Geometry of the Magnet in Geant

by Ilse Koenig, October 16, 1997







Fig 1: Geometry tree of the coils in Geant




Fig 2: Drawing of the coils in Geant


The coils keepin volume CKIV is filled with Aluminium$. It contains contains two volumes CKIF and CKIR filled with HELIUM$ (or AIR$), which are smaller at the sector edges. Thus the remaining volume filled with Aluminium$ represents the coils case. This coils case is thicker in the front section, thus two volumes are necessary.
The volume CKRS (the trapez at the end of the coils) is a part of the support structure of the magnet. (The large support ring in front of the coils case sits directly in the CAVE and is part of the module "frames".)



Fig 3: Cut through keepin volume CKIV at x=0.


On both sides of the keepinvolume, exactly at the edges, a half coils is build in (the second half sits in the next sector!). Each coil consists of four parts: Two curved parts (Geant shape TUBS) on both ends and two mirror-symmetric trapezes in the middle.
Each of these volumes contain two volumes: the volume CxSH representing the shielding with the coil volume CxCO inside and the island CxIL. x stands for F=front, T=Top, B=bottom and R=rear for the left coil.
The right coil is created by a 180°-rotation. The top trapez in the left coil is after this rotation the bottom trapez in the right coil and the bottom trapez in the left coil is after this rotation the top trapez in the right coil.



Fig 4: Drawing of the left coil in Geant