#       Idealized_g-2.g4bl
#
#	This is an idealized simulation of the BNL g-2 experiment:
#	3.094 GeV/c mu- are started with polarization=(0,0,1) in a
#	perfectly uniform B field of 1.4513 T; their decay electrons
#	are put into an NTuple for histogramming. This requires hundreds
#	of millions of events, so you probably need to run it on a grid
#	or a cluster. the .root and .out files are named for $first (may
#	need to be changed on a grid).

param -unset first=0 last=999999

# set name of .root and .out files
param histoFile=$first
output $histoFile.out

# set steppingFormat to include the polarization
param steppingFormat=GLOBAL,P,KE,POLAR,B

# physics includes spin tracking; keep only mu- and e-
physics QGSP_BERT spinTracking=1
trackcuts keep=mu-,e-

# beam is polarized.
beam gaussian polarization=0,0,1 particle=mu- meanMomentum=3094 \
	firstEvent=$first lastEvent=$last

# NTuple for electrons
newparticlentuple Electrons require=PDGid==11 kill=1

# B is used to expand the world to 100 meters square (more than enough)
box B height=1 width=100000 length=100000
place B z=0 y=500

# F gives the field.
fieldexpr F height=1000 width=100000 length=100000 By=1.4513
place F z=0