▁generated . ▁This ▁signal ▁is ▁transm itted ▁through ▁the ▁sample ▁and ▁collected ▁by ▁two - dimensional ▁detect ors . ▁Since ▁different ▁gra ins ▁satisfy ▁the ▁[[ B rag g ▁condition ]] ▁at ▁different ▁angles , ▁the ▁sample ▁is ▁rot ated ▁to ▁pro be ▁the ▁complete ▁sample ▁structure . ▁Cru cial ▁for ▁ 3 D X R D ▁is ▁the ▁idea ▁to ▁m im ic ▁a ▁three - dimensional ▁det ector ▁by ▁position ing ▁a ▁number ▁of ▁two - dimensional ▁detect ors ▁at ▁different ▁distances ▁from ▁the ▁centre ▁of ▁rotation ▁of ▁the ▁sample , ▁and ▁expos ing ▁these ▁either ▁simultaneously ▁( many ▁detect ors ▁are ▁semi - trans parent ▁to ▁hard ▁X - ray s ) ▁or ▁at ▁different ▁times . ▁ ▁At ▁present ▁( A pril ▁ 2 0 1 7 ), ▁a ▁ 3 D X R D ▁mic ros cope ▁is ▁installed ▁at ▁the ▁Material s ▁Science ▁beam line ▁of ▁the ▁E SR F . ▁ ▁Software ▁▁ ▁To ▁determine ▁the ▁cry stal log raph ic ▁orientation ▁of ▁the ▁gra ins ▁in ▁the ▁considered ▁sample , ▁the ▁following ▁software ▁packages ▁are ▁in ▁use : ▁F able ▁and ▁Gra in Sp ot ter . ▁Re construct ing ▁the ▁ 3 D ▁shape ▁of ▁the ▁gra ins ▁is ▁n ont rivial ▁and ▁three ▁approaches ▁are ▁available ▁to ▁do ▁so , ▁respectively ▁based ▁on ▁simple ▁back - pro jection , ▁forward ▁projection , ▁algebraic ▁reconst ruction ▁technique ▁and ▁Monte ▁Carlo ▁method - based ▁reconst ruction . ▁ ▁App lications ▁▁ ▁With ▁ 3 D