Remote determination of sample temperature by neutron resonance spectroscopy

Spatially resolved remote measurement of temperature by neutron resonance absorption

“…Initially we established that thewidth of the experimental transmission dipsexhibited a measurable dependence on the sample temperature by normalizing the experimental transmission at elevated temperatures to thetransmission obtained at 25 o C, similar to the analysis described in references [32] and [37]. The effect of the increase in the width of the resonance dips with increasing temperature is clearlyvisible in the transmission ratios shown in Figs.…”

“…Such anapproach allows a direct adjustment of the effective sample temperature (e.g. [33], [36], [37], [40], [51]) and of the areal number density (e.g. [27]- [37], [40], [41], [52]) from a fit to the experimental datawithout any calibration requirements.…”

“…[33], [36], [37], [40], [51]) and of the areal number density (e.g. [27]- [37], [40], [41], [52]) from a fit to the experimental datawithout any calibration requirements. It requires, however, a good knowledge of the response functionof the TOF-spectrometer, a model to account for the Doppler broadening and an experimentaltransmission which does not suffer from bias effects due to background contributions, dead time effectsor detector instabilities.The empirical analysis utilized in the present study was intended to demonstrate the possibility of temperature mapping with relatively high spatial resolution in a realistic experimental setup.The challenge of fitting nearly a quarter million spectra required for the spatially resolved temperature mapping is addressed in our study by fitting a simplified empirical function (equations3 and 4).…”

“…Such profiles can be used for a temperaturereconstruction as shown in previous studies, e.g. [32] and [37]. However, this method is not adequate for spatially resolved mapping, for which the transmission through an area assmall as a 55 m pixel has to be analyzed.…”

“…Therefore the method in Refs. [32] and [37], which relies on the ratio oftransmission profiles at a given energy, suffers from limited counting statistics. A method based onfitting transmission profiles by an analytical expression provides more precise temperatures and isbetter suited for a spatially resolved temperature reconstruction.…”