I simulate the geometry of detector CB
and there is a question connected with simulation of light-guide.
It has shape like this :
we have such a trapezia with circular form of corners as a 1 surface
and a circle at another side of light guide.
(where the PM has to be mounted).
They are coupled as it is shown in the picture in attachment.
I will be grateful for any advise how to simulate this shape, using ROOT
With best regards,
As far as I can understand your shape from the drawing, you might do the following:
trapezia part: use TGeoTrd1
TGeoShape *trd = new TGeoTrd1(“trd”, params…);
rounded corners: use the outscribed tube (or cone - I do not well understand the Z profile of the trapezia part), that ‘cuts’ a bit the corners in the desired way
TGeoShape *cone = new TGeoCone(“con”, params…);
I gues the ‘circular part’ is a tube:
TGeoShape *tube = new TGeoTube(“tub”, params…);
define the required translations according the reference frameat your choice:
TGeoTranslation *tr1 = new TGeoTranslation(0,0,Ztrd)
TGeoTranslation *tr2 = new TGeoTranslation(0,0,Ztub)
make your piece as a composite shape:
TGeoCompositeShape piece = new TGeoCompositeShape(“MyPiece”, "(trdcon)+tub"); meaning: intersect the trap with the outscribed cone and then make the union with the tube.
Attach your piece to some volume and you are done…
If you are a bit familiar with TGeo classes, it will be easy, otherwise, it might take you a while… To visualize, use raytracing (the only supported so far for composite shapes).
Good luck and send me the picture when you have done it…