TY - GEN
T1 - Optimal shape of a cold-neutron triple-axis spectrometer
AU - Lefmann, Kim
AU - Filges, U.
AU - Treue, F.
AU - Kirkensgaard, Jacob Judas Kain
AU - Plesner, B.
AU - Hansen, K.S.
AU - Klenø, Kaspar Hewitt
N1 - Proceedings of the International Workshop on Neutron Optics NOP2010
PY - 2011/4/1
Y1 - 2011/4/1
N2 - We have performed a McStas optimization of the primary spectrometer for a generic 40 m long, cold-neutron triple-axis spectrometer with a doubly focusing monochromator. The optimal design contains an elliptically focusing guide, a virtual source point before a low-grade PG monochromator, and non-equidistant focusing at the monochromator. The flux at 5 meV shows a gain factor 12 over the classical design with a straight 12×3cm2, m=2 guide and a vertically focusing PG monochromator. In addition, the energy resolution was found to be improved. This unexpectedly large design improvement agrees with the Liouville theorem and can be understood as the product of many smaller gain factors, combined with a more optimal utilization of the beam divergence within the guide. Our results may be relevant for a possible upgrade of a number of cold-neutron triple-axis spectrometers - and for a possible triple-axis spectrometer at the European Spallation Source.
AB - We have performed a McStas optimization of the primary spectrometer for a generic 40 m long, cold-neutron triple-axis spectrometer with a doubly focusing monochromator. The optimal design contains an elliptically focusing guide, a virtual source point before a low-grade PG monochromator, and non-equidistant focusing at the monochromator. The flux at 5 meV shows a gain factor 12 over the classical design with a straight 12×3cm2, m=2 guide and a vertically focusing PG monochromator. In addition, the energy resolution was found to be improved. This unexpectedly large design improvement agrees with the Liouville theorem and can be understood as the product of many smaller gain factors, combined with a more optimal utilization of the beam divergence within the guide. Our results may be relevant for a possible upgrade of a number of cold-neutron triple-axis spectrometers - and for a possible triple-axis spectrometer at the European Spallation Source.
U2 - 10.1016/j.nima.2010.06.273
DO - 10.1016/j.nima.2010.06.273
M3 - Conference article
SN - 0168-9002
VL - 634
SP - S1-S6
JO - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1 (Suppl. 1)
ER -