I can't think of any reason why not.  If you have a logical volume which you're placing in a mother volume there's no reason you can't use random numbers to define the x, y and z co-ordinates of it.

I'd recommend an array of G4VPlacement() objects which you just loop over changing the location parameter to random values of X, Y and Z.  You'll need some form of if loop to prevent them overlapping or being formed outside the boundary of the mother volume but that should be the only challenge.

Thanks Simon.

A colleague of mine solved the problem and looking at the code he has done exactly what you recommended.

He's simply defined the volume and logical volume then created a while loop to run through a given number of daughter volumes with an if statement to check for overlaps. If thats ok a G4VPlacement is called with the randomised XYZ positions. 

There was no need to create replica volumes, rather just place the same volume a number of times

24

It is simple.

You need to define a sphere in a "for" loop with the required number. For randomly positioning them you should use G4UniformRand() to build x,y and z positions separately inside the mother volume and apply them in G4ThreeVector().

Mohammed Ouar did you find it, please? thank you in advance