Band volume for x - ray scattering

From Optical Imaging and Spectroscopy (Wiley - OSA 2009)
By David J. Brady
www.opticalimaging.org
Figure 10.21

lambda=2;
pa=ParametricPlot3D[{Sin[t]Cos[p]/lambda,Sin[t]Sin[p]/lambda,Cos[t]/lambda},{p,-Pi/6,Pi/6},{t,Pi/6,Pi/3},Lighting->{{"Ambient",GrayLevel[.8,.5],{{5,5,4},{5,5,0}}}}]

lambda=1;
pb=ParametricPlot3D[{Sin[t]Cos[p]/lambda,Sin[t]Sin[p]/lambda,Cos[t]/lambda},{p,-Pi/6,Pi/6},{t,Pi/6,Pi/3},Lighting->{{"Ambient",GrayLevel[.8,.5],{{5,5,4},{5,5,0}}}}]

pt=-Pi/6;
pc=ParametricPlot3D[{Sin[t]Cos[pt]/l,Sin[t]Sin[pt]/l,Cos[t]/l},{t,Pi/6,Pi/3},{l,1,2},Lighting->{{"Ambient",GrayLevel[.8,.5],{{5,5,4},{5,5,0}}}}]

tp=Pi/6;
pd=ParametricPlot3D[{Sin[tp]Cos[p]/l,Sin[tp]Sin[p]/l,Cos[tp]/l},{p,-Pi/6,Pi/6},{l,1,2},Lighting->{{"Ambient",GrayLevel[.8,.5],{{5,5,4},{5,5,0}}}}]

Show[{pb,pa,pc,pd},PlotRange->{{-1,1},{-1,1},{-1,1}}]