Simulation of vertically focused monochromator by Monte-Carlo method

The vertically focused monochromator of the neutron powder diffractometer was simulated using Monte-Carlo method. The effective dimension, curvature radius and tilting angle of monochromator were obtained. The intensity gains comparing to flat monochromator and the neutron intensity distribution at sample position were also given. The result shows that there is not evident intensity gain for greater size sample because of the limit of hole dimension. Only for smaller size sample there is evident intensity gain. (authors)