“…A prototype VLAD detector with four RD units has been built to test the feasibility of HINS measurements in the severe condition of the VESUVIO beam line [16]. The RD units were installed on an aluminium frame at different angular position, namely 2°, 3.5° and 5°, at the edge of an extended vacuum tank (see Fig.…”

“…Background from the aluminium can has been subtracted taking as a reference an empty can run. The residual background has been eliminated with a standard procedure used for VESUVIO measurements [16]. A suitable analytical function has been fitted to the background, taking care in excluding the elastic peaks and the peak wings (where the inelastic scattering information is located).…”

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

“…As a matter of fact, the standard neutron detectors based on scintillation materials (Li-glass(Ce) or ZnS(Ag)) and/or gas counters ( 3 He tubes) at different pressures (1-20 atm), show an efficiency that decreases as 1=v; v being the neutron velocity. An advantage for an inverse geometry instrument is the possibility to use of the so-called Resonance Detector (RD) configuration, proposed between the end of 1970s and the beginning of 1980s [4][5][6][7][8][9][10][11][12][13][14], and developed in the last years [15][16][17][18][19][20][21] for the VESUVIO spectrometer [22] (ISIS spallation neutron source, United Kingdom). In the RD configuration, neutrons are revealed by using a detection system composed of an analyzer foil, made of a material such as 238 U or 197 Au, and a photon detector.…”