LHCBGAUSS-1334.photonacceptance

Port merge of branch 'LHCBGAUSS-1334.photonacceptance'

See merge request !264 (merged) into 'Sim09' and !281 (merged) into 'master'

(cherry picked from commit 5bc5b33f)

e7f309a2 change from 4000mrad to 400mrad for photon acceptance as wanted