3D atom probe working principle Needle Position lon Analyze sample detector excitation area MCPs sequence R~50 nm T~20-100K 000 XP YI ToFI X2,Y2,ToF2 X3,Y3,ToF3 X4 Y4 ToF DC 3-8kV Xs,Ys,ToFs e●●8。●ee 500nm v.por Flying time(ToF) lon collide position →X-Y lon excitation sequence →Z lon flying time →Type of lon 15Analyze area Needle sample Flying time (ToF) MCPs Position detector Ion excitation sequence Ion collide position Ion excitation sequence Ion flying time X-Y Z Type of Ion 3D atom probe working principle 15