Connect a ray box to a low voltage power supply ... and passes straight through into air without being bent. The critical angle for the type of glass used to make the prism = 42 o.

Schematic of a grazing incidence small and wide angle X-ray scattering (GISAXS/GIWAXS) experimental setup showing the incident (αi) and the scattered angles along the horizontal (2θf) and vertical (αf ...