[ 1 ]  [ 2 ]  [ 3 ]  [ 4 ]  [ 5 ]  [ 6 ]  [ 7 ]  [ 8 ]  [ 9 ]  [ 10 ]  [ 11 ]  [ back ] 

There is nothing of really complicated in this problem from the point of view of material description, and few different materials are necessary. The cards MATERIAL and COMPOUND as well as the cards ASSIGNMAT are self-explanatory. Of course the reliability of results is strongly dependent on the accurate knowledge of the chemical compositions. Here some attention has to be put on the description of the specific PVC used in the experiment, since the additives and densities are variable from one PVC to another. The composition of the residual gas has been assumed to be the same as for air.

In order to overcome the difficulties due to the low interaction probability at the operating pressure of the machine (13.3÷133.0 nPa = 10^–10÷10^–9 torr), calculations are performed with gas density corresponding to atmospheric pressure.

Therefore, the obtained results will have to be linearly scaled to the actual operating pressure.

Giuseppe Battistoni; INFN, Milano
Alberto Fassò; SLAC, California

Last updated: 10th of October, 2008