The mushroom concept

by Dr Rob Bewley (ISIS)

Wednesday 31 Jan 2018, 10:00 → 11:30 Europe/Berlin

JCNS Seminar room

Not long ago measuring 3D systems on a direct geometry time of flight spectrometers was a difficult and inefficient task and not often done as it was far better to go to a triple axis machine. However, these days instrument’s like LET(ISIS) and IN5(ILL) with a large coverage of position sensitive detectors and new software [1] routinely map out the whole of S(Q,w) space in single crystals. These measurements are very time consuming though, typically taking a day or two per scan. This can make measurements on small/weakly scattering crystals or parametric studies either impossible or impractical.

In this presentation I will present a concept for a new type of time of flight indirect geometry spectrometer which is also capable of mapping out the whole of S(Q,w) space, but in time scales at least an order of magnitude faster than the direct geometry machines. It also has the advantage of being much cheaper and having a small footprint.

1 R.A. Ewings, A. Buts, M.D. Lee, J. van Duijn, I. Bustinduy, T.G. Perring, Nucl. Instrum. Methods Phys. Res. Sect. A 834 (2016) 132

MUSHROOM.pdf